AeroElectric-Archive.digest.vol-mv
June 26, 2015 - August 19, 2015
Does the VP-X have an alarm channel for Over-Voltage?=C2- If so, was that
alarm triggered?
-Jeff
On Friday, June 26, 2015 10:16 AM, donjohnston <don@velocity-xl.com> w
rote:
m>
As it has been explained to me, the voltage regulator is determining the fa
ult. The VP-X is reporting the fault.
My meter has a hold feature but it's manual, not a peak hold.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444069#444069
-
S -
-
=C2- =C2- =C2- =C2- =C2- -Matt Dralle, List Admin.
________________________________________________________________________________
| From: | "Bill Bradburry" <bbradburry(at)verizon.net> |
| Subject: | GNS430W and TruTrak AP |
What happens to the voltage on the essential buss if it is loaded too
heavily and the diode does not have a heat sink installed?
I am having my radio and my autopilot reset from time to time in flight and
I suspect that the voltage on the essential buss is dropping to a level that
causes this. I plan to check the voltage on the buss next time I am at the
airport to try and confirm the voltage idea.
What can cause the voltage to drop if that is the problem? High resistance
connections? What else should I check?
Bill
________________________________________________________________________________
| Subject: | Re: GNS430W and TruTrak AP |
| From: | "user9253" <fransew(at)gmail.com> |
If the diode is too hot to touch, it should have a heat sink.
It is unlikely that normal current through a diode will drop the voltage enough
to cause avionics to reboot. More likely is a loose connection.
Does the problem occur while the ebus switch is on?
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444074#444074
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: GNS430W and TruTrak AP |
At 01:56 PM 6/26/2015, you wrote:
>
>
>What happens to the voltage on the essential buss if it is loaded too
>heavily and the diode does not have a heat sink installed?
>
>I am having my radio and my autopilot reset from time to time in flight and
>I suspect that the voltage on the essential buss is dropping to a level that
>causes this. I plan to check the voltage on the buss next time I am at the
>airport to try and confirm the voltage idea.
>
>What can cause the voltage to drop if that is the problem? High resistance
>connections? What else should I check?
Diodes don't do that. Your data acquisition and
diagnosis problem is not unlike that described
in another thread on this forum theorizing about
root cause of an OV trip.
Transient events are . . . just that . . .SHORT.
Probability of capturing data with the ordinary
shop tools that will flashlight a path to discovery
is slim.
Does your diode get too hot to touch? What is it
mounted to and what kind of diode? Try flying with
the alternate feed switch ON thus bypassing the
normal feed through the diode.
In the mean time, I'll continue a recently resurrected
notion of devising some data capture tools that can
be easily acquired or perhaps mailed around. Playing
'swap-tronics' until the problem goes away is not
very professional or satisfying.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Alternator problem? |
At 12:05 PM 6/26/2015, you wrote:
>
>As it has been explained to me, the voltage regulator is determining
>the fault. The VP-X is reporting the fault.
>
>My meter has a hold feature but it's manual, not a peak hold.
If we were conducting this investigation
in B-31 at Beech (Flight Test) we would
get out a data acquisition system capable
gathering 5 channels of voltage at 2%
or better accuracy for 100 samples per
second or faster.
Monitor battery voltage at the battery
Monitor B-terminal voltage at the alternator
Monitor Alternator Field voltage at the
alternator
Monitor Bus Sense voltage at the regulator
Monitor Bus Voltage at the Regulator.
Then go fly and see if the problem will
duplicate.
The data traces will reveal how the major
players behave before, during and after
the event . . . and probably narrow the
options for root cause.
That regulator has 'selective ov trip'.
When an ov condition is detected, the field
voltage from the regulator MUST be high
for the ov trip to be triggered.
This logic allows more than one alternator
to parallel on a bus and avoid an ov trip
for both alternators should only one of them
mis-behave. Knowing what I do about the
hardware, it seems most likely that the ov
sensing system is being irritated by some
phenomenon in the system.
In the early days of crowbar ov system
development, we were chagrined to discover
that SOME airplanes had extra-ordinarily
significant transient sources that would
nuisance trip our regulators. Regulars
with years of satisfactory service on
thousands of airframes.
I'm not aware of recent examples of
'extra ordinary irritation' but I wouldn't
discount it.
Can you pair the ov trip even with any particular
action elsewhere in the system?
Bob . . .
________________________________________________________________________________
| Subject: | Re: Alternator problem? |
> If we were conducting this investigation in B-31 at Beech (Flight Test) we would
get out a data acquisition system...
Hey Bob,
Yeah, my kingdom for a DAQ that I could put on this. :(
> Can you pair the ov trip even with any particular action elsewhere in the system?
No. Like I said, the engine runs thus far have all been short (~5 min) and I've
been focusing on fuel and temp related indicators.
The engine issues have been resolved so now the engine runs should be longer and
I should be able to better monitor the electrical side to identify if there's
an event which precedes it or if it's random.
Right now I'm trying to decide if I should pull the alternator or wait and see.
Thanks,
Don
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444084#444084
________________________________________________________________________________
| Subject: | Re: Alternator problem? |
| From: | "user9253" <fransew(at)gmail.com> |
> As it has been explained to me, the voltage regulator is determining the fault.
The VP-X is reporting the fault.
Looking at the LR3C documentation, there is no output terminal dedicated to providing
an over-voltage warning. Therefore the only way that the LR3C can indicate
over-voltage is by the crowbar circuit shorting out terminal 6. If terminal
6 gets its power from the VP-X and not from a circuit breaker, then the VP-X
should report over-current, not over-voltage. I do not know how the VP-X works,
but expect that it monitors system voltage independently from the LR3C.
If the VP-X reports over-voltage, a troubleshooter might ask, is it telling the
truth or lying? What is the over-voltage setpoint? How long must the voltage
be over the setpoint before tripping? Can the pilot change the over-voltage
setpoint?
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444085#444085
________________________________________________________________________________
| Subject: | Re: Alternator problem? |
| From: | Charlie England <ceengland7(at)gmail.com> |
On Sat, Jun 27, 2015 at 7:04 AM, donjohnston <don@velocity-xl.com> wrote:
> don@velocity-xl.com>
>
>
> > If we were conducting this investigation in B-31 at Beech (Flight Test)
> we would get out a data acquisition system...
>
> Hey Bob,
>
> Yeah, my kingdom for a DAQ that I could put on this. :(
>
>
> > Can you pair the ov trip even with any particular action elsewhere in
> the system?
>
>
> No. Like I said, the engine runs thus far have all been short (~5 min) and
> I've been focusing on fuel and temp related indicators.
>
> The engine issues have been resolved so now the engine runs should be
> longer and I should be able to better monitor the electrical side to
> identify if there's an event which precedes it or if it's random.
>
> Right now I'm trying to decide if I should pull the alternator or wait and
> see.
>
> Thanks,
> Don
>
>
Pardon my density, but with an externally regulated alternator, how is it
possible for the alternator itself to be the cause of overvoltage? Isn't it
just a few coils of wire on some iron? It can't produce any significant
voltage at all without field current supplied by the regulator, right? It's
hard for me to envision any fault within the alternator that would produce
*higher* than design voltage. Any short or open circuit inside the
alternator should produce either lower or no voltage output, unless I'm
missing something.
Charlie
________________________________________________________________________________
| Subject: | Re: Alternator problem? |
| From: | "user9253" <fransew(at)gmail.com> |
Good question Charlie. I also want to know what can go wrong with an externally
regulated alternator that would cause over voltage.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444088#444088
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Alternator problem? |
At 08:35 AM 6/27/2015, you wrote:
>
>Good question Charlie. I also want to know what can go wrong with
>an externally regulated alternator that would cause over voltage.
>Joe
>
>--------
>Joe Gores
Cogent questions gentlemen. The short answer is,
it can't. The long answer is that the transfer
function of voltage control in some regulators
doesn't handle brush-bounce well. This can
COMBINE with poor design of the OV trip system
to create some vexing symptoms. I can relate a
first hand-experience with OV trips in brand new
airplanes that go back over 30 years . . . with
engineers in three institutions pointing fingers
at each other while your's truly kept reminding
them of the obvious. That problem was only
recently solved by a long recommended replacement
of a regulator that should not have been qualified
onto the airplane in the first place.
If and LR3 is manifesting poor response to
brush-bounce, this will be a first in my experience.
It would be the collision of THREE conditions, each
at the extremes of their production tolerances,
or perhaps a manufacturing error.
I think this quite improbable but easy to check
with the swapping of one of the two waring factions.
The regulator probably being the easiest. There
are some peek, poke and ponder exercises to
conducted before we play swap-tronics.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Alternator problem? |
At 07:04 AM 6/27/2015, you wrote:
>
>
> > If we were conducting this investigation in B-31 at Beech (Flight
> Test) we would get out a data acquisition system...
>
>Hey Bob,
>
>Yeah, my kingdom for a DAQ that I could put on this. :(
The Force is in sympathy with you. Paul Fisher
and I will be stirring this into the list of
things to do . . . as soon as we clear the decks
of another commitment . . . probably after
OSH. The availability of off-the-shelf DAS
hardware and supporting graphical user
interface leaves no excuses for not crafting
a suite of hardware that addresses capabilities
we've dreamed about here on the List for 20
years.
There's no 'hard' work to be done here . . .
only assemble off the shelf stuff into
useful tools. It's all about the packaging.
By the way, this is not a state secret project.
If any members on the List have ECB layout
capabilities and reasonable skills at slinging
solder, contact me off-list and we'll see how
your skill-set offer might fit into this
project.
I'm contemplating this becoming a tool for
DIY efforts, perhaps a tool that could be rented
and shipped around the country as needed, and
it certainly has possibilities as an article
for KitPlanes.
The time for OBAM aviation to acquire routine
access to low cost measurement tools arrived a few
years ago and we were asleep at the keyboard.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Alternator problem? |
I'll try an answer with either what I know or what I've been told:
The VP-X monitors the system voltage. When it hits 32v, it shuts off the power
to the field and reports an overvoltage fault. (see attached)
I don't know exactly where it's monitoring the system voltage. I would guess at
it's connection to the system bus.
The only "adjustment" to the overvoltage trigger level is whether it's installed
in a 14v or 28v system. On a 28v system, the OV trigger is hard set at 32v.
Vertical Power offered to bench check the VP-X. But since this is early in the
game, I was hoping to get some more ideas and data before going down that road.
Speaking of data, I did run across this little guy:
DataQ Instruments DI-149
http://www.dataq.com/products/di-149/index.html?gclid=Cj0KEQjwk7msBRCJj67khY2z_NIBEiQAPTFjv9iqePcOkNiAMApB_amhAfmVZ-fp0KOI3tHOgpWA9VoaAnUa8P8HAQ
I'm wondering if it would be helpful to identify what's happening.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444092#444092
________________________________________________________________________________
| Subject: | Re: Alternator problem? |
| From: | Etienne Phillips <etienne.phillips(at)gmail.com> |
Hi Bob
Have you considered using the Red Pitaya as a base for signal gathering?
It's an open source DAQ that already has a lot of the hard work done. It's
not dirt cheap ($320) but may offer a quick route to a portable, rentable
or EAA chapter own-able device that would fit the bill.
Check out www.redpitaya.com
Thanks
Etienne
On 27 June 2015 at 16:39, Robert L. Nuckolls, III <
nuckolls.bob(at)aeroelectric.com> wrote:
> At 07:04 AM 6/27/2015, you wrote:
>
> don@velocity-xl.com>
>
>
> > If we were conducting this investigation in B-31 at Beech (Flight Test)
> we would get out a data acquisition system...
>
> Hey Bob,
>
> Yeah, my kingdom for a DAQ that I could put on this. :(
>
>
> The Force is in sympathy with you. Paul Fisher
> and I will be stirring this into the list of
> things to do . . . as soon as we clear the decks
> of another commitment . . . probably after
> OSH. The availability of off-the-shelf DAS
> hardware and supporting graphical user
> interface leaves no excuses for not crafting
> a suite of hardware that addresses capabilities
> we've dreamed about here on the List for 20
> years.
>
> There's no 'hard' work to be done here . . .
> only assemble off the shelf stuff into
> useful tools. It's all about the packaging.
>
> By the way, this is not a state secret project.
> If any members on the List have ECB layout
> capabilities and reasonable skills at slinging
> solder, contact me off-list and we'll see how
> your skill-set offer might fit into this
> project.
>
> I'm contemplating this becoming a tool for
> DIY efforts, perhaps a tool that could be rented
> and shipped around the country as needed, and
> it certainly has possibilities as an article
> for KitPlanes.
>
> The time for OBAM aviation to acquire routine
> access to low cost measurement tools arrived a few
> years ago and we were asleep at the keyboard.
>
>
> Bob . . .
>
> *
>
>
> *
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Alternator problem? |
At 06:34 AM 6/26/2015, you wrote:
I'm in the process of trying to track down an over voltage fault.
So far the engine runs that I've been doing have been relatively
short duration (mostly around 5-10min) while I'm getting the engine
dialed in. On about 4 occasions I've noticed the alternator circuit
has faulted for "over voltage".
I'm running a 28v electrical system
VP-X Pro
B&C LR3C voltage regulator
Kelly Aerospace 50a alternator
Continental IO-550 engine.
Vertical Power and B&C have had me check a number things. All checks
have shown voltage levels, drops and wire resistance to be well
within parameters.
How are your LR3 and VPX system configured? The
LR3 is fitted with crowbar OV protection. If I
understand your symptoms, it's an OV sense and
protection function within the VPX that tripping?
Can you de-program the VPX ov function? Or raise
it's trip point to some big number? You don't need
TWO ov protection systems.
>B&C is recommending to pull the alternator and have it checked.
In the great spaghetti-mix that is aviation
accessories, marketing and business models,
it's difficult to keep track of who's alternator
is being built by whom and with what, if any,
improvements.
The alternators involved in the three-decade saga
of new airplane OV trips were the occasionally-unfair
targets of accusatory assertions . . . but they
DID demonstrate varying degrees of brush-bounce
that often faded to acceptable levels after the first
20 hours or so of operation. For a time, brand new
alternators were being pulled off engines to be
'broke in' on a test stand before being re-installed.
A poorly understood work-around for what was a fundamental
design flaw in the regulator.
The whole legacy family of gear-driven alternators
for Continental engines have been the subject
of numerous 'investigations' . . . to this very day
. . . in spite of the fact that the car-builders
put those issues to bed three or four decades ago.
Such is the plight of consumers deprived of choices
outside the bounds of the cookie-cutter TC airplane
business.
Given what I DO KNOW about that family
of alternators and what I DO NOT know about the
VPX OV sense and response philosophy, it may well
be that your symptoms have root cause in
conditions not unlike those I've described
earlier in this thread. The problem may have
nothing to do with the LR3 and everything to
do with a discontinuity in assembly of
simple-ideas that govern performance.
>I"m just wondering if anyone has run into anything similar with
>these alternators before I pull it ship it out.
I have seen NO requirements that quantify, put
limits on or offer diagnosis tools for the detection
of brush bounce in airplane alternators. I've never
been able to measure it on the test bench . . .
the only way I could strengthen the hypothesis that it
existed was to add a filter to the field terminals of
the alternator and demonstrating that the problem
went away.
The filter only protected the poorly designed
ov sense system from a noise that was common to
and present in most alternators as a matter of
simple physics . . . noise so small that it was
difficult to detect amongst the other noises (All
well within MIL-STD-704 recommendations).
Just for grins, we could craft a little filter
assembly to jury-rig to the back of your alternator.
This experiment is not without risk of the
various participants 'relaxing' because your
particular manifestation went away. If
brush noise is indeed root to your symptoms,
it's indication of a fundamental design deficiency
in the ov sense system . . . NOT THE ALTERNATOR.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Alternator problem? |
At 10:06 AM 6/27/2015, you wrote:
Instead of impossible, I'd venture 'incredibly unlikely'. As in more
probable that I'll be hit by lightning before I send this. However I
can envision a scenario where a stray bit of internal debris shorts
some alternator output over to the field coil. Even less likely here
where the situation appears to be intermittent.
The question was asked but since it is not even worth consideration
at this point, I'm going to add
Actually, Mooney experienced just such an event
back about 1980. I recall peering into the teardown
of an alternator that should have got some
combination of craftsmen and inspectors fired.
So it's not totally outside the realm of possibility.
But yes . . . in this ISO9000 world of 'perfection'
it should be exceedingly remote.
I wish I could remember the name of the engineer
I interacted with at Mooney. A solidly grounded,
common sense fellow with an airs of personality
that put a lot of people off. He had a small, red,
rubber coated steel mallet on which he inscribed
the non de plume, "PATIENCE".
I never witness it personally, but he was renowned
for expressing occasional bouts of frustration
by abusing the corner of his desk with "Patience".
Indeed, there were markings in the finish that
attested to his vice. He proved to be one of my
most valuable collaborators over those years.
On numerous occasions since, I have wondered
if there would be value in acquiring a "Son of
Patience". On further reflection, pounding on
a conference room table with a red hammer these
days would probably get me a visit from a host
of stern faced folks 'concerned' about my ability
to integrate in the modern culture.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Alternator problem? |
At 11:04 AM 6/27/2015, you wrote:
>Hi Bob
>
>Have you considered using the Red Pitaya as a
>base for signal gathering? It's an open source
>DAQ that already has a lot of the hard work
>done. It's not dirt cheap ($320) but may offer a
>quick route to a portable, rentable or EAA
>chapter own-able device that would fit the bill.
>
>Check out <http://www.redpitaya.com>www.redpitaya.com=C2
>
>Thanks
>Etienne
To be sure, you've discovered one of a host
of potential possibilities. My current thoughts
are based on a VERY low cost DAS device I mentioned
here on the List a few days ago.
http://tinyurl.com/nvduk9x
For what ever it may lack in capability, you
sure can't argue about the price . . . especially
since it comes with a capable graphical user
interface and writes data to tabular files
for analysis with other tools.
I'm thinking of dropping this device onto a
'mother board' fitted with, what we'll have to
deduce, a useful collection of signal conditioners
for voltage, current, pressure, temperatures, etc.
Theres a REALLY handy current transducer with
great accuracy and frequency response
http://tinyurl.com/p9fk8po
The 6A version is easily adapted to sense currents
from hundreds of milliamps to hundreds of amps. Voltage
signal conditioning is easy. Temperature is easy in
the realm of solid state tranducers up to 100C, but
a channel of K thermocouple data would probably be good
too.
Pressure 4-20 mA pressure transducers are COTS
items.
I've got $hundreds$ in DAS equipment on the
shelf that I've used to great advantage in the
TC world . . . but too complex to install/operate/
resolve in the OBAM world. This is an exercise
in extracting lab grade data from a KISS box.
Need to make this so $low$ and simple that fewer
folk in the OBAM market are put off by the expense
risk and willing to try it for themselves.
This is the rolling-stock-consist for a train of ideas in
the current pot of idea-stew. I'm 'seeing' a board
about 2.5 x 3.5 inches that would mount the pic-stick
and 5-8 channels of signal conditioning for a BOM cost on
the order of $50-60.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Alternator problem? |
nuckolls.bob(at)aeroelect wrote:
>
> In the great spaghetti-mix that is aviation
> accessories, marketing and business models,
> it's difficult to keep track of who's alternator
> is being built by whom and with what, if any,
> improvements.
All I can say with certainty is that the P/N of the alternator is 646843. According
to what I've been able to determine it's a TCM 60a alternator. I was told
that line of business was sold to Kelly Aerospace.
> The alternators involved in the three-decade saga of new airplane OV trips were
the occasionally-unfair targets of accusatory assertions . . . but they DID
demonstrate varying degrees of brush-bounce that often faded to acceptable levels
after the first 20 hours or so of operation.
You just went over my head with "brush-bounce". :(
> Given what I DO KNOW about that family of alternators and what I DO NOT know
about the VPX OV sense and response philosophy, it may well be that your symptoms
have root cause in conditions not unlike those I've described earlier in
this thread. The problem may have nothing to do with the LR3 and everything to
do with a discontinuity in assembly of simple-ideas that govern performance.
If this means that it's possible that I did something wrong putting this system
together, there is absolutely no doubt about that! :)
If so, can you give me some idea of where I may have a disconnection in the "discontinuity
in assembly of simple-ideas that govern performance"
> Just for grins, we could craft a little filter assembly to jury-rig to the back
of your alternator. This experiment is not without risk of the various participants
'relaxing' because your particular manifestation went away. If brush
noise is indeed root to your symptoms, it's indication of a fundamental design
deficiency in the ov sense system . . . NOT THE ALTERNATOR.
I'm all for grins! Can you give me an idea where to get or how to build this filter?
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444101#444101
________________________________________________________________________________
| Subject: | Re: Alternator problem? |
| From: | "user9253" <fransew(at)gmail.com> |
Directions for making a filter:
http://www.sanantoniohams.org/tips/whine.htm
> You just went over my head with "brush-bounce".
Alternators have bushes that ride on slip rings. If the rings are not concentric,
the brushes will move up and down in their holders.
> can you give me some idea of where I may have a disconnection in the "discontinuity
in assembly of simple-ideas that govern performance
I get the impression that Bob is inferring that he does not trust the VP-X.
I suggest that instead of pulling the alternator, that you replace the voltage
regulator with a generic Ford VR166 or equivalent. There is a list in Bob's book.
The over-voltage and low voltage features of the LR3 are not needed in your
application if the VP-X provides over-voltage and the EFIS gives low voltage
warning.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444104#444104
________________________________________________________________________________
| Subject: | Re: Alternator problem? |
| From: | Verso Electronics <versoelectric(at)GMAIL.COM> |
On Jun 27, 2015, at 4:40 PM, "user9253" wrote:
> The over-voltage and low voltage features of the LR3 are not needed in your application
if the VP-X provides over-voltage and the EFIS gives low voltage warning.
Does the VP-X initiate a crowbar in the presence of over-voltage, or simply report
it through alarm output?
Eric
________________________________________________________________________________
| From: | Paul Millner <millner(at)me.com> |
| Subject: | Re: Alternator problem? |
Bob,
In our '70's Cardinals, Cessna installed an electrolytic capacitor across the OV
unit to minimize such trips...
Paul
________________________________________________________________________________
If you're posting a message... doesn't that mean you're logged in?
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444122#444122
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Alternator problem? |
>
>You just went over my head with "brush-bounce". :(
The term "bounce" is probably inappropriate . . .
"discontinuity" is probably a better description.
Brush bounce is a real phenomenon usually promoted
by out-of-round slip rings or gross contamination
of the surface.
An artfully crafted slip ring receives final
finish with the armature shaft captured between
centers and cut with a diamond tipped tool with
cutting depth and rates so tiny that the finish
is mirror smooth.
Now, press a chunk of carbon to that surface while
it romps along at 200 inches per second . . . and
that 'smoothness' can take on a new character
as tiny bits of material transfers from the brush
to the slip-ring. Over time measured in hours,
a 'film' is formed on the copper. The charcater and
rate of deposition is a function of current magnitude
and direction in the brush, moisture, brush material makeup,
pressure, and probably a few other things the sub-microscopic/
molecular level. See: http://tinyurl.com/q9q62eb
It ALWAYS happens and is built into the nature of
machines with brushes. Problems can manifest when
some feature of associated electronics is
sensitive to the discontinuity. The 30 year arm
wrestling match with the TC regulator has roots
in just such a sensitivity
>I'm all for grins! Can you give me an idea where to get or how to
>build this filter?
What is the center-to-center distance for
the F1 to F2 terminals on your alternator?
I crafted a filter to conduct some experiments
on the problem aircraft that seemed to 'fix' the
problem . . . more appropriately 'mask' the
problem. It didn't fix the design descrepancy
in the regulator . . . only broke the propagation
mode between the antagonist (perfectly normal
brush behavior) and the victim (an uber-sensitive
OV sense mechanism).
As a quick, interim experiment, try connecdting a high
quality, 1 uF capacitor from F1 to F2 on your alternator.
NOT an electrolytic but a some form of metal-film device.
I've got a few hundred laying around . . . can send
you one of those right away.
Bob . . .
________________________________________________________________________________
| From: | "user9253" <fransew(at)gmail.com> |
Below is a quote from a RV-12 builder in Australia, as posted on VansAirforce:
> I've had a constant `bzzt....bzzt...bzzt' sound in my headset repeated at exactly
one second intervals. Both pilot and co-pilot sides were affected. The sound
level stayed constant despite adjusting the intercom squelch and volume knobs,
and was unaffected by the transponder, radio, autopilot or lights. At first
I thought the sounds were related to the flashing warning signs on the Dynon,
but later realised they were exactly timed to the digital clock on the display.
The noise would start as soon as the boot sequence got to `starting network
manager'. If I unplugged the GPS antenna from the AV5000 module so that the
system couldn't pick up the time signal from the satellites, the clock would
not appear and neither would the noise. Dynon initially thought it might be related
to the transponder, but neither disconnecting the transponder, the EMS,
or anything else seemed to make any difference. If the clock was active, so was
the noise. The only way to get rid of it was to disconnect the GPS antenna,
which wasn't really a good solution. However, flying with the noise wasn't an
option either as it was as irritating as a dripping tap.
> However, I got lucky this afternoon when a local electronics guru happened to
be at the field. He spent a couple of hours trouble-shooting the system, checking
the Skyview settings, the radio, tracing the wiring diagram, pulling pins,
etc, until he eventually discovered that the noise was apparently being generated
by interference between the music jack wires and the tunnel harness, which
runs to the ADAHRS mounted in the tail cone. When the GPS antenna was connected,
it appears that EMF generated in the network cable was being fed into the
audio wires that run close to the cable in the tunnel, and was therefore audible
in the headsets. Disconnecting the two audio wires fixed the problem. It
was a simple solution, but tracking down the cause has been a very frustrating
exercise. Glad it's been fixed now.
The length of the shared wire harness is five feet. We will never know the true
cause. But is it more likely that the audio interference was due to the proximity
of wires, or due to the fact that the stereo music input jack was grounded
locally to the airframe (without isolating washers) instead of having a dedicated
ground wire running back to the instrument panel ground?
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444125#444125
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Alternator problem? |
At 06:40 PM 6/27/2015, you wrote:
Directions for making a filter:
http://www.sanantoniohams.org/tips/whine.htm
> You just went over my head with "brush-bounce".
Alternators have bushes that ride on slip rings. If the rings are
not concentric, the brushes will move up and down in their holders.
. . . and under some conditions, experience
periodic disconnections from the slip ring . . .
Which is probably not the phenomenon were
working with here . . . as described in my
recent post, the discontinuity of interest
may have more to with quality of brush-track
than from mechanical imperfections in surface
or concentricity . . . but in any case SHOULD
NOT be a component of root cause for OV trips
in a well design OV sense system.
By the way, it's been a persistent notion in some
circles for decades that 'automotive' hardware
with brushes are ill-suited to use on aircraft due
to effects of altitude leading to mis-interpreted
assumptions that atmospheric pressure has a profound
effect on brush performance. As pointed out in the
the article I cited earlier, MOISTURE is a high-influence
predictor of brush performance . . . and failure to
perform at altitude has a lot to do with humidity
and nearly nothing to do with altitude.
"Altitude rated" brushes are really "low humidity
rated" devices with chemistry added to the brush-makeup
that compensates for reduced atmospheric moisture at
altitude. But even those effects are much more pronounced
on high current density brushes that ride on commutators
as opposed to 3A max, 1A normal loads on alternator
slip-rings. The collective experience of both TC
and OBAM aviation communities have demonstrated that
altitude effects are VERY low on the totem-pole
of stresses that raise risk.
> can you give me some idea of where I may have a disconnection in
the "discontinuity in assembly of simple-ideas that govern performance
I get the impression that Bob is inferring that he does not trust the VP-X.
Didn't say that. What I'm saying is that I do
not have enough information about the VP-X OV
protection philosophy to discount the possibility
that NORMAL alternator-noises are participating in nuisance
trips.
I suggest that instead of pulling the alternator, that you replace
the voltage regulator with a generic Ford VR166 or equivalent. There
is a list in Bob's book. The over-voltage and low voltage features
of the LR3 are not needed in your application if the VP-X provides
over-voltage and the EFIS gives low voltage warning.
An excellent experiment. If the VR-166 style
regulators are presently fitted with OV protection,
it's performance benchmarks are certainly going
to be different than an LR3. If the nuisance
trips go away with THAT regulator, then there
is reason to investigate the LR-3 more closely.
If they continue, then the difficulty will be
have root cause in features found elsewhere.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Alternator problem? |
> I suggest that instead of pulling the alternator, that you replace the voltage
regulator with a generic Ford VR166 or equivalent. There is a list in Bob's
book. The over-voltage and low voltage features of the LR3 are not needed in your
application if the VP-X provides over-voltage and the EFIS gives low voltage
warning.
>
> An excellent experiment. If the VR-166 style
> regulators are presently fitted with OV protection,
> it's performance benchmarks are certainly going
> to be different than an LR3. If the nuisance
> trips go away with THAT regulator, then there
> is reason to investigate the LR-3 more closely.
> If they continue, then the difficulty will be
> have root cause in features found elsewhere.
I thought that voltage regulators were voltage specific? Are these generic VR's
available in 28v versions?
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444130#444130
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Alternator problem? |
>I thought that voltage regulators were voltage specific? Are these
>generic VR's available in 28v versions?
OOPS! You caught us with our perceptions down . . .
yes, the VR166 is 14v only. Scratch that idea.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Alternator problem? |
| From: | "user9253" <fransew(at)gmail.com> |
> I thought that voltage regulators were voltage specific? Are these generic VR's
available in 28v versions?
Oops, my mistake. I forgot about the 28 volt system. I do not know of any generic
28 volt regulators.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444134#444134
________________________________________________________________________________
| From: | Charlie England <ceengland7(at)gmail.com> |
On 6/28/2015 12:24 PM, user9253 wrote:
>
> Below is a quote from a RV-12 builder in Australia, as posted on VansAirforce:
>
>> I've had a constant `bzzt....bzzt...bzzt' sound in my headset repeated at exactly
one second intervals. Both pilot and co-pilot sides were affected. The sound
level stayed constant despite adjusting the intercom squelch and volume knobs,
and was unaffected by the transponder, radio, autopilot or lights. At first
I thought the sounds were related to the flashing warning signs on the Dynon,
but later realised they were exactly timed to the digital clock on the display.
The noise would start as soon as the boot sequence got to `starting network
manager'. If I unplugged the GPS antenna from the AV5000 module so that the
system couldn't pick up the time signal from the satellites, the clock would
not appear and neither would the noise. Dynon initially thought it might be related
to the transponder, but neither disconnecting the transponder, the EMS,
or anything else seemed to make any difference. If the clock was active, so was
the noise. The only way to get rid of it was to di!
> sconnect the GPS antenna, which wasn't really a good solution. However, flying
with the noise wasn't an option either as it was as irritating as a dripping
tap.
>> However, I got lucky this afternoon when a local electronics guru happened
to be at the field. He spent a couple of hours trouble-shooting the system, checking
the Skyview settings, the radio, tracing the wiring diagram, pulling pins,
etc, until he eventually discovered that the noise was apparently being generated
by interference between the music jack wires and the tunnel harness,
which runs to the ADAHRS mounted in the tail cone. When the GPS antenna was connected,
it appears that EMF generated in the network cable was being fed into
the audio wires that run close to the cable in the tunnel, and was therefore
audible in the headsets. Disconnecting the two audio wires fixed the problem.
It was a simple solution, but tracking down the cause has been a very frustrating
exercise. Glad it's been fixed now.
> The length of the shared wire harness is five feet. We will never know the
true cause. But is it more likely that the audio interference was due to the
proximity of wires, or due to the fact that the stereo music input jack was grounded
locally to the airframe (without isolating washers) instead of having
a dedicated ground wire running back to the instrument panel ground?
> Joe
>
> --------
> Joe Gores
For noise problems, I always look at ground issues first. In my opinion,
he needs to fix the ground issue whether that particular problem was
caused by it or not. And if that jack was grounded, then there may be
others that have similar issues.....
Charlie
________________________________________________________________________________
| From: | Charlie England <ceengland7(at)gmail.com> |
| Subject: | Re: Alternator problem? |
On 6/28/2015 3:34 PM, user9253 wrote:
>
>
>> I thought that voltage regulators were voltage specific? Are these generic VR's
available in 28v versions?
> Oops, my mistake. I forgot about the 28 volt system. I do not know of any generic
28 volt regulators.
>
> --------
> Joe Gores
They are out there; just not so easy to find. 1st hit I got:
http://www.ebay.com/itm/NEW-24-VOLT-POSITIVE-OR-NEGITIVE-GROUND-REGULATOR-D2152-FARM-INDUSTRIAL-/151618159386
________________________________________________________________________________
| Subject: | Z-11 Diagram and E-bus feeder length |
| From: | "Garyw" <gaw.ebm(at)gmail.com> |
Z-11 has a note of 6" max write length to the diode and again to the E-bus. Is
this purely a function of the particular write size sunken (16 ga) or is there
and underlying reason to keep this run short?
Tia,
Gary
--------
Gary
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444142#444142
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Z-11 Diagram and E-bus feeder length |
At 06:37 PM 6/28/2015, you wrote:
>
>Z-11 has a note of 6" max write length to the diode and again to the
>E-bus. Is this purely a function of the particular write size sunken
>(16 ga) or is there and underlying reason to keep this run short?
This is a legacy hand-me-down rule-of-thumb
that goes back a few years . . . at least 50
that I know about.
The GENERAL RULE for protection of wires is
defined in AC43-12 and the FARS. But . . .
suppose you wanted to feed some device in
very close proximity to the high current
feeder. The rule of thumb (which I don't
recall having ever been articulated in
regulation) was any wire of 6" or less that
can be 'burned' without putting the airframe
and passengers at risk, does not need to
be protected (meaning fuse, circuit breaker,
fusible link, etc.).
The first time I recall this r-o-t being exercised
was in the wiring of a fat electrolytic capacitor
to the bus (ostensibly for spike/noise/gremlim
protection) and later for the wiring of a 50W zener
to the bus for the same purpose.
In retrospect, I am amazed at the thrashing and
agonizing brought on by worries about spikes, noises
and things that go "bump in the night" when in fact,
DO-160/MIL-STD-704 suggestions applied with understanding
made all those concerns evaporate.
So you will find SOME wires on my drawings marked
with an (*) wherein no protection is shown upstream
of the potential fault path for burning the wire.
In some places I use the symbol (*) to suggest that
the devices so connected should be in close proximity
to each other. So the rationale behind the symbol
may not be immediately obvious . . . but there is
one.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
>For noise problems, I always look at ground issues first. In my
>opinion, he needs to fix the ground issue whether that particular
>problem was caused by it or not. And if that jack was grounded, then
>there may be others that have similar issues.....
>
>Charlie
Yes . . . this is excellent advice on airframes
where no particular philosophy for grounding
has been adopted BEFORE wires were strung.
Over the years, places like Beech, Cessna, et. als.
developed design and process specs for the construction
of new systems in their products. Noise issues were
rare because lessons learned (some of them painful and
expensive) were core knowledge for development
of those specs.
To be sure, the first question to be explored on
discovery of any noise problem in an OBAM aircraft
is, "What does your ground system architecture look
like?"
Bob . . .
________________________________________________________________________________
| Subject: | Re: Alternator problem? |
| From: | "user9253" <fransew(at)gmail.com> |
24 volt Voltage regulator, eBay item number:151689173831, is only $10. Has anyone
ever tried to adapt an internal voltage regulator for external use?
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444149#444149
________________________________________________________________________________
| From: | Charlie England <ceengland7(at)gmail.com> |
| Subject: | Re: Alternator problem? |
On 6/28/2015 9:42 PM, user9253 wrote:
>
> 24 volt Voltage regulator, eBay item number:151689173831, is only $10. Has anyone
ever tried to adapt an internal voltage regulator for external use?
> Joe
>
> --------
> Joe Gores
I wondered about that, as well. Shouldn't be too big a deal for someone
handy with a soldering iron.
Charlie
________________________________________________________________________________
| Subject: | Re: Alternator problem? |
| From: | rnjcurtis <rnjcurtis(at)charter.net> |
I converted a Denso alternator to external using the instructions published on
the EAA site. It is not difficult, but takes a bit of time.
Roger
Sent from: YOGA TABLET 10 HD+
Charlie England wrote:
>
>On 6/28/2015 9:42 PM, user9253 wrote:
>>
>> 24 volt Voltage regulator, eBay item number:151689173831, is only $10. Has
anyone ever tried to adapt an internal voltage regulator for external use?
>> Joe
>>
>> --------
>> Joe Gores
>I wondered about that, as well. Shouldn't be too big a deal for someone
>handy with a soldering iron.
>
>Charlie
>
>
________________________________________________________________________________
| Subject: | Re: Alternator problem? |
| From: | rnjcurtis <rnjcurtis(at)charter.net> |
In rereading the posts, It appears that the conversation was referring to removing
an internal regulator and using it externally. I don't know of anyone doing
this.
Roger
Sent from: YOGA TABLET 10 HD+
rnjcurtis wrote:
I converted a Denso alternator to external using the instructions published on
the EAA site. It is not difficult, but takes a bit of time.
Roger
________________________________________________________________________________
| Subject: | Re: Alternator problem? |
| From: | Charlie England <ceengland7(at)gmail.com> |
I think Joe is referring to actually using the regulator that's made for
internal regulation as an external regulator. A bit more involved than
adapting an external regulator to a '1-wire' alternator (but not a lot
more).
Charlie
On Mon, Jun 29, 2015 at 7:04 AM, rnjcurtis wrote:
>
> I converted a Denso alternator to external using the instructions
> published on the EAA site. It is not difficult, but takes a bit of time.
>
> Roger
>
>
> Sent from: YOGA TABLET 10 HD+
>
> Charlie England wrote:
>
> ceengland7(at)gmail.com>
> >
> >On 6/28/2015 9:42 PM, user9253 wrote:
> >>
> >> 24 volt Voltage regulator, eBay item number:151689173831, is only $10.
> Has anyone ever tried to adapt an internal voltage regulator for external
> use?
> >> Joe
> >>
> >> --------
> >> Joe Gores
> >I wondered about that, as well. Shouldn't be too big a deal for someone
> >handy with a soldering iron.
> >
> >Charlie
> >
> >
> >
> >
>
>
________________________________________________________________________________
| Subject: | Re: Alternator problem? |
I appreciate the suggestions. But I'm not sure if trying to MacGuyver a voltage
regulator is good way to troubleshoot my current issue. [Laughing]
Vertical Power has offered to bench check the VP-X but removing it won't be the
easiest thing and I'm looking at a 10-day turnaround.
So buying a new LR3C-28 at $198 may be a relatively easy and timely (although not
very cost effective) step. If it turns out not to be the VR, I guess I'll
have a spare.
At that point, it would most likely be the VP-X and then I could send that out.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444161#444161
________________________________________________________________________________
| From: | <rnjcurtis(at)charter.net> |
| Subject: | Re:_AeroElectric-List:_Re:_Alternator_problem=3F? |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=
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Alternator problem? |
At 07:31 AM 6/29/2015, you wrote:
>
>In rereading the posts, It appears that the conversation was
>referring to removing an internal regulator and using it
>externally. I don't know of anyone doing this.
There was an article, I think in Sport Aviation
some years ago about making electrical connections
to a dis-mounted replacement for an I-R alternator
regulator for use as a stand-alone external
regulator.
A straight-forward task . . . sometimes. Some
internal regulators utilize and AC voltage sense
path connected to on of the windings. Without
specific knowledge of this feature, the
activity is problematic. The article spoke
to a particular OEM part that was not so
equipped . . . finding one in 28v and knowing
it's pedigree would be difficult.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Alternator problem? |
At 07:45 AM 6/29/2015, you wrote:
>
>I appreciate the suggestions. But I'm not sure if trying to
>MacGuyver a voltage regulator is good way to troubleshoot my current
>issue. [Laughing]
>
>Vertical Power has offered to bench check the VP-X but removing it
>won't be the easiest thing and I'm looking at a 10-day turnaround.
>
>So buying a new LR3C-28 at $198 may be a relatively easy and timely
>(although not very cost effective) step. If it turns out not to be
>the VR, I guess I'll have a spare.
>
>At that point, it would most likely be the VP-X and then I could
>send that out.
It's all most a given that both the LR3 and the
VPX will bench check okay . . . as would the
alternator. Everything is probably performing
as their designers intended.
Let's do the filter thingy first. Need a mailing
address.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Alternator problem? |
Bob,
I couldn't figure out how to do a private message here. So I sent you an email
yesterday with my mailing address.
-Don
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444170#444170
________________________________________________________________________________
| From: | John snapp <matronics.list(at)gmail.com> |
I had the exact problem. The sound was caused by an unshelled RS-232 output of
my GPS that was putting out NMEA sentences every one second. It was being picked
up by a nearby unconnected music input to my audio panel. Grounded the audio
input and all was fine.
John Snapp
+1.303.810.0600
(sent from iPhone)
> On Jun 28, 2015, at 11:24 AM, user9253 wrote:
>
>
> Below is a quote from a RV-12 builder in Australia, as posted on VansAirforce:
>
>> I've had a constant `bzzt....bzzt...bzzt' sound in my headset repeated at exactly
one second intervals. Both pilot and co-pilot sides were affected. The sound
level stayed constant despite adjusting the intercom squelch and volume knobs,
and was unaffected by the transponder, radio, autopilot or lights. At first
I thought the sounds were related to the flashing warning signs on the Dynon,
but later realised they were exactly timed to the digital clock on the display.
The noise would start as soon as the boot sequence got to `starting network
manager'. If I unplugged the GPS antenna from the AV5000 module so that the
system couldn't pick up the time signal from the satellites, the clock would
not appear and neither would the noise. Dynon initially thought it might be related
to the transponder, but neither disconnecting the transponder, the EMS,
or anything else seemed to make any difference. If the clock was active, so was
the noise. The only way to get rid of it was to di!
> sconnect the GPS antenna, which wasn't really a good solution. However, flying
with the noise wasn't an option either as it was as irritating as a dripping
tap.
>> However, I got lucky this afternoon when a local electronics guru happened to
be at the field. He spent a couple of hours trouble-shooting the system, checking
the Skyview settings, the radio, tracing the wiring diagram, pulling pins,
etc, until he eventually discovered that the noise was apparently being generated
by interference between the music jack wires and the tunnel harness, which
runs to the ADAHRS mounted in the tail cone. When the GPS antenna was connected,
it appears that EMF generated in the network cable was being fed into the
audio wires that run close to the cable in the tunnel, and was therefore audible
in the headsets. Disconnecting the two audio wires fixed the problem. It
was a simple solution, but tracking down the cause has been a very frustrating
exercise. Glad it's been fixed now.
>
> The length of the shared wire harness is five feet. We will never know the true
cause. But is it more likely that the audio interference was due to the proximity
of wires, or due to the fact that the stereo music input jack was grounded
locally to the airframe (without isolating washers) instead of having a
dedicated ground wire running back to the instrument panel ground?
> Joe
>
> --------
> Joe Gores
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=444125#444125
>
>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| Subject: | Ground loop proves to be mighty painful! |
| From: | "rparigoris" <rparigor(at)suffolk.lib.ny.us> |
Hi group
I never thought much about it before today, but I found out ground loop can be
mighty painful!
I have done a fair share amount of TIG welding over the years. I have done a fair
amount of milling 304 Stainless steel as well. No matter how careful with Stainless
milling, once in a while you end up getting a microscopic splinter. I
have pretty good close up vision and sometimes have a hard time even with magnifier.
I never did a little milled, do a little TIGing, mill, TIG etc. many times before.
Well, today a few times I had a microscopic splinter in my left wire feed hand
that managed to touch the welding rod with my elbow resting on the aluminium welding
table: "WOW"! I guess the splinter however small was more connected to
my biological saline solution.
That minute amount of electron flow really got my attention. To add insult to injury,
I couldn't find the darn splinter one time by sight. It took three iterations
of using ground loop to find it!
As far as ground loops go: I'll take a little static listening to the radio anytime
over TIG splinters ;-)
Ron Parigoris
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444177#444177
________________________________________________________________________________
| Subject: | Re: Alternator problem? |
| From: | Charlie England <ceengland7(at)gmail.com> |
Cheap troubleshooting by substitution (only), as implied by the previous
suggestion of using a COTS Ford regulator to substitute for the existing
unit (not possible due to existing unit being 28v instead of 14v).
Turning alternators on/off is a completely different issue, and begs the
question: Why?
On Mon, Jun 29, 2015 at 7:47 AM, wrote:
>
>
> I think Joe is referring to actually using the regulator that's made for
> internal regulation as an external regulator. A bit more involved than
> adapting an external regulator to a '1-wire' alternator (but not a lot
> more).
>
> In doing this, wouldn=99t one be just moving the problems that have
been
> discussed in great detail, of why we should not use internally regulated
> alternators. The internal regulators do not react kindly to turning the
> alternator on and off.
>
> Roger
>
>
________________________________________________________________________________
| Subject: | Re: Ground loop proves to be mighty painful! |
| From: | Bob Verwey <bob.verwey(at)gmail.com> |
Ron thats funny!
On Monday, June 29, 2015, rparigoris wrote:
> rparigor(at)suffolk.lib.ny.us >
>
> Hi group
>
> I never thought much about it before today, but I found out ground loop
> can be mighty painful!
>
> I have done a fair share amount of TIG welding over the years. I have done
> a fair amount of milling 304 Stainless steel as well. No matter how careful
> with Stainless milling, once in a while you end up getting a microscopic
> splinter. I have pretty good close up vision and sometimes have a hard time
> even with magnifier.
>
> I never did a little milled, do a little TIGing, mill, TIG etc. many times
> before.
>
> Well, today a few times I had a microscopic splinter in my left wire feed
> hand that managed to touch the welding rod with my elbow resting on the
> aluminium welding table: "WOW"! I guess the splinter however small was more
> connected to my biological saline solution.
>
> That minute amount of electron flow really got my attention. To add insult
> to injury, I couldn't find the darn splinter one time by sight. It took
> three iterations of using ground loop to find it!
>
> As far as ground loops go: I'll take a little static listening to the
> radio anytime over TIG splinters ;-)
>
> Ron Parigoris
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=444177#444177
>
>
--
Best...
Bob Verwey
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Alternator problem? |
>In doing this, wouldn=99t one be just moving the
>problems that have been discussed in great
>detail, of why we should not use internally
>regulated alternators.=C2 The internal regulators
>do not react kindly to turning the alternator on and off.
It's not a matter of 'not taking kindly' . . . its the
conditions surrounding a failure modes. Off the shelf, internally
regulated alternators have a runaway failure mode wherein the
alternator CANNOT be shut off from outside. This is why
some folks remove the built in regulator (B&C) and others
wire around the regulator (Plane-Power) to effect positive
external control of field excitation for the purpose of
turning it ON or OFF at will, or shutting it down if
the regulator goes TU.
A myth commonly circulated throughout the vehicular
DC power systems world is that it is undesirable,
dangerous, deleterious, or (as has been articulated
here on the List) just plain stupid to turn an
operating alternator ON and OFF at will. It's
a well circulated, overly fertilized myth easily
demonstrated to be horse-pucky. The desirability
for and effects of random or purposeful control
of an alternator at will are completely benign
to the alternator and equipment it powers.
But if the regulator wanders into the weeds,
you gotta have a method to turn the thing OFF
(or disconnect it from the airplane) in a timely
fashion while minimizing smoke and flames.
Bob . . .
________________________________________________________________________________
| From: | "Valin Thorn" <valin(at)starflight.aero> |
| Subject: | Diode Reverse Voltage Leak or Invalid Measurement Setup? |
Hello,
We're getting set to do power on testing of our electrical system and
avionics. We're using the (Bob's) Z-12 power grid at 28 VDC with a 12 VDC
bus and 12VDC hot battery bus.
We have schottkey diodes isolating the various buses.
With the positive battery terminal connected and the 12 VDC hot battery lead
connected, but NOT the battery ground to the single point ground, I checked
the voltage at various points and saw the 12+ VDC where it should be but was
surprised to measure about 3.5 VDC on the Main Bus and even the Ground Bus.
The meter set up was with the VOM meter ground lead to the battery ground
(not connected to the airplane's ground bus) and then the positive prove to
the various measurement locations.
At first I thought we must have a pin out wrong in a connector somewhere -
and maybe we do. After some trouble shooting, I was able to determine that
the voltage seems to be leaking in reverse past the diode from the 12 VDC
Hot Batt Bus to the 12VDC Bus and then through the 24 to 12 VDC converter to
the Main Bus. But somehow, when I put the meter's positive probe on the
ground bus, it also shows 3.5 VDC. So not even sure this is a valid way to
test that I'm using.
Here's our Power Grid. Sorry Bob that it is in my pictogram format. The
anode side of Diode B is where I'm seeing 3.5 VDC with 12VDC on the cathode
side, as expected, coming from the hot battery bus.
I did a test of a spare diode of the same model on the bench with a single
12 VDC battery and measure 4.9 VDC on the anode side of the diode with the
cathode connected to the battery's positive terminal. See photo below.
My questions.
1. Is this even a valid voltage measurement setup? Is this real? If
both the positive and negative side of the electrical system are showing 3.5
VDC relative to the unattached battery ground, then there is no electrical
potential difference/voltage between them.
2. Are these the wrong diodes for this application? (spec sheet
attached)
3. What should I do?
I'd sure appreciate some help with this. Oh, and Happy Independence Day!
Thanks!
Valin
(Confused)
________________________________________________________________________________
| Subject: | Re: Diode Reverse Voltage Leak or Invalid Measurement |
Setup?
| From: | Charlie England <ceengland7(at)gmail.com> |
Not really relevant to your question, but the spec sheet has the wrong
symbol for the diodes (zener instead of Schottky).
In general, if you leave the ground side of a circuit floating and measure
from the floating ground to the actual supply ground, you will see some
voltage (in some cases, the full voltage of the supply). For your voltage
test of the diode pack, try inserting a 12V load (light, etc) in series
with the diode, connected from the diode anode (your red test lead point)
to the battery ground terminal. Measure voltage on the same points shown in
your pic. I'll bet that the load (light) won't illuminate, and you won't
see any voltage. All semiconductors have some leakage, but won't supply
significant current because the leakage is so low. Your spec sheet says
IsubR is 2 mA at 45 volts, so would be much lower at 12 volts.
My terminology probably isn't precise (I was a repair grunt; not an
engineer), but hopefully the idea is still there.
Charlie
On Sat, Jul 4, 2015 at 2:03 PM, Valin Thorn wrote:
> Hello,
>
>
> We=99re getting set to do power on testing of our electrical system
and
> avionics. We=99re using the (Bob=99s) Z-12 power grid at 28
VDC with a 12
> VDC bus and 12VDC hot battery bus.
>
>
> We have schottkey diodes isolating the various buses.
>
>
> With the positive battery terminal connected and the 12 VDC hot battery
> lead connected, but NOT the battery ground to the single point ground, I
> checked the voltage at various points and saw the 12+ VDC where it should
> be but was surprised to measure about 3.5 VDC on the Main Bus and even th
e
> Ground Bus.
>
>
> The meter set up was with the VOM meter ground lead to the battery ground
> (not connected to the airplane=99s ground bus) and then the positiv
e prove to
> the various measurement locations.
>
>
> At first I thought we must have a pin out wrong in a connector somewhere
=93
> and maybe we do. After some trouble shooting, I was able to determine
> that the voltage seems to be leaking in reverse past the diode from the 1
2
> VDC Hot Batt Bus to the 12VDC Bus and then through the 24 to 12 VDC
> converter to the Main Bus. But somehow, when I put the meter=99s p
ositive
> probe on the ground bus, it also shows 3.5 VDC. So not even sure this is
> a valid way to test that I=99m using
>
>
> Here=99s our Power Grid. Sorry Bob that it is in my pictogram form
at The
> anode side of Diode B is where I=99m seeing 3.5 VDC with 12VDC on t
he cathode
> side, as expected, coming from the hot battery bus.
>
>
> I did a test of a spare diode of the same model on the bench with a singl
e
> 12 VDC battery and measure 4.9 VDC on the anode side of the diode with th
e
> cathode connected to the battery=99s positive terminal. See photo
below.
>
>
> My questions.
>
>
> 1. Is this even a valid voltage measurement setup? Is this real? I
f
> both the positive and negative side of the electrical system are showing
> 3.5 VDC relative to the unattached battery ground, then there is no
> electrical potential difference/voltage between them
>
> 2. Are these the wrong diodes for this application? (spec sheet
> attached)
>
> 3. What should I do?
>
>
> I=99d sure appreciate some help with this Oh, and Happy I
ndependence Day!
>
>
> Thanks!
>
>
> Valin
> (Confused)
>
>
________________________________________________________________________________
| From: | Jeff <jluckey(at)pacbell.net> |
| Subject: | Re: Diode Reverse Voltage Leak or Invalid Measurement |
Setup?
________________________________________________________________________________
| Subject: | Re: Diode Reverse Voltage Leak or Invalid Measurement |
Setup?
| From: | "Eric M. Jones" <emjones(at)charter.net> |
This is the Schottky diode that I sell with an appropriate heat sink, and it's
a great part. You could have contacted me, but this is a general interest anyway,
so an answer helps everyone.
All standard voltmeters have a built-in load. This is as it should be. If they
did not, then nothing would make much sense. For special purposes, voltmeters
can be built with arbitrarily high resistance (or a tiny load, called impedance
in meters, etc.), but they all still have some load.
All electronic parts, even relays and switches, have "leakage". Insulation can
still be measured in ohms, no matter how good, (millions and billions of ohms...)
So if you built a simple switch with nearly perfect insulation and applied a voltage
to it, a voltmeter with infinite ohms resistance would still measure a voltage
"through" the switch...whether or not the switch was on or off! That's
why voltages are not measured through switches, relays, and any other parts.
I note this in some of my literature, that a voltage measurement without a load
will give meaningless results. A Schottky diode has a very low Vf forward voltage
drop (lower than P-N diodes). This saves power, but the Schottky also has
a greater reverse current "leakage". The reverse current typically won't leak
enough power to light even the smallest LED, but some builders worry that this
is a defect.
It really isn't. It's just reality.
For those who are mystified by electrons. Check the attached.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444394#444394
Attachments:
http://forums.matronics.com//files/dabbling_with_electricity_103.pdf
________________________________________________________________________________
| From: | "Valin Thorn" <valin(at)starflight.aero> |
| Subject: | Diode Reverse Voltage Leak or Invalid Measurement |
Setup?
Thanks Charlie and Eric! Very helpful.
Though after reading your article, Eric, I'm even more uncertain of how
electro-physics works. :)
Valin
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Valin
Thorn
Sent: Saturday, July 04, 2015 1:03 PM
Subject: AeroElectric-List: Diode Reverse Voltage Leak or Invalid
Measurement Setup?
Hello,
We're getting set to do power on testing of our electrical system and
avionics. We're using the (Bob's) Z-12 power grid at 28 VDC with a 12 VDC
bus and 12VDC hot battery bus.
We have schottkey diodes isolating the various buses.
With the positive battery terminal connected and the 12 VDC hot battery lead
connected, but NOT the battery ground to the single point ground, I checked
the voltage at various points and saw the 12+ VDC where it should be but was
surprised to measure about 3.5 VDC on the Main Bus and even the Ground Bus.
The meter set up was with the VOM meter ground lead to the battery ground
(not connected to the airplane's ground bus) and then the positive prove to
the various measurement locations.
At first I thought we must have a pin out wrong in a connector somewhere -
and maybe we do. After some trouble shooting, I was able to determine that
the voltage seems to be leaking in reverse past the diode from the 12 VDC
Hot Batt Bus to the 12VDC Bus and then through the 24 to 12 VDC converter to
the Main Bus. But somehow, when I put the meter's positive probe on the
ground bus, it also shows 3.5 VDC. So not even sure this is a valid way to
test that I'm using.
Here's our Power Grid. Sorry Bob that it is in my pictogram format. The
anode side of Diode B is where I'm seeing 3.5 VDC with 12VDC on the cathode
side, as expected, coming from the hot battery bus.
I did a test of a spare diode of the same model on the bench with a single
12 VDC battery and measure 4.9 VDC on the anode side of the diode with the
cathode connected to the battery's positive terminal. See photo below.
My questions.
1. Is this even a valid voltage measurement setup? Is this real? If
both the positive and negative side of the electrical system are showing 3.5
VDC relative to the unattached battery ground, then there is no electrical
potential difference/voltage between them.
2. Are these the wrong diodes for this application? (spec sheet
attached)
3. What should I do?
I'd sure appreciate some help with this. Oh, and Happy Independence Day!
Thanks!
Valin
(Confused)
________________________________________________________________________________
| From: | "Ross Home" <rossmickey(at)comcast.net> |
| Subject: | SL-15 Unswitched Audio Connection |
I have a SL-15 Audio Selector Panel that has two "unswitched" audio
connections. One is hooked up to my AOA warning. I would like to use the
other for the audio of the Advanced Flight System 5600 EFIS I am installing.
The SL-15 uses Molex 08-05-0301 connectors which are discontinued and I
cannot find them anywhere.
My three options seem to be:
Find someone who has a connector I can purchase (failed so far but maybe one
of you has an extra)
Take out the connector that is in there for a speaker I am not using and use
it. (Suggestions on how to remove the connector without buying the
specified tool please)
Hook the EFIS audio line with the AOA audio line which may not work at all
if one is loading the wire all the time.
Thanks so much,
Ross Mickey
N9PT
________________________________________________________________________________
| From: | ARGOLDMAN(at)aol.com |
| Subject: | Re: SL-15 Unswitched Audio Connection |
the Molex 08-05-0301 itself is not a connector but refers to the finger
spring contacts. They are , I believe gold plated and indeed are not
available. Newark lists the following substitutes.
* _39X7518_
(http://www.newark.com/molex/08-50-0187/contact-socket-20-18awg-crimp/dp/39X7518) - Product Range:6838 Series; For Use With:KK
6442, 41695 Series Crimp Terminal Housings; Contact Gender:Socket; Contact
Material:Brass; Contact Plating:Tin; Contact Termination Type:Crimp ;RoHS
Compliant: Yes
* _20H0074_
(http://www.newark.com/molex/08-50-0187/contact-socket-20-18awg-crimp/dp/20H0074) - Product Range:6838 Series; For Use With:KK
6442, 41695 Series Crimp Terminal Housings; Contact Gender:Socket; Contact
Material:Brass; Contact Plating:Tin; Contact Termination Type:Crimp ;RoHS
Compliant: Yes
* _01E9145_
(http://www.newark.com/molex/08-55-0103/contact-female-24-18awg-crimp/dp/01E9145) - Product Range:KK Series; For Use With:KK Series
Crimp Terminal Housings; Contact Gender:Socket; Contact Material:Brass;
Contact Plating:Gold; Contact Termination Type:Crimp; Wire Size AWG Min:24AWG
;RoHS Compliant: Yes
The connector body , itself is also available and are listed with the
above.
Since they are not gold plated (with the exception of the 01E9145, if the
housing is not appropriate, I would use a slight smear of an anti
oxidation grease on the connector. The connector body is readily available. If
you
look up the below numbers at digikey, I believe when you look at one of the
selections, the bottom of the description will list what connector bodies
are appropriate for that contact. You just have to do a little detective
work.
In a message dated 7/9/2015 11:02:34 A.M. Central Daylight Time,
rossmickey(at)comcast.net writes:
Molex 08-05-0301
________________________________________________________________________________
| From: | "Ralph E. Capen" <recapen(at)earthlink.net> |
| Subject: | Re: SL-15 Unswitched Audio Connection |
If I recall correctly, the SL-15 is equivalent to the PS Engineering PMA7000 series
(I have one of those).
I'll look to see if I have any additional/spare connectors as I wired mine. I
recall they were on a metal tape and I simply cut off the ones I needed.....
-----Original Message-----
From: Ross Home
Sent: Jul 9, 2015 11:59 AM
Subject: AeroElectric-List: SL-15 Unswitched Audio Connection
I have a SL-15 Audio Selector Panel that has two unswitched audio connections.
One is hooked up to my AOA warning. I would like to use the other for the audio
of the Advanced Flight System 5600 EFIS I am installing. The SL-15 uses Molex
08-05-0301 connectors which are discontinued and I cannot find them anywhere.
My three options seem to be: Find someone who has a connector I can purchase
(failed so far but maybe one of you has an extra) Take out the connector
that is in there for a speaker I am not using and use it. (Suggestions on how
to remove the connector without buying the specified tool please) Hook the EFIS
audio line with the AOA audio line which may not work at all if one is loading
the wire all the time. Thanks so much, Ross MickeyN9PT
________________________________________________________________________________
| From: | "Ross Home" <rossmickey(at)comcast.net> |
| Subject: | SL-15 Unswitched Audio Connection |
Yes, that is the one. Thanks.
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Ralph E. Capen
Sent: Thursday, July 09, 2015 9:49 AM
Subject: Re: AeroElectric-List: SL-15 Unswitched Audio Connection
-->
If I recall correctly, the SL-15 is equivalent to the PS Engineering PMA7000 series
(I have one of those).
I'll look to see if I have any additional/spare connectors as I wired mine. I
recall they were on a metal tape and I simply cut off the ones I needed.....
-----Original Message-----
From: Ross Home
Sent: Jul 9, 2015 11:59 AM
Subject: AeroElectric-List: SL-15 Unswitched Audio Connection
I have a SL-15 Audio Selector Panel that has two unswitched audio connections.
One is hooked up to my AOA warning. I would like to use the other for the audio
of the Advanced Flight System 5600 EFIS I am installing. The SL-15 uses Molex
08-05-0301 connectors which are discontinued and I cannot find them anywhere.
My three options seem to be: Find someone who has a connector I can purchase
(failed so far but maybe one of you has an extra) Take out the connector
that is in there for a speaker I am not using and use it. (Suggestions on how
to remove the connector without buying the specified tool please) Hook the EFIS
audio line with the AOA audio line which may not work at all if one is loading
the wire all the time. Thanks so much, Ross MickeyN9PT
________________________________________________________________________________
| From: | Charlie England <ceengland7(at)gmail.com> |
| Subject: | Re: SL-15 Unswitched Audio Connection |
On 7/9/2015 10:59 AM, Ross Home wrote:
>
> I have a SL-15 Audio Selector Panel that has two unswitched audio
> connections. One is hooked up to my AOA warning. I would like to use
> the other for the audio of the Advanced Flight System 5600 EFIS I am
> installing. The SL-15 uses Molex 08-05-0301 connectors which are
> discontinued and I cannot find them anywhere.
>
> My three options seem to be:
>
> Find someone who has a connector I can purchase (failed so far but
> maybe one of you has an extra)
>
> Take out the connector that is in there for a speaker I am not using
> and use it. (Suggestions on how to remove the connector without
> buying the specified tool please)
>
> Hook the EFIS audio line with the AOA audio line which may not work at
> all if one is loading the wire all the time.
>
> Thanks so much,
>
> Ross Mickey
>
> N9PT
>
>
Is this it?
08-05-0301 Molex Connector Corporation | WM6390CT-ND DigiKey Electronics
If so, and I owned it, I'd solder wires to the edge connector to make a
'pigtail' connector using a dSub connector, with a strain relief to
protect the wires. Those things are perfect examples of 'Aviation Quality'.
If you have that spare that can be moved, there's usually a little tab
on the back side that prevents it from backing out. If you have
something thin and narrow enough, you should be able to slide it in from
the 'front' (non-wire) end and push the tab away from it's mating lock
point in the shell.
Charlie
________________________________________________________________________________
| From: | "Ross Home" <rossmickey(at)comcast.net> |
| Subject: | SL-15 Unswitched Audio Connection |
Yes, that is it. Thanks.
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Charlie
England
Sent: Thursday, July 09, 2015 11:16 AM
Subject: Re: AeroElectric-List: SL-15 Unswitched Audio Connection
On 7/9/2015 10:59 AM, Ross Home wrote:
I have a SL-15 Audio Selector Panel that has two "unswitched" audio
connections. One is hooked up to my AOA warning. I would like to use the
other for the audio of the Advanced Flight System 5600 EFIS I am installing.
The SL-15 uses Molex 08-05-0301 connectors which are discontinued and I
cannot find them anywhere.
My three options seem to be:
Find someone who has a connector I can purchase (failed so far but maybe one
of you has an extra)
Take out the connector that is in there for a speaker I am not using and use
it. (Suggestions on how to remove the connector without buying the
specified tool please)
Hook the EFIS audio line with the AOA audio line which may not work at all
if one is loading the wire all the time.
Thanks so much,
Ross Mickey
N9PT
Is this it?
If so, and I owned it, I'd solder wires to the edge connector to make a
'pigtail' connector using a dSub connector, with a strain relief to protect
the wires. Those things are perfect examples of 'Aviation Quality'.
If you have that spare that can be moved, there's usually a little tab on
the back side that prevents it from backing out. If you have something thin
and narrow enough, you should be able to slide it in from the 'front'
(non-wire) end and push the tab away from it's mating lock point in the
shell.
Charlie
________________________________________________________________________________
| From: | Bill Putney <billp(at)wwpc.com> |
| Subject: | Re: SL-15 Unswitched Audio Connection |
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: SL-15 Unswitched Audio Connection |
At 10:59 AM 7/9/2015, you wrote:
>I have a SL-15 Audio Selector Panel that has two "unswitched" audio
>connections. One is hooked up to my AOA warning. I would like to
>use the other for the audio of the Advanced Flight System 5600 EFIS
>I am installing. The SL-15 uses Molex 08-05-0301 connectors which
>are discontinued and I cannot find them anywhere.
>
>My three options seem to be:
>
>Find someone who has a connector I can purchase (failed so far but
>maybe one of you has an extra)
How many pins are in these connectors?
That style of connector was received with considerable
excitement at Cessna . . . waaayyyy back when. For
a few years, we made up our own audio switching and
signal routing junction box utilizing the .156 spaced,
card edge connectors. They were the "Amp Leaf" from
Amp-Inc.
http://tinyurl.com/qbqndka
http://tinyurl.com/p2dfvfs
Later, others jumped in with their own offerings
. . . one of which was the KK series from Molex
http://tinyurl.com/7t6jjsc
Cessna got out of that activity after a few
years in favor of exploiting off-the-shelf
devices . . . that first experiment into
rudimentary avionics manufacturing had some
reliability issues. I wasn't directly involved
in the engineering gyrations . . . but I got
to observe it and write about it. There proved
to be other form-factors for bringing wires
off pc boards that were a quantum jump in
reliability for black-boxes on airplanes.
Nonetheless, King radio, Narco and others
produced a goodly number of devices with this
technology. The .156" card-edge has been
'not recommended for new design' for a very
long time.
This poses problems for exploiting the utility
of these venerable devices. Quite often, extending
the air-worthiness of these devices goes beyond
finding pins for adding features. What's a OBAM'er
to do when the existing connector has degraded to
one step above trash . . . or worse.
I've stroked new service life into several devices
by replacing the crimped pin connector with solder
flag connectors. Like this . . .
http://tinyurl.com/nbuab2a
Unfortunately, not ALL sizes are available but
with some creative application of time/effort and
JB weld, you can fabricate a connector of any desired
size that offers you all new pins. Check out all
the images in the third link above.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: SL-15 Unswitched Audio Connection |
>If you have that spare that can be moved, there's usually a little
>tab on the back side that prevents it from backing out. If you have
>something thin and narrow enough, you should be able to slide it in
>from the 'front' (non-wire) end and push the tab away from it's
>mating lock point in the shell.
Here's a DIY extraction tool
for the leaf-style card edge
connector pins.
http://tinyurl.com/nknv4bk
Made this from a pocket screwdriver
sacrificed to the task while on a
field-trip . . . A little creating
grinding will get you the right dimensions
for your target connector.
Bob . . .
________________________________________________________________________________
| Subject: | Insulation displacement connectors???? |
| From: | Charlie England <ceengland7(at)gmail.com> |
Anyone know if any type of insulation displacement crimp connectors have
ever been used in aircraft applications? I used hundreds (thousands?) of
EA-7759 Plain B Wire Connectors, similar to
http://www.ebay.com/itm/371364009928?rmvSB=true
in burglar alarm & other data cable installations, & never have had a
failed connection in 3 decades (though admittedly, I was stripping &
twisting the wires prior to crimping). For those who haven't seen these,
they have 'teeth' inside that pierce the insulation when crimped.
I'm looking at the need to 'daisy chain' several signal grounds from a
single dSub pin (in this case, an intercom), and these tiny connectors
really look attractive to stagger the joints over several inches of wire
near the pin. I tested one by opening the closed end with a pair of pliers,
running the 'trunk' wire through the connector, inserting the 'branch'
wire, and crimping (no wire stripping involved). Seems to work fine in
penetrating the tefzel insulation, and I can't budge the wires with a
manual tug test.
I have no desire to do this for high current applications, but for signal
wires, it sure makes an attractive package due to it's small size. Not sure
about the type of insulation, but I'm pretty sure it won't spontaneously
combust & drag the plane out of the sky.
Thoughts?
Charlie
________________________________________________________________________________
| From: | Bill Putney <billp(at)wwpc.com> |
| Subject: | Re: Insulation displacement connectors???? |
Charlie,
I know splicers use to love these things but even the telco's outlawed
these in the 70's (i think). I'm surprised you can even find them on eBay.
I guess you can use whatever you want to bet your life on in
experimental but I'd stick with what's in common aeronautical use.
Bill
On 7/15/15 3:12 PM, Charlie England wrote:
> Anyone know if any type of insulation displacement crimp connectors
> have ever been used in aircraft applications? I used hundreds
> (thousands?) of EA-7759 Plain B Wire Connectors, similar to
> http://www.ebay.com/itm/371364009928?rmvSB=true
>
> in burglar alarm & other data cable installations, & never have had a
> failed connection in 3 decades (though admittedly, I was stripping &
> twisting the wires prior to crimping). For those who haven't seen
> these, they have 'teeth' inside that pierce the insulation when crimped.
>
> I'm looking at the need to 'daisy chain' several signal grounds from a
> single dSub pin (in this case, an intercom), and these tiny connectors
> really look attractive to stagger the joints over several inches of
> wire near the pin. I tested one by opening the closed end with a pair
> of pliers, running the 'trunk' wire through the connector, inserting
> the 'branch' wire, and crimping (no wire stripping involved). Seems to
> work fine in penetrating the tefzel insulation, and I can't budge the
> wires with a manual tug test.
>
> I have no desire to do this for high current applications, but for
> signal wires, it sure makes an attractive package due to it's small
> size. Not sure about the type of insulation, but I'm pretty sure it
> won't spontaneously combust & drag the plane out of the sky.
>
> Thoughts?
>
> Charlie
> *
>
>
> *
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Insulation displacement connectors???? |
At 05:12 PM 7/15/2015, you wrote:
>Anyone know if any type of insulation
>displacement crimp connectors have ever been
>used in aircraft applications? I used hundreds
>(thousands?) of EA-7759 Plain B Wire Connectors, similar to=C2
><http://www.ebay.com/itm/371364009928?rmvSB=true>http://www.ebay.com/itm/
371364009928?rmvSB=true
>
>in burglar alarm & other data cable
>installations, & never have had a failed
>connection in 3 decades (though admittedly, I
>was stripping & twisting the wires prior to
>crimping). For those who haven't seen these,
>they have 'teeth' inside that pierce the insulation when crimped
Suggest you use bussed d-sub connectors
http://tinyurl.com/nzm3e2f
I've got some bussing boards available if
you want them.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Insulation displacement connectors???? |
| From: | Charlie England <ceengland7(at)gmail.com> |
Outlawed in the '70s? Maybe so on that particular connector, but I've
watched AT&T techs use
http://www.specialized.net/Specialized/3M-Scotchlok-IDC-UR2-Connectors-1926-AWG-100Pk-4051.aspx
as recently as a few weeks ago.
I appreciate the 'be safe' sentiment, but 'bet your life' on the signal
wires in an intercom? Isn't that a bit of a knee-jerk reaction to anything
unfamiliar? If I'm not mistaken, this list came out of the desire to find
products and techniques that are *not* 'in common aeronautical use', so we
can improve on the products and/or techniques. We wouldn't have composite
airframes (or even aluminum ones) if someone hadn't been the 1st to use
something that was not 'in common aeronautical use'.
It would be more helpful to me if you could say something at least
marginally quantified, like, 'That terminal fails in 0.05% of connections,
vs a 0.00004% failure rate for PIDG terminals'.
Thanks,
Charlie
On Wed, Jul 15, 2015 at 5:57 PM, Bill Putney wrote:
> Charlie,
>
> I know splicers use to love these things but even the telco's outlawed
> these in the 70's (i think). I'm surprised you can even find them on eBay.
>
> I guess you can use whatever you want to bet your life on in experimental
> but I'd stick with what's in common aeronautical use.
>
> Bill
>
> On 7/15/15 3:12 PM, Charlie England wrote:
>
> Anyone know if any type of insulation displacement crimp connectors have
> ever been used in aircraft applications? I used hundreds (thousands?) of
> EA-7759 Plain B Wire Connectors, similar to
> http://www.ebay.com/itm/371364009928?rmvSB=true
>
> in burglar alarm & other data cable installations, & never have had a
> failed connection in 3 decades (though admittedly, I was stripping &
> twisting the wires prior to crimping). For those who haven't seen these,
> they have 'teeth' inside that pierce the insulation when crimped.
>
> I'm looking at the need to 'daisy chain' several signal grounds from a
> single dSub pin (in this case, an intercom), and these tiny connectors
> really look attractive to stagger the joints over several inches of wire
> near the pin. I tested one by opening the closed end with a pair of pliers,
> running the 'trunk' wire through the connector, inserting the 'branch'
> wire, and crimping (no wire stripping involved). Seems to work fine in
> penetrating the tefzel insulation, and I can't budge the wires with a
> manual tug test.
>
> I have no desire to do this for high current applications, but for
> signal wires, it sure makes an attractive package due to it's small size.
> Not sure about the type of insulation, but I'm pretty sure it won't
> spontaneously combust & drag the plane out of the sky.
>
> Thoughts?
>
> Charlie
>
>
> *
>
>
> *
>
>
________________________________________________________________________________
| Subject: | Re: Insulation displacement connectors???? |
| From: | Charlie England <ceengland7(at)gmail.com> |
On Wed, Jul 15, 2015 at 8:25 PM, Robert L. Nuckolls, III <
nuckolls.bob(at)aeroelectric.com> wrote:
> At 05:12 PM 7/15/2015, you wrote:
>
> Anyone know if any type of insulation displacement crimp connectors have
> ever been used in aircraft applications? I used hundreds (thousands?) of
> EA-7759 Plain B Wire Connectors, similar to=C3=82
> http://www.ebay.com/itm/371364009928?rmvSB=true
>
> in burglar alarm & other data cable installations, & never have had a
> failed connection in 3 decades (though admittedly, I was stripping &
> twisting the wires prior to crimping). For those who haven't seen these,
> they have 'teeth' inside that pierce the insulation when crimped
>
>
> Suggest you use bussed d-sub connectors
>
> http://tinyurl.com/nzm3e2f
>
> I've got some bussing boards available if
> you want them.
>
>
> Bob . . .
>
>
Thanks, Bob; I've already got one of those dSub avionics GND busses mounted
in the plane. My specific application for those crimps is the signal ground
terminal in a DRE intercom (it has two ground pins in the 25pin dSub which
are electrically common internally). My intent was to run one of the gnd
pins to the avionics GND bus and the other to the gnd terminals of the
various inputs/outputs (mic, headset, music, etc) to the intercom. The
crimps would have been used to bring the various signal ground wires to
within the 1st few inches of dSub connector on the DRE.
Would it work as well to just take all those signal grounds to the avionics
dSub ground bus? I was trying to take the signal grounds directly to the
intercom to keep ground loop possibilities to an absolute minimum, and an
additional dSub bus for just 3 or 4 wires seems to be overkill (and bulky).
Thanks,
Charlie
________________________________________________________________________________
| From: | Bill Putney <billp(at)wwpc.com> |
| Subject: | Re: Insulation displacement connectors???? |
I know a lot of guys have the old beans squirreled away but they tend to
make noisy connections and are corrosion prone. The Scotchloks are what
the telco's moved to after they outlawed the beans.
I take things about my airplane very seriously. If nothing else I use
the "How stupid would I feel" rule. Like how stupid would I feel if my
intercom quit on short final to a busy towered airport in marginal
weather because I didn't take the time to strip the wires and use the
right connectors?
It's a human factors thing. People can handle about 3 things going wrong
before they completely unravel. If the weather suddenly gets bad you can
turn around and go the other way, add strong winds in that reverse
direction now depleting your fuel faster than you planned. If the
intercom goes out and you can't contact Flightwatch or ATC to find out
where the closest open airport is and you've got a real problem It
wouldn't have been a big problem in CAVU but this day it's the third
thing. I don't mean to say that every shortcut you take is going to kill
you but you never know what the third thing is going to be.
There are old pilots and there are bold pilots but there are very few
old bold pilots.
Bill
On 7/16/15 05:52, Charlie England wrote:
> Outlawed in the '70s? Maybe so on that particular connector, but I've
> watched AT&T techs use
> http://www.specialized.net/Specialized/3M-Scotchlok-IDC-UR2-Connectors-1926-AWG-100Pk-4051.aspx
> as recently as a few weeks ago.
>
> I appreciate the 'be safe' sentiment, but 'bet your life' on the
> signal wires in an intercom? Isn't that a bit of a knee-jerk reaction
> to anything unfamiliar? If I'm not mistaken, this list came out of the
> desire to find products and techniques that are *not* 'in common
> aeronautical use', so we can improve on the products and/or
> techniques. We wouldn't have composite airframes (or even aluminum
> ones) if someone hadn't been the 1st to use something that was not 'in
> common aeronautical use'.
>
> It would be more helpful to me if you could say something at least
> marginally quantified, like, 'That terminal fails in 0.05% of
> connections, vs a 0.00004% failure rate for PIDG terminals'.
>
> Thanks,
>
> Charlie
>
> On Wed, Jul 15, 2015 at 5:57 PM, Bill Putney > wrote:
>
> Charlie,
>
> I know splicers use to love these things but even the telco's
> outlawed these in the 70's (i think). I'm surprised you can even
> find them on eBay.
>
> I guess you can use whatever you want to bet your life on in
> experimental but I'd stick with what's in common aeronautical use.
>
> Bill
>
> On 7/15/15 3:12 PM, Charlie England wrote:
>> Anyone know if any type of insulation displacement crimp
>> connectors have ever been used in aircraft applications? I used
>> hundreds (thousands?) of EA-7759 Plain B Wire Connectors, similar to
>> http://www.ebay.com/itm/371364009928?rmvSB=true
>>
>> in burglar alarm & other data cable installations, & never have
>> had a failed connection in 3 decades (though admittedly, I was
>> stripping & twisting the wires prior to crimping). For those who
>> haven't seen these, they have 'teeth' inside that pierce the
>> insulation when crimped.
>>
>> I'm looking at the need to 'daisy chain' several signal grounds
>> from a single dSub pin (in this case, an intercom), and these
>> tiny connectors really look attractive to stagger the joints over
>> several inches of wire near the pin. I tested one by opening the
>> closed end with a pair of pliers, running the 'trunk' wire
>> through the connector, inserting the 'branch' wire, and crimping
>> (no wire stripping involved). Seems to work fine in penetrating
>> the tefzel insulation, and I can't budge the wires with a manual
>> tug test.
>>
>> I have no desire to do this for high current applications, but
>> for signal wires, it sure makes an attractive package due to it's
>> small size. Not sure about the type of insulation, but I'm pretty
>> sure it won't spontaneously combust & drag the plane out of the sky.
>>
>> Thoughts?
>>
>> Charlie
>> *
>>
>>
>> *
>
> *
>
> ist" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
> tp://forums.matronics.com
> _blank">http://www.matronics.com/contribution
>
> *
>
>
> *
>
>
> *
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Insulation displacement connectors???? |
>
>It would be more helpful to me if you could say something at least
>marginally quantified, like, 'That terminal fails in 0.05% of
>connections, vs a 0.00004% failure rate for PIDG terminals'.
How about, "I used ID connectors and ribbon cable
in a pitch trim project on a Lear waaayyy back when.
At about the 15-year mark, I inquired of the field
service guys who were supporting that product. Failure
rates were pleasingly low; that product was
a fleet retrofit of about 500+ airplanes and the
pitch trim controllers came in for attention about
5x a year . . . so about 1%/year for the design.
The ID connection devices accounted for about 50% of the
service issues.
Further, that box was located in the vertical fin,
just under the leading edge of the stabilizer . . .
hence, subject to about the worst of the sheltered
environs on the aircraft.
From that experience I would deduce that while
the failure rates for ID connections were low,
they still accounted for the majority of field
failures in the design.
Keep in mind also that the teleco's and network
communities have been using ID connections for
decades . . . of course the environments are not nearly
as severe as the interior of a biz-jet's vertical fin . . .
but still subject to humidity, temperature cycles and
exposure to noxious atmosphere. It would seem that
an ID connector used with wires in the connector's
design window is a low risk venture.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Insulation displacement connectors???? |
>
>Thanks, Bob; I've already got one of those dSub avionics GND busses
>mounted in the plane. My specific application for those crimps is
>the signal ground terminal in a DRE intercom (it has two ground pins
>in the 25pin dSub which are electrically common internally). My
>intent was to run one of the gnd pins to the avionics GND bus and
>the other to the gnd terminals of the various inputs/outputs (mic,
>headset, music, etc) to the intercom. The crimps would have been
>used to bring the various signal ground wires to within the 1st few
>inches of dSub connector on the DRE.
>
>Would it work as well to just take all those signal grounds to the
>avionics dSub ground bus? I was trying to take the signal grounds
>directly to the intercom to keep ground loop possibilities to an
>absolute minimum, and an additional dSub bus for just 3 or 4 wires
>seems to be overkill (and bulky).
The core idea for the AGB was to craft a single
point ground for all signals, power and shields.
If it's just 3-4 wires and just shields, why
not solder and heat-shrink?
In reliability studies, a connector drives up
parts count . . . a soldered joint is calculated
as the joining of several parts into one part
such that there is better than 10 to the minus
bazillion reliability. Solder and shrink is almost
never a bad idea. Is is frowned upon in the factories
because solder is a skill-driven process with tools
that burn fingers, upholstery, carpets, etc. But
for the OBAM aircraft crowd, solder should represent
no unsurmountable hazard.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Insulation displacement connectors???? |
| From: | Eric Page <edpav8r(at)yahoo.com> |
One additional data point. I used IDCs very similar to those in the OP's qu
estion (mine were blue and slightly smaller) to wire an alarm system in my l
ast home in 2004. Those connections were in an attic in Phoenix, where unde
r-roof temperatures were regularly above 120 deg F (no mechanical stress or v
ibration, and very low humidity). The alarm system was functioning perfectl
y when I sold the house in March, almost eleven years after installation.
Eric
> On Jul 16, 2015, at 7:59 AM, Robert L. Nuckolls, III <nuckolls.bob@aeroele
ctric.com> wrote:
>
>>
>> It would be more helpful to me if you could say something at least margin
ally quantified, like, 'That terminal fails in 0.05% of connections, vs a 0.
00004% failure rate for PIDG terminals'.
>
> How about, "I used ID connectors and ribbon cable
> in a pitch trim project on a Lear waaayyy back when.
> At about the 15-year mark, I inquired of the field
> service guys who were supporting that product. Failure
> rates were pleasingly low; that product was
> a fleet retrofit of about 500+ airplanes and the
> pitch trim controllers came in for attention about
> 5x a year . . . so about 1%/year for the design.
> The ID connection devices accounted for about 50% of the
> service issues.
>
> Further, that box was located in the vertical fin,
> just under the leading edge of the stabilizer . . .
> hence, subject to about the worst of the sheltered
> environs on the aircraft.
>
> =46rom that experience I would deduce that while
> the failure rates for ID connections were low,
> they still accounted for the majority of field
> failures in the design.
>
> Keep in mind also that the teleco's and network
> communities have been using ID connections for
> decades . . . of course the environments are not nearly
> as severe as the interior of a biz-jet's vertical fin . . .
> but still subject to humidity, temperature cycles and
> exposure to noxious atmosphere. It would seem that
> an ID connector used with wires in the connector's
> design window is a low risk venture.
>
> Bob . . .
________________________________________________________________________________
| From: | "Ross Home" <rossmickey(at)comcast.net> |
I know that asking about the cause of a buzz in your radios is like asking a
mechanic about a noise you hear when you are driving but since you are all
here and know way more than me I will describe my situation and how I plan
to proceed.
Set-up
RV-6A
GX-60 Com
SL-30 Com
SL-15 Intercom
Two COMANT VHF COMMUNICATIONS
<http://www.aircraftspruce.com/catalog/avpages/comant122.php> antenna
mounted on the centerline of the belly (one below the seat, one below the
baggage compartment)
I am getting significant static like noise when I connect either radio to
the front antenna. I have switched the antennas with no change. The front
antenna connection goes pretty much straight down to the floor with a short
male-male piece of coax (which I have changed with no result) to connect the
female ends of the antenna and radio coax. The antenna wire crosses a bunch
of wires at a 90 degree angle and goes right next to where I have a
temporary battery placed.
My conclusions:
The radios, antennas and cables are all ok so I must be picking up
interference from either the wires or the battery.
Solution:
Move the battery and see if it helps (I would have last night but ran out of
time)
What do you think?
Also, I get a very slight hum when I put my hand near (1 inch away) or touch
the SL-30. It doesn't bother me but I find it interesting that I just have
to get near the radio for the noise to happen.
Thanks all,
Ross Mickey
N9PT
RV-6A
________________________________________________________________________________
| Subject: | Re: Insulation displacement connectors???? |
| From: | Charlie England <ceengland7(at)gmail.com> |
wrote:
>
>>
>>Thanks, Bob; I've already got one of those dSub avionics GND busses
>>mounted in the plane. My specific application for those crimps is
>>the signal ground terminal in a DRE intercom (it has two ground pins
>>in the 25pin dSub which are electrically common internally). My
>>intent was to run one of the gnd pins to the avionics GND bus and
>>the other to the gnd terminals of the various inputs/outputs (mic,
>>headset, music, etc) to the intercom. The crimps would have been
>>used to bring the various signal ground wires to within the 1st few
>>inches of dSub connector on the DRE.
>>
>>Would it work as well to just take all those signal grounds to the
>>avionics dSub ground bus? I was trying to take the signal grounds
>>directly to the intercom to keep ground loop possibilities to an
>>absolute minimum, and an additional dSub bus for just 3 or 4 wires
>>seems to be overkill (and bulky).
>
> The core idea for the AGB was to craft a single
> point ground for all signals, power and shields.
> If it's just 3-4 wires and just shields, why
> not solder and heat-shrink?
>
> In reliability studies, a connector drives up
> parts count . . . a soldered joint is calculated
> as the joining of several parts into one part
> such that there is better than 10 to the minus
> bazillion reliability. Solder and shrink is almost
> never a bad idea. Is is frowned upon in the factories
> because solder is a skill-driven process with tools
> that burn fingers, upholstery, carpets, etc. But
> for the OBAM aircraft crowd, solder should represent
> no unsurmountable hazard.
>
>
> Bob . . .
Solder/shrink is what I've done in other places, so that's no problem. But a 10
second operation vs a 10 minute one surely is tempting. :-)
________________________________________________________________________________
| Subject: | Re: Insulation displacement connectors???? |
| From: | David Josephson <dlj04(at)josephson.com> |
In a word, no. B connectors are ugly, but work well given two
conditions: (a) DC sealing current to re-establish connection when
compromised by oxidation, and (b) no vibration. The later jelly-B
connectors try to solve the oxidation problem by immersing the pierces
wire in vaseline to keep air out. Not in my airplane.
________________________________________________________________________________
| Subject: | Re: Insulation displacement connectors???? |
| From: | David Josephson <dlj04(at)josephson.com> |
In a word, no. B connectors are ugly, but work well given two
conditions: (a) DC sealing current to re-establish connection when
compromised by oxidation, and (b) no vibration. The later jelly-B
connectors try to solve the oxidation problem by immersing the pierces
wire in vaseline to keep air out. Not in my airplane.
________________________________________________________________________________
| From: | "Ross Home" <rossmickey(at)comcast.net> |
More info.
My plane is not in a state that allows me to start the engine (wings are
off) so this is occurring with just the master switch on. No strobes or
landing lights on, just panel instruments on. The main change since I last
used the radios is the installation of a Advanced Flight System 5600 EFIS
but the only wiring from that which are near my antenna cable are the GPS,
Comm Radio and Autopilot serial/ARINC wires.
Ross
From: Ross Home [mailto:rossmickey(at)comcast.net]
Sent: Thursday, July 16, 2015 8:57 AM
Subject: Radio Buzz
I know that asking about the cause of a buzz in your radios is like asking a
mechanic about a noise you hear when you are driving but since you are all
here and know way more than me I will describe my situation and how I plan
to proceed.
Set-up
RV-6A
GX-60 Com
SL-30 Com
SL-15 Intercom
Two COMANT VHF COMMUNICATIONS
<http://www.aircraftspruce.com/catalog/avpages/comant122.php> antenna
mounted on the centerline of the belly (one below the seat, one below the
baggage compartment)
I am getting significant static like noise when I connect either radio to
the front antenna. I have switched the antennas with no change. The front
antenna connection goes pretty much straight down to the floor with a short
male-male piece of coax (which I have changed with no result) to connect the
female ends of the antenna and radio coax. The antenna wire crosses a bunch
of wires at a 90 degree angle and goes right next to where I have a
temporary battery placed.
My conclusions:
The radios, antennas and cables are all ok so I must be picking up
interference from either the wires or the battery.
Solution:
Move the battery and see if it helps (I would have last night but ran out of
time)
What do you think?
Also, I get a very slight hum when I put my hand near (1 inch away) or touch
the SL-30. It doesn't bother me but I find it interesting that I just have
to get near the radio for the noise to happen.
Thanks all,
Ross Mickey
N9PT
RV-6A
________________________________________________________________________________
| From: | "user9253" <fransew(at)gmail.com> |
Is the temporary battery powering the avionics? Is the negative battery terminal
grounded to the airframe?
Turn everything on, then measure the voltage between the negative battery terminal
and the radio case. How many millivolts?
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444845#444845
________________________________________________________________________________
| From: | n1deltawhiskey(at)comcast.net |
| Subject: | Re: RE: Radio Buzz |
Ross,
What you are picking up is probably some sort of RFI or EMI. I doubt it will be
coming from your battery unless you have some grounding issues, and may not even
be coming from your wires.
That leaves the noise generators which includes all of your other avionics and
electrical devices and systems including strobes, engine/ignition system, etc.
And that is assuming there is no noise generated because of ground loops in your
aircraft. So the process is to eliminate noise generators, one by one, assuming
there is no noise in your antenna/cable/radio when tested with ALL other
electrical equipment turned off. If your radio still generates noise when you
put your hand near it, I would consider grounding the case.
Then, turn on one electrical device at a time to see if it generates any noise.
With my GX-60, I noticed the Dynon D10A introduced some hum in the system when
turned on. The strobe circuit also introduced some noise. Test each electrical
system sequentially to find the biggest "offenders". This process will give
you some idea of where to look to attempt to reduce noise in the com system.
I recently had my transponder checked and asked about noise in the radio system.
He commented that some noise tended to "go with the territory".
Not necessarily related, I queried him about very loud feedback when attempting
to transmit. Turns out that a setting in the GX-60 for the microphone was set
to the maximum as shipped from the factory. The point here is to also check you
GX-60 setup parameters. Some adjustments there might assist in correcting your
issues.
Doug Windhorn
________________________________________________________________________________
| From: | <kboatright1(at)comcast.net> |
| Subject: | Re: RE: Radio Buzz |
http://www.warbirdinformationexchange.org/phpBB3/viewtopic.php?f=3&t=
52024
From: Ross Home
Sent: Thursday, July 16, 2015 6:19 PM
Subject: AeroElectric-List: RE: Radio Buzz
More info
My plane is not in a state that allows me to start the engine (wings are
off) so this is occurring with just the master switch on. No strobes or
landing lights on, just panel instruments on. The main change since I
last used the radios is the installation of a Advanced Flight System
5600 EFIS but the only wiring from that which are near my antenna cable
are the GPS, Comm Radio and Autopilot serial/ARINC wires.
Ross
From: Ross Home [mailto:rossmickey(at)comcast.net]
Sent: Thursday, July 16, 2015 8:57 AM
Subject: Radio Buzz
I know that asking about the cause of a buzz in your radios is like
asking a mechanic about a noise you hear when you are driving but since
you are all here and know way more than me I will describe my situation
and how I plan to proceed.
Set-up
RV-6A
GX-60 Com
SL-30 Com
SL-15 Intercom
Two COMANT VHF COMMUNICATIONS antenna mounted on the centerline of the
belly (one below the seat, one below the baggage compartment)
I am getting significant static like noise when I connect either radio
to the front antenna. I have switched the antennas with no change. The
front antenna connection goes pretty much straight down to the floor
with a short male-male piece of coax (which I have changed with no
result) to connect the female ends of the antenna and radio coax. The
antenna wire crosses a bunch of wires at a 90 degree angle and goes
right next to where I have a temporary battery placed.
My conclusions:
The radios, antennas and cables are all ok so I must be picking up
interference from either the wires or the battery.
Solution:
Move the battery and see if it helps (I would have last night but ran
out of time)
What do you think?
Also, I get a very slight hum when I put my hand near (1 inch away) or
touch the SL-30. It doesn=99t bother me but I find it interesting
that I just have to get near the radio for the noise to happen.
Thanks all,
Ross Mickey
N9PT
RV-6A
________________________________________________________________________________
| From: | Dj Merrill <deej(at)deej.net> |
| Subject: | Re: RE: Radio Buzz |
On 7/16/2015 6:19 PM, Ross Home wrote:
> My plane is not in a state that allows me to start the engine (wings are
> off) so this is occurring with just the master switch on. No strobes or
> landing lights on, just panel instruments on.
Just a random thought, but is this inside your hangar? Is there
anything on in the hangar, like lights, a refrigerator, etc?
The noise might not be coming from anything in the plane.
-Dj
--
Dj Merrill - N1JOV - EAA Chapter 87
Sportsman 2+2 Builder #7118 N421DJ - http://deej.net/sportsman/
Glastar Flyer N866RH - http://deej.net/glastar/
________________________________________________________________________________
| From: | "Bill Bradburry" <bbradburry(at)verizon.net> |
The last couple of days I have been getting duplicates of every msg from the
Aeroelectric list. Is anyone else having this problem? I don't think it is
on my end since only the list emails are affected.
Bill
________________________________________________________________________________
| Subject: | Re: RE: Radio Buzz |
| From: | Kelly McMullen <kellym(at)aviating.com> |
Excellent thought. I had squelch break of sorts on my SL30 until I
realized it came and went with the light switch. One florescent tube was
causing its ballast to put out a bunch of RFI. New tube, noise gone.
On 7/16/2015 6:20 PM, Dj Merrill wrote:
>
> On 7/16/2015 6:19 PM, Ross Home wrote:
>> My plane is not in a state that allows me to start the engine (wings are
>> off) so this is occurring with just the master switch on. No strobes or
>> landing lights on, just panel instruments on.
>
> Just a random thought, but is this inside your hangar? Is there
> anything on in the hangar, like lights, a refrigerator, etc?
>
> The noise might not be coming from anything in the plane.
>
> -Dj
>
________________________________________________________________________________
| Subject: | Re: Double Trouble |
| From: | Graeme Hart <graeme.hart(at)onecoolkat.com> |
Tm8gcHJvYmxlbSBoZXJlLiBJIGFtIG9ubHkgcmVjZWl2aW5nIG9uZSBjb3B5Lg0KDQo+IE9uIDE3
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PiB3cm90ZToNCj4+DQo+PiBUaGUgbGFzdCBjb3VwbGUgb2YgZGF5cyBJIGhhdmUgYmVlbiBnZXR0
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PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09
PT09DQo+Pg0K
________________________________________________________________________________
| Subject: | Re: RE: Radio Buzz |
| From: | Hal Benjamin <halbenjamin101(at)gmail.com> |
I have a handheld radio in my hanger that I listen to while doing my preflight.
Battery chargers for electronic devices often cause noise.
Hal Benjamin
RV4, Long Island, NY
Sent from my iPad
> On Jul 17, 2015, at 1:16 AM, Kelly McMullen wrote:
>
>
> Excellent thought. I had squelch break of sorts on my SL30 until I realized it
came and went with the light switch. One florescent tube was causing its ballast
to put out a bunch of RFI. New tube, noise gone.
>
>> On 7/16/2015 6:20 PM, Dj Merrill wrote:
>>
>>> On 7/16/2015 6:19 PM, Ross Home wrote:
>>> My plane is not in a state that allows me to start the engine (wings are
>>> off) so this is occurring with just the master switch on. No strobes or
>>> landing lights on, just panel instruments on.
>>
>> Just a random thought, but is this inside your hangar? Is there
>> anything on in the hangar, like lights, a refrigerator, etc?
>>
>> The noise might not be coming from anything in the plane.
>>
>> -Dj
>
>
>
>
>
________________________________________________________________________________
| Subject: | Re: Double Trouble |
| From: | Charlie England <ceengland7(at)gmail.com> |
On Thu, Jul 16, 2015 at 10:38 PM, Bill Bradburry
wrote:
> The last couple of days I have been getting duplicates of every msg from
> the Aeroelectric list. Is anyone else having this problem? I don
=99t think
> it is on my end since only the list emails are affected.
>
>
> Bill
>
>
It's probably a glitch with your ISP, or some intermediate transfer point
in the interwebs. :-) I've had similar things happen in the past, and they
typically resolve themselves in a few days.
Charlie
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 10:57 AM 7/16/2015, you wrote:
>I know that asking about the cause of a buzz in your radios is like
>asking a mechanic about a noise you hear when you are driving but
>since you are all here and know way more than me I will describe my
>situation and how I plan to proceed.
>
>Set-up
>RV-6A
>GX-60 Com
>SL-30 Com
>SL-15 Intercom
>Two
><http://www.aircraftspruce.com/catalog/avpages/comant122.php>COMANT
>VHF COMMUNICATIONS antenna mounted on the centerline of the belly
>(one below the seat, one below the baggage compartment)
>
>I am getting significant static like noise when I connect either
>radio to the front antenna.
This sounds like a radiated noise issue which is almost
never an issue with grounding or other installation
errors . . . it's usually some device that is not
designed to live in harmony on airplanes.
Find a hand-held radio. Adjust to unused frequency
and open the squelch so you can hear the background
'hiss'. Then use it to 'probe' about the various
devices on the airplane.
Hand-held vhf transceivers and 9v transistor am radios
have been quite useful for probing noise sources of
all stripe.
Also, conduct a power-down study. Pull all fuses/breakers
that power up the ship's accessories. If noise is gone,
replace fuses one at a time until the noise comes back.
Bob . . .
________________________________________________________________________________
| From: | "Ross Home" <rossmickey(at)comcast.net> |
I will try this.
What is puzzling is that the antenna connection that leads to the rear
antenna is at the firewall about 18 inches and level with my GX-60. I can
easily unhook the GX-60 cable from the front antenna (which is under the
floor directly beneath the GX-60) and hook it to the rear antenna connection
which is at the same height as the GX-60 and the noise goes away. All of
the wires that the GX-60 cable passes are the same in either case except,
when it is connected to the front antenna, it crosses these wires at a 90
degree angle instead of running parallel to them when it goes the rear
antenna connection.
Like I said earlier, I switched the two antenna to see if one was bad with
no change.
I am using a ground block for all grounding as suggested by Bob and the
battery is attached to it.
This also occurred out of the hangar so it isn't noise being generated
outside of the airplane.
Thank you all
Ross
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Friday, July 17, 2015 7:30 AM
Subject: Re: AeroElectric-List: Radio Buzz
At 10:57 AM 7/16/2015, you wrote:
I know that asking about the cause of a buzz in your radios is like asking a
mechanic about a noise you hear when you are driving but since you are all
here and know way more than me I will describe my situation and how I plan
to proceed.
Set-up
RV-6A
GX-60 Com
SL-30 Com
SL-15 Intercom
Two COMANT VHF COMMUNICATIONS
<http://www.aircraftspruce.com/catalog/avpages/comant122.php> antenna
mounted on the centerline of the belly (one below the seat, one below the
baggage compartment)
I am getting significant static like noise when I connect either radio to
the front antenna.
This sounds like a radiated noise issue which is almost
never an issue with grounding or other installation
errors . . . it's usually some device that is not
designed to live in harmony on airplanes.
Find a hand-held radio. Adjust to unused frequency
and open the squelch so you can hear the background
'hiss'. Then use it to 'probe' about the various
devices on the airplane.
Hand-held vhf transceivers and 9v transistor am radios
have been quite useful for probing noise sources of
all stripe.
Also, conduct a power-down study. Pull all fuses/breakers
that power up the ship's accessories. If noise is gone,
replace fuses one at a time until the noise comes back.
Bob . . .
________________________________________________________________________________
| From: | Kelly McMullen <kellym(at)aviating.com> |
Since you have ruled out external sources, it sort of points to the
front antenna cable. I thought you said you had tried swapping cables.
Try removing antenna from airframe, connecting it directly to radio and
see if there is noise.
I can't explain it, but I know of one case where noise was coming via
ground, and isolating the antenna from ground cured the problem. Perhaps
a ground loop between coax shield and the airframe ground.
On 7/17/2015 7:51 AM, Ross Home wrote:
>
> I will try this.
>
> What is puzzling is that the antenna connection that leads to the rear
> antenna is at the firewall about 18 inches and level with my GX-60. I
> can easily unhook the GX-60 cable from the front antenna (which is
> under the floor directly beneath the GX-60) and hook it to the rear
> antenna connection which is at the same height as the GX-60 and the
> noise goes away. All of the wires that the GX-60 cable passes are the
> same in either case except, when it is connected to the front antenna,
> it crosses these wires at a 90 degree angle instead of running
> parallel to them when it goes the rear antenna connection.
>
> Like I said earlier, I switched the two antenna to see if one was bad
> with no change.
>
> I am using a ground block for all grounding as suggested by Bob and
> the battery is attached to it.
>
> This also occurred out of the hangar so it isnt noise being generated
> outside of the airplane.
>
> Thank you all
>
> Ross
>
> *From:*owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] *On Behalf Of
> *Robert L. Nuckolls, III
> *Sent:* Friday, July 17, 2015 7:30 AM
> *To:* aeroelectric-list(at)matronics.com
> *Subject:* Re: AeroElectric-List: Radio Buzz
>
> At 10:57 AM 7/16/2015, you wrote:
>
> I know that asking about the cause of a buzz in your radios is
> like asking a mechanic about a noise you hear when you are driving
> but since you are all here and know way more than me I will
> describe my situation and how I plan to proceed.
>
> Set-up
> RV-6A
> GX-60 Com
> SL-30 Com
> SL-15 Intercom
> Two COMANT VHF COMMUNICATIONS
> <http://www.aircraftspruce.com/catalog/avpages/comant122.php>
> antenna mounted on the centerline of the belly (one below the
> seat, one below the baggage compartment)
>
> I am getting significant static like noise when I connect either
> radio to the front antenna.
>
>
> This sounds like a radiated noise issue which is almost
> never an issue with grounding or other installation
> errors . . . it's usually some device that is not
> designed to live in harmony on airplanes.
>
> Find a hand-held radio. Adjust to unused frequency
> and open the squelch so you can hear the background
> 'hiss'. Then use it to 'probe' about the various
> devices on the airplane.
>
> Hand-held vhf transceivers and 9v transistor am radios
> have been quite useful for probing noise sources of
> all stripe.
>
> Also, conduct a power-down study. Pull all fuses/breakers
> that power up the ship's accessories. If noise is gone,
> replace fuses one at a time until the noise comes back.
>
>
> Bob . . .
>
> **
> **
> **
> **
> **
> **
> **
> *http://www.matronics.com/Navigator?AeroElectric-List*
> **
> **
> *http://forums.matronics.com*
> **
> **
> **
> **
> *http://www.matronics.com/contribution*
> **
> **
> http://www.matronics.com/contribution
________________________________________________________________________________
| From: | ARGOLDMAN(at)aol.com |
Bob's idea is probably right, but with two basically identical antennas I
would vote for a problem with the problem antenna, probably the coax-
connector-or connection to the antenna or a faulty antenna, if it is store
bought. Connect your portable to each antenna to re re re varify that the front
antenna is indeed the one that is giving the problem. Then do a continuity
check to see if somewhere the cable has been kinked and is intermittently
shorting (move as much of it as you can around.
If the noise is coming from inside of the aircraft, shutting all things off
(with the exception of the errant radio and listening would probably be a
good first test. If quiet, turn on each separate one (disconnect them via
their fuses/CBs, not just their switches.
If it is coming from the hanger, merely reverse the location of the
aircraft and the problem may go to the other antenna. A better test is to take
the beast out of the hanger and try to duplicate the problem. My vote is the
antenna or its lead/connectors, etc.
By the way. communication waves are vertically polarized your antennas
are horizontally polarized. I dont know how much of a problem this is. That
is for others to comment about
Rich
In a message dated 7/17/2015 9:34:07 A.M. Central Daylight Time,
nuckolls.bob(at)aeroelectric.com writes:
At 10:57 AM 7/16/2015, you wrote:
I know that asking about the cause of a buzz in your radios is like asking
a mechanic about a noise you hear when you are driving but since you are
all here and know way more than me I will describe my situation and how I
plan to proceed.
Set-up
RV-6A
GX-60 Com
SL-30 Com
SL-15 Intercom
Two _COMANT VHF COMMUNICATIONS_
(http://www.aircraftspruce.com/catalog/avpages/comant122.php) antenna mounted on the centerline of the belly (one
below the seat, one below the baggage compartment)
I am getting significant static like noise when I connect either radio to
the front antenna.
This sounds like a radiated noise issue which is almost
never an issue with grounding or other installation
errors . . . it's usually some device that is not
designed to live in harmony on airplanes.
Find a hand-held radio. Adjust to unused frequency
and open the squelch so you can hear the background
'hiss'. Then use it to 'probe' about the various
devices on the airplane.
Hand-held vhf transceivers and 9v transistor am radios
have been quite useful for probing noise sources of
all stripe.
Also, conduct a power-down study. Pull all fuses/breakers
that power up the ship's accessories. If noise is gone,
replace fuses one at a time until the noise comes back.
Bob . . .
________________________________________________________________________________
| From: | ARGOLDMAN(at)aol.com |
I just looked up your antenna-- forget the part of polarization in the last
post..It is possible that you have an infant mortality.
Rich
In a message dated 7/17/2015 9:34:07 A.M. Central Daylight Time,
nuckolls.bob(at)aeroelectric.com writes:
At 10:57 AM 7/16/2015, you wrote:
I know that asking about the cause of a buzz in your radios is like asking
a mechanic about a noise you hear when you are driving but since you are
all here and know way more than me I will describe my situation and how I
plan to proceed.
Set-up
RV-6A
GX-60 Com
SL-30 Com
SL-15 Intercom
Two _COMANT VHF COMMUNICATIONS_
(http://www.aircraftspruce.com/catalog/avpages/comant122.php) antenna mounted on the centerline of the belly (one
below the seat, one below the baggage compartment)
I am getting significant static like noise when I connect either radio to
the front antenna.
This sounds like a radiated noise issue which is almost
never an issue with grounding or other installation
errors . . . it's usually some device that is not
designed to live in harmony on airplanes.
Find a hand-held radio. Adjust to unused frequency
and open the squelch so you can hear the background
'hiss'. Then use it to 'probe' about the various
devices on the airplane.
Hand-held vhf transceivers and 9v transistor am radios
have been quite useful for probing noise sources of
all stripe.
Also, conduct a power-down study. Pull all fuses/breakers
that power up the ship's accessories. If noise is gone,
replace fuses one at a time until the noise comes back.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 11:05 AM 7/17/2015, you wrote:
>Since you have ruled out external sources, it sort of points to the
>front antenna cable. I thought you said you had tried swapping cables.
>Try removing antenna from airframe, connecting it directly to radio
>and see if there is noise.
>I can't explain it, but I know of one case where noise was coming
>via ground, and isolating the antenna from ground cured the problem.
>Perhaps a ground loop between coax shield and the airframe ground.
>
>On 7/17/2015 7:51 AM, Ross Home wrote:
>>I will try this.
>>
>>What is puzzling is that the antenna connection that leads to the
>>rear antenna is at the firewall about 18 inches and level with my
>>GX-60. I can easily unhook the GX-60 cable from the front antenna
>>(which is under the floor directly beneath the GX-60) and hook it
>>to the rear antenna connection which is at the same height as the
>>GX-60 and the noise goes away. All of the wires that the GX-60
>>cable passes are the same in either case except, when it is
>>connected to the front antenna, it crosses these wires at a 90
>>degree angle instead of running parallel to them when it goes the
>>rear antenna connection.
Routing of coax cables to antennas is NEVER
a component of received noise . . . in the
heavy iron we route coaxes where there is opportunity
and room. The whole idea behind the industry standard
practices for (1) limiting noise from antagonists,
(2) improving resistance to noise by judicious
design of potential victims and last (3) reducing
risk of over-whelming propagation path (mounting
an antenna under the cowl will probably pick up
ignition noise). When a noise coming in through
the receiver's antenna port is detected, placement
of the coax isn't even a distant finisher in the
quest for resolution.
Assuming you have paid due diligence to standard practices
for installing the two antennas then the fact that
the forward-most antenna seems to be the key propagation
port, then the noise source is most likely forward ON
the aircraft. If it were off the aircraft, both
antennas would hear it.
This problem has a lot in common with Col_Mustard-
did-it-in-the-library-with-a-rope . . . you gotta
gather all the clues available to you BEFORE picking
up hammers-n-saws . . . or screwdrivers.
Antennas don't go BAD in a manner that makes one
a source of noise while others are not. They either
work good . . . or they don't . . . but they're never
'noisy'. Start with a 'cold' panel and bring up
equipment one item at a time . . . then confirm
your preliminary findings with a sniffer receiver.
Only THEN will hammers, saws and screwdrivers
contribute to resolution of the problem.
Bob . . .
________________________________________________________________________________
| From: | "Ross Home" <rossmickey(at)comcast.net> |
Thanks so much, Bob. I will do as you suggest when I get back out to the
hangar.
Just for my education. Since the location of the coax is not an issue, am I
to understand that the interference I am experiencing is being picked up by
the forward antenna itself?
In surfing the web about comm antenna, I read about the importance of having
good electrical bonding of the antenna to the aircraft ground.
The electrical bonding of the antennas to the aircraft skin is best
accomplished by direct metal-to metal contact of the antenna base to the
aircraft skin. To accomplish this, the aircraft paint in the mounting area
will need to be removed and the surface alodined to protect aluminum against
corrosion. An alternate method for providing electrical bonding is through
the mounting screws, which attach to a backing plate inside the aircraft
skin. Remove any interior paint in the area where the backing plate is
placed to assure a good ground. Coat this area with alodine to minimize
corrosion. To test the electrical bonding of the blade to the aircraft, a
reading of .003 ohms between the antenna base plate and ground should be
achieved.
I am using the second method and will have to check if my installation meets
the .003 ohm test. If the front antenna does not meet this, would this
cause a buzz or just degrade the performance of the antenna?
Ross
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Friday, July 17, 2015 11:45 AM
Subject: Re: AeroElectric-List: Radio Buzz
At 11:05 AM 7/17/2015, you wrote:
Since you have ruled out external sources, it sort of points to the front
antenna cable. I thought you said you had tried swapping cables.
Try removing antenna from airframe, connecting it directly to radio and see
if there is noise.
I can't explain it, but I know of one case where noise was coming via
ground, and isolating the antenna from ground cured the problem. Perhaps a
ground loop between coax shield and the airframe ground.
On 7/17/2015 7:51 AM, Ross Home wrote:
I will try this.
What is puzzling is that the antenna connection that leads to the rear
antenna is at the firewall about 18 inches and level with my GX-60. I can
easily unhook the GX-60 cable from the front antenna (which is under the
floor directly beneath the GX-60) and hook it to the rear antenna connection
which is at the same height as the GX-60 and the noise goes away. All of
the wires that the GX-60 cable passes are the same in either case except,
when it is connected to the front antenna, it crosses these wires at a 90
degree angle instead of running parallel to them when it goes the rear
antenna connection.
Routing of coax cables to antennas is NEVER
a component of received noise . . . in the
heavy iron we route coaxes where there is opportunity
and room. The whole idea behind the industry standard
practices for (1) limiting noise from antagonists,
(2) improving resistance to noise by judicious
design of potential victims and last (3) reducing
risk of over-whelming propagation path (mounting
an antenna under the cowl will probably pick up
ignition noise). When a noise coming in through
the receiver's antenna port is detected, placement
of the coax isn't even a distant finisher in the
quest for resolution.
Assuming you have paid due diligence to standard practices
for installing the two antennas then the fact that
the forward-most antenna seems to be the key propagation
port, then the noise source is most likely forward ON
the aircraft. If it were off the aircraft, both
antennas would hear it.
This problem has a lot in common with Col_Mustard-
did-it-in-the-library-with-a-rope . . . you gotta
gather all the clues available to you BEFORE picking
up hammers-n-saws . . . or screwdrivers.
Antennas don't go BAD in a manner that makes one
a source of noise while others are not. They either
work good . . . or they don't . . . but they're never
'noisy'. Start with a 'cold' panel and bring up
equipment one item at a time . . . then confirm
your preliminary findings with a sniffer receiver.
Only THEN will hammers, saws and screwdrivers
contribute to resolution of the problem.
Bob . . .
http://www.matronics.com/Navigator?AeroElectric-List
http://www.matronics.com/contribution
________________________________________________________________________________
| Subject: | Re: Young Aviators & B-25 intercom |
| From: | "jrevens" <jrevens(at)comcast.net> |
With a tremendous amount of work by the EAA Mile High Chapter 43 Young Aviators
group, and many volunteers, the mock-up of a B-25 cockpit will be at KidVenture/Oshkosh
this year. I want to thank Bob Nuckolls for the part he played in generously
donating parts & his expertise to the intercom part of this tremendous
undertaking. Thank you again, Bob!!!
It is still somewhat a work in progress, but it looks very good, and a large group
of the kids & their parents, as well as other Chapter 43 volunteers will
be there to conduct tours and tell the B-25 story. They are a pretty excited and
proud bunch of young people!
--------
John Evens
Thorp T-18 N71JE (built & flying)
Kitfox SS7 N27JE (building)
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444883#444883
________________________________________________________________________________
| From: | Janet Amtmann <jgamtmann2(at)gmail.com> |
This is not aircraft related (but I do have an RV6) but is electronic
related. Many years ago I converted an old Porsche 356 from 6V to 12V.
There were no 12V windshield wiper motors available so I had to use the
original 6V wiper motor which drew about 5-10A. Speed was controlled with
a rheostat, but adding another dropping resistor generated heat and made
the speed control ineffective. Someone assembled a transistor circuit for
me that dropped the 12V supply to a constant 6V (independent of current
draw) and everything worked well. I am now restoring this car and this
device became lost. Does anyone of you electronic experts (maybe Bob N)
know of a circuit I can build or purchase a device that will give me the
constant 6V at 5 or 10A?
Jurgen Amtmann
________________________________________________________________________________
| Subject: | Shopping at AirVenture |
| From: | "Art Zemon" <art(at)zemon.name> |
=0AFolks,=0A =0AI am building a BD-4C (4 place, high wing) and plan to buil
d the electrical system between this AirVenture and the next. If you were i
n my shoes, is there anything that you would buy at AirVenture this summer?
Tools? Wire? Etc?=0A =0AMy impression of the fly-mart is not great. And I
have not been bowled over by tremendous deals in past years, as I wandered
hangars A-D. But maybe I just don't know what I'm looking for so I figured
I would ask here.=0A =0AThanks,=0A -- Art Z.=0A =0A--[ http://CheerfulCu
rmudgeon.com/ ]( http://CheerfulCurmudgeon.com/ )"If I am not for myself, w
ho is for me? And if I am only for myself, what am I? And if not now, when?
" Hillel
________________________________________________________________________________
| From: | Kenneth Johnson <kjohnsondds(at)yahoo.com> |
| Subject: | Re: Shopping at AirVenture |
Hi Art,You have to determine what you need for your airplane.=C2- Most ai
rcraft supplies companies will give a 10% discount on major purchases.=C2
- Take your order to several places and see where you get the best deal.
=C2-
On Friday, July 17, 2015 8:37 PM, Art Zemon wrote:
Folks,=C2-I am building a BD-4C (4 place, high wing) and plan to build t
he electrical system between this AirVenture and the next. If you were in m
y shoes, is there anything that you would buy at AirVenture this summer? To
ols? Wire? Etc?=C2-My impression of the fly-mart is not great. And I have
not been bowled over by tremendous deals in past years, as I wandered hang
ars A-D. But maybe I just don't know what I'm looking for so I figured I wo
uld ask here.=C2-Thanks,=C2- =C2- -- Art Z.=C2---
http://CheerfulCurmudgeon.com/
"If I am not for myself, who is for me? And if I am only for myself, what a
m I? And if not now, when?" Hillel
________________________________________________________________________________
| Subject: | Re: Shopping at AirVenture |
| From: | C&K <yellowduckduo(at)gmail.com> |
The only real electrical score I ever made at OSH was for a used tefzel
wire stripper from one of the outside stalls.
Non aviation strippers nick the wire when used on thin tefzel insulation.
Ken
On 17/07/2015 9:37 PM, Art Zemon wrote:
>
> Folks,
>
> I am building a BD-4C (4 place, high wing) and plan to build the
> electrical system between this AirVenture and the next. If you were in
> my shoes, is there anything that you would buy at AirVenture this
> summer? Tools? Wire? Etc?
>
> My impression of the fly-mart is not great. And I have not been bowled
> over by tremendous deals in past years, as I wandered hangars A-D. But
> maybe I just don't know what I'm looking for so I figured I would ask
> here.
>
> Thanks,
>
> -- Art Z.
>
> --
> http://CheerfulCurmudgeon.com/
>
> /"If I am not for myself, who is for me? And if I am only for myself,
> what am I? And if not now, when?" Hillel/
>
> http://www.matronics.com/contribution
________________________________________________________________________________
| Subject: | Re: Voltage reducer |
| From: | "user9253" <fransew(at)gmail.com> |
Search for PWM Motor Speed Controller. Maybe something like this will work:
http://www.ebay.com/itm/9-60V-40A-DC-Motor-Speed-Control-PWM-HHO-RC-Controller-12V-24V-48V-1500W-MAX-/261421453931?pt=LH_DefaultDomain_0&hash=item3cddeed26b
The rated capacity of some items from China are exaggerated, so get 2 or 3 times
the expected load capacity.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444901#444901
________________________________________________________________________________
| From: | A R Goldman <argoldman(at)aol.com> |
| Subject: | Re: Shopping at AirVenture |
Art
The fly market,over the last sever years, with few exceptions can really be c
alled the flam market.
If your electrical installation is anything other than real basic get a good
quality automatic wire stripper (grabs the wire and strips it) make sure it
is for tefzel wire. Standard strippers that look the same will not cut the t
efzel smoothly--or at all
They are not cheap. I got mine from pegasus racing (a rv builder) comes with
a replacement set of cutters
The other thing you will need is a good ratchet type crimper for terminals
Additionally if you are going to use sub-d plugs get a crimped for the pins/
sockets
B&c might be a one stop shop for you and will be located in one of the main b
ooths
For your terminals use PIDG. And don't use hardware store types
If you can find a good used ratchet type terminal crimper that would probabl
y be ok as they don't wear much but I would stay away from a used stripper a
nd sub-d crimpr. Use machined pins
Other things to get are heat shrink tubing of various sizes
See what they have for wire marking
Be careful about the wire that is being offered
Make sure it is tefzel. Lots of places try to sell old stocks of obsolete w
ire
Just some thoughts
Rich
Sent from my iPhone
> On Jul 17, 2015, at 8:37 PM, Art Zemon wrote:
>
> Folks,
>
> I am building a BD-4C (4 place, high wing) and plan to build the electrica
l system between this AirVenture and the next. If you were in my shoes, is t
here anything that you would buy at AirVenture this summer? Tools? Wire? Etc
?
>
> My impression of the fly-mart is not great. And I have not been bowled ove
r by tremendous deals in past years, as I wandered hangars A-D. But maybe I j
ust don't know what I'm looking for so I figured I would ask here.
>
> Thanks,
> -- Art Z.
>
> --
> http://CheerfulCurmudgeon.com/
>
> "If I am not for myself, who is for me? And if I am only for myself, what a
m I? And if not now, when?" Hillel
>
>
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>
________________________________________________________________________________
| Subject: | Re: Shopping at AirVenture |
| From: | Kent or Jackie Ashton <kjashton(at)vnet.net> |
> On Jul 17, 2015, at 9:37 PM, Art Zemon wrote:
> is there anything that you would buy at AirVenture this summer? Tools? Wire?
Etc?
Shrink-wrap! A fistfull of 1/4 down to 3/32 and all the colors of the rainbow.
Clear version too, if you want to make wire labels and shrink-wrap them. The
ordinary stuff works OK. There are some special tough irradiated versions
that are desirable in some areas.
-Kent
________________________________________________________________________________
| Subject: | Instrument lights |
| From: | Peter Pengilly <peter(at)sportingaero.com> |
Dear All,
After a minor panel re-build I'm trying to provide lighting for a couple of
round instruments. I have found a pair of eyebrow lights in my spares box,
but they have 24v bulbs. Does anyone know of a 12v alternative to a CM327
instrument bulb?
Thanks, Peter
________________________________________________________________________________
| From: | Bill Putney <billp(at)wwpc.com> |
| Subject: | Re: Instrument lights |
Peter,
That would be a #330 lamp (probably CM330 is a specific manufacturer).
Bill
On 7/18/15 09:39, Peter Pengilly wrote:
>
> Dear All,
> After a minor panel re-build I'm trying to provide lighting for a
> couple of round instruments. I have found a pair of eyebrow lights in
> my spares box, but they have 24v bulbs. Does anyone know of a 12v
> alternative to a CM327 instrument bulb?
> Thanks, Peter
>
> *
>
>
> *
________________________________________________________________________________
| From: | "The Kuffels" <kuffel(at)cyberport.net> |
| Subject: | Re: Instrument lights |
Peter,
Mouser Electronics (mouser.com) lists the CM327 as a T-1 3/4 midget
flange base incandescent bulb. The 14 volt equivalent is either the
CM330 ($0.55@) or the long life (15,000 hours) CM382 ($0.80@).
Tom
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Voltage reducer |
At 09:57 PM 7/17/2015, you wrote:
>
>Search for PWM Motor Speed Controller. Maybe something like this will work:
>http://www.ebay.com/itm/9-60V-40A-DC-Motor-Speed-Control-PWM-HHO-RC-Controller-12V-24V-48V-1500W-MAX-/261421453931?pt=LH_DefaultDomain_0&hash=item3cddeed26b
>The rated capacity of some items from China are exaggerated, so get
>2 or 3 times the expected load capacity.
I've used several similar products and they seemed to
be of good value. You will want to limit the 'travel'
on the control potentiometer such that output never
exceeds 7v on a 14v system. The stock controller will
allow output all the way up to what ever the bus
voltage is.
You can do this with a mechanical stop on a pointer
knob . . . or perhaps add a resistor in series with
the potentiometer body such that full travel on
the pot represents only 1/2 of the original electrical
travel.
Bob . . .
________________________________________________________________________________
| From: | "Ross Mickey (home)" <rossmickey(at)comcast.net> |
I have identified that the buzz/static is coming from the new AFS 5600 EFIS I
just installed. I have lessened the static sound some by re routing some wi
res. I also now can see that the rear antenna is being slightly affected als
o. All of the grounds look good going to a common ground block attached to t
he battery.
Now what do I do?
Ross Mickey
> On Jul 17, 2015, at 12:43 PM, Ross Home wrote:
>
> Thanks so much, Bob. I will do as you suggest when I get back out to the h
angar.
>
> Just for my education. Since the location of the coax is not an issue, am
I to understand that the interference I am experiencing is being picked up b
y the forward antenna itself?
>
> In surfing the web about comm antenna, I read about the importance of havi
ng good electrical bonding of the antenna to the aircraft ground.
>
> The electrical bonding of the antennas to the aircraft skin is best accomp
lished by direct metal-to metal contact of the antenna base to the aircraft s
kin. To accomplish this, the aircraft paint in the mounting area will need t
o be removed and the surface alodined to protect aluminum against corrosion.
An alternate method for providing electrical bonding is through the mountin
g screws, which attach to a backing plate inside the aircraft skin. Remove a
ny interior paint in the area where the backing plate is placed to assure a g
ood ground. Coat this area with alodine to minimize corrosion. To test the e
lectrical bonding of the blade to the aircraft, a reading of .003 ohms betwe
en the antenna base plate and ground should be achieved.
>
> I am using the second method and will have to check if my installation mee
ts the .003 ohm test. If the front antenna does not meet this, would this c
ause a buzz or just degrade the performance of the antenna?
>
> Ross
>
> From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelect
ric-list-server(at)matronics.com] On Behalf Of Robert L. Nuckolls, III
> Sent: Friday, July 17, 2015 11:45 AM
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: Radio Buzz
>
> At 11:05 AM 7/17/2015, you wrote:
>
> Since you have ruled out external sources, it sort of points to the front a
ntenna cable. I thought you said you had tried swapping cables.
> Try removing antenna from airframe, connecting it directly to radio and se
e if there is noise.
> I can't explain it, but I know of one case where noise was coming via grou
nd, and isolating the antenna from ground cured the problem. Perhaps a groun
d loop between coax shield and the airframe ground.
>
> On 7/17/2015 7:51 AM, Ross Home wrote:
>
> I will try this.
>
> What is puzzling is that the antenna connection that leads to the rear ant
enna is at the firewall about 18 inches and level with my GX-60. I can easi
ly unhook the GX-60 cable from the front antenna (which is under the floor d
irectly beneath the GX-60) and hook it to the rear antenna connection which i
s at the same height as the GX-60 and the noise goes away. All of the wires
that the GX-60 cable passes are the same in either case except, when it is c
onnected to the front antenna, it crosses these wires at a 90 degree angle i
nstead of running parallel to them when it goes the rear antenna connection.
>
> Routing of coax cables to antennas is NEVER
> a component of received noise . . . in the
> heavy iron we route coaxes where there is opportunity
> and room. The whole idea behind the industry standard
> practices for (1) limiting noise from antagonists,
> (2) improving resistance to noise by judicious
> design of potential victims and last (3) reducing
> risk of over-whelming propagation path (mounting
> an antenna under the cowl will probably pick up
> ignition noise). When a noise coming in through
> the receiver's antenna port is detected, placement
> of the coax isn't even a distant finisher in the
> quest for resolution.
>
> Assuming you have paid due diligence to standard practices
> for installing the two antennas then the fact that
> the forward-most antenna seems to be the key propagation
> port, then the noise source is most likely forward ON
> the aircraft. If it were off the aircraft, both
> antennas would hear it.
>
> This problem has a lot in common with Col_Mustard-
> did-it-in-the-library-with-a-rope . . . you gotta
> gather all the clues available to you BEFORE picking
> up hammers-n-saws . . . or screwdrivers.
>
> Antennas don't go BAD in a manner that makes one
> a source of noise while others are not. They either
> work good . . . or they don't . . . but they're never
> 'noisy'. Start with a 'cold' panel and bring up
> equipment one item at a time . . . then confirm
> your preliminary findings with a sniffer receiver.
>
> Only THEN will hammers, saws and screwdrivers
> contribute to resolution of the problem.
>
>
> Bob . . .
>
>
>
> http://www.matronics.com/Navigator?AeroElectric-List
> http://forums.matronics.com
> http://www.matronics.com/contribution
>
>
>
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>
________________________________________________________________________________
| From: | Dj Merrill <deej(at)deej.net> |
On 7/19/2015 3:15 PM, Ross Mickey (home) wrote:
> I have identified that the buzz/static is coming from the new AFS 5600
> EFIS I just installed.
>
> Now what do I do?
First thing I'd do is contact AFS and see if they have any thoughts.
Others might have reported similar issues and they may have some ready
ideas to try.
-Dj
--
Dj Merrill - N1JOV - EAA Chapter 87
Sportsman 2+2 Builder #7118 N421DJ - http://deej.net/sportsman/
Glastar Flyer N866RH - http://deej.net/glastar/
________________________________________________________________________________
| From: | Kelly McMullen <kellym(at)aviating.com> |
Turn the EFIS off with circuit breaker. See if the noise goes away. Then
call AFS/Dynon for advice if that proves to be the source of the noise.
On 7/19/2015 12:15 PM, Ross Mickey (home) wrote:
> I have identified that the buzz/static is coming from the new AFS 5600
> EFIS I just installed. I have lessened the static sound some by re
> routing some wires. I also now can see that the rear antenna is being
> slightly affected also. All of the grounds look good going to a common
> ground block attached to the battery.
>
> Now what do I do?
>
> Ross Mickey
>
>
> On Jul 17, 2015, at 12:43 PM, Ross Home > wrote:
>
>> Thanks so much, Bob. I will do as you suggest when I get back out to
>> the hangar.
>>
>> Just for my education. Since the location of the coax is not an
>> issue, am I to understand that the interference I am experiencing is
>> being picked up by the forward antenna itself?
>>
>> In surfing the web about comm antenna, I read about the importance of
>> having good electrical bonding of the antenna to the aircraft ground.
>>
>> The electrical bonding of the antennas to the aircraft skin is best
>> accomplished by direct metal-to metal contact of the antenna base to
>> the aircraft skin. To accomplish this, the aircraft paint in the
>> mounting area will need to be removed and the surface alodined to
>> protect aluminum against corrosion. An alternate method for providing
>> electrical bonding is through the mounting screws, which attach to a
>> backing plate inside the aircraft skin. Remove any interior paint in
>> the area where the backing plate is placed to assure a good ground.
>> Coat this area with alodine to minimize corrosion. To test the
>> electrical bonding of the blade to the aircraft, a reading of .003
>> ohms between the antenna base plate and ground should be achieved.
>>
>> I am using the second method and will have to check if my
>> installation meets the .003 ohm test. If the front antenna does not
>> meet this, would this cause a buzz or just degrade the performance of
>> the antenna?
>>
>> Ross
>>
>> *From:*owner-aeroelectric-list-server(at)matronics.com
>>
>> [mailto:owner-aeroelectric-list-server(at)matronics.com] *On Behalf Of
>> *Robert L. Nuckolls, III
>> *Sent:* Friday, July 17, 2015 11:45 AM
>> *To:* aeroelectric-list(at)matronics.com
>>
>> *Subject:* Re: AeroElectric-List: Radio Buzz
>>
>> At 11:05 AM 7/17/2015, you wrote:
>>
>> Since you have ruled out external sources, it sort of points to
>> the front antenna cable. I thought you said you had tried
>> swapping cables.
>> Try removing antenna from airframe, connecting it directly to
>> radio and see if there is noise.
>> I can't explain it, but I know of one case where noise was coming
>> via ground, and isolating the antenna from ground cured the
>> problem. Perhaps a ground loop between coax shield and the
>> airframe ground.
>>
>> On 7/17/2015 7:51 AM, Ross Home wrote:
>>
>> I will try this.
>>
>> What is puzzling is that the antenna connection that leads to
>> the rear antenna is at the firewall about 18 inches and level
>> with my GX-60. I can easily unhook the GX-60 cable from the
>> front antenna (which is under the floor directly beneath the
>> GX-60) and hook it to the rear antenna connection which is at
>> the same height as the GX-60 and the noise goes away. All of
>> the wires that the GX-60 cable passes are the same in either
>> case except, when it is connected to the front antenna, it
>> crosses these wires at a 90 degree angle instead of running
>> parallel to them when it goes the rear antenna connection.
>>
>>
>> Routing of coax cables to antennas is NEVER
>> a component of received noise . . . in the
>> heavy iron we route coaxes where there is opportunity
>> and room. The whole idea behind the industry standard
>> practices for (1) limiting noise from antagonists,
>> (2) improving resistance to noise by judicious
>> design of potential victims and last (3) reducing
>> risk of over-whelming propagation path (mounting
>> an antenna under the cowl will probably pick up
>> ignition noise). When a noise coming in through
>> the receiver's antenna port is detected, placement
>> of the coax isn't even a distant finisher in the
>> quest for resolution.
>>
>> Assuming you have paid due diligence to standard practices
>> for installing the two antennas then the fact that
>> the forward-most antenna seems to be the key propagation
>> port, then the noise source is most likely forward ON
>> the aircraft. If it were off the aircraft, both
>> antennas would hear it.
>>
>> This problem has a lot in common with Col_Mustard-
>> did-it-in-the-library-with-a-rope . . . you gotta
>> gather all the clues available to you BEFORE picking
>> up hammers-n-saws . . . or screwdrivers.
>>
>> Antennas don't go BAD in a manner that makes one
>> a source of noise while others are not. They either
>> work good . . . or they don't . . . but they're never
>> 'noisy'. Start with a 'cold' panel and bring up
>> equipment one item at a time . . . then confirm
>> your preliminary findings with a sniffer receiver.
>>
>> Only THEN will hammers, saws and screwdrivers
>> contribute to resolution of the problem.
>>
>>
>> Bob . . .
>>
>> **
>> **
>> **
>> **
>> **
>> **
>> **
>> **http://www.matronics.com/Navigator?AeroElectric-List****
>> ****
>> ****
>> ***http://forums.matronics.com*****
>> ******
>> ******
>> ******
>> ******
>> ****http://www.matronics.com/contribution******
>> ******
>> ******
>> **
>> *D=============================================
>> lectric-List"">http://www.matronics.com/Navigator?AeroElectric-List
>> D=============================================
>> //forums.matronics.com
>> D=============================================
>> ot;">http://www.matronics.com/contribution
>> D=============================================
>> *
>> **
> http://www.matronics.com/contribution
________________________________________________________________________________
| From: | "user9253" <fransew(at)gmail.com> |
Is the AFS 5600 EFIS wired according to the installation manual? Usually shielded
cables are grounded at the source end only, but not always. Can you identify
one or more wires from the AFS 5600 EFIS that are causing the noise?
Is the squelch on the com radio adjusted too sensitive?
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444951#444951
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 02:24 PM 7/19/2015, you wrote:
>
>On 7/19/2015 3:15 PM, Ross Mickey (home) wrote:
> > I have identified that the buzz/static is coming from the new AFS 5600
> > EFIS I just installed.
> >
> > Now what do I do?
A number of appliances with LCD screens
were notorious radiators. I think the problems
were centered around the micro-watt dc to ac
converter used to bias up the screen. I'd not
heard of any difficulties in years . . . I
assumed that everyone had figured it out by
now . . . but apparently not.
The fact that moving wires made difference
suggests that the noises MAY be radiated from
wire bundles as opposed to from the LCD face.
Again, the hand-held transceiver can be used
to 'sniff' around the box . . . much like you
would use a freon leak detector to find a bad
joint. You may want to make a 'special' antenna
for the hand held that is only an inch or so long
so that its not terribly efficient . . .
Bob . . .
________________________________________________________________________________
| From: | "Ross Mickey (home)" <rossmickey(at)comcast.net> |
I identified it was the EFIS by pulling the fuse.
Ross Mickey
541-954-7521
> On Jul 19, 2015, at 2:10 PM, Kelly McMullen wrote:
>
>
> Turn the EFIS off with circuit breaker. See if the noise goes away. Then call
AFS/Dynon for advice if that proves to be the source of the noise.
>
>> On 7/19/2015 12:15 PM, Ross Mickey (home) wrote:
>> I have identified that the buzz/static is coming from the new AFS 5600 EFIS
I just installed. I have lessened the static sound some by re routing some wires.
I also now can see that the rear antenna is being slightly affected also.
All of the grounds look good going to a common ground block attached to the battery.
>>
>> Now what do I do?
>>
>> Ross Mickey
>>
>>
>>
>>> On Jul 17, 2015, at 12:43 PM, Ross Home > wrote:
>>>
>>> Thanks so much, Bob. I will do as you suggest when I get back out to the hangar.
>>>
>>> Just for my education. Since the location of the coax is not an issue, am
I to understand that the interference I am experiencing is being picked up by
the forward antenna itself?
>>>
>>> In surfing the web about comm antenna, I read about the importance of having
good electrical bonding of the antenna to the aircraft ground.
>>>
>>> The electrical bonding of the antennas to the aircraft skin is best accomplished
by direct metal-to metal contact of the antenna base to the aircraft skin.
To accomplish this, the aircraft paint in the mounting area will need to be
removed and the surface alodined to protect aluminum against corrosion. An alternate
method for providing electrical bonding is through the mounting screws,
which attach to a backing plate inside the aircraft skin. Remove any interior
paint in the area where the backing plate is placed to assure a good ground.
Coat this area with alodine to minimize corrosion. To test the electrical bonding
of the blade to the aircraft, a reading of .003 ohms between the antenna
base plate and ground should be achieved.
>>>
>>> I am using the second method and will have to check if my installation meets
the .003 ohm test. If the front antenna does not meet this, would this cause
a buzz or just degrade the performance of the antenna?
>>>
>>> Ross
>>>
>>> *From:*owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] *On Behalf Of *Robert L. Nuckolls, III
>>> *Sent:* Friday, July 17, 2015 11:45 AM
>>> *To:* aeroelectric-list(at)matronics.com
>>> *Subject:* Re: AeroElectric-List: Radio Buzz
>>>
>>> At 11:05 AM 7/17/2015, you wrote:
>>>
>>> Since you have ruled out external sources, it sort of points to
>>> the front antenna cable. I thought you said you had tried
>>> swapping cables.
>>> Try removing antenna from airframe, connecting it directly to
>>> radio and see if there is noise.
>>> I can't explain it, but I know of one case where noise was coming
>>> via ground, and isolating the antenna from ground cured the
>>> problem. Perhaps a ground loop between coax shield and the
>>> airframe ground.
>>>
>>> On 7/17/2015 7:51 AM, Ross Home wrote:
>>>
>>> I will try this.
>>>
>>> What is puzzling is that the antenna connection that leads to
>>> the rear antenna is at the firewall about 18 inches and level
>>> with my GX-60. I can easily unhook the GX-60 cable from the
>>> front antenna (which is under the floor directly beneath the
>>> GX-60) and hook it to the rear antenna connection which is at
>>> the same height as the GX-60 and the noise goes away. All of
>>> the wires that the GX-60 cable passes are the same in either
>>> case except, when it is connected to the front antenna, it
>>> crosses these wires at a 90 degree angle instead of running
>>> parallel to them when it goes the rear antenna connection.
>>>
>>>
>>> Routing of coax cables to antennas is NEVER
>>> a component of received noise . . . in the
>>> heavy iron we route coaxes where there is opportunity
>>> and room. The whole idea behind the industry standard
>>> practices for (1) limiting noise from antagonists,
>>> (2) improving resistance to noise by judicious
>>> design of potential victims and last (3) reducing
>>> risk of over-whelming propagation path (mounting
>>> an antenna under the cowl will probably pick up
>>> ignition noise). When a noise coming in through
>>> the receiver's antenna port is detected, placement
>>> of the coax isn't even a distant finisher in the
>>> quest for resolution.
>>>
>>> Assuming you have paid due diligence to standard practices
>>> for installing the two antennas then the fact that
>>> the forward-most antenna seems to be the key propagation
>>> port, then the noise source is most likely forward ON
>>> the aircraft. If it were off the aircraft, both
>>> antennas would hear it.
>>>
>>> This problem has a lot in common with Col_Mustard-
>>> did-it-in-the-library-with-a-rope . . . you gotta
>>> gather all the clues available to you BEFORE picking
>>> up hammers-n-saws . . . or screwdrivers.
>>>
>>> Antennas don't go BAD in a manner that makes one
>>> a source of noise while others are not. They either
>>> work good . . . or they don't . . . but they're never
>>> 'noisy'. Start with a 'cold' panel and bring up
>>> equipment one item at a time . . . then confirm
>>> your preliminary findings with a sniffer receiver.
>>>
>>> Only THEN will hammers, saws and screwdrivers
>>> contribute to resolution of the problem.
>>>
>>>
>>> Bob . . .
>>>
>>> **
>>> **
>>> **
>>> **
>>> **
>>> **
>>> **
>>> **http://www.matronics.com/Navigator?AeroElectric-List****
>>> ****
>>> ****
>>> ***http://forums.matronics.com*****
>>> ******
>>> ******
>>> ******
>>> ******
>>> ****http://www.matronics.com/contribution******
>>> ******
>>> ******
>>> **
>>> *D============================================= lectric-List"">http://www.matronics.com/Navigator?AeroElectric-List D============================================= //forums.matronics.com D============================================= ot;">http://www.matronics.com/contribution D============================================= *
>>> **
>> http://www.matronics.com/contribution
>
>
>
>
>
________________________________________________________________________________
| From: | "Ross Mickey (home)" <rossmickey(at)comcast.net> |
I will try to rig a short antenna. As it is, I get about 6-9 inches from the
EFIS to set off the sniffer (a handheld radio)
Ross Mickey
541-954-7521
> On Jul 19, 2015, at 3:22 PM, Robert L. Nuckolls, III <nuckolls.bob@aeroele
ctric.com> wrote:
>
> At 02:24 PM 7/19/2015, you wrote:
>>
>> On 7/19/2015 3:15 PM, Ross Mickey (home) wrote:
>> > I have identified that the buzz/static is coming from the new AFS 5600
>> > EFIS I just installed.
>> >
>> > Now what do I do?
>
> A number of appliances with LCD screens
> were notorious radiators. I think the problems
> were centered around the micro-watt dc to ac
> converter used to bias up the screen. I'd not
> heard of any difficulties in years . . . I
> assumed that everyone had figured it out by
> now . . . but apparently not.
>
> The fact that moving wires made difference
> suggests that the noises MAY be radiated from
> wire bundles as opposed to from the LCD face.
> Again, the hand-held transceiver can be used
> to 'sniff' around the box . . . much like you
> would use a freon leak detector to find a bad
> joint. You may want to make a 'special' antenna
> for the hand held that is only an inch or so long
> so that its not terribly efficient . . .
>
>
> Bob . . .
>
>
>
==========================
=========
==========================
=========
==========================
=========
==========================
=========
>
________________________________________________________________________________
| From: | "Ross Mickey (home)" <rossmickey(at)comcast.net> |
Everything wired as shown in diagrams. My antenna on my handheld is to good so
I can't differentiate wires.
Ross Mickey
541-954-7521
> On Jul 19, 2015, at 3:06 PM, user9253 wrote:
>
>
> Is the AFS 5600 EFIS wired according to the installation manual? Usually shielded
cables are grounded at the source end only, but not always. Can you identify
one or more wires from the AFS 5600 EFIS that are causing the noise?
> Is the squelch on the com radio adjusted too sensitive?
> Joe
>
> --------
> Joe Gores
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=444951#444951
>
>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | Charlie England <ceengland7(at)gmail.com> |
Try it with no antenna at all. If you don't get any noise that way, just
stick a short piece of safety wire into the center of the antenna
connector & try that. (Don't transmit. :-) )
On 7/19/2015 6:18 PM, Ross Mickey (home) wrote:
>
> Everything wired as shown in diagrams. My antenna on my handheld is to good so
I can't differentiate wires.
>
> Ross Mickey
> 541-954-7521
>
>
>> On Jul 19, 2015, at 3:06 PM, user9253 wrote:
>>
>>
>> Is the AFS 5600 EFIS wired according to the installation manual? Usually shielded
cables are grounded at the source end only, but not always. Can you identify
one or more wires from the AFS 5600 EFIS that are causing the noise?
>> Is the squelch on the com radio adjusted too sensitive?
>> Joe
>>
>> --------
>> Joe Gores
>>
________________________________________________________________________________
| From: | "user9253" <fransew(at)gmail.com> |
If I dim my Dynon D-180 screen, it makes noise in the headset. I leave the screen
on full bright (never fly at night) and the noise is not noticeable.
Joe
> A number of appliances with LCD screens
> were notorious radiators. I think the problems
> were centered around the micro-watt dc to ac
> converter used to bias up the screen. I'd not
> heard of any difficulties in years . . . I
> assumed that everyone had figured it out by
> now . . . but apparently not.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444958#444958
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 05:06 PM 7/19/2015, you wrote:
>
>Is the AFS 5600 EFIS wired according to the installation
>manual? Usually shielded cables are grounded at the source end
>only, but not always. Can you identify one or more wires from the
>AFS 5600 EFIS that are causing the noise?
> Is the squelch on the com radio adjusted too sensitive?
As a general rule, no appliance slated to use
in airplanes should require ANY special attention
on the part of the installer to mitigate a noise
issue. The qualification testing for TC aircraft
puts your black box out on a copper-top table, wires
it up to function stand-alone with no less than 2 meters
of "ship's wiring" and it should be neither sensitive
to or an emitter of unfriendly energy sources.
If any manufacturer suggests 'adding filters, moving
wires, adjusting antenna locations, etc. . . they
are admitting to their lack of due diligence in
design/fabrication of their product.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 06:16 PM 7/19/2015, you wrote:
>I will try to rig a short antenna. As it is, I get about 6-9 inches
>from the EFIS to set off the sniffer (a handheld radio)
>
>Ross Mickey
Your zeroing in on the root cause . . . I have
an h-t antenna that's only about an inch long with
a 1/2" disk soldered to the end. This can be used
to probe wires, openings in enclosures, lcd screens,
etc.
Of course, this only works with noise sources that have
strong amplitude modulated components . . . but if you
can 'hear' it in your nav-comm, you can generally 'sniff
it' with a hand-held.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 08:00 PM 7/19/2015, you wrote:
>
>If I dim my Dynon D-180 screen, it makes noise in the headset. I
>leave the screen on full bright (never fly at night) and the noise
>is not noticeable.
>Joe
Unfortunately, all too common . . .
Bob . . .
________________________________________________________________________________
| From: | "Ross Home" <rossmickey(at)comcast.net> |
With my dumbed down handheld sniffer I have identified the major culprit and
perhaps a second. The main interference (80%-90%) is from an 18" piece of
unused OAT wire that is plugged into the main harness with pos, signal and
shield all pinned in the harness. In talking with AFS tech support, the
three options are, 1) connect the pos and signal wires together 2) connect
the signal and shield together or 3) unpin all three wires from the harness
and remove the whole thing.
The second culprit is a couple of the serial port wires (2 of the 4). These
are emanating some interference which is probably caused by my error. I
connected a black the wire coming out of the premade harness (which is
connected to the four shield wires for the serial ports) to ground rather
than to the chassis of the EFIS. The new harnesses from AFS (mine is two
years old) do not have this but take care of connecting the serial shields
to the chassis in the pinning of the harness.
I will check these out on Weds when I get back to the hangar.
Thank you all for your help.
Ross
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Monday, July 20, 2015 6:12 AM
Subject: Re: AeroElectric-List: Radio Buzz
At 06:16 PM 7/19/2015, you wrote:
I will try to rig a short antenna. As it is, I get about 6-9 inches from the
EFIS to set off the sniffer (a handheld radio)
Ross Mickey
Your zeroing in on the root cause . . . I have
an h-t antenna that's only about an inch long with
a 1/2" disk soldered to the end. This can be used
to probe wires, openings in enclosures, lcd screens,
etc.
Of course, this only works with noise sources that have
strong amplitude modulated components . . . but if you
can 'hear' it in your nav-comm, you can generally 'sniff
it' with a hand-held.
Bob . . .
http://www.matronics.com/Navigator?AeroElectric-List
http://www.matronics.com/contribution
________________________________________________________________________________
| From: | rayj <raymondj(at)frontiernet.net> |
Does the disk make the the "detector" directionally sensitive, like I'm
guessing a loop would?
Raymond Julian
Kettle River, MN
The things we admire in men, kindness and generosity, openness, honesty,
understanding and feeling are the concomitants of failure in our system.
And those traits we detest, sharpness, greed, acquisitiveness, meanness,
egotism and self-interest are the traits of success. And while men
admire the quality of the first they love the produce of the second.
-John Steinbeck, novelist, Nobel laureate (1902-1968)
On 07/20/2015 08:12 AM, Robert L. Nuckolls, III wrote:
> At 06:16 PM 7/19/2015, you wrote:
>> I will try to rig a short antenna. As it is, I get about 6-9 inches
>> from the EFIS to set off the sniffer (a handheld radio)
>>
>> Ross Mickey
>
> Your zeroing in on the root cause . . . I have
> an h-t antenna that's only about an inch long with
> a 1/2" disk soldered to the end. This can be used
> to probe wires, openings in enclosures, lcd screens,
> etc.
>
> Of course, this only works with noise sources that have
> strong amplitude modulated components . . . but if you
> can 'hear' it in your nav-comm, you can generally 'sniff
> it' with a hand-held.
>
>
> Bob . . .
>
> *
>
>
> *
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 11:14 AM 7/20/2015, you wrote:
With my dumbed down handheld sniffer I have identified the major
culprit and perhaps a second. The main interference (80%-90%) is
from an 18" piece of unused OAT wire that is plugged into the main
harness with pos, signal and shield all pinned in the harness. In
talking with AFS tech support, the three options are, 1) connect the
pos and signal wires together 2) connect the signal and shield
together or 3) unpin all three wires from the harness and remove the
whole thing.
I would vote for removing any unused wires
from the connector.
The second culprit is a couple of the serial port wires (2 of the
4). These are emanating some interference which is probably caused
by my error. I connected a black the wire coming out of the premade
harness (which is connected to the four shield wires for the serial
ports) to ground rather than to the chassis of the EFIS. The new
harnesses from AFS (mine is two years old) do not have this but take
care of connecting the serial shields to the chassis in the pinning
of the harness.
Hmmmm . . . there's no good reason for serial
wires to radiate. Single wire data at the
higher speeds (20-100 kBits/sec) were subject
to some electro-static coupling issues but
the designers of RS232 transmitters offered
connections for a capacitor to slow the transition
edges of the data. Twisted pair data architectures
eliminated this risk.
I'm disappointed that the EFIS designers didn't
do a better job of managing this but yes, at
VHF, the long pig-tail on the shield ground could
add enough impedance to allow those pesky edges
to couple out. This may well be an instance where
the long pigtail not only added the series impedance,
it became the VHF friendly radiator for the noise.
I will check these out on Weds when I get back to the hangar.
Let us know what you discover . . . be sure to
let the supplier know too . . . they MIGHT see
fit to fix this at the next upgrade opportunity.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Shopping at AirVenture |
| From: | Art Zemon <art(at)zemon.name> |
Thanks, everybody=2E
=C2- =C2- -- Art Z=2E
Sent from my LG tablet so please excuse typos and brevity=2E
________________________________________________________________________________
| From: | "Ross Home" <rossmickey(at)comcast.net> |
| Subject: | Radio Buzz.......................NO More |
Yesterday, I unpinned the 18" piece of unused OAT cable as well as three
unused "input" wires that were connected to my AFS 5600 main harness as well
as grounding the serial port shield to the chassis. I am happy to say that
both radios are clear as a bell.
Thank you all for your help in identifying the problem. One step closer to
getting my baby back into the air.
Ross Mickey
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Ross Home
Sent: Monday, July 20, 2015 9:14 AM
Subject: RE: AeroElectric-List: Radio Buzz
With my dumbed down handheld sniffer I have identified the major culprit and
perhaps a second. The main interference (80%-90%) is from an 18" piece of
unused OAT wire that is plugged into the main harness with pos, signal and
shield all pinned in the harness. In talking with AFS tech support, the
three options are, 1) connect the pos and signal wires together 2) connect
the signal and shield together or 3) unpin all three wires from the harness
and remove the whole thing.
The second culprit is a couple of the serial port wires (2 of the 4). These
are emanating some interference which is probably caused by my error. I
connected a black the wire coming out of the premade harness (which is
connected to the four shield wires for the serial ports) to ground rather
than to the chassis of the EFIS. The new harnesses from AFS (mine is two
years old) do not have this but take care of connecting the serial shields
to the chassis in the pinning of the harness.
I will check these out on Weds when I get back to the hangar.
Thank you all for your help.
Ross
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Monday, July 20, 2015 6:12 AM
Subject: Re: AeroElectric-List: Radio Buzz
At 06:16 PM 7/19/2015, you wrote:
I will try to rig a short antenna. As it is, I get about 6-9 inches from the
EFIS to set off the sniffer (a handheld radio)
Ross Mickey
Your zeroing in on the root cause . . . I have
an h-t antenna that's only about an inch long with
a 1/2" disk soldered to the end. This can be used
to probe wires, openings in enclosures, lcd screens,
etc.
Of course, this only works with noise sources that have
strong amplitude modulated components . . . but if you
can 'hear' it in your nav-comm, you can generally 'sniff
it' with a hand-held.
Bob . . .
http://www.matronics.com/Navigator?AeroElectric-List
http://forums.matronics.com
http://www.matronics.com/contribution
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Radio Buzz.......................NO More |
At 09:42 AM 7/23/2015, you wrote:
>Yesterday, I unpinned the 18" piece of unused OAT cable as well as
>three unused "input" wires that were connected to my AFS 5600 main
>harness as well as grounding the serial port shield to the
>chassis. I am happy to say that both radios are clear as a bell.
>
>Thank you all for your help in identifying the problem. One step
>closer to getting my baby back into the air.
>
>Ross Mickey
Thank you for bringing this to the List . . . this
has been a useful demonstration of the value for
tracking down root cause, propagation mode and
mitigation of an unfriendly transfer of energy
from one system to another.
It's all physics . . . when boiled down to the
controlling simple-ideas, the fix becomes simple
as well. Our science and art of building and
operating successful aircraft is burdened
with a lot of guessing, too little understanding
and most important, a lack of interest.
For most of my tenure at Beech, I was chartered
and financed independently of project budgets
to track down and identify such things.
I wrote perhaps a dozen white papers
describing the efforts, discoveries, deductions
and remedies for a variety of antagonists . . .
some of costing hundreds of thousands of dollars
in warranty, re-certification and/or lost
customer confidence.
But as of this writing, I'll bet any one of
those situations could pop up again at the new
Textron . . . and nobody would remember that
we had been there, done that. They'll struggle
through it all over again.
This is why it is so important that the any
'new' problem be approached with the same
kind of inquiry and deduction that folks are
expected to exercise when figuring out that
Col-Mustard-did-it-in-the-library-with-a-gun.
The processes are identical.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | VOR antenna question |
At 06:47 AM 7/22/2015, you wrote:
Hi, Bob -
I have a 1962 Skylane, and I am not satisfied
with its VOR/GS performance at all. Add to that
the fact that the autopilot won't track worth a
damn, and I'm wondering if the Nav receiver/antenna setup is at fault.
How steady is the CDI display when receiving VOR? Are
the CDI warning flags lifted? Could you hand-fly the
airplane accurately using the display? If so, then
it seems unlikely that quality of data from VOR Rx
to AP is probably not the issue. If the
CDI warning flags are not dropping, then your
tracking problem is probably centered elsewhere.
I've decided to do a little troubleshooting
before I send the S-Tec 55x in for a major
(expensive) overhaul.=C2 At the very least, I want
to replace the VOR/GS coax and balun (The antenna
is a horizontal dipole on the top of the vertical stabilizer, like many
182s).
The balun is a typical made-from-coax affair that
has never been changed since the airplane was new
in 1962, as far as I can tell.=C2 I'm sure it has
drowned in water - or at least moisture - for a
very long time.=C2 The dipole is then just connected directly to the balun.
My questions are these:
1. The first thing is to replace the long run of
coax. What coax do you recommend? I know RG 58
will work (50 ohm), but I've heard there are much
better, lower-loss cables for this application.
Yes. A much more robust and lower loss product
like RG141/142/400 is never a bad bet. There
are less expensive 50-ohm coaxes with better
performance than RG58 like the LMR195, same
size and connectors as RG58, similar outside
insulation but better shield construction and
lower loss insulation around the center
conductor . . . but a little fussier to work
with than the double-shield, Tef-like products
cited earlier. I'd go with 141/142/400 but the
195 is fine too.
2. From what I read, the only purpose of the
balun is to keep RF off the braid on the coax;
the balun's matching function really doesn't do much for performance.
Yes. "Keeping RF of the braid" is a transmitting
issue . . and yes, it takes laboratory grade
instrumentation and observation methods to
deduce any benefits for adding the balun to
a VOR antenna. All other things being equal,
the pilot would not be able to tell whether
or not a balun was installed.
Since this is a receive-only setup, do I even
need to worry about a balun, or could I just
connect my new coax (unbalanced) to the antenna and forget about it?
We built thousands of airplanes at Cessna in the 60's
and 70's that were wired that way . . . and VOR performance
of vacuum tube receivers was deemed adequate. And
again, all things being equal, the pilots would not
know if a balun was present or not.
3. If you think a balun is worth it, where can I
find a decent 1:1 potted balun, so I don't have
to worry about fabricating a new coax one?
If the airplane's factory-delivered configuration
included a balun, then there's always risk of running
afoul of the TC-rule-gods.
They're easy to build, especially from RF141/142/400
coaxes that will readily stand off the effects of
soldering.
http://tinyurl.com/yytxwd3
So it's kinda your choice. A fresh hunk of modern
coax simply tied to the VOR whiskers will perform
nicely. Whether or not this produces better VOR/AP
performance is problematic.
Bob . . .
________________________________________________________________________________
| From: | William Hibbing <n744bh(at)bellsouth.net> |
| Subject: | Re: VOR antenna question |
Give Kenny Poyner=C2- a call at 817-215-7637 (Cobham) and explain the sit
uation to him.=C2- He is a whiz at the S-Tec a/p's and can be very helpfu
l.=C2- Bill
On Thursday, July 23, 2015 11:05 AM, "Robert L. Nuckolls, III" wrote:
At 06:47 AM 7/22/2015, you wrote:
Hi, Bob -
I have a 1962 Skylane, and I am not satisfied with its VOR/GS performanceat
all. Add to that the fact that the autopilot won't track worth a damn,and
I'm wondering if the Nav receiver/antenna setup is at fault.
=C2-=C2- How steady is the CDI display when receiving VOR? Are
=C2-=C2- the CDI warning flags lifted? Could you hand-fly the
=C2-=C2- airplane accurately using the display? If so, then
=C2-=C2- it seems unlikely that quality of data from VOR Rx
=C2-=C2- to AP is probably not the issue. If the
=C2-=C2- CDI warning flags are not dropping, then your
=C2-=C2- tracking problem is probably centered elsewhere.
I've decided to do a little troubleshooting before I send the S-Tec 55xin f
or a major (expensive) overhaul.=C3=82=C2- At the very least, I want tore
place the VOR/GS coax and balun (The antenna is a horizontal dipole onthe t
op of the vertical stabilizer, like many 182s).
The balun is a typical made-from-coax affair that has never been changedsin
ce the airplane was new in 1962, as far as I can tell.=C3=82=C2- I'm sure
it has drowned in water - or at least moisture - for a very longtime.=C3=82
=C2- The dipole is then just connected directly to thebalun.
My questions are these:
1. The first thing is to replace the long run of coax. What coax do youreco
mmend?=C2- I know RG 58 will work (50 ohm), but I've heard thereare much
better, lower-loss cables for this application.
=C2-=C2-=C2- Yes. A much more robust and lower loss product
=C2-=C2-=C2- like RG141/142/400 is never a bad bet. There
=C2-=C2-=C2- are less expensive 50-ohm coaxes with better
=C2-=C2-=C2- performance than RG58 like the LMR195, same
=C2-=C2-=C2- size and connectors as RG58, similar outside
=C2-=C2-=C2- insulation but better shield construction and
=C2-=C2-=C2- lower loss insulation around the center
=C2-=C2-=C2- conductor . . . but a little fussier to work
=C2-=C2-=C2- with than the double-shield, Tef-like products
=C2-=C2-=C2- cited earlier. I'd go with 141/142/400 but the
=C2-=C2-=C2- 195 is fine too.
2. From what I read, the only purpose of the balun is to keep RF off thebra
id on the coax; the balun's matching function really doesn't do muchfor per
formance.
=C2-=C2-=C2- Yes. "Keeping RF of the braid" is atransmitting
=C2-=C2-=C2- issue . .=C2- and yes, it takes laboratorygrade
=C2-=C2-=C2- instrumentation and observation methods to
=C2-=C2-=C2- deduce any benefits for adding the balun to
=C2-=C2-=C2- a VOR antenna.=C2- All other things beingequal,
=C2-=C2-=C2- the pilot would not be able to tell whether
=C2-=C2-=C2- or not a balun was installed.
Since this is a receive-only setup, do I even need to worry about abalun, o
r could I just connect my new coax (unbalanced) to the antennaand forget ab
out it?
=C2-=C2-=C2- We built thousands of airplanes at Cessna in the60's
=C2-=C2-=C2- and 70's that were wired that way . . . and VORperforman
ce
=C2-=C2-=C2- of vacuum tube receivers was deemed adequate. And
=C2-=C2-=C2- again, all things being equal, the pilots wouldnot
=C2-=C2-=C2- know if a balun was present or not.
3. If you think a balun is worth it, where can I find a decent 1:1 pottedba
lun, so I don't have to worry about fabricating a new coaxone?
=C2-=C2- If the airplane's factory-delivered configuration
=C2-=C2- included a balun, then there's always risk of running
=C2-=C2- afoul of the TC-rule-gods.
=C2-=C2- They're easy to build, especially from RF141/142/400
=C2-=C2- coaxes that will readily stand off the effects of
=C2-=C2- soldering.
http://tinyurl.com/yytxwd3
=C2-=C2- So it's kinda your choice. A fresh hunk of modern
=C2-=C2- coax simply tied to the VOR whiskers will perform
=C2-=C2- nicely. Whether or not this produces better VOR/AP
=C2-=C2- performance is problematic.
=C2- Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: VOR antenna question |
At 11:46 AM 7/23/2015, you wrote:
>Give Kenny Poyner a call at 817-215-7637 (Cobham) and explain the
>situation to him. He is a whiz at the S-Tec a/p's and can be very helpful.
>Bill
Thanks for the heads-up Bill, I've forwarded the suggestion
to Jim . . .
>On Thursday, July 23, 2015 11:05 AM, "Robert L. Nuckolls, III"
> wrote:
>
>
>At 06:47 AM 7/22/2015, you wrote:
>Hi, Bob -
>
>
>I have a 1962 Skylane, and I am not satisfied with its VOR/GS
>performance at all. Add to that the fact that the autopilot won't
>track worth a damn, and I'm wondering if the Nav receiver/antenna
>setup is at fault.
Bob . . .
________________________________________________________________________________
| Subject: | ARINC 429 wiring practices |
| From: | Charlie England <ceengland7(at)gmail.com> |
I'm in the process of wiring my panel, which includes an old Garmin 430
(non-WAAS), an AFS AF4500S EFIS, AFS ARINC module, and AFS Pilot
autopilot. I'm using the AF3000-4000 Installation Guide, v7.4. Looking
through the AFS docs, their wiring diagrams are a bit...inconsistent... on
how to treat the ARINC and serial port data wiring.
So I did some digging in the InterWebs to find the 'proper' way to wire
ARINC 429 stuff. Two different sources say to ground the ARINC 429 shield
at source, destination, and at every 'break point' where additional
receivers are added, in daisy chain fashion. Easy enough; I can handle
that.
There are 3 ARINC data runs between the ARINC module and the 430. Should
each get its own shielded twisted pair, or would it be kosher to run 3
pairs in one shielded cable (and/or variations on that theme)?
In various places, there are both single and bi-directional serial runs
between/among the EFIS, 430, and other devices. In one case, they specify
that a ground return *isn't needed* (obviously depending on system
ground(s) between the EFIS & the 430). In most cases, they show a separate
ground return wire, *within* the shield of the cable. Now, I'd understand
that if the serial lines were 'balanced' (floating return), but all the
serial ground returns are electrically bonded to the chassis of the
AF4500S. Any noise imposed on the shield goes to exactly the same place
inside the unit as the separate ground return. Seems silly to run an extra
ground wire that's at the same potential as the shield.
Any thoughts on this from those who have either designed or done the actual
work on a/c using ARINC 429 and/or serial port technology?
Thanks,
Charlie
________________________________________________________________________________
| Subject: | Re: ARINC 429 wiring practices |
| From: | Christopher Cee Stone <rv8iator(at)gmail.com> |
Hello Charlie,
My -8 panel is holds a 430W, AF4500, ARINC module, AF3500 and AF-pilot.
I followed the AFS wiring schematic exactly. No shielded cables except for
the run to the magnetometer and serial port connections. All remaining
connections between the ARINC 429 module, the 430 and the AF4500 are AWG22
single wire bundled into a harness with zip ties.
I attached the ARINC 429 box to the underside of the AF4500 with self
adhering velcro. Thus all signal wire runs are short, less than 24 inches.
System works flawlessly.
[image: Inline image 2]
[image: Inline image 3]
Chris Stone
RV-8
80802
On Sun, Jul 26, 2015 at 12:11 PM, Charlie England
wrote:
> I'm in the process of wiring my panel, which includes an old Garmin 430
> (non-WAAS), an AFS AF4500S EFIS, AFS ARINC module, and AFS Pilot
> autopilot. I'm using the AF3000-4000 Installation Guide, v7.4. Looking
> through the AFS docs, their wiring diagrams are a bit...inconsistent... on
> how to treat the ARINC and serial port data wiring.
>
> So I did some digging in the InterWebs to find the 'proper' way to wire
> ARINC 429 stuff. Two different sources say to ground the ARINC 429 shield
> at source, destination, and at every 'break point' where additional
> receivers are added, in daisy chain fashion. Easy enough; I can handle
> that.
>
> There are 3 ARINC data runs between the ARINC module and the 430. Should
> each get its own shielded twisted pair, or would it be kosher to run 3
> pairs in one shielded cable (and/or variations on that theme)?
>
> In various places, there are both single and bi-directional serial runs
> between/among the EFIS, 430, and other devices. In one case, they specify
> that a ground return *isn't needed* (obviously depending on system
> ground(s) between the EFIS & the 430). In most cases, they show a separate
> ground return wire, *within* the shield of the cable. Now, I'd understand
> that if the serial lines were 'balanced' (floating return), but all the
> serial ground returns are electrically bonded to the chassis of the
> AF4500S. Any noise imposed on the shield goes to exactly the same place
> inside the unit as the separate ground return. Seems silly to run an extra
> ground wire that's at the same potential as the shield.
>
> Any thoughts on this from those who have either designed or done the
> actual work on a/c using ARINC 429 and/or serial port technology?
>
> Thanks,
>
> Charlie
>
> *
>
>
> *
>
>
________________________________________________________________________________
| Subject: | Re: ARINC 429 wiring practices |
| From: | David Josephson <dlj04(at)josephson.com> |
I built nav processors for survey planes using several ARINC 429 devices
tied together. Twisted pair wire was sufficient although we used
shielded. Shielding for differential serial data like that is to reduce
electromagnetic interference (transmitted and received) among the other
systems, so tying the shield to chassis at one end should be fine. EMI
was the only place where we had problems, and in some cases we needed to
swap which end was shielded to get the quietest results. Some of our
signals used multiple pairs inside one shield and that worked fine. No
use for a separate ground wire.
David Josephson
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: ARINC 429 wiring practices |
>
>Any thoughts on this from those who have either designed or done the
>actual work on a/c using ARINC 429 and/or serial port technology?
ARINC 429 is implemented on aircraft of all
sizes wherein local grounds for appliances
can be yards apart and serial data is conducted
on wires that traverse the wild and wooly environs
for all manner of potential antagonist and victim.
The short story is that for a single-engine,
light aircraft with all the goodies mounted
on the panel and sharing local grounds, the
risks for loss of serial data signal integrity
are zero.
There is no value in adding any sort of ground
external to a shielded-twisted-pair . . . why
anyone would suggest such at thing is a mystery.
There is no value in grounding a shield at both
ends . . . shields on STP data lines are just that,
stop-gaps for electrostatically coupled noises
into or out of the lines which are already
protected by the physics of twisted, balanced
signal paths. Telephone companies have successfully
exploited this particular physics in the fabrication
and operation of phone lines in bundles with
hundreds of other signals and traversing horrible
environs over many miles.
The twisted, balanced pair is about as bullet
proof as you can get without shielding. Ground
the shields at either end and only once.
Bob . . .
________________________________________________________________________________
| Subject: | Re: ARINC 429 wiring practices |
| From: | Charlie England <ceengland7(at)gmail.com> |
Thanks for the pics. I suspected that the elaborate shielding described in
the ARINC docs was a bit of overkill, but I went ahead with actual shielded
twisted pair. I'm about 75% done at this point; should have waited a couple
of days. :-)
Charlie
On Mon, Jul 27, 2015 at 9:16 AM, Christopher Cee Stone
wrote:
> Hello Charlie,
>
> My -8 panel is holds a 430W, AF4500, ARINC module, AF3500 and AF-pilot.
>
> I followed the AFS wiring schematic exactly. No shielded cables except
> for the run to the magnetometer and serial port connections. All remaining
> connections between the ARINC 429 module, the 430 and the AF4500 are AWG22
> single wire bundled into a harness with zip ties.
>
> I attached the ARINC 429 box to the underside of the AF4500 with self
> adhering velcro. Thus all signal wire runs are short, less than 24 inches.
>
> System works flawlessly.
>
>
> Chris Stone
> RV-8
> 80802
>
> On Sun, Jul 26, 2015 at 12:11 PM, Charlie England
> wrote:
>
>> I'm in the process of wiring my panel, which includes an old Garmin 430
>> (non-WAAS), an AFS AF4500S EFIS, AFS ARINC module, and AFS Pilot
>> autopilot. I'm using the AF3000-4000 Installation Guide, v7.4. Looking
>> through the AFS docs, their wiring diagrams are a bit...inconsistent... on
>> how to treat the ARINC and serial port data wiring.
>>
>> So I did some digging in the InterWebs to find the 'proper' way to wire
>> ARINC 429 stuff. Two different sources say to ground the ARINC 429 shield
>> at source, destination, and at every 'break point' where additional
>> receivers are added, in daisy chain fashion. Easy enough; I can handle
>> that.
>>
>> There are 3 ARINC data runs between the ARINC module and the 430. Should
>> each get its own shielded twisted pair, or would it be kosher to run 3
>> pairs in one shielded cable (and/or variations on that theme)?
>>
>> In various places, there are both single and bi-directional serial runs
>> between/among the EFIS, 430, and other devices. In one case, they specify
>> that a ground return *isn't needed* (obviously depending on system
>> ground(s) between the EFIS & the 430). In most cases, they show a separate
>> ground return wire, *within* the shield of the cable. Now, I'd understand
>> that if the serial lines were 'balanced' (floating return), but all the
>> serial ground returns are electrically bonded to the chassis of the
>> AF4500S. Any noise imposed on the shield goes to exactly the same place
>> inside the unit as the separate ground return. Seems silly to run an extra
>> ground wire that's at the same potential as the shield.
>>
>> Any thoughts on this from those who have either designed or done the
>> actual work on a/c using ARINC 429 and/or serial port technology?
>>
>> Thanks,
>>
>> Charlie
>>
>> *
>>
>> ist" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
>> tp://forums.matronics.com <http://forums.matronics.com>
>> _blank">http://www.matronics.com/contribution
>>
>> *
>>
>>
>
________________________________________________________________________________
| Subject: | Re: ARINC 429 wiring practices |
| From: | Charlie England <ceengland7(at)gmail.com> |
Thanks to David & Bob.
Bob,
My question about the 'extra' ground wire was related to the serial
port(s), not ARINC. IIRC, serial stuff is typically unbalanced, with a
signal line and a shield/ground return. In the case of the AFS docs, they
show in one case (to external GPS) a pair of signal wires (bi-directional
data), and a ground wire, all wrapped in a shield. In another case
(magnetometer) they show a pair of RS422 signal wires, a power wire, and a
ground wire, all wrapped in a shield. That's the practice of embedding an
extra ground wire inside a shield (when the shield can serve as ground)
that I was really questioning.
Charlie
On Mon, Jul 27, 2015 at 10:23 AM, Robert L. Nuckolls, III <
nuckolls.bob(at)aeroelectric.com> wrote:
>
> Any thoughts on this from those who have either designed or done the
> actual work on a/c using ARINC 429 and/or serial port technology?
>
>
> ARINC 429 is implemented on aircraft of all
> sizes wherein local grounds for appliances
> can be yards apart and serial data is conducted
> on wires that traverse the wild and wooly environs
> for all manner of potential antagonist and victim.
>
> The short story is that for a single-engine,
> light aircraft with all the goodies mounted
> on the panel and sharing local grounds, the
> risks for loss of serial data signal integrity
> are zero.
>
> There is no value in adding any sort of ground
> external to a shielded-twisted-pair . . . why
> anyone would suggest such at thing is a mystery.
> There is no value in grounding a shield at both
> ends . . . shields on STP data lines are just that,
> stop-gaps for electrostatically coupled noises
> into or out of the lines which are already
> protected by the physics of twisted, balanced
> signal paths. Telephone companies have successfully
> exploited this particular physics in the fabrication
> and operation of phone lines in bundles with
> hundreds of other signals and traversing horrible
> environs over many miles.
>
> The twisted, balanced pair is about as bullet
> proof as you can get without shielding. Ground
> the shields at either end and only once.
>
> Bob . . .
>
> *
>
>
> *
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: ARINC 429 wiring practices |
At 04:34 PM 7/27/2015, you wrote:
Thanks to David & Bob.=C2
Bob,
My question about the 'extra' ground wire was
related to the serial port(s), not ARINC. IIRC,
serial stuff is typically unbalanced, with a
signal line and a shield/ground return. In the
case of the AFS docs, they show in one case (to
external GPS) a pair of signal wires
(bi-directional data), and a ground wire, all
wrapped in a shield. In another case
(magnetometer) they show a pair of RS422 signal
wires, a power wire, and a ground wire, all
wrapped in a shield. That's the practice of
embedding an extra ground wire inside a shield
(when the shield can serve as ground) that I was really questioning.
The 'extra' wire you're describing . . . is it bare?
. . . and what is the nature of the shield material?
. . . what you are describing is reminiscent
of a product from Belden Wire called "Beldfoil"
shielded wire. Instead of braiding strands of wire
over the bundle, they wrap an aluminum foil shield
over it. VERY effective shielding but electrical
connection to thin aluminum is hard to make up.
The solution was to bundle a bare stranded wire
in with the other wires. Given that it is not
insulated, it makes connection with the shielding
at innumerable places along the length of the cable.
http://tinyurl.com/nhpjmup
Given that electro-static shield currents are
very low, it matters not that the ground connection
to the foil is not gas-tight. Hence, the shield ground
has a hi order of integrity to the task and the foil
shielding is electro-statically superior and much
less expensive than braid . . . a kind of win-win.
Unfortunately, this technology is not generally
offered in combination with our favorite insulations
so you don't see this wire used in TC or military
aircraft . . . but it's fine for our purposes.
That 'extra' wire CAN be used as a part of the
power path as long as it's 22AWG current ratings
are observed . . . with the caveat that the
return path power wire be included in the bundle
so that you get parallel path cancellation for
electro-magnetic coupling. But as a general rule,
you're almost never wrong to use the shield
for electro-static decoupling and attach it
to ground one time only at either end.
Bob . . .
________________________________________________________________________________
| Subject: | Re: ARINC 429 wiring practices |
| From: | Charlie England <ceengland7(at)gmail.com> |
Understand about Belfoil shielded wire; I've built my share of cables using
it in one of my previous lives as a sound engineer & audio tech. It's
unrelated to my question. As a reminder, my question is about the AFS
*documents*, not actual wire. I should have attached an image of the
diagram with the 1st post. Image attached now.
See the wiring from the 'EFIS Main Cable' connector to the Nav Radio,
Altitude Encoder Output to Transponder, GPS, and Magnetometer. All are
shown with a separate ground wire, drawn within the shield. None of the
devices draw significant current, and all the 'ground' return pins shown in
the EFIS Main Connector are electrically common to the chassis of the EFIS
itself. My question is about the 'extra' ground wire, drawn within the
shield for each of these destinations.
The only connection that does make sense to me is the 'EFIS Audio Output',
which logically shows a signal wire and a shield return, without the extra
ground wire.
On Thu, Jul 30, 2015 at 8:48 AM, Robert L. Nuckolls, III <
nuckolls.bob(at)aeroelectric.com> wrote:
> At 04:34 PM 7/27/2015, you wrote:
> Thanks to David & Bob.=C3=82
>
> Bob,
>
> My question about the 'extra' ground wire was related to the serial
> port(s), not ARINC. IIRC, serial stuff is typically unbalanced, with a
> signal line and a shield/ground return. In the case of the AFS docs, they
> show in one case (to external GPS) a pair of signal wires (bi-directional
> data), and a ground wire, all wrapped in a shield. In another case
> (magnetometer) they show a pair of RS422 signal wires, a power wire, and
a
> ground wire, all wrapped in a shield. That's the practice of embedding an
> extra ground wire inside a shield (when the shield can serve as ground)
> that I was really questioning.
>
>
> The 'extra' wire you're describing . . . is it bare?
> . . . and what is the nature of the shield material?
>
> . . . what you are describing is reminiscent
> of a product from Belden Wire called "Beldfoil"
> shielded wire. Instead of braiding strands of wire
> over the bundle, they wrap an aluminum foil shield
> over it. VERY effective shielding but electrical
> connection to thin aluminum is hard to make up.
>
> The solution was to bundle a bare stranded wire
> in with the other wires. Given that it is not
> insulated, it makes connection with the shielding
> at innumerable places along the length of the cable.
>
> http://tinyurl.com/nhpjmup
>
> Given that electro-static shield currents are
> very low, it matters not that the ground connection
> to the foil is not gas-tight. Hence, the shield ground
> has a hi order of integrity to the task and the foil
> shielding is electro-statically superior and much
> less expensive than braid . . . a kind of win-win.
> Unfortunately, this technology is not generally
> offered in combination with our favorite insulations
> so you don't see this wire used in TC or military
> aircraft . . . but it's fine for our purposes.
>
> That 'extra' wire CAN be used as a part of the
> power path as long as it's 22AWG current ratings
> are observed . . . with the caveat that the
> return path power wire be included in the bundle
> so that you get parallel path cancellation for
> electro-magnetic coupling. But as a general rule,
> you're almost never wrong to use the shield
> for electro-static decoupling and attach it
> to ground one time only at either end.
>
>
> Bob . . .
>
> *
>
===========
www.matronics.com/Navigator?AeroElectric-List>
===========
===========
om/contribution>
===========
>
> *
>
>
________________________________________________________________________________
| From: | "Ross Home" <rossmickey(at)comcast.net> |
| Subject: | ARINC 429 wiring practices |
I just got done installing a 5600. I wired it as shown. Each Serial
Port bundle has a RX, TX, Gnd and shield. The shields for the four
ports are all connected together at the main harness connector with a
black wire coming out of the connector that gets grounded to the
chassis. I used whatever TX, RX wires I needed for the particular
instrument. I ran all of the Gnd wires to my ground block since that is
where all of my instruments are grounded. Everything works great ever
since I got rid of the 18=9D length of unused OAT cable.
If your question is why they want us to ground each serial port, I
can=99t tell you. I just did it. Have you called AFS and asked
them?
Ross
N9PT
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Charlie England
Sent: Thursday, July 30, 2015 12:47 PM
Subject: Re: AeroElectric-List: ARINC 429 wiring practices
Understand about Belfoil shielded wire; I've built my share of cables
using it in one of my previous lives as a sound engineer & audio tech.
It's unrelated to my question. As a reminder, my question is about the
AFS *documents*, not actual wire. I should have attached an image of the
diagram with the 1st post. Image attached now.
See the wiring from the 'EFIS Main Cable' connector to the Nav Radio,
Altitude Encoder Output to Transponder, GPS, and Magnetometer. All are
shown with a separate ground wire, drawn within the shield. None of the
devices draw significant current, and all the 'ground' return pins shown
in the EFIS Main Connector are electrically common to the chassis of the
EFIS itself. My question is about the 'extra' ground wire, drawn within
the shield for each of these destinations.
The only connection that does make sense to me is the 'EFIS Audio
Output', which logically shows a signal wire and a shield return,
without the extra ground wire.
On Thu, Jul 30, 2015 at 8:48 AM, Robert L. Nuckolls, III
>
wrote:
At 04:34 PM 7/27/2015, you wrote:
Thanks to David & Bob.=C3=82
Bob,
My question about the 'extra' ground wire was related to the serial
port(s), not ARINC. IIRC, serial stuff is typically unbalanced, with a
signal line and a shield/ground return. In the case of the AFS docs,
they show in one case (to external GPS) a pair of signal wires
(bi-directional data), and a ground wire, all wrapped in a shield. In
another case (magnetometer) they show a pair of RS422 signal wires, a
power wire, and a ground wire, all wrapped in a shield. That's the
practice of embedding an extra ground wire inside a shield (when the
shield can serve as ground) that I was really questioning.
The 'extra' wire you're describing . . . is it bare?
. . . and what is the nature of the shield material?
. . . what you are describing is reminiscent
of a product from Belden Wire called "Beldfoil"
shielded wire. Instead of braiding strands of wire
over the bundle, they wrap an aluminum foil shield
over it. VERY effective shielding but electrical
connection to thin aluminum is hard to make up.
The solution was to bundle a bare stranded wire
in with the other wires. Given that it is not
insulated, it makes connection with the shielding
at innumerable places along the length of the cable.
http://tinyurl.com/nhpjmup
Given that electro-static shield currents are
very low, it matters not that the ground connection
to the foil is not gas-tight. Hence, the shield ground
has a hi order of integrity to the task and the foil
shielding is electro-statically superior and much
less expensive than braid . . . a kind of win-win.
Unfortunately, this technology is not generally
offered in combination with our favorite insulations
so you don't see this wire used in TC or military
aircraft . . . but it's fine for our purposes.
That 'extra' wire CAN be used as a part of the
power path as long as it's 22AWG current ratings
are observed . . . with the caveat that the
return path power wire be included in the bundle
so that you get parallel path cancellation for
electro-magnetic coupling. But as a general rule,
you're almost never wrong to use the shield
for electro-static decoupling and attach it
to ground one time only at either end.
Bob . . .
ist"
target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
tp://forums.matronics.com
_blank">http://www.matronics.com/contribution
________________________________________________________________________________
| Subject: | Re: ARINC 429 wiring practices |
| From: | Charlie England <ceengland7(at)gmail.com> |
I haven't asked them yet, because I already have a strong suspicion of what
their answer will be: 'to shield the ground from noise'. Serial data needs
a ground return, but since the ground return pins in the connector are all
bonded to the case of the EFIS, any noise on the shield is also on those
ground return pins. Which begs the question: why have the extra ground
wire? My suspicion is that they are following some 'certified aircraft'
practice that was started back in mythological times and hasn't been
updated with current knowledge. That's why I've been asking here; we've
seen other 'stuff' in certified a/c that can be done better or simpler,
based on current knowledge.
Glad to hear that you've got yours working noise-free.
Charlie
On Thu, Jul 30, 2015 at 3:48 PM, Ross Home wrote:
> I just got done installing a 5600. I wired it as shown. Each Serial Por
t
> bundle has a RX, TX, Gnd and shield. The shields for the four ports are
> all connected together at the main harness connector with a black wire
> coming out of the connector that gets grounded to the chassis. I used
> whatever TX, RX wires I needed for the particular instrument. I ran all
of
> the Gnd wires to my ground block since that is where all of my instrument
s
> are grounded. Everything works great ever since I got rid of the 18
=9D
> length of unused OAT cable.
>
>
> If your question is why they want us to ground each serial port, I can
=99t
> tell you. I just did it. Have you called AFS and asked them?
>
>
> Ross
>
> N9PT
>
>
> *From:* owner-aeroelectric-list-server(at)matronics.com [mailto:
> owner-aeroelectric-list-server(at)matronics.com] *On Behalf Of *Charlie
> England
> *Sent:* Thursday, July 30, 2015 12:47 PM
> *To:* aeroelectric-list(at)matronics.com
> *Subject:* Re: AeroElectric-List: ARINC 429 wiring practices
>
>
> Understand about Belfoil shielded wire; I've built my share of cables
> using it in one of my previous lives as a sound engineer & audio tech. It
's
> unrelated to my question. As a reminder, my question is about the AFS
> *documents*, not actual wire. I should have attached an image of the
> diagram with the 1st post. Image attached now.
>
>
> See the wiring from the 'EFIS Main Cable' connector to the Nav Radio,
> Altitude Encoder Output to Transponder, GPS, and Magnetometer. All are
> shown with a separate ground wire, drawn within the shield. None of the
> devices draw significant current, and all the 'ground' return pins shown
in
> the EFIS Main Connector are electrically common to the chassis of the EFI
S
> itself. My question is about the 'extra' ground wire, drawn within the
> shield for each of these destinations.
>
>
> The only connection that does make sense to me is the 'EFIS Audio Output'
,
> which logically shows a signal wire and a shield return, without the extr
a
> ground wire.
>
>
> On Thu, Jul 30, 2015 at 8:48 AM, Robert L. Nuckolls, III <
> nuckolls.bob(at)aeroelectric.com> wrote:
>
> At 04:34 PM 7/27/2015, you wrote:
> Thanks to David & Bob.=C3=82
>
> Bob,
>
> My question about the 'extra' ground wire was related to the serial
> port(s), not ARINC. IIRC, serial stuff is typically unbalanced, with a
> signal line and a shield/ground return. In the case of the AFS docs, they
> show in one case (to external GPS) a pair of signal wires (bi-directional
> data), and a ground wire, all wrapped in a shield. In another case
> (magnetometer) they show a pair of RS422 signal wires, a power wire, and
a
> ground wire, all wrapped in a shield. That's the practice of embedding an
> extra ground wire inside a shield (when the shield can serve as ground)
> that I was really questioning.
>
>
> The 'extra' wire you're describing . . . is it bare?
> . . . and what is the nature of the shield material?
>
> . . . what you are describing is reminiscent
> of a product from Belden Wire called "Beldfoil"
> shielded wire. Instead of braiding strands of wire
> over the bundle, they wrap an aluminum foil shield
> over it. VERY effective shielding but electrical
> connection to thin aluminum is hard to make up.
>
> The solution was to bundle a bare stranded wire
> in with the other wires. Given that it is not
> insulated, it makes connection with the shielding
> at innumerable places along the length of the cable.
>
> http://tinyurl.com/nhpjmup
>
> Given that electro-static shield currents are
> very low, it matters not that the ground connection
> to the foil is not gas-tight. Hence, the shield ground
> has a hi order of integrity to the task and the foil
> shielding is electro-statically superior and much
> less expensive than braid . . . a kind of win-win.
> Unfortunately, this technology is not generally
> offered in combination with our favorite insulations
> so you don't see this wire used in TC or military
> aircraft . . . but it's fine for our purposes.
>
> That 'extra' wire CAN be used as a part of the
> power path as long as it's 22AWG current ratings
> are observed . . . with the caveat that the
> return path power wire be included in the bundle
> so that you get parallel path cancellation for
> electro-magnetic coupling. But as a general rule,
> you're almost never wrong to use the shield
> for electro-static decoupling and attach it
> to ground one time only at either end.
>
>
> Bob . . .
>
>
> *ist" target="_blank">http://www.matronics.com/Navigator?AeroElectric-L
ist <http://www.matronics.com/Navigator?AeroElectric-List>*
>
> *tp://forums.matronics.com <http://forums.matronics.com>*
>
> *_blank">http://www.matronics.com/contribution *
>
>
> *
>
===========
www.matronics.com/Navigator?AeroElectric-List>
===========
===========
om/contribution>
===========
>
> *
>
>
________________________________________________________________________________
| From: | Bob Verwey <bob.verwey(at)gmail.com> |
| Subject: | grounding mag p lead shield...which side? |
switch side or mag side?
________________________________________________________________________________
| Subject: | Re: grounding mag p lead shield...which side? |
| From: | Charlie England <ceengland7(at)GMAIL.COM> |
On 7/31/2015 6:01 AM, Bob Verwey wrote:
> switch side or mag side?
>
Suspend normal thought about shields when looking at magnetos.
The shield is the return path to short out the mag when the mag switch
is 'off' (note the quotes).
http://www.aeroelectric.com/articles/MagnetoSwitchOptions.pdf
Center conductor to the points in the mag, shield grounded to the mag case.
At the other end, center conductor to one terminal of your mag switch,
and the shield to the other terminal. When the switch is *closed*
(continuity across the terminals), the mag is *off*. When the switch is
*open* (off, in normal terminology), the mag is *on*.
________________________________________________________________________________
| Subject: | Re: grounding mag p lead shield...which side? |
| From: | John Tipton <jmtipton(at)btopenworld.com> |
Correct: that is why we are told (this side of the pond anyway) during our t
raining to treat the prop as always being live, just in case the grounded (
mag switches in the off position) wire 'isn't' grounded
John
Sent from my iPad
----x--O--x----
> On 31 Jul 2015, at 02:43 pm, Charlie England wrote:
>
>> On 7/31/2015 6:01 AM, Bob Verwey wrote:
>> switch side or mag side?
> Suspend normal thought about shields when looking at magnetos.
>
> The shield is the return path to short out the mag when the mag switch is '
off' (note the quotes).
> http://www.aeroelectric.com/articles/MagnetoSwitchOptions.pdf
>
> Center conductor to the points in the mag, shield grounded to the mag case
.
>
> At the other end, center conductor to one terminal of your mag switch, and
the shield to the other terminal. When the switch is *closed* (continuity a
cross the terminals), the mag is *off*. When the switch is *open* (off, in n
ormal terminology), the mag is *on*.
>
>
==========================
=========
==========================
=========
==========================
=========
==========================
=========
>
________________________________________________________________________________
| Subject: | Re: grounding mag p lead shield...which side? |
| From: | Charlie England <ceengland7(at)gmail.com> |
I should have added:
Be sure to check the switch for 'closed' position (continuity between
terminals) *before* hooking up the mag wires. A regular ohm meter can't
tell the difference between shorted terminals of the switch turned on,
and the very low DC resistance of the mag's coil primary winding (that's
where the P-leads are connected) when the switch is switched open.
If you're using regular SPST toggle switches as mag switches, just mount
them 'upside down' so that the switch's 'on' label is on the bottom.
On 7/31/2015 8:59 AM, John Tipton wrote:
> Correct: that is why we are told (this side of the pond anyway) during
> our training to treat the prop as always being live, just in case the
> grounded (mag switches in the off position) wire 'isn't' grounded
>
> John
>
> Sent from my iPad
>
> ----x--O--x----
>
> On 31 Jul 2015, at 02:43 pm, Charlie England > wrote:
>
>> On 7/31/2015 6:01 AM, Bob Verwey wrote:
>>> switch side or mag side?
>>>
>> Suspend normal thought about shields when looking at magnetos.
>>
>> The shield is the return path to short out the mag when the mag
>> switch is 'off' (note the quotes).
>> http://www.aeroelectric.com/articles/MagnetoSwitchOptions.pdf
>>
>> Center conductor to the points in the mag, shield grounded to the mag
>> case.
>>
>> At the other end, center conductor to one terminal of your mag
>> switch, and the shield to the other terminal. When the switch is
>> *closed* (continuity across the terminals), the mag is *off*. When
>> the switch is *open* (off, in normal terminology), the mag is *on*.
>> **
> --> http://www.matronics.com/Navigator?AeroElectric-List
> http://www.matronics.com/contribution
> <3D%22http://www.matronics.com/contribution%22>
> *
________________________________________________________________________________
| Subject: | Re: grounding mag p lead shield...which side? |
| From: | Bob Verwey <bob.verwey(at)gmail.com> |
Thats why I love this list! Thanks Charlie!
On Friday, July 31, 2015, Charlie England wrote:
> On 7/31/2015 6:01 AM, Bob Verwey wrote:
>
> switch side or mag side?
>
> Suspend normal thought about shields when looking at magnetos.
>
> The shield is the return path to short out the mag when the mag switch is
> 'off' (note the quotes).
> http://www.aeroelectric.com/articles/MagnetoSwitchOptions.pdf
>
> Center conductor to the points in the mag, shield grounded to the mag case.
>
> At the other end, center conductor to one terminal of your mag switch, and
> the shield to the other terminal. When the switch is *closed* (continuity
> across the terminals), the mag is *off*. When the switch is *open* (off, in
> normal terminology), the mag is *on*.
>
> *
>
>
> *
>
>
--
Best...
Bob Verwey
________________________________________________________________________________
| Subject: | Re: RG400 Splice |
| From: | "Greenbacks, UnLtd." <n4zq(at)verizon.net> |
I may have a need to lengthen two of the four antenna cables to my Ryan TCAD9900B
by approximately 6.
Short of fabricating an extension with connectors on each end, would it be preferable
to splice directly to the existing cables?
Thanks
N4ZQ
________________________________________________________________________________
| From: | Bill Putney <billp(at)wwpc.com> |
| Subject: | Re: RG400 Splice |
If you can't find 6" of slack to pull from somewhere in the airframe
you're stuck. You might be able to reroute the cables to get the extra 6".
Here's a whole lot of technical reasons why you should replace all your
cables (not splice them) if that's what you need to do;
1) According to the installation manual all four cables MUST be the same
length. Changing the length of just two of the cables is going to make
target bearing inaccurate. The TCAD uses signal arrival time (phase) to
determine the bearing to the target. changing a cables length will
change the length of time it takes a signal to get through that cable
retaliative to the time the same signal takes to get through the other
cables.
The cables need to have 3.0 dB of loss +/-0.5 dB. The TCAD uses relative
signal strength to determine the range to the target. Without using
connectors it is nearly impossible to keep a constant impedance. A
soldered splice just won't work well at these frequencies. In addition,
the reflections caused by the impedance mismatch is going to add
additional loss and may create ghost aircraft. I'm not sure about the
ghosts but seems like a possibility given what the TCAD is trying to do.
Splicing the additional cable will add 4 more connectors per cable. Good
quality connectors rated for operation at these frequencies that are
properly installed will add about 0.11 dB per connector for a total of
0.44 dB. Getting real close to the 0.5 dB tolerance you have in the spec
for the cables. Of course you don't know how much of that tolerance (or
in which direction, + or -) has been used by the original installer. The
installation manual doesn't talk about fabricating these cables but
rather lists prefabricated cable sets that are compatible. My guess that
they want the cables manufactured and tested as a set with a network
analyzer so that they know that the cables are of equal length
(electrical phase-wise) and equal loss at the 3 dB spec.
Piecing out the cable length with homemade extensions seems like a bad
idea to me. You're taking a very expensive piece of avionics and
sacrificing it's accuracy for the price of a new cable set.
Bill
On 8/2/15 06:42, Greenbacks, UnLtd. wrote:
>
> I may have a need to lengthen two of the four antenna cables to my Ryan TCAD9900B
by approximately 6.
> Short of fabricating an extension with connectors on each end, would it be preferable
to splice directly to the existing cables?
>
> Thanks
>
> N4ZQ
>
>
________________________________________________________________________________
| From: | Sheldon Olesen <saolesen(at)sirentel.net> |
| Subject: | Contactor or master switch problem? |
I have been having some starting and electrical issues which I think may involve
the master switch or the battery contactor.
My son and I were going out flying one day last week, had preflighted the plane,
and after we pulled the plane from the hanger we switched on the master switch.
The electronics came on briefly and then faded away. There was no power
for the starter. I thought that was odd because the plane normally has charger
attached while in the hanger. The Odyssey specific charger indicated the battery
was charged. After a quick trip home to find a volt meter we tested the
voltage which was 13+v. We had the charger on while we gone so the reading was
skewed because of that. We pulled the plane out and the electronics and starter
worked normally.
On Sat., I flew 8 trips of Young Eagles with no starting or electrical problems.
After the event was over, a trip to the fuel pump had the electronics working
but the starter contactor clicking but no prop rotation. I cycled the master
switch several times and finally the engine turned over like nothing was wrong.
I have a 1200 nm trip coming up soon so I need an answer so there are no
problems along the way.
The battery is a PC680 about 2 years old. The master switch (Carling) and battery
contactor (B&C) are about 7 years old and have around 630 hours. Apparently
the volts and amps are there but getting choked off before they can do their
work. Right now, my thought is to replace them both, but especially the master
switch, due to my impending trip. Any thoughts, better ideas or am I missing
something?
Sheldon Olesen
Sent from my iPad
________________________________________________________________________________
| From: | <rnjcurtis(at)charter.net> |
| Subject: | Re: Q?Re:_AeroElectric-List:_Contactor_or_master_switch_problem=3F? |
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________________________________________________________________________________
| From: | <m.j.gregory(at)talk21.com> |
| Subject: | Contactor or master switch problem? |
Hello Sheldon,
Before changing anything, I suggest you carry out a thorough check of the
connections to all of the relevant components, especially those of the
battery terminals, the starter and the ground returns. Look particularly at
the braided grounding strap between the engine and the battery negative.
Your time of 630 hours is not particularly high for the master switch and
battery contactor, but if the connections all check out then you could
change the component that is more difficult to access in the field and take
with you a spare for the other. This would give you a chance to find out
which is giving the trouble without having too much of a problem to fix on
your long trip.
Good luck!
Mike
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Sheldon
Olesen
Sent: 02 August 2015 22:10
Subject: AeroElectric-List: Contactor or master switch problem?
-->
I have been having some starting and electrical issues which I think may
involve the master switch or the battery contactor.
My son and I were going out flying one day last week, had preflighted the
plane, and after we pulled the plane from the hanger we switched on the
master switch. The electronics came on briefly and then faded away. There
was no power for the starter. I thought that was odd because the plane
normally has charger attached while in the hanger. The Odyssey specific
charger indicated the battery was charged. After a quick trip home to find
a volt meter we tested the voltage which was 13+v. We had the charger on
while we gone so the reading was skewed because of that. We pulled the
plane out and the electronics and starter worked normally.
On Sat., I flew 8 trips of Young Eagles with no starting or electrical
problems. After the event was over, a trip to the fuel pump had the
electronics working but the starter contactor clicking but no prop rotation.
I cycled the master switch several times and finally the engine turned over
like nothing was wrong. I have a 1200 nm trip coming up soon so I need an
answer so there are no problems along the way.
The battery is a PC680 about 2 years old. The master switch (Carling) and
battery contactor (B&C) are about 7 years old and have around 630 hours.
Apparently the volts and amps are there but getting choked off before they
can do their work. Right now, my thought is to replace them both, but
especially the master switch, due to my impending trip. Any thoughts,
better ideas or am I missing something?
Sheldon Olesen
Sent from my iPad
________________________________________________________________________________
| Subject: | Re: Contactor or master switch problem? |
| From: | Charlie England <ceengland7(at)gmail.com> |
On 8/2/2015 5:58 PM, rnjcurtis(at)charter.net wrote:
>
>
> **
>
> I have been having some starting and electrical issues which I think
> may involve the master switch or the battery contactor.
>
> My son and I were going out flying one day last week, had preflighted
> the plane, and after we pulled the plane from the hanger we switched
> on the master switch. The electronics came on briefly and then faded
> away. There was no power for the starter. I thought that was odd
> because the plane normally has charger attached while in the hanger.
> The Odyssey specific charger indicated the battery was charged. After
> a quick trip home to find a volt meter we tested the voltage which was
> 13+v. We had the charger on while we gone so the reading was skewed
> because of that. We pulled the plane out and the electronics and
> starter worked normally.
>
> On Sat., I flew 8 trips of Young Eagles with no starting or
> electrical problems. After the event was over, a trip to the fuel
> pump had the electronics working but the starter contactor clicking
> but no prop rotation. I cycled the master switch several times and
> finally the engine turned over like nothing was wrong. I have a 1200
> nm trip coming up soon so I need an answer so there are no problems
> along the way.
>
> The battery is a PC680 about 2 years old. The master switch (Carling)
> and battery contactor (B&C) are about 7 years old and have around 630
> hours. Apparently the volts and amps are there but getting choked off
> before they can do their work. Right now, my thought is to replace
> them both, but especially the master switch, due to my impending
> trip. Any thoughts, better ideas or am I missing something?
>
> I had a similar problem a couple of years back. I would have
> to turn the master on and off several times to get power to
> the starter and electronics. Once the power came up it would
> run flawlessly until the next time I tried to start it.
>
> The problem turned out to be a bad, internal
> contact corrosion, master solenoid. I replaced it and the
> problem went away completely. After I replaced it I sent the
> defective unit to Bob N and he dissected it, took pictures,
> and posted on this forum. It is likely that you have a
> similar problem.
>
> Roger
>
I'd probably vote with Roger. If you hear the master contactor 'clack'
with its normal sound every time you flip the master switch, then the
switch is almost certainly doing its job properly. The 'clack' means
that the master switch is sending activation current to the contactor,
and the solenoid in the contactor is moving the contacts together (the
clack). That leaves the contacts themselves, assuming that you've
checked all the connections, including ground side connections.
Charlie
________________________________________________________________________________
| Subject: | Re: Contactor or master switch problem? |
| From: | "user9253" <fransew(at)gmail.com> |
My guess is the contactor is at fault. Once a contactor is energized, it does
not take as much current to hold it closed. If the master switch conducted enough
current to energize the contactor, then the switch should be able to hold
the contactor closed. But if you replace both, there is no guessing.
Also check the terminals on the fat wires, including the battery ground.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=445525#445525
________________________________________________________________________________
| From: | Justin Jones <jmjones2000(at)mindspring.com> |
| Subject: | Re: Contactor or master switch problem? |
I'm with everyone else, and bet your problems are related to the contactor. I have
had numerous contractors fail over the years. This is the reason I decided
to go with the solid state master relay. Cost was higher but the weight is similar
and it works flawlessly so far. No more "click" means no more arcing and
worn out mechanical components. Solid state relays are known to last for millions
of cycles. More than we could ever do. The peace of mind alone is worth
the added cost. By the time you buy 2 contactors, you have paid for this unit.
I was worried at first that it would not charge the battery through the relay but
that proved to be no factor. It charges fine. So far, I am very happy with
it.
Rated at:
12.5V DC
300A continuous
500A (1sec) inrush
Seems robust enough so far.
http://www.waytekwire.com/item/44407/300A-Solid-State-Battery/
Data Sheet:
http://www.waytekwire.com/datasheet/44407.pdf
Justin
> On Aug 2, 2015, at 23:14, user9253 wrote:
>
>
> My guess is the contactor is at fault. Once a contactor is energized, it does
not take as much current to hold it closed. If the master switch conducted
enough current to energize the contactor, then the switch should be able to hold
the contactor closed. But if you replace both, there is no guessing.
> Also check the terminals on the fat wires, including the battery ground.
> Joe
>
> --------
> Joe Gores
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=445525#445525
>
>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| Subject: | Re: RG400 Splice |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
> I may have a need to lengthen two of the four antenna cables to my Ryan TCAD9900B
by approximately 6. Short of fabricating an extension with connectors on
each end, would it be preferable to splice directly to the existing cables? N4ZQ
I'd follow Bill's suggestions, but if it absolutely has to be lengthened there
are connectors to do it properly. There are good You Tube videos online regarding
this.
But whatever you do, remember that the RF signal is carried in the insulation,
NOT the center conductor nor the shield! This makes all other joining schemes
problematic.
See my attached "Dabbling with Electricity" for this and other matters.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=445533#445533
Attachments:
http://forums.matronics.com//files/dabbling_with_electricity_868.pdf
________________________________________________________________________________
| Subject: | crimping question |
| From: | "blues750" <den_beaulieu(at)yahoo.com> |
Best practices or caveats? When needing to put multiple wires to a single Faston
type connector... do you butt splice multiple wires then use single lead
to Faston spade or bring multiple wires into the Faston female connector and crimp?
Thanks for indulging me...
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=445622#445622
________________________________________________________________________________
| Subject: | Re: crimping question |
Like many things, it depends. Two, three or maybe four (depends on the wire size),
and I'll put them all in a single connector. If they don't fit, I like to
splice the wires into a single lead.
But again, it depends on the size of the wires and their purpose. Six 20AWG wires
supplying devices that are on all the time probably wouldn't work well spliced
into a single 20AWG wire. But something like ground wires going to momentary
switches would be okay.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=445624#445624
________________________________________________________________________________
| Subject: | Re: RG400 Splice |
> But whatever you do, remember that the RF signal is carried in the insulation,
NOT the center conductor nor the shield!
This is the kind of stuff that makes my head explode. :(
You're saying the signal is carried by the thing that is not supposed to conduct
electricity?
And I'm not doubting you. It's just that makes as much sense (to me) as my car
battery being jammed full of AAA's. [Laughing]
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=445625#445625
________________________________________________________________________________
| Subject: | Re: RG400 Splice |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
> You're saying the signal is carried by the thing that is not supposed to conduct
electricity? Don Johnson
The signal (which is obviously the important stuff) is DRIVEN by the "wave guide"
which is the metal parts, but transmitted inside the wave guide...which is
the insulation. It turns out that the wave velocity is exactly the same as the
speed of light inside the insulating material-- Vacuum, Teflon or PE for example.
I point this out to make sure that builders understand the reason for proper termination
(which includes joints) of the coaxial cable. I can't be "pig-tailed"
at high frequencies without enormous loss of signal strength. At low frequencies
(like audio) it just doesn't matter.
Electricity is strange. Please read my "Dabbling with Electricity".
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=445627#445627
________________________________________________________________________________
| Subject: | Re: RG400 Splice |
Those videos are great.
This is what prompted my statement.
https://www.youtube.com/watch?v=s_8n2Qgguto
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=445641#445641
________________________________________________________________________________
| From: | <r.r.hall(at)cox.net> |
| Subject: | Re: crimping question |
I think it depends on the type/size of wire and type/size of fastener. A better
solution might be ring type fasteners on a post
---- blues750 wrote:
>
> Best practices or caveats? When needing to put multiple wires to a single Faston
type connector... do you butt splice multiple wires then use single lead to
Faston spade or bring multiple wires into the Faston female connector and crimp?
>
> Thanks for indulging me...
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=445622#445622
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: RG400 Splice |
At 06:56 PM 8/5/2015, you wrote:
>
>
> > You're saying the signal is carried by the thing that is not
> supposed to conduct electricity? Don Johnson
>
>
>The signal (which is obviously the important stuff) is DRIVEN by the
>"wave guide" which is the metal parts, but transmitted inside the
>wave guide...which is the insulation. It turns out that the wave
>velocity is exactly the same as the speed of light inside the
>insulating material-- Vacuum, Teflon or PE for example.
There is no parallel between coaxial transmission
lines and waveguide.
Transmission lines are metallic conductors with
predictable surge impedance and velocity factor
that is constant with frequency.
Waveguides are as their name suggests, pipes
for the conduct of electromagnetic energy,
a constriction of free space that allows one
to direct the energy from the antenna (a little
radiator at one end of the 'pipe' over some
distance and around corners before it is launched
into free space . . . usually at the focal point of
some reflective dish.
A wave traversing the length of a guide literally
reflects from wall-to-wall and in a manner that
is influenced by the size and shape of the guide
with respect to the operating frequency. Waveguide
also exhibits a 'velocity factor' which is a function
size and operating frequency. As one squirts energy
down a wave guide in lower frequencies, the velocity
factor increases until at some lower limit (cutoff
frequency) the velocity factor is for all practical
purposes infinite and no energy makes it down the
pipe.
Coax cable exhibits no such characteristic in
that it's a conductor constrained within a die-electric
and waveguide is a simple constriction of free space.
Losses in waveguide and coax are separate operators.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: crimping question |
At 03:25 PM 8/5/2015, you wrote:
>
>Best practices or caveats? When needing to put multiple wires to a
>single Faston type connector... do you butt splice multiple wires
>then use single lead to Faston spade or bring multiple wires into
>the Faston female connector and crimp?
>
>Thanks for indulging me...
See http://tinyurl.com/l67uj8h
The practical limits for multiple wires into single
joints are driven by TOTAL cross section of copper
in the wire-grip must be within the terminal's
design limits. TOTAL cross section of insulation
in cannot exceed terminal design limits but ther
is a lot of leeway there. Some tools feature
user adjustments to the insulation-grip dies
to accommodate a range of volumes.
http://tinyurl.com/93yweyd
Finally, TOTAL current through the pathway's
highest resistance MIGHT be a factor for
temperature rise in the conductor . . . but
this is rarely a concern.
It matters not what kind of device is accepting
multiple wires, they're all constrained by the
same factors.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Contactor or master switch problem? |
At 04:10 PM 8/2/2015, you wrote:
>
>
>I have been having some starting and electrical issues which I think
>may involve the master switch or the battery contactor.
>
>My son and I were going out flying one day last week, had
>preflighted the plane, and after we pulled the plane from the hanger
>we switched on the master switch. The electronics came on briefly
>and then faded away. There was no power for the starter. I thought
>that was odd because the plane normally has charger attached while
>in the hanger. The Odyssey specific charger indicated the battery
>was charged. After a quick trip home to find a volt meter we tested
>the voltage which was 13+v. We had the charger on while we gone so
>the reading was skewed because of that. We pulled the plane out and
>the electronics and starter worked normally.\
The legacy "beer-barrel" contactors are
large area, low pressure switching devices.
Emacs!
http://tinyurl.com/5uh3b8
The highest risk for failure is corrosion
since these are not a sealed device and
the contacts are pure . . . or nearly pure
copper.
http://tinyurl.com/pw342c3
We've had discussions like this on the List
for decades . . . invariably, the conversations
morph into reliability discussions wherein
there is no distinction made between "system
reliability" (relative criticality and risks
imposed by failure) and "service life" (the
critter has simply used up all it's nine lives).
This style of contactor is the LEAST expensive
product suited to our task but as such, it can
be expected to have a shorter service life than
say a hermetically sealed, $high$ contactor.
As I've suggested for years, your decisions
need to be tempered with trade offs for
cost of ownership, impacts on system performance
and risks associated with failure to perform.
Obviously, for the time any of us expect to
own and operate a single-engine, light aircraft,
the cost-of-ownership question is a no-brainer.
The $24 contactor
http://tinyurl.com/nzern26
Is guaranteed to offer a lower cost per
flight-hour than these oft recommened
upgrades . . .
Tyco EV200 . . . which is a bit 'noisy'
http://tinyurl.com/qyexahd
http://tinyurl.com/p2uwagu
or a Gigavac GX-11 noise free . . .
http://tinyurl.com/qa9m9ne
http://tinyurl.com/pdknjb2
How about performance? Hmmm . . . they
have few differences to offer in terms of
weight savings or fuel consumption. They
either work . . . or not.
Okay, how about risk? There's a constellation
of reasons why a contactor may fail to
perform including wiring and control switches.
Prudent failure mode effects analysis dictates
that we ASSUME the contactor is going to fail,
irrespective of it's pedigree or price.
That thinking is what prompted the creation
of the E-bus many years ago and the two-layered,
three energy sourced architecture illustrated
in Figure Z-13/8
http://tinyurl.com/kgg8nva
Once you're homework is done, the loss of
ANY contactor is at worst an inconvenience
on the order of having a flat tire or having
lots of bird-poop to clean off the airplane
before you can go flying. Risks to airframe
and occupants are zero.
The key to comfortable flight in a complex
machine is a three-legged stool.
1. absolute reliability (wing spars, prop bolts,
well maintained batteries, etc)
2. failure tolerance (e-bus, two alternators)
3. understanding of how any failure critical
to comfortable termination of flight will
manifest and crafting a plan-b to deal with
it. See:
http://tinyurl.com/kqo7jx8
http://tinyurl.com/lrjlhhq
I owned an airport back about 1989. Had
occasion to replace two beer-barrel contactors
in the rental fleet in six months . . . both had
been in service for many years. They only
cost about $18 back then. It was less time consuming
to replace the contactors than to get the bird-poop
off an airplane that had been sitting a pole-barn
hangars for a few weeks.
Then there is the ultimate fall-back position:
Whether flying the J-3 or an A-36 with all the
goodies, this collection of stuff in my flight
bag has a 99.9 probability of getting me where
I want to go even if the whole panel is dark.
http://tinyurl.com/ok7sjzt
Just make sure the batteries are all FRESH.
I put new cells in at the beginning of every
long x-c flight . . . they're cheap.
Bob . . .
________________________________________________________________________________
| Subject: | Re: crimping question |
| From: | "blues750" <den_beaulieu(at)yahoo.com> |
Thanks so very much for the replies and links...I have a sense on how to proceed
now. This forum is an amazing asset to have available!!
Dave
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=445650#445650
________________________________________________________________________________
| From: | Sheldon Olesen <saolesen(at)sirentel.net> |
| Subject: | Re: Contactor or master switch problem? |
________________________________________________________________________________
| Subject: | Alternator B-lead circuit protection |
| From: | Dan Charrois <dan(at)syz.com> |
Hi everyone. I have a quick question with regards to protecting alternator B-leads.
A lot of people do so with ANL fuses, yet I know some aircraft (like my C150) do
so with a circuit breaker. Of course, a disadvantage of the ANL is that if
it blew while on a trip, after fixing whatever caused the problem, a person would
have to source a new fuse which could result in the aircraft being grounded
waiting for one to be shipped (are ANL fuses that easy to find? I'm in Canada,
so my usual sources of parts are Aircraft Spruce, which doesn't seem to carry
them, or "chain" stores like Canadian Tire, which doesn't seem to either.
Though it does appear that Digikey carries them, so at least there is a source
here without having to go through the customs hassles of ordering from somewhere
like B&C). The natural advantage of a circuit breaker, of course, is that
it can be reset without replacing things once the problem is fixed.
But I don't like much the idea of bringing B-leads into the area behind the panel,
or even into the cockpit for that matter, and am unsure as to whether a circuit
breaker would cause more problems than it prevents due to nuisance trips.
I know it's not "conventionally" done, but is there any problem with locating
a B-lead circuit breaker under the cowling in the engine compartment if a person
were to go the circuit breaker route? After all, if a B-lead were to have
a current spike tripping the fuse or breaker, the cowling would likely have
to be pulled anyway to see what's going on.
Or is it better to just go the fuse route? And if so, any advantages of ANL over
MIDI style?
Thanks for any advice!
Dan
---
Dan Charrois
President, Syzygy Research & Technology
Phone: 780-961-2213
________________________________________________________________________________
| Subject: | Re: Alternator B-lead circuit protection |
| From: | Jared Yates <email(at)jaredyates.com> |
My tool bag carries them! They are cheap enough and small enough to bring
a spare or two along, as to help mitigate that concern.
could result in the aircraft being grounded waiting for one to be shipped
> (are ANL fuses that easy to find? I'm in Canada, so my usual sources of
> parts are Aircraft Spruce, which doesn't seem to carry them, or "chain"
> stores like Canadian Tire, which doesn't seem to either.
________________________________________________________________________________
| From: | "Rene" <rene(at)felker.com> |
| Subject: | Alternator B-lead circuit protection |
I used a CB mounted in the engine compartment.
I had a 60 amp alternator and went to a 70 amp alternator. I did not change
the CB (you see what is coming). On a long trip back East (from Utah), I
had the CB trip twice in flight. I did not think I could draw 60
amps......but I can. So when I got back I upgraded to a 70 amp CB.....no
trips since.
I have two batteries on board and on reduced load can go an entire flight
without the alternator.
Rene'
801-721-6080
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Dan
Charrois
Sent: Friday, August 07, 2015 2:41 AM
Subject: AeroElectric-List: Alternator B-lead circuit protection
Hi everyone. I have a quick question with regards to protecting alternator
B-leads.
A lot of people do so with ANL fuses, yet I know some aircraft (like my
C150) do so with a circuit breaker. Of course, a disadvantage of the ANL is
that if it blew while on a trip, after fixing whatever caused the problem, a
person would have to source a new fuse which could result in the aircraft
being grounded waiting for one to be shipped (are ANL fuses that easy to
find? I'm in Canada, so my usual sources of parts are Aircraft Spruce,
which doesn't seem to carry them, or "chain" stores like Canadian Tire,
which doesn't seem to either. Though it does appear that Digikey carries
them, so at least there is a source here without having to go through the
customs hassles of ordering from somewhere like B&C). The natural advantage
of a circuit breaker, of course, is that it can be reset without replacing
things once the problem is fixed.
But I don't like much the idea of bringing B-leads into the area behind the
panel, or even into the cockpit for that matter, and am unsure as to whether
a circuit breaker would cause more problems than it prevents due to nuisance
trips. I know it's not "conventionally" done, but is there any problem with
locating a B-lead circuit breaker under the cowling in the engine
compartment if a person were to go the circuit breaker route? After all, if
a B-lead were to have a current spike tripping the fuse or breaker, the
cowling would likely have to be pulled anyway to see what's going on.
Or is it better to just go the fuse route? And if so, any advantages of ANL
over MIDI style?
Thanks for any advice!
Dan
---
Dan Charrois
President, Syzygy Research & Technology
Phone: 780-961-2213
________________________________________________________________________________
| Subject: | Re: Alternator B-lead circuit protection |
| From: | C&K <yellowduckduo(at)gmail.com> |
I've used a circuit breaker or maxi fuse with 40 amp alternators when
the battery is in the fuselage.
I would hesitate to use a C/B on the hot side of the FW since they are
likely more sensitive to the surrounding environment than fuses or an ANL.
Many automotive audio system vendors stock ANLs and they can always be
hotwired making them into essentially a fusable link.
Ken
On 07/08/2015 4:41 AM, Dan Charrois wrote:
>
> Hi everyone. I have a quick question with regards to protecting alternator B-leads.
>
> A lot of people do so with ANL fuses, yet I know some aircraft (like my C150)
do so with a circuit breaker. Of course, a disadvantage of the ANL is that if
it blew while on a trip, after fixing whatever caused the problem, a person
would have to source a new fuse which could result in the aircraft being grounded
waiting for one to be shipped (are ANL fuses that easy to find? I'm in Canada,
so my usual sources of parts are Aircraft Spruce, which doesn't seem to
carry them, or "chain" stores like Canadian Tire, which doesn't seem to either.
Though it does appear that Digikey carries them, so at least there is a source
here without having to go through the customs hassles of ordering from somewhere
like B&C). The natural advantage of a circuit breaker, of course, is that
it can be reset without replacing things once the problem is fixed.
>
> But I don't like much the idea of bringing B-leads into the area behind the panel,
or even into the cockpit for that matter, and am unsure as to whether a
circuit breaker would cause more problems than it prevents due to nuisance trips.
I know it's not "conventionally" done, but is there any problem with locating
a B-lead circuit breaker under the cowling in the engine compartment if a
person were to go the circuit breaker route? After all, if a B-lead were to
have a current spike tripping the fuse or breaker, the cowling would likely have
to be pulled anyway to see what's going on.
>
> Or is it better to just go the fuse route? And if so, any advantages of ANL
over MIDI style?
>
> Thanks for any advice!
>
> Dan
> ---
> Dan Charrois
> President, Syzygy Research & Technology
> Phone: 780-961-2213
>
>
________________________________________________________________________________
| Subject: | Re: Alternator B-lead circuit protection |
| From: | "user9253" <fransew(at)gmail.com> |
If the ANL fuse is sized right and the terminals are kept tight, it should never
blow unless there is a bigger problem. There is less to go wrong with a fuse
compared to a circuit breaker. I would use a fuse located near the contactors.
The protective device does not have to be resetable for once in a lifetime event.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=445669#445669
________________________________________________________________________________
| Subject: | Re: Alternator B-lead circuit protection |
| From: | Tomhanaway <tomhanaway1(at)gmail.com> |
I agree that if a properly sized ANL fuse blows, you've probably got bigger problems.
However, I just carry a spare one in my kit
Sent from my iPad
> On Aug 7, 2015, at 9:23 AM, user9253 wrote:
>
>
> If the ANL fuse is sized right and the terminals are kept tight, it should never
blow unless there is a bigger problem. There is less to go wrong with a fuse
compared to a circuit breaker. I would use a fuse located near the contactors.
> The protective device does not have to be resetable for once in a lifetime event.
> Joe
>
> --------
> Joe Gores
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=445669#445669
>
>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | ARGOLDMAN(at)aol.com |
| Subject: | Re: Alternator B-lead circuit protection |
Uh- Yep
When discharged the battery will immediately take all of the available
alternator current if you have underrated the breaker, it will break.
The breaker, in any circuit should be sized to protect the wire, not the
deliverer of electrons nor those things that use them.
Rich
In a message dated 8/7/2015 8:03:45 A.M. Central Daylight Time,
rene(at)felker.com writes:
--> AeroElectric-List message posted by: "Rene"
I used a CB mounted in the engine compartment.
I had a 60 amp alternator and went to a 70 amp alternator. I did not
change
the CB (you see what is coming). On a long trip back East (from Utah), I
had the CB trip twice in flight. I did not think I could draw 60
amps......but I can. So when I got back I upgraded to a 70 amp CB.....no
trips since.
I have two batteries on board and on reduced load can go an entire flight
without the alternator.
Rene'
801-721-6080
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Dan
Charrois
Sent: Friday, August 07, 2015 2:41 AM
Subject: AeroElectric-List: Alternator B-lead circuit protection
Hi everyone. I have a quick question with regards to protecting alternator
B-leads.
A lot of people do so with ANL fuses, yet I know some aircraft (like my
C150) do so with a circuit breaker. Of course, a disadvantage of the ANL
is
that if it blew while on a trip, after fixing whatever caused the problem,
a
person would have to source a new fuse which could result in the aircraft
being grounded waiting for one to be shipped (are ANL fuses that easy to
find? I'm in Canada, so my usual sources of parts are Aircraft Spruce,
which doesn't seem to carry them, or "chain" stores like Canadian Tire,
which doesn't seem to either. Though it does appear that Digikey carries
them, so at least there is a source here without having to go through the
customs hassles of ordering from somewhere like B&C). The natural
advantage
of a circuit breaker, of course, is that it can be reset without replacing
things once the problem is fixed.
But I don't like much the idea of bringing B-leads into the area behind the
panel, or even into the cockpit for that matter, and am unsure as to
whether
a circuit breaker would cause more problems than it prevents due to
nuisance
trips. I know it's not "conventionally" done, but is there any problem
with
locating a B-lead circuit breaker under the cowling in the engine
compartment if a person were to go the circuit breaker route? After all,
if
a B-lead were to have a current spike tripping the fuse or breaker, the
cowling would likely have to be pulled anyway to see what's going on.
Or is it better to just go the fuse route? And if so, any advantages of
ANL
over MIDI style?
Thanks for any advice!
Dan
---
Dan Charrois
President, Syzygy Research & Technology
Phone: 780-961-2213
________________________________________________________________________________
| Subject: | Re: Ryan TCAD 9900B |
| From: | "Greenbacks, UnLtd." <n4zq(at)verizon.net> |
I am searching for a wiring schematic for the Ryan TCAD 9900B.
Ryan was absorbed into Avidyne who has discontinued all support for the 9900B.
Ive got at least one or more faulty suppression diodes on the incoming grey code
lines
and a diagram would be helpful.
Thanks,
Angier Ames
N4ZQ
________________________________________________________________________________
| Subject: | Re: Ryan TCAD 9900B |
| From: | Ronald Cox <flyboyron(at)gmail.com> |
Angier,
A quick Google search turned this up, on 'Lectric Bob's site.
http://www.aeroelectric.com/Installation_Data/TAS6XX_Install%20Manual_Rev04
_Oct05.pdf
Not a full schematic, but shows some detail you may or may not already have
.
Ron Cox
Glasair Super II F/T
*"Everyone wants to live at the expense of the state. They forget that the
state lives at the expense of everyone." - French statesman Frederic
Bastiat (1801-1850)*
On Fri, Aug 7, 2015 at 6:41 PM, Greenbacks, UnLtd. wrote
:
> n4zq(at)verizon.net>
>
> I am searching for a wiring schematic for the Ryan TCAD 9900B.
> Ryan was absorbed into Avidyne who has discontinued all support for the
> 9900B.
> I=99ve got at least one or more faulty suppression diodes on the in
coming
> grey code lines
> and a diagram would be helpful.
>
> Thanks,
>
> Angier Ames
> N4ZQ
>
===========
===========
===========
===========
>
>
________________________________________________________________________________
| From: | "John Burnaby" <jonlaury(at)impulse.net> |
I'm powering a device with two 220vac sources, one main and one backup. What
kind of diode, or other one-way device can I use to prevent backfeeding a
source wire when it should be off?
This project is taking place in Thailand that uses a neutral, 220 hot and a
ground wire in household wiring.
Thanks,
John
________________________________________________________________________________
| From: | Bob McCallum <robert.mccallum2(at)sympatico.ca> |
John;
Not quite sure what type of "device" you may be referring to, but this
sounds similar (or identical) to a backup generator situation for a house
service. The device "normally" used to make the changeover from one source
to the other is a transfer switch. Functionally it is basically a single
pole double throw relay with the coil attached to the "main" or "primary"
source. The primary source is also attached to the NO contact while the load
is connected to the moveable or common contact, and the secondary source is
connected to the NC contact.
Functionally while the primary source is live the relay is "closed" and
supplies the load form the primary source. Should the primary source be
lost, the relay drops out and connects the load to the secondary or backup
source through the NC contact. With this method you do lose power for a few
milliseconds during the transfer. Something to keep in mind if that would be
critical to your use. When the primary source is restored the relay picks up
and transfers the load back to the primary source. All automatically.
Not sure if this is what you're trying to achieve, but from your original
request it sounds like it is.
Diodes won't do what you're trying to accomplish because they are DC devices
and won't function in an AC circuit. If however your load is able to utilize
DC power then you could rectify the AC through diodes (rectifiers) and then
the paralleling of the sources through the diodes would work to prevent the
back-feeding of one source into the other.
Because you refer to household power I suspect that the relay/transfer
switch method described above is what you're after.
Bob McC
_____
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of John
Burnaby
Sent: Friday, August 07, 2015 9:10 PM
Subject: AeroElectric-List: 220vac diode?
I'm powering a device with two 220vac sources, one main and one backup. What
kind of diode, or other one-way device can I use to prevent backfeeding a
source wire when it should be off?
This project is taking place in Thailand that uses a neutral, 220 hot and a
ground wire in household wiring.
Thanks,
John
________________________________________________________________________________
| Subject: | Re: 220vac diode? |
| From: | Ronald Cox <flyboyron(at)gmail.com> |
A diode won't work for AC, but something like a generator transfer switch
would probably work.
It's just a powered relay.
Ron Cox
On Aug 7, 2015 8:15 PM, "John Burnaby" wrote:
> I=99m powering a device with two 220vac sources, one main and one b
ackup.
> What kind of diode, or other one-way device can I use to prevent
> backfeeding a source wire when it should be off?
>
>
> This project is taking place in Thailand that uses a neutral, 220 hot and
> a ground wire in household wiring.
>
>
> Thanks,
>
> John
>
> *
>
===========
www.matronics.com/Navigator?AeroElectric-List>
===========
===========
om/contribution>
===========
>
> *
>
>
________________________________________________________________________________
| Subject: | Re: 220vac diode? |
| From: | Charlie England <ceengland7(at)gmail.com> |
On 8/7/2015 8:10 PM, John Burnaby wrote:
>
> Im powering a device with two 220vac sources, one main and one
> backup. What kind of diode, or other one-way device can I use to
> prevent backfeeding a source wire when it should be off?
>
> This project is taking place in Thailand that uses a neutral, 220 hot
> and a ground wire in household wiring.
>
> Thanks,
>
> John
>
>
If it's an AC device, diodes won't help.
For a single ended AC source/load, a double throw switch or relay would
work to select source A or source B.
A SPDT relay with the A pole NO and the B pole NC, with the 220 VAC coil
powered by A, would switch and power the load from A until A power is
lost. It would then 'drop out' to the NC (B) pole, powering the load from B.
Charlie
________________________________________________________________________________
| Subject: | Re: 220vac diode? |
| From: | Bill Putney <billp(at)wwpc.com> |
If it's two generators, the general procedure is to use synchronizing lights
(or some type of phasing meter). What you need to do is start the first gen
erator and close the output breaker (not closing it to the load but to the g
enerators bus of the transfer switch). Then start the second generator and a
djust the speed until the second generator is in phase and close its output
breaker. Both generators will stay in phase now on their own. You can paral
lel nearly as many generators as you like in this manor. Now you can flop th
e transfer switch to the generators. I did this every afternoon in Thailand d
uring the rainy season in the mid '60's.
If you are really talking about running a generator with the commercial main
s, DON'T DO IT!
That's called back feeding the grid and you can kill someone who thinks the l
ine is dead when in actuality you are feeding power to the commercial grid. T
his is illegal for good reason. There should always be a transfer switch bet
ween any generator power and the commercial mains that physically isolates t
wo with no possibility of one being tied to the other.
Bill
Sent from my iPad
> On Aug 7, 2015, at 18:58, Ronald Cox wrote:
>
> A diode won't work for AC, but something like a generator transfer switch w
ould probably work.
> It's just a powered relay.
>
> Ron Cox
>
>> On Aug 7, 2015 8:15 PM, "John Burnaby" wrote:
>> I=99m powering a device with two 220vac sources, one main and one b
ackup. What kind of diode, or other one-way device can I use to prevent back
feeding a source wire when it should be off?
>>
>>
>>
>> This project is taking place in Thailand that uses a neutral, 220 hot and
a ground wire in household wiring.
>>
>>
>>
>> Thanks,
>>
>> John
>>
>>
>>
>> ist" target="_blank">http://www.matronics.com/Navigator?AeroElectric-Li
st
>> tp://forums.matronics.com
>> _blank">http://www.matronics.com/contribution
>>
>
>
>
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=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>
________________________________________________________________________________
| Subject: | Re: 220vac diode? |
| From: | Ronald Cox <flyboyron(at)gmail.com> |
I'm pretty sure he knows that he shouldn't back feed the mains, and is
trying to correctly prevent the situation your bringing up.
I believe he's trying to switch safely between, not parallel, two sources.
Ron Cox
On Friday, August 7, 2015, Bill Putney wrote:
> If it's two generators, the general procedure is to use synchronizing
> lights (or some type of phasing meter). What you need to do is start the
> first generator and close the output breaker (not closing it to the load
> but to the generators bus of the transfer switch). Then start the second
> generator and adjust the speed until the second generator is in phase and
> close its output breaker. Both generators will stay in phase now on thei
r
> own. You can parallel nearly as many generators as you like in this manor
.
> Now you can flop the transfer switch to the generators. I did this every
> afternoon in Thailand during the rainy season in the mid '60's.
>
> If you are really talking about running a generator with the commercial
> mains, DON'T DO IT!
>
> That's called back feeding the grid and you can kill someone who thinks
> the line is dead when in actuality you are feeding power to the commercia
l
> grid. This is illegal for good reason. There should always be a transfer
> switch between any generator power and the commercial mains that physical
ly
> isolates two with no possibility of one being tied to the other.
>
> Bill
>
> Sent from my iPad
>
> On Aug 7, 2015, at 18:58, Ronald Cox > wrote:
>
> A diode won't work for AC, but something like a generator transfer switch
> would probably work.
> It's just a powered relay.
>
> Ron Cox
> On Aug 7, 2015 8:15 PM, "John Burnaby" > wrote:
>
>> I=99m powering a device with two 220vac sources, one main and one
backup.
>> What kind of diode, or other one-way device can I use to prevent
>> backfeeding a source wire when it should be off?
>>
>>
>>
>> This project is taking place in Thailand that uses a neutral, 220 hot an
d
>> a ground wire in household wiring.
>>
>>
>>
>> Thanks,
>>
>> John
>>
>> *
>>
>> ist" target="_blank">http://www.matronics.com/Navigator?AeroElectric-L
ist <http://www.matronics.com/Navigator?AeroElectric-List>
>> tp://forums.matronics.com <http://forums.matronics.com>
>> _blank">http://www.matronics.com/contribution
>>
>> *
>>
>> *
>
> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
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> lectric-List"">http://www.matronics.com/Navigator?AeroElectric-List
> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
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=3D
> //forums.matronics.com <http://forums.matronics.com>
> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
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> ot;">http://www.matronics.com/contribution
> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D
>
> *
>
> *
>
===========
www.matronics.com/Navigator?AeroElectric-List>
===========
===========
om/contribution>
===========
>
> *
>
>
--
*"Everyone wants to live at the expense of the state. They forget that the
state lives at the expense of everyone." - French statesman Frederic
Bastiat (1801-1850)*
________________________________________________________________________________
| Subject: | 220 VAC Diode Functionality |
| From: | Paul Millner <millner(at)me.com> |
On 8/7/2015 7:53 PM, Bill Putney wrote:
> If you are really talking about running a generator with the
> commercial mains, DON'T DO IT!
In general, Bill is of course correct, as he generally is. However,
there is a safe way to do this... with a very robust reverse current
relay that prevents a watt from ever exiting your on-premises system
toward the mains.
There are certification requirements, too, from the utility, which one
ignores at one's own risk of course. But it can be done safely, and even
legally... but it's not super inexpensive.
Easier is an isolation relay that allows EITHER mains power or
self-generation. But this is not a bumpless transfer (power fails and
then is restored...)
Paul
________________________________________________________________________________
| From: | "Bill Bradburry" <bbradburry(at)verizon.net> |
| Subject: | Duplicate Messages |
Just to pass this on.
I had done an upgrade to my Microsoft Office and somehow this upgrade made a
duplicate of my rule to move aeroelectric messages to a folder. I
discovered this rule duplication, removed it and now everything is fine.
Bill
________________________________________________________________________________
| From: | Ryan Brown <ribrdb(at)gmail.com> |
| Subject: | electrical system planning |
I'm working on figuring out the system architecture for my plane.
It's an rv9 with all glass panel and an O320 with electrically dependent
fuel injection (EFII).
The mission is typically cross countries including some night flight and
IFR, though it would typically be going through a layer of clouds to VFR on
top.
Here's what I've got for my load analysis:
Fuel pump: 5 A
Ignition/Fuel injectors: 5 A
So already the SD-8 is out.
For minimal comfortable flight I'd add:
Primary EFIS: 3.1 A
Transponder: 0.4 A
Total: 13.5
Add in the rest of the avionics for normal flight:
gtn650 nav/com 2.2A
intercom 0.1A
adsb in 0.2A
Backup efis 3.1 A
(total 19.1)
Then 10A for pitot heat, and lights:
strobes 2.5A
position lights 1.2A
landing lights 1.8A
I'm not including the motors for trim, flaps, or auto pilot here. Also I'm
assuming the comms aren't transmitting. Are these the right assumptions for
the load analysis?
It seems like Z-12 is the best option for me here. I have to use a 20-30
amp backup alternator to keep the engine running. That gives me enough
juice to keep nearly everything running, so Z-13/8 doesn't seem useful.
Z-12 shows an SD-20 backup alternator with it's own switch. I'm assuming
normal operation is with Master on ALT and Aux Alternator on OFF. When you
get low volts warning, you switch Master to BAT and Aux Alternator to ON.
Is there some advantage to wiring it this way instead of having the standby
alternator take over automatically when the voltage drops? Or is that
actually what Z-12 is showing, and you'd normally fly with Aux Alternator
ON?
Also I see that Z-12 shows Battery, Master, and Endurance busses. What's
the point? It seems I'd put the minimum equipment on the battery bus, and
everything else could be on master. It's probably just as many switch flips
to shed load on the master bus as it is to reconfigure the endurance bus.
I guess the endurance bus also give you an extra route to the battery if
the master switch or battery contactor fails, but why not just put the
important devices on the battery bus?
________________________________________________________________________________
| Subject: | Re: Newbie with PM alternator feed question |
| From: | "blues750" <den_beaulieu(at)yahoo.com> |
Follow on questions...
Having trouble reconciling the tinyurl link wiring that you posted versus the wiring
diagram for the B&C OVPM package (505-500) I planned on using. Appear to
be only one relay to control on/off of the alternator via the capacitor and
R/R versus your sketch with two relays for two of three phases. Also, why the
need to fuse each phase of the alternator prior to the R/R as depicted in the
B&C diagram? I feel like I'm missing parts of the big picture [Embarassed]
Thanks for indulging my queries!
Dave
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=445797#445797
Attachments:
http://forums.matronics.com//files/505_500_rev_j_191.pdf
________________________________________________________________________________
| Subject: | Re: Newbie with PM alternator feed question |
| From: | "user9253" <fransew(at)gmail.com> |
Bob's drawing uses two relays because they switch the AC from the dynamo. B&C
uses only one relay because it switches the rectified DC. Either way will work.
It is not a good idea to put fuses or circuit breakers in series. The B&C drawing
has 3 in series: the 40 amp battery fuse, the 30 amp breaker, and the 20
amp fuses. A short circuit that trips the 30 amp breaker is likely to also blow
the 40 amp fuse. Not only would dynamo power be lost, but also the battery.
The 20 amp fuses are not necessary because dynamo current is self limiting.
What really needs protection are the dynamo wires and aircraft battery. The 30
amp breaker satisfies that requirement in the B&C drawing, as does the 40 amp
fuse in Bob's drawing.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=445800#445800
________________________________________________________________________________
| Subject: | Re: Newbie with PM alternator feed question |
| From: | "blues750" <den_beaulieu(at)yahoo.com> |
user9253 wrote:
> Bob's drawing uses two relays because they switch the AC from the dynamo. B&C
uses only one relay because it switches the rectified DC. Either way will work.
> It is not a good idea to put fuses or circuit breakers in series. The B&C
drawing has 3 in series: the 40 amp battery fuse, the 30 amp breaker, and the
20 amp fuses. A short circuit that trips the 30 amp breaker is likely to also
blow the 40 amp fuse. Not only would dynamo power be lost, but also the battery.
> The 20 amp fuses are not necessary because dynamo current is self limiting.
What really needs protection are the dynamo wires and aircraft battery. The
30 amp breaker satisfies that requirement in the B&C drawing, as does the 40
amp fuse in Bob's drawing.
> Joe
Thanks Joe...
(1) Is dynamo current "self limiting" a characteristic of all 3 phase PM type alternators?
(dynamos?) Would gladly eliminate those three 20 amp c/b's if not
required!
(2) Was planning on a 40A ANL type fuse for the 10 ga wire from the relay to the
primary bus.
(3) Was not planning on fuse/circuit protection from the battery to the primary
bus.
Appreciate all thoughts and input. I hope to post my schematic as an attachment
as soon as I have an idea of what I'm doing [Shocked]
Dave
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=445801#445801
________________________________________________________________________________
| Subject: | Re: Newbie with PM alternator feed question |
| From: | "user9253" <fransew(at)gmail.com> |
All alternators and dynamos are self current limiting. They can only do so much
work. If loaded to much more than their rated capacity, the voltage will start
to drop. Another concern is heat. If fully loaded, an alternator could get
too hot if not adequately ventilated.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=445802#445802
________________________________________________________________________________
| From: | Justin Jones <jmjones2000(at)mindspring.com> |
| Subject: | Re: electrical system planning |
Ryan,
I have a very similar setup using the efii system and used the Z13/8 diagram
(modified for the efii components). I am very happy with it and would be gl
ad to share my diagram with you if you'd like. I used a standard aircraft pr
imary alternator and used the B&C 410H on the vacuum pump as my backup.
Keep in mind that it is unlikely that all of your electrical components will
run continuously all the time. Also, you can manually load shed during oper
ations that require the use of your backup alternator if needed. The 410H is
a hefty alternator and will put plenty of amps to keep up with your system.
A low voltage warning system is absolutely critical!
Justin
> On Aug 10, 2015, at 17:55, Ryan Brown wrote:
>
> I'm working on figuring out the system architecture for my plane.
> It's an rv9 with all glass panel and an O320 with electrically dependent f
uel injection (EFII).
> The mission is typically cross countries including some night flight and I
FR, though it would typically be going through a layer of clouds to VFR on t
op.
>
> Here's what I've got for my load analysis:
> Fuel pump: 5 A
> Ignition/Fuel injectors: 5 A
>
> So already the SD-8 is out.
> For minimal comfortable flight I'd add:
> Primary EFIS: 3.1 A
> Transponder: 0.4 A
>
> Total: 13.5
>
> Add in the rest of the avionics for normal flight:
> gtn650 nav/com 2.2A
> intercom 0.1A
> adsb in 0.2A
> Backup efis 3.1 A
> (total 19.1)
>
> Then 10A for pitot heat, and lights:
> strobes 2.5A
> position lights 1.2A
> landing lights 1.8A
>
> I'm not including the motors for trim, flaps, or auto pilot here. Also I'm
assuming the comms aren't transmitting. Are these the right assumptions for
the load analysis?
>
> It seems like Z-12 is the best option for me here. I have to use a 20-30 a
mp backup alternator to keep the engine running. That gives me enough juice t
o keep nearly everything running, so Z-13/8 doesn't seem useful.
>
> Z-12 shows an SD-20 backup alternator with it's own switch. I'm assuming n
ormal operation is with Master on ALT and Aux Alternator on OFF. When you ge
t low volts warning, you switch Master to BAT and Aux Alternator to ON.
>
> Is there some advantage to wiring it this way instead of having the standb
y alternator take over automatically when the voltage drops? Or is that actu
ally what Z-12 is showing, and you'd normally fly with Aux Alternator ON?
>
> Also I see that Z-12 shows Battery, Master, and Endurance busses. What's t
he point? It seems I'd put the minimum equipment on the battery bus, and eve
rything else could be on master. It's probably just as many switch flips to s
hed load on the master bus as it is to reconfigure the endurance bus.
> I guess the endurance bus also give you an extra route to the battery if t
he master switch or battery contactor fails, but why not just put the import
ant devices on the battery bus?
>
>
>
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=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>
________________________________________________________________________________
| Subject: | Bending copper (bus) bar |
| From: | "JOHN TIPTON" <jmtipton(at)btopenworld.com> |
Hi Guys
I'll be using the almost (standard) method for connecting the battery contactor
to starter contactor on a Rv9a with copper bar, also using a lighter gauge copper
bar from the live feed to the ammeter shunt, this requires a bend in the
copper bar: should copper bar be bent cold or with heat applied
Regards
John
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=446020#446020
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Bending copper (bus) bar |
At 09:10 AM 8/16/2015, you wrote:
>
>
>Hi Guys
>
>I'll be using the almost (standard) method for connecting the
>battery contactor to starter contactor on a Rv9a with copper bar,
>also using a lighter gauge copper bar from the live feed to the
>ammeter shunt, this requires a bend in the copper bar: should copper
>bar be bent cold or with heat applied
What are the dimensions of the "bar"?
I usually make such parts from 0.06 to 0.09
material and just bend it cold over a not-sharp
radius . . . ~ 1/8"
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Newbie with PM alternator feed question |
>
>(1) Is dynamo current "self limiting" a characteristic of all 3
>phase PM type alternators? (dynamos?) Would gladly eliminate those
>three 20 amp c/b's if not required!
the PM alternators will self-destruct if presented
with a hard short on their windings generated by
failure of the rectifier=regulator. Use in-line
fuses. One for the single phase machines, two for
the three phase machines. These need no be crew-
accessible.
>(2) Was planning on a 40A ANL type fuse for the 10 ga wire from the
>relay to the primary bus.
What is the rated output of your altenrator?
An inline maxi-fuse of next-step higher value
would be fine and a lot less bulky.
>(3) Was not planning on fuse/circuit protection from the battery to
>the primary bus.
Most people do not . . . including hundreds of
thousands of TC aircraft.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Newbie with PM alternator feed question |
At 05:59 PM 8/10/2015, you wrote:
>
>Follow on questions...
>
>Having trouble reconciling the tinyurl link wiring that you posted
>versus the wiring diagram for the B&C OVPM package (505-500) I
>planned on using. Appear to be only one relay to control on/off of
>the alternator via the capacitor and R/R versus your sketch with two
>relays for two of three phases. Also, why the need to fuse each
>phase of the alternator prior to the R/R as depicted in the B&C
>diagram? I feel like I'm missing parts of the big picture [Embarassed]
OV protection is a separate issue from
the protection of wires. The single
pole relay in series with the DC output
of a R/R ALWAYS works to protect the
ship's systems. However, that relay ALSO
serves the legacy purpose of offering any
time, any conditions, ON-OFF control
of the engine driven power source from
the pilot's position.
If one embraces the goal of generating
a MAX COLD power condition for ALT OFF
then one is encouraged to open the power
source as far upstream as practical.
Hence, relay(s) in the AC winding leads.
You need to break TWO leads of a 3-phase
machine to bring it to heel. A two-pole
relay would work . . . but inexpensive,
automotive relays in 2-poles at that current
are more rare and expensive that using
two, robust single-pole devices to do
the job.
Two relays was a cost-of-ownership . . .
not a functional design decision.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Bending copper (bus) bar |
| From: | Stuart Hutchison <stuart(at)stuarthutchison.com.au> |
If you bend thin material once with a blunt radius, say 1/8, then cold is fine.
If you do more bending it will work harden and may crack under stress and vibration.
In difference to steel, annealing copper is achieved by heating to cherry
hot and quenching in water or oil.
> On 16 Aug 2015, at 18:10, JOHN TIPTON wrote:
>
>
> Hi Guys
>
> I'll be using the almost (standard) method for connecting the battery contactor
to starter contactor on a Rv9a with copper bar, also using a lighter gauge
copper bar from the live feed to the ammeter shunt, this requires a bend in the
copper bar: should copper bar be bent cold or with heat applied
>
> Regards
>
> John
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=446020#446020
>
>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| Subject: | Re: Bending copper (bus) bar |
| From: | Stuart Hutchison <stuart(at)stuarthutchison.com.au> |
If you bend thin material once with a blunt radius, say 1/8, then cold is fine.
If you do more bending it will work harden and may crack under stress and vibration.
In difference to steel, annealing copper is achieved by heating to cherry
hot and quenching in water or oil.
Cheers, Stu
> On 16 Aug 2015, at 18:10, JOHN TIPTON wrote:
>
>
> Hi Guys
>
> I'll be using the almost (standard) method for connecting the battery contactor
to starter contactor on a Rv9a with copper bar, also using a lighter gauge
copper bar from the live feed to the ammeter shunt, this requires a bend in the
copper bar: should copper bar be bent cold or with heat applied
>
> Regards
>
> John
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=446020#446020
>
>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: electrical system planning |
At 04:55 PM 8/10/2015, you wrote:
>I'm working on figuring out the system architecture for my plane.
THE VERY FIRST TASK in crafting the elegant solution
for architecture in a projet like yours is to download
this form:
http://tinyurl.com/7jqypwj
and develop a load-picture for the various
phases of flight.
Do one page for each bus. Electrically dependent
engine stuff on battery bus, plan-b loads on
and E-bus, everything else on the main bus.
THEN . . . set design goals for endurance under
an alternator out condition and either
size a WELL MAINTAINED battery to meet that
goal or craft some combination of battery and
second alternator to meet the goal.
Then let's talk about the architecture that's
most friendly to meeting your design goals.
Are those 5A figures REAL, MEASURED current
values? Breaker sizes from a wiring diagram
are never indicative of ENERGY required to
operate the system.
This is a study the economics of energy
management to achieve operational goals
that determine whether a failure is
an emergency or a ho-hum event.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Newbie with PM alternator feed question |
| From: | "user9253" <fransew(at)gmail.com> |
> the PM alternators will self-destruct if presented
> with a hard short on their windings generated by
> failure of the rectifier=regulator.
Bob,
What self destructs, the winding or the magnets or both? I am guessing the magnets
only but do not know. Was I wrong to state that all alternators are self
current limiting?
Thanks, Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=446059#446059
________________________________________________________________________________
| From: | Ryan Brown <ribrdb(at)gmail.com> |
| Subject: | Re: electrical system planning |
Thanks Bob.
The 5A figures are the estimates I got from the manufacturer for average
consumption. I haven't measured it myself. The breaker size is 10A.
I filled out a spreadsheet with the load analysis for each stage here:
https://goo.gl/0FPFIQ
I'm not entirely sure I have everything assigned to the right bus.
I estimate the plane will hold 5.5 hours of fuel, so I guess that's what my
endurance goal should be.
That's over 70 amp hours just to keep the engine running, so it seems a
backup alternator is a better bet than batteries.
One question I have is if my endurance goal should be 5.5 hours with pitot
heat on. I don't plan on tons of ifr flight, and I kind of doubt my brain
could handle 5 hours of instrument flight. So it seems like lower endurance
for ifr cruise could be acceptable.
If I do want to keep the heater on with the backup alternator I need a
little more than 20 amps. I'm a little confused looking at the alternators
here. The SD-20 is described as a 20/30A alternator. What does that mean. I
saw some mention that the vacuum pad on a continental spins faster, does
that mean it's 30A on a continental and 20A on a lycoming?
The plane power FS14 is just listed as 30A, so I assume it can actually put
out 30A on a lycoming.
On Sun, Aug 16, 2015 at 9:50 AM Robert L. Nuckolls, III <
nuckolls.bob(at)aeroelectric.com> wrote:
> At 04:55 PM 8/10/2015, you wrote:
>
> I'm working on figuring out the system architecture for my plane.
>
>
> THE VERY FIRST TASK in crafting the elegant solution
> for architecture in a projet like yours is to download
> this form:
>
> http://tinyurl.com/7jqypwj
>
> and develop a load-picture for the various
> phases of flight.
>
> Do one page for each bus. Electrically dependent
> engine stuff on battery bus, plan-b loads on
> and E-bus, everything else on the main bus.
>
> THEN . . . set design goals for endurance under
> an alternator out condition and either
> size a WELL MAINTAINED battery to meet that
> goal or craft some combination of battery and
> second alternator to meet the goal.
>
> Then let's talk about the architecture that's
> most friendly to meeting your design goals.
>
> Are those 5A figures REAL, MEASURED current
> values? Breaker sizes from a wiring diagram
> are never indicative of ENERGY required to
> operate the system.
>
> This is a study the economics of energy
> management to achieve operational goals
> that determine whether a failure is
> an emergency or a ho-hum event.
>
> Bob . . .
>
> *
>
>
> *
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Newbie with PM alternator feed question |
At 10:04 PM 8/16/2015, you wrote:
>
>
> > the PM alternators will self-destruct if presented
> > with a hard short on their windings generated by
> > failure of the rectifier=regulator.
>
>Bob,
>What self destructs, the winding or the magnets or both? I am
>guessing the magnets only but do not know. Was I wrong to state
>that all alternators are self current limiting?
This windings are at-risk. Browse through
the various forums that feature engines with
built in PM alternators, Jabiru in particular
and you'll read builder stories of woe over
smelly wires that don't look so good either . . .
http://tinyurl.com/obudcwn
The term 'current limited' is not necessarily
applicable throughout the full spectrum
of load conditions. I have a bench supply that
is electronically current limited and will
not self destruct for any load condition down
to a dead short. But that kind of current limiting
is seldom found in the wild.
With respect to generators vs. alternators, the
physics that drive performance and stresses to
least robust components have prompted us to
assert that 'inherent current limiting' in
the physics of alternators makes the I-limit
control relay common to generator controllers
unnecessary . . . but you can burn windings in
EITHER machine when you venture outside the
condition of what one might call 'mild overloading'.
I was appalled at my recent discovery of a
kit or recommendation by the Jabiru factory that
bi-filar (two wires in parallel) windings of
their 3300 alternator be rewired in series to
'produce more output at lower rpm'. A very sad
demonstration of . . . well . . . 'nuf said . . .
http://tinyurl.com/obudcwn
Yes, available VOLTAGE goes up by 2x for any
given rpm . . . but available current drops by
half . . . and loading on individual wires
doubles. Given the strong positive temperature
coefficient of resistance for copper, risk
for destructive overheat goes up by more than
half because the wires dissipate MORE energy
as their operating temperature RISES. It's
a positive feedback effect that hastens the
march to self-destruction.
I show fuses in these leads to do what fuses
do best . . . protect wires from the hard-falut
condition with would arise from shorted semi-
conductors in the rectifier/regulator. But if
those same wires are not properly sized and
cooled to meet design goals they can
probably be 'smoked' at current levels far
below those expected in the hard-fault condition.
In the mean time, the magnets are happily spinning
in total ignorance of the havoc they can sow
upon their copper brothers just a few millimeters
away.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: electrical system planning |
A t 11:29 PM 8/16/2015, you wrote:
>Thanks Bob.
>The 5A figures are the estimates I got from the
>manufacturer for average consumption. I haven't
>measured it myself. The breaker size is 10A.
When you get this airplane flying, I'd REALLY
like to get some data off it that describes
ENERGY measurements . . . but 5A probably
works for now.
>I filled out a spreadsheet with the load
>analysis for each stage here:=C2
https://goo.gl/0FPFIQ
>I'm not entirely sure I have everything assigned to the right bus.
>
>I estimate the plane will hold 5.5 hours of
>fuel, so I guess that's what my endurance goal should be.
No guessing here . . . that's a number YOU pick
based on how you intend to use the airplane. If
you plan on frequent departures from airports
often clagged in and surrounded by mountains, then
the idea of endurance to carry you to demonstrably
lower-risk haven is a part of solid reasoning. But
if that comfortable termination of flight is
never more than say 2 hours away, then designing
and maintained that level of endurance is not
unreasonable.
The main thing is to know what the endurance numbers
are, preventative maintenance to insure those
numbers and risks go down markedly.
>That's over 70 amp hours just to keep the engine
>running, so it seems a backup alternator is a better bet than batteries.
Bingo!
A second engine driven power source is ALWAYS the
best cost-weight-performance alternative to ANY
chemical system.
>One question I have is if my endurance goal
>should be 5.5 hours with pitot heat on. I don't
>plan on tons of ifr flight, and I kind of doubt
>my brain could handle 5 hours of instrument
>flight. So it seems like lower endurance for ifr cruise could be
acceptable.
Probably so . . .
>
>If I do want to keep the heater on with the
>backup alternator I need a little more than 20
>amps. I'm a little confused looking at the
>alternators here. The SD-20 is described as a
>20/30A alternator. What does that mean. I saw
>some mention that the vacuum pad on a
>continental spins faster, does that mean it's
>30A on a continental and 20A on a lycoming?
I am not sure of the details . . . I've not had occasion
to touch the phycics of that product in about 20
years but I do understand that under presently
demonstrated conditions, its output can be that
high.
>The plane power FS14 is just listed as 30A, so I
>assume it can actually put out 30A on a lycoming.
Pitot heat was never a really good idea on light
aircraft . . . yeah, it MAY have saved the bacon
for a hand-full of pilots in years gone by but
far more airplanes belabored with ice have gone down
in spite of knowing exactly what their airspeed
was before they hit the rocks.
Having 'little chippers' to deal with some forms
of ice (heated windshield patches, boots, pitot
heat) have offered too many pilots a false sense
of capability to deal with mother nature's vagaries.
Modern weather observation and prediction systems
are so capable that go-no go decision to launch
is far wiser than any notion of being able to 'deal
with a little ice' . . . same thing with those
little yellow, orange and red areas on the radar . . .
good reasons to just stay on the ground or take
another route.
My preference for conducting the FMEA says
keeping the tube warm is at the bottom of the
list with respect to other appliances on board.
Just for grins, noodle through the plan-c for dealing
with loss of airspeed indication. What do you KNOW
about handling qualities, changes of trim and
power that speak to impending stall? If that
airspeed value becomes suspect for what you believe
is high-probability of ice, I'll suggest that
plans to seek warmer environs far outweighs
any value of knowing exactly what your airspeed
unless you think that climbing is the path to
salvation . . . which is very seldom the case.
IAS as a warning for impending stall is
based on a CLEAN wing. I got a really big
lesson in fouled aerodynamics when a landing
in Hutchinson KS ended with the airplane plopping
down hard in the flare while yours truly was
patting himself on the butt for having kept
the needles centered for over fifteen minutes
in the clouds, outbound through procedure turns
and then all the way back to the threshold.
My instructor was grinning ear to ear and said,
"Okay Nuckolls . . . while you were glued to the
glass, your wings were taking on new shapes with
unpredictable performance. None of that C-172-
full-stall-flare stuff in instrument conditions.
Fly it like a Grumman . . . carrier landings are
called for unless you are CERTAIN that your wings
are golden."
You need to make up your own mind but it seems
to me that a Z-12 system with a 15 a.h. SVLA
battery would provide a comfortable reduction
in risks . . . especially if you consider pitot
heat to be more cosmetic than practical.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Anything 'unique' about incorporating EarthX? |
>When using a LR3C-14 regulator and SB1B-14 regulator in a Z-12 with
>an EarthX battery, what is the closest we can have the two
>regulators set at without the two fighting for the load?
>
>EarthX would like their battery charged between 13.8 and 14.6. I
>was thinking that the customer could set the LR3C at 14.6 and the
>SB1B at 13.8. Would this work?
Not necessary. A STANDBY system is not intended to charge
batteries . . . only support the bus such that what ever
energy is in the battery is not taxed. The open circuit
terminal voltage for an EarthX is 13.3v give or take.
So set the SB1 for 13.5, the LR3 for 14.5 and all will
be right with the universe.
Bob . . .
________________________________________________________________________________
| Subject: | Re: electrical system planning |
| From: | Ryan Brown <ribrdb(at)gmail.com> |
Thanks. I agree pitot heat does seem optional for the type of flying I plan
on doing. I'd much rather just stay away from ice than try to fly through
it.
So Z12 is what I was leaning towards. But I wonder what's the purpose of
having the endurance bus if I have a 20 amp standby alternator? In
alternator out conditions I can just keep the master on, and run just about
anything I want. Why not just have an alternate feed switch for the master
bus in case the master switch or battery contactor fails?
On Aug 17, 2015 7:41 AM, "Robert L. Nuckolls, III" <
nuckolls.bob(at)aeroelectric.com> wrote:
> A t 11:29 PM 8/16/2015, you wrote:
>
> Thanks Bob.
> The 5A figures are the estimates I got from the manufacturer for average
> consumption. I haven't measured it myself. The breaker size is 10A.
>
>
> When you get this airplane flying, I'd REALLY
> like to get some data off it that describes
> ENERGY measurements . . . but 5A probably
> works for now.
>
>
> I filled out a spreadsheet with the load analysis for each stage here:=C3
=82
> https://goo.gl/0FPFIQ
> I'm not entirely sure I have everything assigned to the right bus.
>
> I estimate the plane will hold 5.5 hours of fuel, so I guess that's what
> my endurance goal should be.
>
>
> No guessing here . . . that's a number YOU pick
> based on how you intend to use the airplane. If
> you plan on frequent departures from airports
> often clagged in and surrounded by mountains, then
> the idea of endurance to carry you to demonstrably
> lower-risk haven is a part of solid reasoning. But
> if that comfortable termination of flight is
> never more than say 2 hours away, then designing
> and maintained that level of endurance is not
> unreasonable.
>
> The main thing is to know what the endurance numbers
> are, preventative maintenance to insure those
> numbers and risks go down markedly.
>
> That's over 70 amp hours just to keep the engine running, so it seems a
> backup alternator is a better bet than batteries.
>
>
> Bingo!
>
> A second engine driven power source is ALWAYS the
> best cost-weight-performance alternative to ANY
> chemical system.
>
>
> One question I have is if my endurance goal should be 5.5 hours with pito
t
> heat on. I don't plan on tons of ifr flight, and I kind of doubt my brain
> could handle 5 hours of instrument flight. So it seems like lower enduran
ce
> for ifr cruise could be acceptable.
>
>
> Probably so . . .
>
>
> If I do want to keep the heater on with the backup alternator I need a
> little more than 20 amps. I'm a little confused looking at the alternator
s
> here. The SD-20 is described as a 20/30A alternator. What does that mean.
I
> saw some mention that the vacuum pad on a continental spins faster, does
> that mean it's 30A on a continental and 20A on a lycoming?
>
>
> I am not sure of the details . . . I've not had occasion
> to touch the phycics of that product in about 20
> years but I do understand that under presently
> demonstrated conditions, its output can be that
> high.
>
> The plane power FS14 is just listed as 30A, so I assume it can actually
> put out 30A on a lycoming.
>
>
> Pitot heat was never a really good idea on light
> aircraft . . . yeah, it MAY have saved the bacon
> for a hand-full of pilots in years gone by but
> far more airplanes belabored with ice have gone down
> in spite of knowing exactly what their airspeed
> was before they hit the rocks.
>
> Having 'little chippers' to deal with some forms
> of ice (heated windshield patches, boots, pitot
> heat) have offered too many pilots a false sense
> of capability to deal with mother nature's vagaries.
>
> Modern weather observation and prediction systems
> are so capable that go-no go decision to launch
> is far wiser than any notion of being able to 'deal
> with a little ice' . . . same thing with those
> little yellow, orange and red areas on the radar . . .
> good reasons to just stay on the ground or take
> another route.
>
> My preference for conducting the FMEA says
> keeping the tube warm is at the bottom of the
> list with respect to other appliances on board.
> Just for grins, noodle through the plan-c for dealing
> with loss of airspeed indication. What do you KNOW
> about handling qualities, changes of trim and
> power that speak to impending stall? If that
> airspeed value becomes suspect for what you believe
> is high-probability of ice, I'll suggest that
> plans to seek warmer environs far outweighs
> any value of knowing exactly what your airspeed
> unless you think that climbing is the path to
> salvation . . . which is very seldom the case.
>
> IAS as a warning for impending stall is
> based on a CLEAN wing. I got a really big
> lesson in fouled aerodynamics when a landing
> in Hutchinson KS ended with the airplane plopping
> down hard in the flare while yours truly was
> patting himself on the butt for having kept
> the needles centered for over fifteen minutes
> in the clouds, outbound through procedure turns
> and then all the way back to the threshold.
>
> My instructor was grinning ear to ear and said,
> "Okay Nuckolls . . . while you were glued to the
> glass, your wings were taking on new shapes with
> unpredictable performance. None of that C-172-
> full-stall-flare stuff in instrument conditions.
> Fly it like a Grumman . . . carrier landings are
> called for unless you are CERTAIN that your wings
> are golden."
>
> You need to make up your own mind but it seems
> to me that a Z-12 system with a 15 a.h. SVLA
> battery would provide a comfortable reduction
> in risks . . . especially if you consider pitot
> heat to be more cosmetic than practical.
>
> Bob . . .
>
> *
>
===========
www.matronics.com/Navigator?AeroElectric-List>
===========
===========
om/contribution>
===========
>
> *
>
>
________________________________________________________________________________
| Subject: | Re: electrical system planning |
| From: | "user9253" <fransew(at)gmail.com> |
> Why not just have an alternate feed switch for the master bus in case the master
switch or battery contactor fails?
Use a DPDT switch wired so that when the alternate feed in turned on, the starter
circuit will be disabled. Not having that feature will risk burning up the
alternate feed switch while starting the engine with the master contactor inadvertently
shut off.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=446116#446116
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: electrical system planning |
At 11:12 AM 8/18/2015, you wrote:
>Thanks. I agree pitot heat does seem optional for the type of flying
>I plan on doing. I'd much rather just stay away from ice than try to
>fly through it.
>
>So Z12 is what I was leaning towards. But I wonder what's the
>purpose of having the endurance bus if I have a 20 amp standby
>alternator? In alternator out conditions I can just keep the master
>on, and run just about anything I want. Why not just have an
>alternate feed switch for the master bus in case the master switch
>or battery contactor fails?
there are dozens of variations on a theme . . .
Z-12 is Z-11 with the addition of a standby
alternator that auto-switches when fitted with
the SB-1 regulator that does not give up
any of the risk management features of Z-11.
You may choose to have avionics busses and
associated master switches. Extra batteries,
or any number of variations. If you don't see
a need for the e-bus and want to leave it off,
by all means. If you have an alternative for
dealing with a contactor failure, that's okay
too.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | The legacy "6-inch rule" |
At 04:51 PM 8/18/2015, you wrote:
>Bob,
>
>On drawing 001-510, the Alternator ANL fuse and 2amp fuse are noted
>as to be located 6" or less from the starter contactor. Why is
>this? Are there any concerns to extending that length? If the
>length can be extended, by how much could one extend it?
There is a legacy rule-of-thumb in TC aircraft
that says it's okay to 'sacrifice' as much as
6" of wire in an unprotected hard-fault. A number
of devices got hooked to Cessna busses back in the
60-70 time frame with no specific protection for
wires because they were close. i.e. the at-risk
wire was 6" or less.
In honor of that rule-of-thumb, we try to put
circuit protection as close as practical to the
source of energy that's going to burn the wire.
Given that 99.99+ percent of all circuit protection
in airplanes goes the lifetime of the vehicle without
having been called upon to protect wires, then
the 'risk' for going beyond the 6" rule is
vanishingly small . . .
Also, suggest you look into stocking the mini-anl style
limiters. MUCH less expensive, much more compact.
Bob . . .
________________________________________________________________________________
| From: | Justin Jones <jmjones2000(at)mindspring.com> |
| Subject: | Re: electrical system planning |
All of Bob's Z diagrams are phenomenal and do the job well. When deciding on
the diagram to use, keep in mind the more batteries and more complexity, th
e more weight you will add to your small aircraft.
I'm sure anything you choose will suit you well and you will be happy about y
our decision.
I fly in remote Alaska and chose the Z13/8 (with a B&C 410H http://www.bandc
.biz/alternator20ampshomebuilt1.aspx ) and am happy with it. The EFII system
uses surprisingly small amperage when it's running, and when you wire the Z
13/8 to the EFII system you have redundancy and reliability with 2 alternato
rs and a battery. The 410h alternator provides plenty of amperage to run the
full EFII system.
I wired my system, and set procedures with the ability to shut the master sw
itch off, allowing the engine to continue to run (dual ECUs). I don't think I
will ever have to do this, but it is nice to NOT have a master switch that w
ill shut the engine off.
I also used milspec lever-lock switches for all of the EFII components to pr
ohibit inadvertent actuation.
I am willing to share any pictures, part numbers, or drawings to anyone inte
rested.
I would like to take this opportunity to thank Bob Nuckolls for his knowledg
e, patience, time, and willingness to help and teach us. Experimental aviat
ion as a whole would not be as safe or the same without you.
Justin
> On Aug 18, 2015, at 18:30, Robert L. Nuckolls, III <nuckolls.bob@aeroelect
ric.com> wrote:
>
> At 11:12 AM 8/18/2015, you wrote:
>
>> Thanks. I agree pitot heat does seem optional for the type of flying I pl
an on doing. I'd much rather just stay away from ice than try to fly through
it.
>>
>> So Z12 is what I was leaning towards. But I wonder what's the purpose of h
aving the endurance bus if I have a 20 amp standby alternator? In alternator
out conditions I can just keep the master on, and run just about anything I
want. Why not just have an alternate feed switch for the master bus in case
the master switch or battery contactor fails?
>
> there are dozens of variations on a theme . . .
>
> Z-12 is Z-11 with the addition of a standby
> alternator that auto-switches when fitted with
> the SB-1 regulator that does not give up
> any of the risk management features of Z-11.
>
> You may choose to have avionics busses and
> associated master switches. Extra batteries,
> or any number of variations. If you don't see
> a need for the e-bus and want to leave it off,
> by all means. If you have an alternative for
> dealing with a contactor failure, that's okay
> too.
>
>
>
> Bob . . .
>
>
>
==========================
=========
==========================
=========
==========================
=========
==========================
=========
>
________________________________________________________________________________
| Subject: | Re: electrical system planning |
| From: | William Mills <wtrooper(at)gmail.com> |
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________________________________________________________________________________
| Subject: | Re: electrical system planning |
| From: | don van santen <donvansanten(at)gmail.com> |
The battery contactor pulls nearly a full amp. Also it is very easy to shed
unneeded load by shutting the main down and going with the "E" bus.
On Aug 18, 2015 9:20 AM, "Ryan Brown" wrote:
> Thanks. I agree pitot heat does seem optional for the type of flying I
> plan on doing. I'd much rather just stay away from ice than try to fly
> through it.
>
> So Z12 is what I was leaning towards. But I wonder what's the purpose of
> having the endurance bus if I have a 20 amp standby alternator? In
> alternator out conditions I can just keep the master on, and run just abo
ut
> anything I want. Why not just have an alternate feed switch for the maste
r
> bus in case the master switch or battery contactor fails?
> On Aug 17, 2015 7:41 AM, "Robert L. Nuckolls, III" <
> nuckolls.bob(at)aeroelectric.com> wrote:
>
>> A t 11:29 PM 8/16/2015, you wrote:
>>
>> Thanks Bob.
>> The 5A figures are the estimates I got from the manufacturer for average
>> consumption. I haven't measured it myself. The breaker size is 10A.
>>
>>
>>
>> When you get this airplane flying, I'd REALLY
>> like to get some data off it that describes
>> ENERGY measurements . . . but 5A probably
>> works for now.
>>
>>
>> I filled out a spreadsheet with the load analysis for each stage here:
=C3=82
>> https://goo.gl/0FPFIQ
>> I'm not entirely sure I have everything assigned to the right bus.
>>
>> I estimate the plane will hold 5.5 hours of fuel, so I guess that's what
>> my endurance goal should be.
>>
>>
>> No guessing here . . . that's a number YOU pick
>> based on how you intend to use the airplane. If
>> you plan on frequent departures from airports
>> often clagged in and surrounded by mountains, then
>> the idea of endurance to carry you to demonstrably
>> lower-risk haven is a part of solid reasoning. But
>> if that comfortable termination of flight is
>> never more than say 2 hours away, then designing
>> and maintained that level of endurance is not
>> unreasonable.
>>
>> The main thing is to know what the endurance numbers
>> are, preventative maintenance to insure those
>> numbers and risks go down markedly.
>>
>> That's over 70 amp hours just to keep the engine running, so it seems a
>> backup alternator is a better bet than batteries.
>>
>>
>> Bingo!
>>
>> A second engine driven power source is ALWAYS the
>> best cost-weight-performance alternative to ANY
>> chemical system.
>>
>>
>> One question I have is if my endurance goal should be 5.5 hours with
>> pitot heat on. I don't plan on tons of ifr flight, and I kind of doubt m
y
>> brain could handle 5 hours of instrument flight. So it seems like lower
>> endurance for ifr cruise could be acceptable.
>>
>>
>> Probably so . . .
>>
>>
>> If I do want to keep the heater on with the backup alternator I need a
>> little more than 20 amps. I'm a little confused looking at the alternato
rs
>> here. The SD-20 is described as a 20/30A alternator. What does that mean
. I
>> saw some mention that the vacuum pad on a continental spins faster, does
>> that mean it's 30A on a continental and 20A on a lycoming?
>>
>>
>> I am not sure of the details . . . I've not had occasion
>> to touch the phycics of that product in about 20
>> years but I do understand that under presently
>> demonstrated conditions, its output can be that
>> high.
>>
>> The plane power FS14 is just listed as 30A, so I assume it can actually
>> put out 30A on a lycoming.
>>
>>
>> Pitot heat was never a really good idea on light
>> aircraft . . . yeah, it MAY have saved the bacon
>> for a hand-full of pilots in years gone by but
>> far more airplanes belabored with ice have gone down
>> in spite of knowing exactly what their airspeed
>> was before they hit the rocks.
>>
>> Having 'little chippers' to deal with some forms
>> of ice (heated windshield patches, boots, pitot
>> heat) have offered too many pilots a false sense
>> of capability to deal with mother nature's vagaries.
>>
>> Modern weather observation and prediction systems
>> are so capable that go-no go decision to launch
>> is far wiser than any notion of being able to 'deal
>> with a little ice' . . . same thing with those
>> little yellow, orange and red areas on the radar . . .
>> good reasons to just stay on the ground or take
>> another route.
>>
>> My preference for conducting the FMEA says
>> keeping the tube warm is at the bottom of the
>> list with respect to other appliances on board.
>> Just for grins, noodle through the plan-c for dealing
>> with loss of airspeed indication. What do you KNOW
>> about handling qualities, changes of trim and
>> power that speak to impending stall? If that
>> airspeed value becomes suspect for what you believe
>> is high-probability of ice, I'll suggest that
>> plans to seek warmer environs far outweighs
>> any value of knowing exactly what your airspeed
>> unless you think that climbing is the path to
>> salvation . . . which is very seldom the case.
>>
>> IAS as a warning for impending stall is
>> based on a CLEAN wing. I got a really big
>> lesson in fouled aerodynamics when a landing
>> in Hutchinson KS ended with the airplane plopping
>> down hard in the flare while yours truly was
>> patting himself on the butt for having kept
>> the needles centered for over fifteen minutes
>> in the clouds, outbound through procedure turns
>> and then all the way back to the threshold.
>>
>> My instructor was grinning ear to ear and said,
>> "Okay Nuckolls . . . while you were glued to the
>> glass, your wings were taking on new shapes with
>> unpredictable performance. None of that C-172-
>> full-stall-flare stuff in instrument conditions.
>> Fly it like a Grumman . . . carrier landings are
>> called for unless you are CERTAIN that your wings
>> are golden."
>>
>> You need to make up your own mind but it seems
>> to me that a Z-12 system with a 15 a.h. SVLA
>> battery would provide a comfortable reduction
>> in risks . . . especially if you consider pitot
>> heat to be more cosmetic than practical.
>>
>> Bob . . .
>>
>> *
>>
>> ist" target="_blank">http://www.matronics.com/Navigator?AeroElectric-L
ist <http://www.matronics.com/Navigator?AeroElectric-List>
>> tp://forums.matronics.com <http://forums.matronics.com>
>> _blank">http://www.matronics.com/contribution
>>
>> *
>>
>> *
>
===========
www.matronics.com/Navigator?AeroElectric-List>
===========
===========
om/contribution>
===========
>
> *
>
>
________________________________________________________________________________
| Subject: | Thermocouple Questions... |
| From: | Phillip Perry <philperry9(at)gmail.com> |
Hello,
Last night I started connecting my Type-K sensors up to the airplane
instrumentation. Trimming the single conductor leads from the
instrumentation to match the length of the leads on the thermocouple.
Then in the process of crimping a wire I managed to cut one of the leads
June 26, 2015 - August 19, 2015
AeroElectric-Archive.digest.vol-mv