Today's Message Index:
----------------------
1. 05:14 AM - Re: Audio panel #inputs vs #sources (Ralph E. Capen)
2. 06:06 AM - Re: Question about Annunciating Lights (Peter Laurence)
3. 07:34 AM - Re: AeroElectric-List Digest: 14 Msgs - 01/10/08 (Giffen Marr)
4. 07:44 AM - Re: Intercom wires (Robert L. Nuckolls, III)
5. 07:44 AM - Annunicator panels (Robert L. Nuckolls, III)
6. 07:48 AM - Re: Audio panel #inputs vs #sources (Robert L. Nuckolls, III)
7. 08:23 AM - Re: ELT/PLB (Steve Thomas)
8. 08:25 AM - Re: Re: Shielded Wire (Robert L. Nuckolls, III)
9. 08:30 AM - Re: Audio panel #inputs vs #sources (Ralph E. Capen)
10. 08:48 AM - Re: Re: ELT/PLB (Hinde, Frank George (Corvallis))
11. 09:33 AM - Re: Re: ELT/PLB (Matt Prather)
12. 09:34 AM - Re: Re: ELT/PLB (Matt Prather)
13. 10:04 AM - Re: Re: ELT/PLB (paul wilson)
14. 10:14 AM - Re: Re: ELT/PLB (Hinde, Frank George (Corvallis))
15. 10:50 AM - Re: Question about Annunciating Lights (Allen Fulmer)
16. 10:55 AM - Toggle switch tool (B Tomm)
17. 11:28 AM - Re: Toggle switch tool (DaveG601XL)
18. 11:43 AM - Re: Annunicator panels (Carlos Trigo)
19. 11:51 AM - Re: Question about Annunciating Lights (Scott R. Shook)
20. 12:02 PM - Re: Re: ELT/PLB (Steve Thomas)
21. 12:30 PM - Re: Re: ELT/PLB (Hinde, Frank George (Corvallis))
22. 12:41 PM - Re: Question about Annunciating Lights (Carl Morgan)
23. 01:00 PM - Re: Re: ELT/PLB (raymondj)
24. 01:13 PM - Re: Question about Annunciating Lights (Greg Young)
25. 02:08 PM - Re: Toggle switch tool (Robert L. Nuckolls, III)
26. 02:34 PM - Re: Re: ELT/PLB ()
27. 03:34 PM - Re: Toggle switch tool (FLAGSTONE)
28. 05:34 PM - Re: Re: ELT/PLB (Charlie England)
29. 05:45 PM - Re: Toggle switch tool (Jim Baker)
30. 07:07 PM - Re: Re: ELT/PLB (B Tomm)
31. 08:12 PM - Re: Question about Annunciating Lights (Fiveonepw@aol.com)
32. 08:29 PM - Re: Question about Annunciating Lights (Fiveonepw@aol.com)
33. 10:33 PM - Terminal Tool TT5000 (Michael D. Cencula)
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Subject: | Re: Audio panel #inputs vs #sources |
Bob,
I have heard 100ohm, 470ohm, and 510ohm. I'm guessing that either will function
properly and that the 470 and 510's will decrease the volume more in addition
to preventing the backfeed.
Ralph
-----Original Message-----
>From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
>Sent: Jan 10, 2008 9:10 PM
>To: aeroelectric-list@matronics.com
>Subject: Re: AeroElectric-List: Audio panel #inputs vs #sources
>
>
>At 11:16 AM 1/9/2008 -0500, you wrote:
>
>><recapen@earthlink.net>
>>
>>Folks,
>>
>>I have three inputs that should be 'unswitched':
>>AOA warning
>>Traffic Alert
>>AF3400EM Engine monitor
>>
>>My audio panel (PS Engineering PMA7000MS) has two unswitched inputs.
>>Can I tie two of the sources to one input? I think there would only be an
>>issue if they both went off at teh same time.
>>Alternatively, I can put the third to a switched input and leave the
>>switch on.
>
> Put 100 ohm resistors in series with EACH of the three output
> before bringing them together whether switched or not. See:
>
>http://aeroelectric.com/articles/Rev11/18Audio_R11.pdf
>
> Bob . . .
>
>
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Subject: | Re: Question about Annunciating Lights |
For all of you that don't know, Mark makes a great static port!
Peter Laurence
Here's another take on rollin' yer own:
http://websites.expercraft.com/n51pw/index.php?q=log_entry&log_id=512
6
Click on fotos for bigger view and Next Entry>> for more info (several
pages) including wiring diagram, part #s etc...
From The PossumWorks in TN
Mark Phillips
-------------------------------------------------------------------------
-----
Start the year off right. Easy ways to stay in shape in the new year.
Message 3
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Subject: | RE: AeroElectric-List Digest: 14 Msgs - 01/10/08 |
I am planning on using the cheapest ELT available to meet the FAR 91
Requirements and a 406 PLB. The current cost of ELT's meeting the 406
requirements are out of sight as compared to the 121.5 units. The other
advantage is the PLB is not much larger then a cell phone as compared to the
ELT. Only advantage to the ELT is the battery life may be longer then the
PLB.
Giff Marr
LIV-P/Mistral 65%
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
AeroElectric-List Digest Server
Sent: Friday, January 11, 2008 1:56 AM
Subject: AeroElectric-List Digest: 14 Msgs - 01/10/08
*
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Total Messages Posted Thu 01/10/08: 14
----------------------------------------------------------
Today's Message Index:
----------------------
1. 05:17 AM - Re: Strobe discharge pop-pop-pop (Ralph E. Capen)
2. 06:19 AM - Re: Question about Annunciating Lights (Brett Ferrell)
3. 09:16 AM - Re: Cheaper 406mhz plb alternative? (David Chalmers)
4. 10:08 AM - Re: Odd ICOM IC-A200 Power/Ground Instructions ()
5. 12:18 PM - Re: Rotax 914 capacitor (Robert L. Nuckolls, III)
6. 01:02 PM - Re: Shielded Wire (Robert L. Nuckolls, III)
7. 02:56 PM - Re: Shielded Wire (Eric M. Jones)
8. 05:19 PM - Re: XM radio power cord (Robert L. Nuckolls, III)
9. 05:41 PM - Re: Strobe discharge pop-pop-pop (Robert L. Nuckolls,
III)
10. 06:01 PM - Re: Question about Annunciating Lights (Robert L.
Nuckolls, III)
11. 06:10 PM - Re: Cheaper 406mhz plb alternative? (Steve Thomas)
12. 06:12 PM - Re: Audio panel #inputs vs #sources (Robert L. Nuckolls,
III)
13. 06:36 PM - Re: XM radio power cord (Dale Ensing)
14. 09:20 PM - Re: Question about Annunciating Lights
(Fiveonepw@aol.com)
________________________________ Message 1
_____________________________________
Time: 05:17:08 AM PST US
From: "Ralph E. Capen" <recapen@earthlink.net>
Subject: Re: AeroElectric-List: Strobe discharge pop-pop-pop
I'll be trying it outside soon and with the engine later - I'm almost
thinking the engine will drown it out...
-----Original Message-----
>From: Ken <klehman@albedo.net>
>Sent: Jan 9, 2008 11:45 PM
>To: aeroelectric-list@matronics.com
>Subject: Re: AeroElectric-List: Strobe discharge pop-pop-pop
>
>
>Ralph
>Have you tried it outside? My radio picks it up when in a metal hangar
>but not when outside. My intercom picks up a little as well via power
>supply or ground but hardly noticeable with the engine idling. So it
>might not be worth pursuing. The chapter on noise and grounding may be
>helpful. And if it is still noticeable a cheap automotive radio power
>filter on the strobe power supplies also helped in my case.
>Ken
>
>Ralph E. Capen wrote:
>>
>> I'm doing some system testing and I can hear a very slight pop each
>> time my
strobes discharge through my headset. It doesn't break the squelch or
prevent me from hearing the radios - or stereo for that matter. No whining
on the charge cycles and I gotta listen carefully to catch the pop - but
it's there.
>>
>> Is this strictly due to the high-voltage discharge in a 12V system?
>> Is there
something I can due to get rid of this? Or should I take gladness that it's
faint, doesn't interfere, it's as good as it gets, have a coke and a smile
and.......?
>>
>> Ralph
>
>
________________________________ Message 2
_____________________________________
Time: 06:19:33 AM PST US
From: Brett Ferrell <bferrell@123mail.net>
Subject: RE: AeroElectric-List: Question about Annunciating Lights
I made my panel out of Honeywell microswitches. It's not really a cheap
way, but the results are nice, and it's fairly straight-forward, with "dead
face"
(labels so you KNOW the lamp is out, because it cannot be read unless
illuminated from behind). I also built a push-to-test circuit.
http://www.velocityxl.com/Electrical.htm
(just the pictures)
http://www.velocityxl.com/annunciator.JPG
http://www.velocityxl.com/press_to_test.JPG
http://www.velocityxl.com/IMAGES2/GRT3.JPG
I bought mine from these folks http://www.fmw411.com/
Brett
Quoting Carl Morgan <zk-vii@rvproject.gen.nz>:
> I took Mark's work as a basis, and this is what I ended up with....
>
> Close up:
> http://www.rvproject.gen.nz/photos/2007-06/Web_Img_9760.jpg
>
> http://www.rvproject.gen.nz/dailylog/dailylog_2007-07-28.html the
> final look,
>
>
> http://www.rvproject.gen.nz/dailylog/dailylog_2007-06-18.html and
> http://www.rvproject.gen.nz/dailylog/dailylog_2007-06-19.html for some
> of the fabrication process.
>
> Just another possible source of ideas.
>
> Carl
>
> --
> Carl Morgan - ZK-VII - RV 7A - Inspection next Tue!
> http://www.rvproject.gen.nz/
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of
> Fiveonepw@aol.com
> Sent: 10 January 2008 18:14
> To: aeroelectric-list@matronics.com
> Subject: Re: AeroElectric-List: Question about Annunciating Lights
>
>
> Here's another take on rollin' yer own:
>
>
> http://websites.expercraft.com/n51pw/index.php?q=log_entry&log_id=5126
>
> Click on fotos for bigger view and Next Entry>> for more info
> (several
> pages) including wiring diagram, part #s etc...
>
> From The PossumWorks in TN
> Mark Phillips
>
>
> ----------------------------------------------------------------------
> ------
> --
> Start the year off right. Easy ways to stay in shape in the new year.
>
>
> 10:16
>
________________________________ Message 3
_____________________________________
Time: 09:16:46 AM PST US
From: "David Chalmers" <david@ChalmersFamily.com>
Subject: Re: AeroElectric-List: Cheaper 406mhz plb alternative?
There's a good review here http://www.equipped.org/SPOT_ORSummer2007.htm
On 1/9/08, Charlie England <ceengland@bellsouth.net> wrote:
>
> ceengland@bellsouth.net>
>
> Anyone know any details about this product?
>
> http://www.findmespot.com/explorespot/spotmessenger.aspx
>
> IF it's using the public SARSAT satellites, maybe it would still work
> after the 1st mandatory subscription lapses. (Still be a lot cheaper
> than typical PLBs with built in GPS.)
>
> Charlie
>
>
________________________________ Message 4
_____________________________________
Time: 10:08:56 AM PST US
From: <gmcjetpilot@yahoo.com>
Subject: AeroElectric-List: Re: Odd ICOM IC-A200 Power/Ground Instructions
Tim the 18 awg and 10 amp fuse is the broad brush approach, one size fits
all. Yes its overkill. You could use a smaller awg wire and fuse. Also
sometimes people gang off of existing 10 amp CB's and therefore
18 awg is the correct wire size. I used 5 amp and stayed with the 18 awg
because I had it; A short run of 20 awg would work fine. They're just
covered their bases.
Notice 13.8 volts spec? You can take some IR loss with a 14.3-14.5 volt
buss.
The wire diagram clearly shows ONE power and ONE ground with a daisy chain
or jumpers. Sorry have no idea what he's talking about. TWIST? Really. May
be this is new and it does help but I am stumped. I went with one wire for
power and ground. George
If you find a 100% answer why, email me please, thanks
PS Its a great radio but instructions are lousy.
>From: Tim Lewis <Tim_Lewis@msm.umr.edu>
>Subject: AeroElectric-List: Odd ICOM IC-A200 Power/Ground Instructions
>The ICOM IC-A200 (VHF Comm radio) installation instruction
(http://www.aeroelectric.com/Installation_Data/Icom_ICA200_Installation_Manu
al.pdf)
>depicts a 10 amp breaker, and tells the installer to "Use
>2 pairs of #18 AWG wires for power and power grounding wiring." This
>struck me as odd, since a single 18 AWG wire is normally used with a
>10 amp breaker, and since the IC-A200 is rated to draw only
>2.6 amps (during transmit).
>I called ICOM tech support and spoke to Mike, who told me that I should
>indeed use two 18 AWG wires for power and two 18 AWG wires for ground,
>and that the two wires should be twisted together "to reduce
>interference". He further recommended twisting the end of the two
>wires together, aided by solder, and crimping this assembly into the
>supplied Molex terminal.
>I expressed some skepticism about the efficacy of twisting two 12V
>power wires together to reduce interference. I was unable to elicit
>an explanation of the mechanism by which the alleged interference
>reduction was to be achieved. I was also unable to elicit an
>explanation of why it should take two 18AWG wires in parallel to
>supply 2.6 Amps (peak) to a radio. I elected not to engage Mike in a
>discussion of the advisability of crimping a connector to a soldered
>wire.
>Does anybody have insight into reasoning or experience that lends
>credibility to the idea that two 18 AWG wires should be used for power
>(and two for
>ground) in an ICOM IC-A200 radio installation?
>Thanks,
>Tim Lewis
---------------------------------
Never miss a thing. Make Yahoo your homepage.
________________________________ Message 5
_____________________________________
Time: 12:18:54 PM PST US
From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
Subject: Re: AeroElectric-List: Rotax 914 capacitor
At 12:13 PM 1/9/2008 -0800, you wrote:
>
>Hi All,
>B&C offer a couple different capacitors, 10,000uF @50VDC and 47,000uF
>@16VDC. Is one of these appropriate for use on the Rotax alternator?
>Thanks, Kevin
This is not a really critical capacitor with
respect to value but 16v is bit low for
a rating. 25V or more is the target. Furhter,
the "rule of thumb" for sizing is 1,000 uF per
amp of alternator output so the 10KuF/50v is
pretty good for the SD-8. Your system would
be better served by 20KuF/25V or larger.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________ Message 6
_____________________________________
Time: 01:02:10 PM PST US
From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
Subject: Re: AeroElectric-List: Shielded Wire
At 06:12 AM 1/10/2008 -0800, you wrote:
>
>Bob:
>
>Maybe this is a little clearer:
>
>All the wires in the wing are shielded.
?Why?
>The wire used is MIL-DTL-27500TG2T14. That particular one is 12AWG, two
>conductor, twisted pair, shielded and sheathed. The unshielded version
>was not available without special order and long lead time. The weight
>difference between shielded and unshielded was 2.75lbs for 1,000 feet
>so I got the shielded version.
>
>There are no manufacturer's recommendations per se. Sizing for loads
>was done as per AC43-13-2A based on the power consumption rating for each
load.
>
>All power loads have a power lead and a return lead. The sensors have
>how ever many wires are required by the sensor.
>
>Ignoring connectors, fuses, switches, ground buss etc, all power loads
>were to be routed as follows:
>
> Power lead: Bat(+) -to- Load.
> Return lead: Load -to- Bat (-) and, Load -to- Airframe (at
>Local
>Ground) -to- Bat (-)
> Shielding: - Bat(-) -to- Airframe (at Local Ground)
>
>I can't find where I read it but something led me to believe that if
>you were going to use shielded wire it was OK to do it the way I did.
I'm not sure I'm interpreting you words into an
accurate schematic of your architecture but since
the use of shielding where shielding adds no value,
then exactly how you wire it has no significance
with respect to performance.
>So, given that I am going to use the wire I have, that I am going to
>run a return lead for all power loads and that I want to hook up the
>shielding on the wire, what is the correct way to do it?
>
>Regarding the return lead, I'm pretty clear that the return lead should
>not be grounded at the Bat (-) and at a Local ground. Quote from your
response:
>
>" One and only one ground . . . local is probably fine
> but not both places . . ."
>
>No problem changing it but why is it such a bad thing to do it that way.
>Using the landing light as an example. What harm does it cause to
>ground it locally and also run a lead back to the bat (-). Why is that
>worse than only grounding locally and the corollary, why is that not
>better than only running the lead back to the bat (-). Is the same
>applicable to the strobe's power unit and the fuel pump. Would it be
>the same for something like a flap actuator motor.
My personal goals for system design are to achieve
the desired level of performance with a minimum of
parts and minimized $time$ to acquire/install/maintain.
You appear to be asking advice for doing things that
I would not choose to do because they do not add
value under the design goals stated. Doing doesn't
necessarily degrade performance but it's certain
not to enhance it. Are there risks for venturing outside
the simple ideas that support conventional wisdom?
Difficult to predict but probably not.
>Regarding the shielding: I'm less clear on this. Removing the local
>ground from the return lead will also take the shielding out of the
>ground path from the Load to the Bat(-). But what about grounding the
shielding itself.
>Again using the landing light as an example, what is the difference
>between grounding at both ends and grounding only at the Bat(-). Is
>the same applicable to the strobe's power unit, fuel pump and flap motor.
>
>Looking forward to your explanations.
A detailed trek through the physics from which
conventional wisdom and common practices evolved
is beyond the scope of what I can do here on
the List. I did a short-course on noise propagation
issues and solutions a few years ago at Hawker-
Beech . . . and that was a 4-hour, Power-Point
presentation.
Suffice it to say that if my mental image
for what you've described is correct,
then there is no reason to expect degradation
of performance and no reason to expect an
enhancement of performance. I.e, shielding
added without specific noise propagation
problems to be solved only adds to weight
of the airplane and cost of ownership. It
follows then that I have no advice based
on physics to offer for "doing it right".
Bob . . .
________________________________ Message 7
_____________________________________
Time: 02:56:00 PM PST US
Subject: AeroElectric-List: Re: Shielded Wire
From: "Eric M. Jones" <emjones@charter.net>
Okay, cut this message out and punch three holes into it and stick it into
your book. This is the cat's meow on coaxial cable shielding and grounding
from Kimmel Gerke Associates. I hope they balance my liberal use of their
stuff with the free advertising given here.
http://www.emiguru.com/kgb/sum1996.htm Kimmel Gerke Bullets.
"For many designers, cables and connectors are an afterthought. After all,
they just connect things together, right? But cables and connectors are
major entry and exit points for EMI into and out of electronic systems. They
act as "hidden antennas" for radiated energy, and "hidden conduits" for
conducted energy.
"In fact, cables and connectors are so important, they are the often the
first things we check out when troubleshooting EMI problems in a system.
Here are a few thoughts on cable and connector design for EMI.
Trade off shielding for filtering. If you don't filter I/O interfaces, then
you must assume that the highest frequencies inside the unit will end up on
the cable wires. (Or you must assume the cables will intercept the highest
frequencies and bring them into the unit.)
"Just because that RS-232 interface is only operating in the kilobaud range
doesn't stop higher frequencies from hitching a "free ride" on the cables.
We've solved many radiated problems (emissions and immunity) by adding
simple filters to interfaces that were only supposed to carry "slow" or "low
frequency" signals.
"The alternate to filtering the cables is shielding the cables. We generally
prefer to filter slower cables, since it's usually more cost effective and
easier to maintain EMI integrity.
"Ground the cable shield. If you do decide to use shielded cables, then the
immediate question becomes how best to ground the cable shield. The correct
method depends on both threat frequencies and circuit impedance levels.
"For problem frequencies below 10 kHz [audio], the preferred approach is to
ground one only one end of the shield. This is to prevent "ground loop"
coupling from the cable shield to the inner wires. This is particularly
important for preventing 60 Hz coupling into low level/high impedance
circuits used in audio or instrumentation systems.
"Unfortunately, this is exactly the wrong thing to do for high frequency
threats.
For most RF situations [above 10 kHz], the preferred approach is to ground
both ends of the cable shield, to minimize coupling at the open end due to
standing wave effects. So what do you do if both threats exist? You can
ground one end with a small capacitor (1,000- 10,000 pf typical) or you can
use two shields
- one grounded on one end, and the other grounded on both ends. In the
latter case, the shields must be insulated from each other.
"One more case where both ends must be grounded is the low frequency/low
impedance case, where magnetic fields are the major culprit. In this case,
the strategy is to minimize "loop size" by providing an adjacent return path
for noise currents. This is often necessary in electrical sub-stations,
where large 60 Hz magnetic fields exist due to the high current levels. Most
of the time, however, single point grounding at low frequencies is the
preferred approach.
"Use Care With Connector Terminations. This is extremely important for
shielded cables with EMI threats above about 1 MHz. Poor joints (or worse,
"pigtail" connections from the shield to the connector) are a leading cause
EMI-induced failures on shielded cables. We've seen 20 dB increases in
emissions, and 10 fold reductions in ESD immunity due to poor connections.
(Remember, with a 1 nsec edge rate, ESD is a 300 MHz EMI problem.)
"To maintain high frequency cable shield integrity, you need a
circumferential bond between the cable shield and the connector shell. In
addition you need full metal-to-metal between the mating connectors.
Finally, you need a solid connector-to-chassis connection. One problem we
often see here is with chassis connectors that overlap connector cutouts.
The imprecise fit creates a slot that very effectively couples high
frequency energy directly to/from the cable shield. Think in terms of a
garden hose -you need a very tight connection at the faucet, or else it
leaks.
"What About The Cable Shield Itself? Yes, this is a valid concern, but only
after you have addressed the connector termination issues. For frequencies
below about 10 MHz, most cable shielding materials behave about the same,
and provide very respectable amounts of shielding. For frequencies above
about 10 MHz, however, the cable construction becomes important. Loose
single braids become increasingly leaky, so above 10 MHz, you may need high
density braid shields. Double braids work very well here, as do braid over
Mylar cable shields. For high frequencies, both shields should be connected
together. "
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones@charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=157322#157322
________________________________ Message 8
_____________________________________
Time: 05:19:04 PM PST US
From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
Subject: Re: AeroElectric-List: XM radio power cord
At 06:06 PM 1/9/2008 -0500, you wrote:
><densing@carolina.rr.com>
>
>A question regarding an XM Express radio that I use in the airplane and
>in the car.
>
>The power cord for the XM radio has a cigarette lighter type plug, is
>about three feet long with a mini coaxial plug on the radio end.
>Clamped on the cord are two cylinder shaped plastic devices (for lack
>of a better descriptive word). There is one on the cig. liter plug end
>and another smaller one on the radio end.
>The wire used in the power cord is very stiff and difficult to keep
>organized and out of the way. I would like to substitute another power
>cord that is coiled and stretchy. Much easier to manage and keep neat.
>What are the devices clamped on the cord and what is their function?
>What will be the impact if I used a power cord without the devices.
I suspect these are ferrite noise filters which
are commonly added to commercial products for the
for the purpose of reducing conducted electro-magnetic
interference between devices connected with the cable.
See:
http://www.aeroelectric.com/Pictures/Filters/Ferrite_EMI_Filter_2.jpg
http://www.aeroelectric.com/Pictures/Filters/Ferrite_EMI_Filter.jpg
If the devices you're seeing are similar in nature, then
it's probable that your device will FUNCTION if fitted
with a cord that does not have the filters.
But like any non-qualified device use in the airplane,
you should be cognizant of potential for interference
from the XM radio . . . whether filtered or not. Do some
tests and be ready to turn the radio OFF anytime another
radio system seems not to behave as expected.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________ Message 9
_____________________________________
Time: 05:41:58 PM PST US
From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
Subject: Re: AeroElectric-List: Strobe discharge pop-pop-pop
At 01:36 PM 1/9/2008 -0500, you wrote:
><recapen@earthlink.net>
>
>I'm doing some system testing and I can hear a very slight pop each
>time my strobes discharge through my headset. It doesn't break the
>squelch or prevent me from hearing the radios - or stereo for that
>matter. No whining on the charge cycles and I gotta listen carefully
>to catch the pop
>- but it's there.
>
>Is this strictly due to the high-voltage discharge in a 12V system? Is
>there something I can due to get rid of this? Or should I take
>gladness that it's faint, doesn't interfere, it's as good as it gets,
>have a coke and a smile and.......?
When you think about the physics of what's going
on inside a xenon flash-tube, it has a great deal
in common with a lightning strike. As we all know,
a lighting strike can be "felt" both in terms of
magnetic and electrostatic effects, both of which
have the ability to radiate some distance and/or
couple to conductors.
What you're hearing is the broad spectrum, radiated
noise coming directly from the confines of the ionized
gasses in the tube when it fires.
When we put the first strobes on Cessna single-engine
airplanes in the 60's, there was a lot of fuss about
this mini-strike being heard in the ADF receivers.
We tried some glass with conductive coatings (reduced
light output) and fine-mesh screen wire (really hard to
work with).
Somebody finally noted that, "Bee, when you're tuned to
a station that was strong enough to be useable for either
listening or navigating, the "pop" was imperceptible
and effects on navigation nil."
Chances are that in flight, you're going to discover
the same thing. Now, if it does turn out to be a problem,
you'll need to repeat the same experiments we tried 40
years ago and perhaps some new ones. I'm aware of no
current tricks of the trade that would a apply.
Bob . . .
________________________________ Message 10
____________________________________
Time: 06:01:33 PM PST US
From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
Subject: Re: AeroElectric-List: Question about Annunciating Lights
At 12:54 PM 1/9/2008 -0500, you wrote:
>Bob, it would help if you also added these pictures to the article...
>
>Bret Smith
>RV-9A "Fuselage"
>Blue Ridge, GA
Done. Thanks!
>> A fine piece of work! I've preserved this data in
>> an excerpt of the websit and posted it to:
>>
>>http://aeroelectric.com/articles/Roll_your_own_Annunicator_Panel.pdf
>
> Bob . . .
>
> ----------------------------------------)
> ( . . . a long habit of not thinking )
> ( a thing wrong, gives it a superficial )
> ( appearance of being right . . . )
> ( )
> ( -Thomas Paine 1776- )
> ----------------------------------------
>
________________________________ Message 11
____________________________________
Time: 06:10:07 PM PST US
From: Steve Thomas <lists@stevet.net>
Subject: Re: AeroElectric-List: Cheaper 406mhz plb alternative?
As far as 406MHz ELT goes, I currently have an ACK installed in my not-
yet-flying Glasair. This unit is not a 406 MHz unit. With the demise of
satellite tracking on 121.5, I wrote to ACK to ask if they had any plans to
release a 406 unit. The reply was that, yes, they have one under
development. It is an exact replacement for the 121.5 unit, uses the same
remote head, and uses easy to replace, commercially available batteries (I
don't remember what kind, but they were not Alkaline). I don't remember the
price exactly, but it was half of what the lowest price alternative was.
They said to keep watching their web site and expected it to be available
within the first half of this year.
On Jan 10, 2008, at 9:01 AM, David Chalmers wrote:
> There's a good review here
> http://www.equipped.org/SPOT_ORSummer2007.htm
>
>
> On 1/9/08, Charlie England <ceengland@bellsouth.net> wrote:
> >
>
> Anyone know any details about this product?
>
> http://www.findmespot.com/explorespot/spotmessenger.aspx
>
> IF it's using the public SARSAT satellites, maybe it would still work
>
>
________________________________ Message 12
____________________________________
Time: 06:12:17 PM PST US
From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
Subject: Re: AeroElectric-List: Audio panel #inputs vs #sources
At 11:16 AM 1/9/2008 -0500, you wrote:
><recapen@earthlink.net>
>
>Folks,
>
>I have three inputs that should be 'unswitched':
>AOA warning
>Traffic Alert
>AF3400EM Engine monitor
>
>My audio panel (PS Engineering PMA7000MS) has two unswitched inputs.
>Can I tie two of the sources to one input? I think there would only be
>an issue if they both went off at teh same time.
>Alternatively, I can put the third to a switched input and leave the
>switch on.
Put 100 ohm resistors in series with EACH of the three output
before bringing them together whether switched or not. See:
http://aeroelectric.com/articles/Rev11/18Audio_R11.pdf
Bob . . .
________________________________ Message 13
____________________________________
Time: 06:36:13 PM PST US
From: "Dale Ensing" <densing@carolina.rr.com>
Subject: Re: AeroElectric-List: XM radio power cord
Thank you Bob. The 'devices' on the power cord look just like the ferrite
filters in the pictures. And thanks for the alert to possible interference
to other radio systems in the airplane.
Dale
> At 06:06 PM 1/9/2008 -0500, you wrote:
>
>><densing@carolina.rr.com>
>>
>>A question regarding an XM Express radio that I use in the airplane
>>and in the car.
>>
>>The power cord for the XM radio has a cigarette lighter type plug, is
>>about three feet long with a mini coaxial plug on the radio end.
>>Clamped on the cord are two cylinder shaped plastic devices (for lack
>>of a better descriptive word). There is one on the cig. liter plug end
>>and another smaller one on the radio end.
>>The wire used in the power cord is very stiff and difficult to keep
>>organized and out of the way. I would like to substitute another power
>>cord that is coiled and stretchy. Much easier to manage and keep neat.
>>What are the devices clamped on the cord and what is their function?
>>What will be the impact if I used a power cord without the devices.
>
> I suspect these are ferrite noise filters which
> are commonly added to commercial products for the
> for the purpose of reducing conducted electro-magnetic
> interference between devices connected with the cable.
>
> See:
>
> http://www.aeroelectric.com/Pictures/Filters/Ferrite_EMI_Filter_2.jpg
>
> http://www.aeroelectric.com/Pictures/Filters/Ferrite_EMI_Filter.jpg
>
> If the devices you're seeing are similar in nature, then
> it's probable that your device will FUNCTION if fitted
> with a cord that does not have the filters.
>
> But like any non-qualified device use in the airplane,
> you should be cognizant of potential for interference
> from the XM radio . . . whether filtered or not. Do some
> tests and be ready to turn the radio OFF anytime another
> radio system seems not to behave as expected.
>
> Bob . . .
________________________________ Message 14
____________________________________
Time: 09:20:38 PM PST US
From: Fiveonepw@aol.com
Subject: Re: AeroElectric-List: Question about Annunciating Lights
In a message dated 01/10/2008 8:21:26 AM Central Standard Time,
bferrell@123mail.net writes:
I made my panel out of Honeywell microswitches.
>>>
Slick! Where were these back when I needed 'em?! Nice work-
Mark
do not archive
**************Start the year off right. Easy ways to stay in shape.
http://body.aol.com/fitness/winter-exercise?NCID=aolcmp00300000002489
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At 04:54 PM 1/9/2008 +0000, you wrote:
><trigo@mail.telepac.pt>
>
>By the way, Bob
>
>On a broader view of noise protection, let me ask a general (perhaps too
>much general) question:
>
>In TC or OBAM aircraft, which of the wires of all used in present electrical
>installations must be (or should be) noise protected, and from those which
>shall be twisted and which shall be made from shielded wire?
>Apart from the ground-loop and careful grounding procedures...
>
>Carlos
Only those called out as shielded in the manufacturer's installation
instructions. These will be generally limited to strobe head wires,
p-leads, spark plug wires, and the occasional avionics system signal
wire.
The notion here is that nobody knows more than the manufacturer about
the probability for the device becoming either an antagonist or a victim.
Having said that, it's not uncommon for a manufacturer to call out
prophylactic noise mitigation processes that make no sense. I.e.,
twisting of power wires going into the back of a transceiver. The
shielding of a power wire coming out of an electronic ignition
power supply. Shielding the b-lead and field-lead on an alternator
(I was at Cessna when we crafted that canard!).
The only risk here is that what ever process is called for is at
worst the byproduct of someone "whistling-in-the-dark" about noises
for which there is no demonstrable experiment. On the upside, the
well crafted system that truly benefits from adding filters or shields
acquires those recommendations for good reasons.
Bob . . .
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Subject: | Annunicator panels |
At 05:06 PM 1/9/2008 +0000, you wrote:
><trigo@mail.telepac.pt>
>
>Bob
>
>In the document you saved to your website, you're missing the building
>pictures... which are very important and are in the bottom of the Van's Air
>Force thread
>
>Carlos
Are you talking about the two shots that were forwarded to
me by another reader? See reposted document with additions
at:
http://aeroelectric.com/articles/Roll_your_own_Annunicator_Panel.pdf
Thanks for the heads-up!
Bob . . .
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Subject: | Re: Audio panel #inputs vs #sources |
At 08:13 AM 1/11/2008 -0500, you wrote:
><recapen@earthlink.net>
>
>Bob,
>
>I have heard 100ohm, 470ohm, and 510ohm. I'm guessing that either will
>function properly and that the 470 and 510's will decrease the volume more
>in addition to preventing the backfeed.
>
>Ralph
Astute supposition sir.
Bob . . . ----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
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Well, a PLB may be less expensive, but it presumes that you are
conscious when you need to activate it. Or that you will successfully
regain consciousness before, well, you know. Steve Fausset had a
personal PLB - didn't do him any good at all. Just a thought.
On Jan 11, 2008, at 7:24 AM, Giffen Marr wrote:
> >
>
> I am planning on using the cheapest ELT available to meet the FAR 91
> Requirements and a 406 PLB. The current cost of ELT's meeting the 406
> requirements are out of sight as compared to the 121.5 units. The
> other
> advantage is the PLB is not much larger then a cell phone as
> compared to the
> ELT. Only advantage to the ELT is the battery life may be longer
> then the
> PLB.
>
> Giff Marr
> LIV-P/Mistral 65%
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
> AeroElectric-List Digest Server
> Sent: Friday, January 11, 2008 1:56 AM
> To: AeroElectric-List Digest List
> Subject: AeroElectric-List Digest: 14 Msgs - 01/10/08
>
> *
>
> =================================================
> Online Versions of Today's List Digest Archive
> =================================================
>
> Today's complete AeroElectric-List Digest can also be found in
> either of the
> two Web Links listed below. The .html file includes the Digest
> formatted in
> HTML for viewing with a web browser and features Hyperlinked Indexes
> and
> Message Navigation. The .txt file includes the plain ASCII version
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> AeroElectric-List Digest and can be viewed with a generic text
> editor such
> as Notepad or with a web browser.
>
> HTML Version:
>
>
> http://www.matronics.com/digest/digestview.php?Style=82701&View=html&Chapter
> 08-01-10&Archive=AeroElectric
>
> Text Version:
>
>
> http://www.matronics.com/digest/digestview.php?Style=82701&View=txt&Chapter
> 2008-01-10&Archive=AeroElectric
>
>
> ===============================================
> EMail Version of Today's List Digest Archive
> ===============================================
>
>
> ----------------------------------------------------------
> AeroElectric-List Digest Archive
> ---
> Total Messages Posted Thu 01/10/08: 14
> ----------------------------------------------------------
>
>
> Today's Message Index:
> ----------------------
>
> 1. 05:17 AM - Re: Strobe discharge pop-pop-pop (Ralph E. Capen)
> 2. 06:19 AM - Re: Question about Annunciating Lights (Brett
> Ferrell)
> 3. 09:16 AM - Re: Cheaper 406mhz plb alternative? (David
> Chalmers)
> 4. 10:08 AM - Re: Odd ICOM IC-A200 Power/Ground Instructions ()
> 5. 12:18 PM - Re: Rotax 914 capacitor (Robert L. Nuckolls, III)
> 6. 01:02 PM - Re: Shielded Wire (Robert L. Nuckolls, III)
> 7. 02:56 PM - Re: Shielded Wire (Eric M. Jones)
> 8. 05:19 PM - Re: XM radio power cord (Robert L. Nuckolls, III)
> 9. 05:41 PM - Re: Strobe discharge pop-pop-pop (Robert L.
> Nuckolls,
> III)
> 10. 06:01 PM - Re: Question about Annunciating Lights (Robert L.
> Nuckolls, III)
> 11. 06:10 PM - Re: Cheaper 406mhz plb alternative? (Steve Thomas)
> 12. 06:12 PM - Re: Audio panel #inputs vs #sources (Robert L.
> Nuckolls,
> III)
> 13. 06:36 PM - Re: XM radio power cord (Dale Ensing)
> 14. 09:20 PM - Re: Question about Annunciating Lights
> (Fiveonepw@aol.com)
>
>
> ________________________________ Message 1
> _____________________________________
>
>
> Time: 05:17:08 AM PST US
> From: "Ralph E. Capen" <recapen@earthlink.net>
> Subject: Re: AeroElectric-List: Strobe discharge pop-pop-pop
>
>
> I'll be trying it outside soon and with the engine later - I'm almost
> thinking the engine will drown it out...
>
> -----Original Message-----
>> From: Ken <klehman@albedo.net>
>> Sent: Jan 9, 2008 11:45 PM
>> To: aeroelectric-list@matronics.com
>> Subject: Re: AeroElectric-List: Strobe discharge pop-pop-pop
>>
>>
>> Ralph
>> Have you tried it outside? My radio picks it up when in a metal
>> hangar
>> but not when outside. My intercom picks up a little as well via power
>> supply or ground but hardly noticeable with the engine idling. So it
>> might not be worth pursuing. The chapter on noise and grounding may
>> be
>> helpful. And if it is still noticeable a cheap automotive radio power
>> filter on the strobe power supplies also helped in my case.
>> Ken
>>
>> Ralph E. Capen wrote:
>>>
>>> I'm doing some system testing and I can hear a very slight pop each
>>> time my
> strobes discharge through my headset. It doesn't break the squelch or
> prevent me from hearing the radios - or stereo for that matter. No
> whining
> on the charge cycles and I gotta listen carefully to catch the pop -
> but
> it's there.
>>>
>>> Is this strictly due to the high-voltage discharge in a 12V system?
>>> Is there
> something I can due to get rid of this? Or should I take gladness
> that it's
> faint, doesn't interfere, it's as good as it gets, have a coke and a
> smile
> and.......?
>>>
>>> Ralph
>>
>>
>
>
> ________________________________ Message 2
> _____________________________________
>
>
> Time: 06:19:33 AM PST US
> From: Brett Ferrell <bferrell@123mail.net>
> Subject: RE: AeroElectric-List: Question about Annunciating Lights
>
>
> I made my panel out of Honeywell microswitches. It's not really a
> cheap
> way, but the results are nice, and it's fairly straight-forward,
> with "dead
> face"
> (labels so you KNOW the lamp is out, because it cannot be read unless
> illuminated from behind). I also built a push-to-test circuit.
>
> http://www.velocityxl.com/Electrical.htm
> (just the pictures)
> http://www.velocityxl.com/annunciator.JPG
> http://www.velocityxl.com/press_to_test.JPG
> http://www.velocityxl.com/IMAGES2/GRT3.JPG
>
> I bought mine from these folks http://www.fmw411.com/
>
> Brett
>
> Quoting Carl Morgan <zk-vii@rvproject.gen.nz>:
>
>> I took Mark's work as a basis, and this is what I ended up with....
>>
>> Close up:
>> http://www.rvproject.gen.nz/photos/2007-06/Web_Img_9760.jpg
>>
>> http://www.rvproject.gen.nz/dailylog/dailylog_2007-07-28.html the
>> final look,
>>
>>
>> http://www.rvproject.gen.nz/dailylog/dailylog_2007-06-18.html and
>> http://www.rvproject.gen.nz/dailylog/dailylog_2007-06-19.html for
>> some
>> of the fabrication process.
>>
>> Just another possible source of ideas.
>>
>> Carl
>>
>> --
>> Carl Morgan - ZK-VII - RV 7A - Inspection next Tue!
>> http://www.rvproject.gen.nz/
>> -----Original Message-----
>> From: owner-aeroelectric-list-server@matronics.com
>> [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of
>> Fiveonepw@aol.com
>> Sent: 10 January 2008 18:14
>> To: aeroelectric-list@matronics.com
>> Subject: Re: AeroElectric-List: Question about Annunciating Lights
>>
>>
>> Here's another take on rollin' yer own:
>>
>>
>> http://websites.expercraft.com/n51pw/index.php?
>> q=log_entry&log_id=5126
>>
>> Click on fotos for bigger view and Next Entry>> for more info
>> (several
>> pages) including wiring diagram, part #s etc...
>>
>> From The PossumWorks in TN
>> Mark Phillips
>>
>>
>> ----------------------------------------------------------------------
>> ------
>> --
>> Start the year off right. Easy ways to stay in shape in the new
>> year.
>>
>>
>> 10:16
>>
>
>
> ________________________________ Message 3
> _____________________________________
>
>
> Time: 09:16:46 AM PST US
> From: "David Chalmers" <david@ChalmersFamily.com>
> Subject: Re: AeroElectric-List: Cheaper 406mhz plb alternative?
>
> There's a good review here http://www.equipped.org/SPOT_ORSummer2007.htm
>
>
> On 1/9/08, Charlie England <ceengland@bellsouth.net> wrote:
>>
>> ceengland@bellsouth.net>
>>
>> Anyone know any details about this product?
>>
>> http://www.findmespot.com/explorespot/spotmessenger.aspx
>>
>> IF it's using the public SARSAT satellites, maybe it would still work
>> after the 1st mandatory subscription lapses. (Still be a lot cheaper
>> than typical PLBs with built in GPS.)
>>
>> Charlie
>>
>>
>
> ________________________________ Message 4
> _____________________________________
>
>
> Time: 10:08:56 AM PST US
> From: <gmcjetpilot@yahoo.com>
> Subject: AeroElectric-List: Re: Odd ICOM IC-A200 Power/Ground
> Instructions
>
> Tim the 18 awg and 10 amp fuse is the broad brush approach, one size
> fits
> all. Yes its overkill. You could use a smaller awg wire and fuse. Also
> sometimes people gang off of existing 10 amp CB's and therefore
> 18 awg is the correct wire size. I used 5 amp and stayed with the 18
> awg
> because I had it; A short run of 20 awg would work fine. They're just
> covered their bases.
>
> Notice 13.8 volts spec? You can take some IR loss with a 14.3-14.5
> volt
> buss.
>
> The wire diagram clearly shows ONE power and ONE ground with a daisy
> chain
> or jumpers. Sorry have no idea what he's talking about. TWIST?
> Really. May
> be this is new and it does help but I am stumped. I went with one
> wire for
> power and ground. George
>
> If you find a 100% answer why, email me please, thanks
>
> PS Its a great radio but instructions are lousy.
>
>
>> From: Tim Lewis <Tim_Lewis@msm.umr.edu>
>> Subject: AeroElectric-List: Odd ICOM IC-A200 Power/Ground
>> Instructions
>
>
>> The ICOM IC-A200 (VHF Comm radio) installation instruction
>
>
> (http://www.aeroelectric.com/Installation_Data/Icom_ICA200_Installation_Manu
> al.pdf)
>
>> depicts a 10 amp breaker, and tells the installer to "Use
>> 2 pairs of #18 AWG wires for power and power grounding wiring."
>> This
>> struck me as odd, since a single 18 AWG wire is normally used with a
>> 10 amp breaker, and since the IC-A200 is rated to draw only
>> 2.6 amps (during transmit).
>
>> I called ICOM tech support and spoke to Mike, who told me that I
>> should
>> indeed use two 18 AWG wires for power and two 18 AWG wires for
>> ground,
>> and that the two wires should be twisted together "to reduce
>> interference". He further recommended twisting the end of the two
>> wires together, aided by solder, and crimping this assembly into the
>> supplied Molex terminal.
>
>> I expressed some skepticism about the efficacy of twisting two 12V
>> power wires together to reduce interference. I was unable to elicit
>> an explanation of the mechanism by which the alleged interference
>> reduction was to be achieved. I was also unable to elicit an
>> explanation of why it should take two 18AWG wires in parallel to
>> supply 2.6 Amps (peak) to a radio. I elected not to engage Mike in a
>> discussion of the advisability of crimping a connector to a soldered
>> wire.
>
>> Does anybody have insight into reasoning or experience that lends
>> credibility to the idea that two 18 AWG wires should be used for
>> power
>> (and two for
>> ground) in an ICOM IC-A200 radio installation?
>
>> Thanks,
>> Tim Lewis
>
>
> ---------------------------------
> Never miss a thing. Make Yahoo your homepage.
>
> ________________________________ Message 5
> _____________________________________
>
>
> Time: 12:18:54 PM PST US
> From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
> Subject: Re: AeroElectric-List: Rotax 914 capacitor
>
>
> At 12:13 PM 1/9/2008 -0800, you wrote:
>
>>
>> Hi All,
>> B&C offer a couple different capacitors, 10,000uF @50VDC and
>> 47,000uF
>> @16VDC. Is one of these appropriate for use on the Rotax alternator?
>> Thanks, Kevin
>
>
> This is not a really critical capacitor with
> respect to value but 16v is bit low for
> a rating. 25V or more is the target. Furhter,
> the "rule of thumb" for sizing is 1,000 uF per
> amp of alternator output so the 10KuF/50v is
> pretty good for the SD-8. Your system would
> be better served by 20KuF/25V or larger.
>
> Bob . . .
>
> ----------------------------------------)
> ( . . . a long habit of not thinking )
> ( a thing wrong, gives it a superficial )
> ( appearance of being right . . . )
> ( )
> ( -Thomas Paine 1776- )
> ----------------------------------------
>
>
> ________________________________ Message 6
> _____________________________________
>
>
> Time: 01:02:10 PM PST US
> From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
> Subject: Re: AeroElectric-List: Shielded Wire
>
>
> At 06:12 AM 1/10/2008 -0800, you wrote:
>
>>
>> Bob:
>>
>> Maybe this is a little clearer:
>>
>> All the wires in the wing are shielded.
>
>
> ?Why?
>
>
>> The wire used is MIL-DTL-27500TG2T14. That particular one is
>> 12AWG, two
>> conductor, twisted pair, shielded and sheathed. The unshielded
>> version
>> was not available without special order and long lead time. The
>> weight
>> difference between shielded and unshielded was 2.75lbs for 1,000 feet
>> so I got the shielded version.
>>
>> There are no manufacturer's recommendations per se. Sizing for loads
>> was done as per AC43-13-2A based on the power consumption rating
>> for each
> load.
>>
>> All power loads have a power lead and a return lead. The sensors
>> have
>> how ever many wires are required by the sensor.
>>
>> Ignoring connectors, fuses, switches, ground buss etc, all power
>> loads
>> were to be routed as follows:
>>
>> Power lead: Bat(+) -to- Load.
>> Return lead: Load -to- Bat (-) and, Load -to- Airframe (at
>> Local
>> Ground) -to- Bat (-)
>> Shielding: - Bat(-) -to- Airframe (at Local Ground)
>>
>> I can't find where I read it but something led me to believe that if
>> you were going to use shielded wire it was OK to do it the way I did.
>
> I'm not sure I'm interpreting you words into an
> accurate schematic of your architecture but since
> the use of shielding where shielding adds no value,
> then exactly how you wire it has no significance
> with respect to performance.
>
>
>> So, given that I am going to use the wire I have, that I am going to
>> run a return lead for all power loads and that I want to hook up the
>> shielding on the wire, what is the correct way to do it?
>>
>> Regarding the return lead, I'm pretty clear that the return lead
>> should
>> not be grounded at the Bat (-) and at a Local ground. Quote from
>> your
> response:
>>
>> " One and only one ground . . . local is probably fine
>> but not both places . . ."
>>
>> No problem changing it but why is it such a bad thing to do it that
>> way.
>> Using the landing light as an example. What harm does it cause to
>> ground it locally and also run a lead back to the bat (-). Why is
>> that
>> worse than only grounding locally and the corollary, why is that not
>> better than only running the lead back to the bat (-). Is the same
>> applicable to the strobe's power unit and the fuel pump. Would it be
>> the same for something like a flap actuator motor.
>
> My personal goals for system design are to achieve
> the desired level of performance with a minimum of
> parts and minimized $time$ to acquire/install/maintain.
>
> You appear to be asking advice for doing things that
> I would not choose to do because they do not add
> value under the design goals stated. Doing doesn't
> necessarily degrade performance but it's certain
> not to enhance it. Are there risks for venturing outside
> the simple ideas that support conventional wisdom?
> Difficult to predict but probably not.
>
>
>> Regarding the shielding: I'm less clear on this. Removing the local
>> ground from the return lead will also take the shielding out of the
>> ground path from the Load to the Bat(-). But what about grounding
>> the
> shielding itself.
>> Again using the landing light as an example, what is the difference
>> between grounding at both ends and grounding only at the Bat(-). Is
>> the same applicable to the strobe's power unit, fuel pump and flap
>> motor.
>>
>> Looking forward to your explanations.
>
> A detailed trek through the physics from which
> conventional wisdom and common practices evolved
> is beyond the scope of what I can do here on
> the List. I did a short-course on noise propagation
> issues and solutions a few years ago at Hawker-
> Beech . . . and that was a 4-hour, Power-Point
> presentation.
>
> Suffice it to say that if my mental image
> for what you've described is correct,
> then there is no reason to expect degradation
> of performance and no reason to expect an
> enhancement of performance. I.e, shielding
> added without specific noise propagation
> problems to be solved only adds to weight
> of the airplane and cost of ownership. It
> follows then that I have no advice based
> on physics to offer for "doing it right".
>
> Bob . . .
>
>
> ________________________________ Message 7
> _____________________________________
>
>
> Time: 02:56:00 PM PST US
> Subject: AeroElectric-List: Re: Shielded Wire
> From: "Eric M. Jones" <emjones@charter.net>
>
>
> Okay, cut this message out and punch three holes into it and stick
> it into
> your book. This is the cat's meow on coaxial cable shielding and
> grounding
> from Kimmel Gerke Associates. I hope they balance my liberal use of
> their
> stuff with the free advertising given here.
>
> http://www.emiguru.com/kgb/sum1996.htm Kimmel Gerke Bullets.
>
> "For many designers, cables and connectors are an afterthought.
> After all,
> they just connect things together, right? But cables and connectors
> are
> major entry and exit points for EMI into and out of electronic
> systems. They
> act as "hidden antennas" for radiated energy, and "hidden conduits"
> for
> conducted energy.
>
>
> "In fact, cables and connectors are so important, they are the often
> the
> first things we check out when troubleshooting EMI problems in a
> system.
> Here are a few thoughts on cable and connector design for EMI.
> Trade off shielding for filtering. If you don't filter I/O
> interfaces, then
> you must assume that the highest frequencies inside the unit will
> end up on
> the cable wires. (Or you must assume the cables will intercept the
> highest
> frequencies and bring them into the unit.)
>
> "Just because that RS-232 interface is only operating in the
> kilobaud range
> doesn't stop higher frequencies from hitching a "free ride" on the
> cables.
> We've solved many radiated problems (emissions and immunity) by adding
> simple filters to interfaces that were only supposed to carry "slow"
> or "low
> frequency" signals.
>
> "The alternate to filtering the cables is shielding the cables. We
> generally
> prefer to filter slower cables, since it's usually more cost
> effective and
> easier to maintain EMI integrity.
>
> "Ground the cable shield. If you do decide to use shielded cables,
> then the
> immediate question becomes how best to ground the cable shield. The
> correct
> method depends on both threat frequencies and circuit impedance
> levels.
>
> "For problem frequencies below 10 kHz [audio], the preferred
> approach is to
> ground one only one end of the shield. This is to prevent "ground
> loop"
> coupling from the cable shield to the inner wires. This is
> particularly
> important for preventing 60 Hz coupling into low level/high impedance
> circuits used in audio or instrumentation systems.
>
> "Unfortunately, this is exactly the wrong thing to do for high
> frequency
> threats.
> For most RF situations [above 10 kHz], the preferred approach is to
> ground
> both ends of the cable shield, to minimize coupling at the open end
> due to
> standing wave effects. So what do you do if both threats exist? You
> can
> ground one end with a small capacitor (1,000- 10,000 pf typical) or
> you can
> use two shields
> - one grounded on one end, and the other grounded on both ends. In the
> latter case, the shields must be insulated from each other.
>
> "One more case where both ends must be grounded is the low frequency/
> low
> impedance case, where magnetic fields are the major culprit. In this
> case,
> the strategy is to minimize "loop size" by providing an adjacent
> return path
> for noise currents. This is often necessary in electrical sub-
> stations,
> where large 60 Hz magnetic fields exist due to the high current
> levels. Most
> of the time, however, single point grounding at low frequencies is the
> preferred approach.
>
> "Use Care With Connector Terminations. This is extremely important for
> shielded cables with EMI threats above about 1 MHz. Poor joints (or
> worse,
> "pigtail" connections from the shield to the connector) are a
> leading cause
> EMI-induced failures on shielded cables. We've seen 20 dB increases in
> emissions, and 10 fold reductions in ESD immunity due to poor
> connections.
> (Remember, with a 1 nsec edge rate, ESD is a 300 MHz EMI problem.)
>
> "To maintain high frequency cable shield integrity, you need a
> circumferential bond between the cable shield and the connector
> shell. In
> addition you need full metal-to-metal between the mating connectors.
> Finally, you need a solid connector-to-chassis connection. One
> problem we
> often see here is with chassis connectors that overlap connector
> cutouts.
> The imprecise fit creates a slot that very effectively couples high
> frequency energy directly to/from the cable shield. Think in terms
> of a
> garden hose -you need a very tight connection at the faucet, or else
> it
> leaks.
>
> "What About The Cable Shield Itself? Yes, this is a valid concern,
> but only
> after you have addressed the connector termination issues. For
> frequencies
> below about 10 MHz, most cable shielding materials behave about the
> same,
> and provide very respectable amounts of shielding. For frequencies
> above
> about 10 MHz, however, the cable construction becomes important. Loose
> single braids become increasingly leaky, so above 10 MHz, you may
> need high
> density braid shields. Double braids work very well here, as do
> braid over
> Mylar cable shields. For high frequencies, both shields should be
> connected
> together. "
>
> --------
> Eric M. Jones
> www.PerihelionDesign.com
> 113 Brentwood Drive
> Southbridge, MA 01550
> (508) 764-2072
> emjones@charter.net
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=157322#157322
>
>
> ________________________________ Message 8
> _____________________________________
>
>
> Time: 05:19:04 PM PST US
> From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
> Subject: Re: AeroElectric-List: XM radio power cord
>
>
> At 06:06 PM 1/9/2008 -0500, you wrote:
>
>> <densing@carolina.rr.com>
>>
>> A question regarding an XM Express radio that I use in the airplane
>> and
>> in the car.
>>
>> The power cord for the XM radio has a cigarette lighter type plug, is
>> about three feet long with a mini coaxial plug on the radio end.
>> Clamped on the cord are two cylinder shaped plastic devices (for lack
>> of a better descriptive word). There is one on the cig. liter plug
>> end
>> and another smaller one on the radio end.
>> The wire used in the power cord is very stiff and difficult to keep
>> organized and out of the way. I would like to substitute another
>> power
>> cord that is coiled and stretchy. Much easier to manage and keep
>> neat.
>> What are the devices clamped on the cord and what is their function?
>> What will be the impact if I used a power cord without the devices.
>
> I suspect these are ferrite noise filters which
> are commonly added to commercial products for the
> for the purpose of reducing conducted electro-magnetic
> interference between devices connected with the cable.
>
> See:
>
> http://www.aeroelectric.com/Pictures/Filters/Ferrite_EMI_Filter_2.jpg
>
> http://www.aeroelectric.com/Pictures/Filters/Ferrite_EMI_Filter.jpg
>
> If the devices you're seeing are similar in nature, then
> it's probable that your device will FUNCTION if fitted
> with a cord that does not have the filters.
>
> But like any non-qualified device use in the airplane,
> you should be cognizant of potential for interference
> from the XM radio . . . whether filtered or not. Do some
> tests and be ready to turn the radio OFF anytime another
> radio system seems not to behave as expected.
>
> Bob . . .
>
>
> ----------------------------------------)
> ( . . . a long habit of not thinking )
> ( a thing wrong, gives it a superficial )
> ( appearance of being right . . . )
> ( )
> ( -Thomas Paine 1776- )
> ----------------------------------------
>
>
> ________________________________ Message 9
> _____________________________________
>
>
> Time: 05:41:58 PM PST US
> From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
> Subject: Re: AeroElectric-List: Strobe discharge pop-pop-pop
>
>
> At 01:36 PM 1/9/2008 -0500, you wrote:
>
>> <recapen@earthlink.net>
>>
>> I'm doing some system testing and I can hear a very slight pop each
>> time my strobes discharge through my headset. It doesn't break the
>> squelch or prevent me from hearing the radios - or stereo for that
>> matter. No whining on the charge cycles and I gotta listen carefully
>> to catch the pop
>> - but it's there.
>>
>> Is this strictly due to the high-voltage discharge in a 12V
>> system? Is
>> there something I can due to get rid of this? Or should I take
>> gladness that it's faint, doesn't interfere, it's as good as it gets,
>> have a coke and a smile and.......?
>
> When you think about the physics of what's going
> on inside a xenon flash-tube, it has a great deal
> in common with a lightning strike. As we all know,
> a lighting strike can be "felt" both in terms of
> magnetic and electrostatic effects, both of which
> have the ability to radiate some distance and/or
> couple to conductors.
>
> What you're hearing is the broad spectrum, radiated
> noise coming directly from the confines of the ionized
> gasses in the tube when it fires.
>
> When we put the first strobes on Cessna single-engine
> airplanes in the 60's, there was a lot of fuss about
> this mini-strike being heard in the ADF receivers.
> We tried some glass with conductive coatings (reduced
> light output) and fine-mesh screen wire (really hard to
> work with).
>
> Somebody finally noted that, "Bee, when you're tuned to
> a station that was strong enough to be useable for either
> listening or navigating, the "pop" was imperceptible
> and effects on navigation nil."
>
> Chances are that in flight, you're going to discover
> the same thing. Now, if it does turn out to be a problem,
> you'll need to repeat the same experiments we tried 40
> years ago and perhaps some new ones. I'm aware of no
> current tricks of the trade that would a apply.
>
> Bob . . .
>
>
> ________________________________ Message 10
> ____________________________________
>
>
> Time: 06:01:33 PM PST US
> From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
> Subject: Re: AeroElectric-List: Question about Annunciating Lights
>
>
> At 12:54 PM 1/9/2008 -0500, you wrote:
>
>> Bob, it would help if you also added these pictures to the article...
>>
>> Bret Smith
>> RV-9A "Fuselage"
>> Blue Ridge, GA
>
>
> Done. Thanks!
>
>
>>> A fine piece of work! I've preserved this data in
>>> an excerpt of the websit and posted it to:
>>>
>>> http://aeroelectric.com/articles/Roll_your_own_Annunicator_Panel.pdf
>>
>> Bob . . .
>>
>> ----------------------------------------)
>> ( . . . a long habit of not thinking )
>> ( a thing wrong, gives it a superficial )
>> ( appearance of being right . . . )
>> ( )
>> ( -Thomas Paine 1776- )
>> ----------------------------------------
>>
>
>
> ________________________________ Message 11
> ____________________________________
>
>
> Time: 06:10:07 PM PST US
> From: Steve Thomas <lists@stevet.net>
> Subject: Re: AeroElectric-List: Cheaper 406mhz plb alternative?
>
> As far as 406MHz ELT goes, I currently have an ACK installed in my
> not-
> yet-flying Glasair. This unit is not a 406 MHz unit. With the
> demise of
> satellite tracking on 121.5, I wrote to ACK to ask if they had any
> plans to
> release a 406 unit. The reply was that, yes, they have one under
> development. It is an exact replacement for the 121.5 unit, uses
> the same
> remote head, and uses easy to replace, commercially available
> batteries (I
> don't remember what kind, but they were not Alkaline). I don't
> remember the
> price exactly, but it was half of what the lowest price alternative
> was.
> They said to keep watching their web site and expected it to be
> available
> within the first half of this year.
>
>
> On Jan 10, 2008, at 9:01 AM, David Chalmers wrote:
>
>> There's a good review here
>> http://www.equipped.org/SPOT_ORSummer2007.htm
>>
>>
>> On 1/9/08, Charlie England <ceengland@bellsouth.net> wrote:
>>>
>>
>> Anyone know any details about this product?
>>
>> http://www.findmespot.com/explorespot/spotmessenger.aspx
>>
>> IF it's using the public SARSAT satellites, maybe it would still work
>>
>>
>
>
> ________________________________ Message 12
> ____________________________________
>
>
> Time: 06:12:17 PM PST US
> From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
> Subject: Re: AeroElectric-List: Audio panel #inputs vs #sources
>
>
> At 11:16 AM 1/9/2008 -0500, you wrote:
>
>> <recapen@earthlink.net>
>>
>> Folks,
>>
>> I have three inputs that should be 'unswitched':
>> AOA warning
>> Traffic Alert
>> AF3400EM Engine monitor
>>
>> My audio panel (PS Engineering PMA7000MS) has two unswitched inputs.
>> Can I tie two of the sources to one input? I think there would
>> only be
>> an issue if they both went off at teh same time.
>> Alternatively, I can put the third to a switched input and leave the
>> switch on.
>
> Put 100 ohm resistors in series with EACH of the three output
> before bringing them together whether switched or not. See:
>
> http://aeroelectric.com/articles/Rev11/18Audio_R11.pdf
>
> Bob . . .
>
>
> ________________________________ Message 13
> ____________________________________
>
>
> Time: 06:36:13 PM PST US
> From: "Dale Ensing" <densing@carolina.rr.com>
> Subject: Re: AeroElectric-List: XM radio power cord
>
>
> Thank you Bob. The 'devices' on the power cord look just like the
> ferrite
> filters in the pictures. And thanks for the alert to possible
> interference
> to other radio systems in the airplane.
> Dale
>
>> At 06:06 PM 1/9/2008 -0500, you wrote:
>>
>>> <densing@carolina.rr.com>
>>>
>>> A question regarding an XM Express radio that I use in the airplane
>>> and in the car.
>>>
>>> The power cord for the XM radio has a cigarette lighter type plug,
>>> is
>>> about three feet long with a mini coaxial plug on the radio end.
>>> Clamped on the cord are two cylinder shaped plastic devices (for
>>> lack
>>> of a better descriptive word). There is one on the cig. liter plug
>>> end
>>> and another smaller one on the radio end.
>>> The wire used in the power cord is very stiff and difficult to keep
>>> organized and out of the way. I would like to substitute another
>>> power
>>> cord that is coiled and stretchy. Much easier to manage and keep
>>> neat.
>>> What are the devices clamped on the cord and what is their function?
>>> What will be the impact if I used a power cord without the devices.
>>
>> I suspect these are ferrite noise filters which
>> are commonly added to commercial products for the
>> for the purpose of reducing conducted electro-magnetic
>> interference between devices connected with the cable.
>>
>> See:
>>
>> http://www.aeroelectric.com/Pictures/Filters/Ferrite_EMI_Filter_2.jpg
>>
>> http://www.aeroelectric.com/Pictures/Filters/Ferrite_EMI_Filter.jpg
>>
>> If the devices you're seeing are similar in nature, then
>> it's probable that your device will FUNCTION if fitted
>> with a cord that does not have the filters.
>>
>> But like any non-qualified device use in the airplane,
>> you should be cognizant of potential for interference
>> from the XM radio . . . whether filtered or not. Do some
>> tests and be ready to turn the radio OFF anytime another
>> radio system seems not to behave as expected.
>>
>> Bob . . .
>
>
> ________________________________ Message 14
> ____________________________________
>
>
> Time: 09:20:38 PM PST US
> From: Fiveonepw@aol.com
> Subject: Re: AeroElectric-List: Question about Annunciating Lights
>
>
> In a message dated 01/10/2008 8:21:26 AM Central Standard Time,
> bferrell@123mail.net writes:
>
>
> I made my panel out of Honeywell microswitches.
>
>>>>
> Slick! Where were these back when I needed 'em?! Nice work-
>
> Mark
> do not archive
>
>
> **************Start the year off right. Easy ways to stay in shape.
> http://body.aol.com/fitness/winter-exercise?NCID=aolcmp00300000002489
>
>
Message 8
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|
Subject: | Re: Shielded Wire |
Before folks get too obsessed with this exercise, know that
Bill Kimmel and Daryl Gerke are the acknowledged gurus of
EMI prevention and control. I've taken Bill's two-day
course and companies I work for have used their assistance
many times for solving protracted problems. I have the
course notebook on shelf above my desk.
MOST of what's addressed in this posting deals with situations
that are not found in your light aircraft electrical system and
only a few issues will be a part of your avionics installation.
Further, these "bullets" are all true but lifted out of context
of the several-to-many minutes of discussion that preceded or
followed it in the course of understanding the physics behind
the idea. "Bullets" or "rules of thumb" are exceedingly poor
substitutes for understanding, especially this set which deal
with situations that the astute system designer should have already
considered the issues before you bought the product.
This illustrates the rationale for my suggestion that the
manufacturer's installation instructions should be your golden
source for how shields should be treated and whether or not
they are even necessary. THOSE are the guys who should have
taken Bill's course (or equal) and they've already done the
homework (EMC lab or extensive field trials where the effects
of EMI were the focus of attention).
For the general population of OBAM aircraft builders to clutch
onto these "twigs of wisdom" in the flood of potential EMI problems
is not a good use of $time$. While the data are good, the likelihood
that the neophyte wire slinger in an RV is going to extract a
project-saving solution to a problem is small and the expenditure
of $time$ will be significant.
If anyone is motivated enough to acquire some skills in this
arena, then it needs to be supported by the sum total of books
and articles from which these gems of wisdom were plucked and
probably the support of a capable teacher to help assemble the
simple-ideas into good inventions. If you do encounter some form
of EMI problem in your project, the likelihood of cherry-picking a
solution from the list below is small.
Bob . . .
At 02:54 PM 1/10/2008 -0800, you wrote:
>
>Okay, cut this message out and punch three holes into it and stick it into
>your book. This is the cat's meow on coaxial cable shielding and grounding
>from Kimmel Gerke Associates. I hope they balance my liberal use of their
>stuff with the free advertising given here.
>
>http://www.emiguru.com/kgb/sum1996.htm Kimmel Gerke Bullets.
>
>"For many designers, cables and connectors are an afterthought. After all,
>they just connect things together, right? But cables and connectors are
>major entry and exit points for EMI into and out of electronic systems.
>They act as "hidden antennas" for radiated energy, and "hidden conduits"
>for conducted energy.
>
>"In fact, cables and connectors are so important, they are the often the
>first things we check out when troubleshooting EMI problems in a system.
>Here are a few thoughts on cable and connector design for EMI.
>Trade off shielding for filtering. If you don't filter I/O interfaces,
>then you must assume that the highest frequencies inside the unit will end
>up on the cable wires. (Or you must assume the cables will intercept the
>highest frequencies and bring them into the unit.)
>
>"Just because that RS-232 interface is only operating in the kilobaud
>range doesn't stop higher frequencies from hitching a "free ride" on the
>cables. We've solved many radiated problems (emissions and immunity) by
>adding simple filters to interfaces that were only supposed to carry
>"slow" or "low frequency" signals.
>
>"The alternate to filtering the cables is shielding the cables. We
>generally prefer to filter slower cables, since it's usually more cost
>effective and easier to maintain EMI integrity.
>
>"Ground the cable shield. If you do decide to use shielded cables, then
>the immediate question becomes how best to ground the cable shield. The
>correct method depends on both threat frequencies and circuit impedance
>levels.
>
>"For problem frequencies below 10 kHz [audio], the preferred approach is
>to ground one only one end of the shield. This is to prevent "ground loop"
>coupling from the cable shield to the inner wires. This is particularly
>important for preventing 60 Hz coupling into low level/high impedance
>circuits used in audio or instrumentation systems.
>
>"Unfortunately, this is exactly the wrong thing to do for high frequency
>threats. For most RF situations [above 10 kHz], the preferred approach is
>to ground both ends of the cable shield, to minimize coupling at the open
>end due to standing wave effects. So what do you do if both threats exist?
>You can ground one end with a small capacitor (1,000- 10,000 pf typical)
>or you can use two shields - one grounded on one end, and the other
>grounded on both ends. In the latter case, the shields must be insulated
>from each other.
>
>"One more case where both ends must be grounded is the low frequency/low
>impedance case, where magnetic fields are the major culprit. In this case,
>the strategy is to minimize "loop size" by providing an adjacent return
>path for noise currents. This is often necessary in electrical
>sub-stations, where large 60 Hz magnetic fields exist due to the high
>current levels. Most of the time, however, single point grounding at low
>frequencies is the preferred approach.
>
>"Use Care With Connector Terminations. This is extremely important for
>shielded cables with EMI threats above about 1 MHz. Poor joints (or worse,
>"pigtail" connections from the shield to the connector) are a leading
>cause EMI-induced failures on shielded cables. We've seen 20 dB increases
>in emissions, and 10 fold reductions in ESD immunity due to poor
>connections. (Remember, with a 1 nsec edge rate, ESD is a 300 MHz EMI problem.)
>
>"To maintain high frequency cable shield integrity, you need a
>circumferential bond between the cable shield and the connector shell. In
>addition you need full metal-to-metal between the mating connectors.
>Finally, you need a solid connector-to-chassis connection. One problem we
>often see here is with chassis connectors that overlap connector cutouts.
>The imprecise fit creates a slot that very effectively couples high
>frequency energy directly to/from the cable shield. Think in terms of a
>garden hose -you need a very tight connection at the faucet, or else it leaks.
>
>"What About The Cable Shield Itself? Yes, this is a valid concern, but
>only after you have addressed the connector termination issues. For
>frequencies below about 10 MHz, most cable shielding materials behave
>about the same, and provide very respectable amounts of shielding. For
>frequencies above about 10 MHz, however, the cable construction becomes
>important. Loose single braids become increasingly leaky, so above 10 MHz,
>you may need high density braid shields. Double braids work very well
>here, as do braid over Mylar cable shields. For high frequencies, both
>shields should be connected together. "
>
>--------
>Eric M. Jones
>www.PerihelionDesign.com
>113 Brentwood Drive
>Southbridge, MA 01550
>(508) 764-2072
>emjones@charter.net
Message 9
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|
Subject: | Re: Audio panel #inputs vs #sources |
Thanks - occasionally, I have an active brain cell or two.....
-----Original Message-----
>From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
>Sent: Jan 11, 2008 10:47 AM
>To: aeroelectric-list@matronics.com
>Subject: Re: AeroElectric-List: Audio panel #inputs vs #sources
>
>
>At 08:13 AM 1/11/2008 -0500, you wrote:
>
>><recapen@earthlink.net>
>>
>>Bob,
>>
>>I have heard 100ohm, 470ohm, and 510ohm. I'm guessing that either will
>>function properly and that the 470 and 510's will decrease the volume more
>>in addition to preventing the backfeed.
>>
>>Ralph
>
> Astute supposition sir.
>
> Bob . . . ----------------------------------------)
>
> ( . . . a long habit of not thinking )
> ( a thing wrong, gives it a superficial )
> ( appearance of being right . . . )
> ( )
> ( -Thomas Paine 1776- )
> ----------------------------------------
>
>
Message 10
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|
Indeed, and you can always activate it when you know you are going down. In fact
I wonder how reliable the G switches are in the case of ELT's anyway...121.5
ELTs are notoriously innefective but the 406 units will still have the same kind
of G switch technology I would presume, how well do they work?
Indeed my Wife is briefed to do exactly this...if the engine quits have the PLB
in your hands and be ready to activate.
As to Steve Fosset I thought he just a had a 121.5 ELT and the same thing on a
fancy wristwatch I doubt if that was a full 406 unit with a 5W transmit signal
(remember that 121.5's only have a 50mW signal I believe)...This is supposed
to be enough power to get out from under tree cover ect.
Personally I want the satellites to have a lock on me BEFORE we hit the ground.
Frank rv7a
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Steve Thomas
Sent: Friday, January 11, 2008 8:22 AM
Subject: AeroElectric-List: Re: ELT/PLB
Well, a PLB may be less expensive, but it presumes that you are conscious when
you need to activate it. Or that you will successfully regain consciousness before,
well, you know. Steve Fausset had a personal PLB - didn't do him any good
at all. Just a thought.
On Jan 11, 2008, at 7:24 AM, Giffen Marr wrote:
> --> <GAMarr@Charter.Net
> >
>
> I am planning on using the cheapest ELT available to meet the FAR 91
> Requirements and a 406 PLB. The current cost of ELT's meeting the 406
> requirements are out of sight as compared to the 121.5 units. The
> other advantage is the PLB is not much larger then a cell phone as
> compared to the ELT. Only advantage to the ELT is the battery life may
> be longer then the PLB.
>
> Giff Marr
> LIV-P/Mistral 65%
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
> AeroElectric-List Digest Server
> Sent: Friday, January 11, 2008 1:56 AM
> To: AeroElectric-List Digest List
> Subject: AeroElectric-List Digest: 14 Msgs - 01/10/08
>
> *
>
> =================================================
> Online Versions of Today's List Digest Archive
> =================================================
>
> Today's complete AeroElectric-List Digest can also be found in either
> of the two Web Links listed below. The .html file includes the Digest
> formatted in HTML for viewing with a web browser and features
> Hyperlinked Indexes and Message Navigation. The .txt file includes
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> browser.
>
> HTML Version:
>
>
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>
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>
> ===============================================
> EMail Version of Today's List Digest Archive
> ===============================================
>
>
> ----------------------------------------------------------
> AeroElectric-List Digest Archive
> ---
> Total Messages Posted Thu 01/10/08: 14
> ----------------------------------------------------------
>
>
> Today's Message Index:
> ----------------------
>
> 1. 05:17 AM - Re: Strobe discharge pop-pop-pop (Ralph E. Capen)
> 2. 06:19 AM - Re: Question about Annunciating Lights (Brett
> Ferrell)
> 3. 09:16 AM - Re: Cheaper 406mhz plb alternative? (David
> Chalmers)
> 4. 10:08 AM - Re: Odd ICOM IC-A200 Power/Ground Instructions ()
> 5. 12:18 PM - Re: Rotax 914 capacitor (Robert L. Nuckolls, III)
> 6. 01:02 PM - Re: Shielded Wire (Robert L. Nuckolls, III)
> 7. 02:56 PM - Re: Shielded Wire (Eric M. Jones)
> 8. 05:19 PM - Re: XM radio power cord (Robert L. Nuckolls, III)
> 9. 05:41 PM - Re: Strobe discharge pop-pop-pop (Robert L.
> Nuckolls,
> III)
> 10. 06:01 PM - Re: Question about Annunciating Lights (Robert L.
> Nuckolls, III)
> 11. 06:10 PM - Re: Cheaper 406mhz plb alternative? (Steve Thomas)
> 12. 06:12 PM - Re: Audio panel #inputs vs #sources (Robert L.
> Nuckolls,
> III)
> 13. 06:36 PM - Re: XM radio power cord (Dale Ensing)
> 14. 09:20 PM - Re: Question about Annunciating Lights
> (Fiveonepw@aol.com)
>
>
> ________________________________ Message 1
> _____________________________________
>
>
> Time: 05:17:08 AM PST US
> From: "Ralph E. Capen" <recapen@earthlink.net>
> Subject: Re: AeroElectric-List: Strobe discharge pop-pop-pop
>
>
> I'll be trying it outside soon and with the engine later - I'm almost
> thinking the engine will drown it out...
>
> -----Original Message-----
>> From: Ken <klehman@albedo.net>
>> Sent: Jan 9, 2008 11:45 PM
>> To: aeroelectric-list@matronics.com
>> Subject: Re: AeroElectric-List: Strobe discharge pop-pop-pop
>>
>>
>> Ralph
>> Have you tried it outside? My radio picks it up when in a metal
>> hangar but not when outside. My intercom picks up a little as well
>> via power supply or ground but hardly noticeable with the engine
>> idling. So it might not be worth pursuing. The chapter on noise and
>> grounding may be helpful. And if it is still noticeable a cheap
>> automotive radio power filter on the strobe power supplies also
>> helped in my case.
>> Ken
>>
>> Ralph E. Capen wrote:
>>>
>>> I'm doing some system testing and I can hear a very slight pop each
>>> time my
> strobes discharge through my headset. It doesn't break the squelch or
> prevent me from hearing the radios - or stereo for that matter. No
> whining on the charge cycles and I gotta listen carefully to catch the
> pop - but it's there.
>>>
>>> Is this strictly due to the high-voltage discharge in a 12V system?
>>> Is there
> something I can due to get rid of this? Or should I take gladness
> that it's faint, doesn't interfere, it's as good as it gets, have a
> coke and a smile and.......?
>>>
>>> Ralph
>>
>>
>
>
> ________________________________ Message 2
> _____________________________________
>
>
> Time: 06:19:33 AM PST US
> From: Brett Ferrell <bferrell@123mail.net>
> Subject: RE: AeroElectric-List: Question about Annunciating Lights
>
>
> I made my panel out of Honeywell microswitches. It's not really a
> cheap way, but the results are nice, and it's fairly straight-forward,
> with "dead face"
> (labels so you KNOW the lamp is out, because it cannot be read unless
> illuminated from behind). I also built a push-to-test circuit.
>
> http://www.velocityxl.com/Electrical.htm
> (just the pictures)
> http://www.velocityxl.com/annunciator.JPG
> http://www.velocityxl.com/press_to_test.JPG
> http://www.velocityxl.com/IMAGES2/GRT3.JPG
>
> I bought mine from these folks http://www.fmw411.com/
>
> Brett
>
> Quoting Carl Morgan <zk-vii@rvproject.gen.nz>:
>
>> I took Mark's work as a basis, and this is what I ended up with....
>>
>> Close up:
>> http://www.rvproject.gen.nz/photos/2007-06/Web_Img_9760.jpg
>>
>> http://www.rvproject.gen.nz/dailylog/dailylog_2007-07-28.html the
>> final look,
>>
>>
>> http://www.rvproject.gen.nz/dailylog/dailylog_2007-06-18.html and
>> http://www.rvproject.gen.nz/dailylog/dailylog_2007-06-19.html for
>> some of the fabrication process.
>>
>> Just another possible source of ideas.
>>
>> Carl
>>
>> --
>> Carl Morgan - ZK-VII - RV 7A - Inspection next Tue!
>> http://www.rvproject.gen.nz/
>> -----Original Message-----
>> From: owner-aeroelectric-list-server@matronics.com
>> [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of
>> Fiveonepw@aol.com
>> Sent: 10 January 2008 18:14
>> To: aeroelectric-list@matronics.com
>> Subject: Re: AeroElectric-List: Question about Annunciating Lights
>>
>>
>> Here's another take on rollin' yer own:
>>
>>
>> http://websites.expercraft.com/n51pw/index.php?
>> q=log_entry&log_id=5126
>>
>> Click on fotos for bigger view and Next Entry>> for more info
>> (several
>> pages) including wiring diagram, part #s etc...
>>
>> From The PossumWorks in TN
>> Mark Phillips
>>
>>
>> ---------------------------------------------------------------------
>> -
>> ------
>> --
>> Start the year off right. Easy ways to stay in shape in the new
>> year.
>>
>>
>> 10:16
>>
>
>
> ________________________________ Message 3
> _____________________________________
>
>
> Time: 09:16:46 AM PST US
> From: "David Chalmers" <david@ChalmersFamily.com>
> Subject: Re: AeroElectric-List: Cheaper 406mhz plb alternative?
>
> There's a good review here
> http://www.equipped.org/SPOT_ORSummer2007.htm
>
>
> On 1/9/08, Charlie England <ceengland@bellsouth.net> wrote:
>>
>> ceengland@bellsouth.net>
>>
>> Anyone know any details about this product?
>>
>> http://www.findmespot.com/explorespot/spotmessenger.aspx
>>
>> IF it's using the public SARSAT satellites, maybe it would still work
>> after the 1st mandatory subscription lapses. (Still be a lot cheaper
>> than typical PLBs with built in GPS.)
>>
>> Charlie
>>
>>
>
> ________________________________ Message 4
> _____________________________________
>
>
> Time: 10:08:56 AM PST US
> From: <gmcjetpilot@yahoo.com>
> Subject: AeroElectric-List: Re: Odd ICOM IC-A200 Power/Ground
> Instructions
>
> Tim the 18 awg and 10 amp fuse is the broad brush approach, one size
> fits all. Yes its overkill. You could use a smaller awg wire and fuse.
> Also sometimes people gang off of existing 10 amp CB's and therefore
> 18 awg is the correct wire size. I used 5 amp and stayed with the 18
> awg because I had it; A short run of 20 awg would work fine. They're
> just covered their bases.
>
> Notice 13.8 volts spec? You can take some IR loss with a 14.3-14.5
> volt buss.
>
> The wire diagram clearly shows ONE power and ONE ground with a daisy
> chain or jumpers. Sorry have no idea what he's talking about. TWIST?
> Really. May
> be this is new and it does help but I am stumped. I went with one wire
> for power and ground. George
>
> If you find a 100% answer why, email me please, thanks
>
> PS Its a great radio but instructions are lousy.
>
>
>> From: Tim Lewis <Tim_Lewis@msm.umr.edu>
>> Subject: AeroElectric-List: Odd ICOM IC-A200 Power/Ground
>> Instructions
>
>
>> The ICOM IC-A200 (VHF Comm radio) installation instruction
>
>
> (http://www.aeroelectric.com/Installation_Data/Icom_ICA200_Installatio
> n_Manu
> al.pdf)
>
>> depicts a 10 amp breaker, and tells the installer to "Use
>> 2 pairs of #18 AWG wires for power and power grounding wiring."
>> This
>> struck me as odd, since a single 18 AWG wire is normally used with a
>> 10 amp breaker, and since the IC-A200 is rated to draw only
>> 2.6 amps (during transmit).
>
>> I called ICOM tech support and spoke to Mike, who told me that I
>> should indeed use two 18 AWG wires for power and two 18 AWG wires for
>> ground, and that the two wires should be twisted together "to reduce
>> interference". He further recommended twisting the end of the two
>> wires together, aided by solder, and crimping this assembly into the
>> supplied Molex terminal.
>
>> I expressed some skepticism about the efficacy of twisting two 12V
>> power wires together to reduce interference. I was unable to elicit
>> an explanation of the mechanism by which the alleged interference
>> reduction was to be achieved. I was also unable to elicit an
>> explanation of why it should take two 18AWG wires in parallel to
>> supply 2.6 Amps (peak) to a radio. I elected not to engage Mike in a
>> discussion of the advisability of crimping a connector to a soldered
>> wire.
>
>> Does anybody have insight into reasoning or experience that lends
>> credibility to the idea that two 18 AWG wires should be used for
>> power (and two for
>> ground) in an ICOM IC-A200 radio installation?
>
>> Thanks,
>> Tim Lewis
>
>
> ---------------------------------
> Never miss a thing. Make Yahoo your homepage.
>
> ________________________________ Message 5
> _____________________________________
>
>
> Time: 12:18:54 PM PST US
> From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
> Subject: Re: AeroElectric-List: Rotax 914 capacitor
>
>
> At 12:13 PM 1/9/2008 -0800, you wrote:
>
>>
>> Hi All,
>> B&C offer a couple different capacitors, 10,000uF @50VDC and 47,000uF
>> @16VDC. Is one of these appropriate for use on the Rotax alternator?
>> Thanks, Kevin
>
>
> This is not a really critical capacitor with
> respect to value but 16v is bit low for
> a rating. 25V or more is the target. Furhter,
> the "rule of thumb" for sizing is 1,000 uF per
> amp of alternator output so the 10KuF/50v is
> pretty good for the SD-8. Your system would
> be better served by 20KuF/25V or larger.
>
> Bob . . .
>
> ----------------------------------------)
> ( . . . a long habit of not thinking )
> ( a thing wrong, gives it a superficial )
> ( appearance of being right . . . )
> ( )
> ( -Thomas Paine 1776- )
> ----------------------------------------
>
>
> ________________________________ Message 6
> _____________________________________
>
>
> Time: 01:02:10 PM PST US
> From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
> Subject: Re: AeroElectric-List: Shielded Wire
>
>
> At 06:12 AM 1/10/2008 -0800, you wrote:
>
>>
>> Bob:
>>
>> Maybe this is a little clearer:
>>
>> All the wires in the wing are shielded.
>
>
> ?Why?
>
>
>> The wire used is MIL-DTL-27500TG2T14. That particular one is
>> 12AWG, two
>> conductor, twisted pair, shielded and sheathed. The unshielded
>> version
>> was not available without special order and long lead time. The
>> weight
>> difference between shielded and unshielded was 2.75lbs for 1,000 feet
>> so I got the shielded version.
>>
>> There are no manufacturer's recommendations per se. Sizing for loads
>> was done as per AC43-13-2A based on the power consumption rating
>> for each
> load.
>>
>> All power loads have a power lead and a return lead. The sensors
>> have
>> how ever many wires are required by the sensor.
>>
>> Ignoring connectors, fuses, switches, ground buss etc, all power
>> loads
>> were to be routed as follows:
>>
>> Power lead: Bat(+) -to- Load.
>> Return lead: Load -to- Bat (-) and, Load -to- Airframe (at
>> Local
>> Ground) -to- Bat (-)
>> Shielding: - Bat(-) -to- Airframe (at Local Ground)
>>
>> I can't find where I read it but something led me to believe that if
>> you were going to use shielded wire it was OK to do it the way I did.
>
> I'm not sure I'm interpreting you words into an
> accurate schematic of your architecture but since
> the use of shielding where shielding adds no value,
> then exactly how you wire it has no significance
> with respect to performance.
>
>
>> So, given that I am going to use the wire I have, that I am going to
>> run a return lead for all power loads and that I want to hook up the
>> shielding on the wire, what is the correct way to do it?
>>
>> Regarding the return lead, I'm pretty clear that the return lead
>> should
>> not be grounded at the Bat (-) and at a Local ground. Quote from
>> your
> response:
>>
>> " One and only one ground . . . local is probably fine
>> but not both places . . ."
>>
>> No problem changing it but why is it such a bad thing to do it that
>> way.
>> Using the landing light as an example. What harm does it cause to
>> ground it locally and also run a lead back to the bat (-). Why is
>> that
>> worse than only grounding locally and the corollary, why is that not
>> better than only running the lead back to the bat (-). Is the same
>> applicable to the strobe's power unit and the fuel pump. Would it be
>> the same for something like a flap actuator motor.
>
> My personal goals for system design are to achieve
> the desired level of performance with a minimum of
> parts and minimized $time$ to acquire/install/maintain.
>
> You appear to be asking advice for doing things that
> I would not choose to do because they do not add
> value under the design goals stated. Doing doesn't
> necessarily degrade performance but it's certain
> not to enhance it. Are there risks for venturing outside
> the simple ideas that support conventional wisdom?
> Difficult to predict but probably not.
>
>
>> Regarding the shielding: I'm less clear on this. Removing the local
>> ground from the return lead will also take the shielding out of the
>> ground path from the Load to the Bat(-). But what about grounding
>> the
> shielding itself.
>> Again using the landing light as an example, what is the difference
>> between grounding at both ends and grounding only at the Bat(-). Is
>> the same applicable to the strobe's power unit, fuel pump and flap
>> motor.
>>
>> Looking forward to your explanations.
>
> A detailed trek through the physics from which
> conventional wisdom and common practices evolved
> is beyond the scope of what I can do here on
> the List. I did a short-course on noise propagation
> issues and solutions a few years ago at Hawker-
> Beech . . . and that was a 4-hour, Power-Point
> presentation.
>
> Suffice it to say that if my mental image
> for what you've described is correct,
> then there is no reason to expect degradation
> of performance and no reason to expect an
> enhancement of performance. I.e, shielding
> added without specific noise propagation
> problems to be solved only adds to weight
> of the airplane and cost of ownership. It
> follows then that I have no advice based
> on physics to offer for "doing it right".
>
> Bob . . .
>
>
> ________________________________ Message 7
> _____________________________________
>
>
> Time: 02:56:00 PM PST US
> Subject: AeroElectric-List: Re: Shielded Wire
> From: "Eric M. Jones" <emjones@charter.net>
>
>
> Okay, cut this message out and punch three holes into it and stick
> it into
> your book. This is the cat's meow on coaxial cable shielding and
> grounding
> from Kimmel Gerke Associates. I hope they balance my liberal use of
> their
> stuff with the free advertising given here.
>
> http://www.emiguru.com/kgb/sum1996.htm Kimmel Gerke Bullets.
>
> "For many designers, cables and connectors are an afterthought.
> After all,
> they just connect things together, right? But cables and connectors
> are
> major entry and exit points for EMI into and out of electronic
> systems. They
> act as "hidden antennas" for radiated energy, and "hidden conduits"
> for
> conducted energy.
>
>
> "In fact, cables and connectors are so important, they are the often
> the
> first things we check out when troubleshooting EMI problems in a
> system.
> Here are a few thoughts on cable and connector design for EMI.
> Trade off shielding for filtering. If you don't filter I/O
> interfaces, then
> you must assume that the highest frequencies inside the unit will
> end up on
> the cable wires. (Or you must assume the cables will intercept the
> highest
> frequencies and bring them into the unit.)
>
> "Just because that RS-232 interface is only operating in the
> kilobaud range
> doesn't stop higher frequencies from hitching a "free ride" on the
> cables.
> We've solved many radiated problems (emissions and immunity) by adding
> simple filters to interfaces that were only supposed to carry "slow"
> or "low
> frequency" signals.
>
> "The alternate to filtering the cables is shielding the cables. We
> generally
> prefer to filter slower cables, since it's usually more cost
> effective and
> easier to maintain EMI integrity.
>
> "Ground the cable shield. If you do decide to use shielded cables,
> then the
> immediate question becomes how best to ground the cable shield. The
> correct
> method depends on both threat frequencies and circuit impedance
> levels.
>
> "For problem frequencies below 10 kHz [audio], the preferred
> approach is to
> ground one only one end of the shield. This is to prevent "ground
> loop"
> coupling from the cable shield to the inner wires. This is
> particularly
> important for preventing 60 Hz coupling into low level/high impedance
> circuits used in audio or instrumentation systems.
>
> "Unfortunately, this is exactly the wrong thing to do for high
> frequency
> threats.
> For most RF situations [above 10 kHz], the preferred approach is to
> ground
> both ends of the cable shield, to minimize coupling at the open end
> due to
> standing wave effects. So what do you do if both threats exist? You
> can
> ground one end with a small capacitor (1,000- 10,000 pf typical) or
> you can
> use two shields
> - one grounded on one end, and the other grounded on both ends. In the
> latter case, the shields must be insulated from each other.
>
> "One more case where both ends must be grounded is the low frequency/
> low
> impedance case, where magnetic fields are the major culprit. In this
> case,
> the strategy is to minimize "loop size" by providing an adjacent
> return path
> for noise currents. This is often necessary in electrical sub-
> stations,
> where large 60 Hz magnetic fields exist due to the high current
> levels. Most
> of the time, however, single point grounding at low frequencies is the
> preferred approach.
>
> "Use Care With Connector Terminations. This is extremely important for
> shielded cables with EMI threats above about 1 MHz. Poor joints (or
> worse,
> "pigtail" connections from the shield to the connector) are a
> leading cause
> EMI-induced failures on shielded cables. We've seen 20 dB increases in
> emissions, and 10 fold reductions in ESD immunity due to poor
> connections.
> (Remember, with a 1 nsec edge rate, ESD is a 300 MHz EMI problem.)
>
> "To maintain high frequency cable shield integrity, you need a
> circumferential bond between the cable shield and the connector
> shell. In
> addition you need full metal-to-metal between the mating connectors.
> Finally, you need a solid connector-to-chassis connection. One
> problem we
> often see here is with chassis connectors that overlap connector
> cutouts.
> The imprecise fit creates a slot that very effectively couples high
> frequency energy directly to/from the cable shield. Think in terms
> of a
> garden hose -you need a very tight connection at the faucet, or else
> it
> leaks.
>
> "What About The Cable Shield Itself? Yes, this is a valid concern,
> but only
> after you have addressed the connector termination issues. For
> frequencies
> below about 10 MHz, most cable shielding materials behave about the
> same,
> and provide very respectable amounts of shielding. For frequencies
> above
> about 10 MHz, however, the cable construction becomes important. Loose
> single braids become increasingly leaky, so above 10 MHz, you may
> need high
> density braid shields. Double braids work very well here, as do
> braid over
> Mylar cable shields. For high frequencies, both shields should be
> connected
> together. "
>
> --------
> Eric M. Jones
> www.PerihelionDesign.com
> 113 Brentwood Drive
> Southbridge, MA 01550
> (508) 764-2072
> emjones@charter.net
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=157322#157322
>
>
> ________________________________ Message 8
> _____________________________________
>
>
> Time: 05:19:04 PM PST US
> From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
> Subject: Re: AeroElectric-List: XM radio power cord
>
>
> At 06:06 PM 1/9/2008 -0500, you wrote:
>
>> <densing@carolina.rr.com>
>>
>> A question regarding an XM Express radio that I use in the airplane
>> and
>> in the car.
>>
>> The power cord for the XM radio has a cigarette lighter type plug, is
>> about three feet long with a mini coaxial plug on the radio end.
>> Clamped on the cord are two cylinder shaped plastic devices (for lack
>> of a better descriptive word). There is one on the cig. liter plug
>> end
>> and another smaller one on the radio end.
>> The wire used in the power cord is very stiff and difficult to keep
>> organized and out of the way. I would like to substitute another
>> power
>> cord that is coiled and stretchy. Much easier to manage and keep
>> neat.
>> What are the devices clamped on the cord and what is their function?
>> What will be the impact if I used a power cord without the devices.
>
> I suspect these are ferrite noise filters which
> are commonly added to commercial products for the
> for the purpose of reducing conducted electro-magnetic
> interference between devices connected with the cable.
>
> See:
>
> http://www.aeroelectric.com/Pictures/Filters/Ferrite_EMI_Filter_2.jpg
>
> http://www.aeroelectric.com/Pictures/Filters/Ferrite_EMI_Filter.jpg
>
> If the devices you're seeing are similar in nature, then
> it's probable that your device will FUNCTION if fitted
> with a cord that does not have the filters.
>
> But like any non-qualified device use in the airplane,
> you should be cognizant of potential for interference
> from the XM radio . . . whether filtered or not. Do some
> tests and be ready to turn the radio OFF anytime another
> radio system seems not to behave as expected.
>
> Bob . . .
>
>
> ----------------------------------------)
> ( . . . a long habit of not thinking )
> ( a thing wrong, gives it a superficial )
> ( appearance of being right . . . )
> ( )
> ( -Thomas Paine 1776- )
> ----------------------------------------
>
>
> ________________________________ Message 9
> _____________________________________
>
>
> Time: 05:41:58 PM PST US
> From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
> Subject: Re: AeroElectric-List: Strobe discharge pop-pop-pop
>
>
> At 01:36 PM 1/9/2008 -0500, you wrote:
>
>> <recapen@earthlink.net>
>>
>> I'm doing some system testing and I can hear a very slight pop each
>> time my strobes discharge through my headset. It doesn't break the
>> squelch or prevent me from hearing the radios - or stereo for that
>> matter. No whining on the charge cycles and I gotta listen carefully
>> to catch the pop
>> - but it's there.
>>
>> Is this strictly due to the high-voltage discharge in a 12V
>> system? Is
>> there something I can due to get rid of this? Or should I take
>> gladness that it's faint, doesn't interfere, it's as good as it gets,
>> have a coke and a smile and.......?
>
> When you think about the physics of what's going
> on inside a xenon flash-tube, it has a great deal
> in common with a lightning strike. As we all know,
> a lighting strike can be "felt" both in terms of
> magnetic and electrostatic effects, both of which
> have the ability to radiate some distance and/or
> couple to conductors.
>
> What you're hearing is the broad spectrum, radiated
> noise coming directly from the confines of the ionized
> gasses in the tube when it fires.
>
> When we put the first strobes on Cessna single-engine
> airplanes in the 60's, there was a lot of fuss about
> this mini-strike being heard in the ADF receivers.
> We tried some glass with conductive coatings (reduced
> light output) and fine-mesh screen wire (really hard to
> work with).
>
> Somebody finally noted that, "Bee, when you're tuned to
> a station that was strong enough to be useable for either
> listening or navigating, the "pop" was imperceptible
> and effects on navigation nil."
>
> Chances are that in flight, you're going to discover
> the same thing. Now, if it does turn out to be a problem,
> you'll need to repeat the same experiments we tried 40
> years ago and perhaps some new ones. I'm aware of no
> current tricks of the trade that would a apply.
>
> Bob . . .
>
>
> ________________________________ Message 10
> ____________________________________
>
>
> Time: 06:01:33 PM PST US
> From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
> Subject: Re: AeroElectric-List: Question about Annunciating Lights
>
>
> At 12:54 PM 1/9/2008 -0500, you wrote:
>
>> Bob, it would help if you also added these pictures to the article...
>>
>> Bret Smith
>> RV-9A "Fuselage"
>> Blue Ridge, GA
>
>
> Done. Thanks!
>
>
>>> A fine piece of work! I've preserved this data in
>>> an excerpt of the websit and posted it to:
>>>
>>> http://aeroelectric.com/articles/Roll_your_own_Annunicator_Panel.pdf
>>
>> Bob . . .
>>
>> ----------------------------------------)
>> ( . . . a long habit of not thinking )
>> ( a thing wrong, gives it a superficial )
>> ( appearance of being right . . . )
>> ( )
>> ( -Thomas Paine 1776- )
>> ----------------------------------------
>>
>
>
> ________________________________ Message 11
> ____________________________________
>
>
> Time: 06:10:07 PM PST US
> From: Steve Thomas <lists@stevet.net>
> Subject: Re: AeroElectric-List: Cheaper 406mhz plb alternative?
>
> As far as 406MHz ELT goes, I currently have an ACK installed in my
> not-
> yet-flying Glasair. This unit is not a 406 MHz unit. With the
> demise of
> satellite tracking on 121.5, I wrote to ACK to ask if they had any
> plans to
> release a 406 unit. The reply was that, yes, they have one under
> development. It is an exact replacement for the 121.5 unit, uses
> the same
> remote head, and uses easy to replace, commercially available
> batteries (I
> don't remember what kind, but they were not Alkaline). I don't
> remember the
> price exactly, but it was half of what the lowest price alternative
> was.
> They said to keep watching their web site and expected it to be
> available
> within the first half of this year.
>
>
> On Jan 10, 2008, at 9:01 AM, David Chalmers wrote:
>
>> There's a good review here
>> http://www.equipped.org/SPOT_ORSummer2007.htm
>>
>>
>> On 1/9/08, Charlie England <ceengland@bellsouth.net> wrote:
>>>
>>
>> Anyone know any details about this product?
>>
>> http://www.findmespot.com/explorespot/spotmessenger.aspx
>>
>> IF it's using the public SARSAT satellites, maybe it would still work
>>
>>
>
>
> ________________________________ Message 12
> ____________________________________
>
>
> Time: 06:12:17 PM PST US
> From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
> Subject: Re: AeroElectric-List: Audio panel #inputs vs #sources
>
>
> At 11:16 AM 1/9/2008 -0500, you wrote:
>
>> <recapen@earthlink.net>
>>
>> Folks,
>>
>> I have three inputs that should be 'unswitched':
>> AOA warning
>> Traffic Alert
>> AF3400EM Engine monitor
>>
>> My audio panel (PS Engineering PMA7000MS) has two unswitched inputs.
>> Can I tie two of the sources to one input? I think there would
>> only be
>> an issue if they both went off at teh same time.
>> Alternatively, I can put the third to a switched input and leave the
>> switch on.
>
> Put 100 ohm resistors in series with EACH of the three output
> before bringing them together whether switched or not. See:
>
> http://aeroelectric.com/articles/Rev11/18Audio_R11.pdf
>
> Bob . . .
>
>
> ________________________________ Message 13
> ____________________________________
>
>
> Time: 06:36:13 PM PST US
> From: "Dale Ensing" <densing@carolina.rr.com>
> Subject: Re: AeroElectric-List: XM radio power cord
>
>
> Thank you Bob. The 'devices' on the power cord look just like the
> ferrite
> filters in the pictures. And thanks for the alert to possible
> interference
> to other radio systems in the airplane.
> Dale
>
>> At 06:06 PM 1/9/2008 -0500, you wrote:
>>
>>> <densing@carolina.rr.com>
>>>
>>> A question regarding an XM Express radio that I use in the airplane
>>> and in the car.
>>>
>>> The power cord for the XM radio has a cigarette lighter type plug,
>>> is
>>> about three feet long with a mini coaxial plug on the radio end.
>>> Clamped on the cord are two cylinder shaped plastic devices (for
>>> lack
>>> of a better descriptive word). There is one on the cig. liter plug
>>> end
>>> and another smaller one on the radio end.
>>> The wire used in the power cord is very stiff and difficult to keep
>>> organized and out of the way. I would like to substitute another
>>> power
>>> cord that is coiled and stretchy. Much easier to manage and keep
>>> neat.
>>> What are the devices clamped on the cord and what is their function?
>>> What will be the impact if I used a power cord without the devices.
>>
>> I suspect these are ferrite noise filters which
>> are commonly added to commercial products for the
>> for the purpose of reducing conducted electro-magnetic
>> interference between devices connected with the cable.
>>
>> See:
>>
>> http://www.aeroelectric.com/Pictures/Filters/Ferrite_EMI_Filter_2.jpg
>>
>> http://www.aeroelectric.com/Pictures/Filters/Ferrite_EMI_Filter.jpg
>>
>> If the devices you're seeing are similar in nature, then
>> it's probable that your device will FUNCTION if fitted
>> with a cord that does not have the filters.
>>
>> But like any non-qualified device use in the airplane,
>> you should be cognizant of potential for interference
>> from the XM radio . . . whether filtered or not. Do some
>> tests and be ready to turn the radio OFF anytime another
>> radio system seems not to behave as expected.
>>
>> Bob . . .
>
>
> ________________________________ Message 14
> ____________________________________
>
>
> Time: 09:20:38 PM PST US
> From: Fiveonepw@aol.com
> Subject: Re: AeroElectric-List: Question about Annunciating Lights
>
>
> In a message dated 01/10/2008 8:21:26 AM Central Standard Time,
> bferrell@123mail.net writes:
>
>
> I made my panel out of Honeywell microswitches.
>
>>>>
> Slick! Where were these back when I needed 'em?! Nice work-
>
> Mark
> do not archive
>
>
> **************Start the year off right. Easy ways to stay in shape.
> http://body.aol.com/fitness/winter-exercise?NCID=aolcmp00300000002489
>
>
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Steve Fosstet might have owned a PLB, but I don't think he was actually
wearing it the day he went down - though it was for several days
incorrectly reported that he was. Please see:
http://en.wikipedia.org/wiki/Disappearance_of_Steve_Fossett
Many times ELT's don't activate on impact. On the other hand, 98% of ELT
activations are false alarms. And when they are activated, it often takes
hours to get somebody to actually try to locate the ELT (probably because
so many activations are false alarms). If I'm in bad enough shape that I
can't manually activate my PLB, I think it's statistically unlikely that
the ELT is going to get help to me fast enough to do any good.
(The 121.5) ELT's seem most effective at giving SAR/CAP something to do,
and in helping SAR/CAP find wreckage - too late. And in providing a A/P's
with a regular supply of flashlight batteries. The requirement for
(technologically immature) ELT's in small airplanes was a political knee
jerk response.
PLB's seem like a great idea. I have much better confidence in a PLB's
ability to actually help a downed aircraft. Too bad carrying one doesn't
provide an AMOC for carrying an ELT - at least in non-commercial ops.
That it's not an AMOC probably discourages the purchase of more PLB's.
Regards,
Matt-
>
> Well, a PLB may be less expensive, but it presumes that you are
> conscious when you need to activate it. Or that you will successfully
> regain consciousness before, well, you know. Steve Fausset had a
> personal PLB - didn't do him any good at all. Just a thought.
>
>
> On Jan 11, 2008, at 7:24 AM, Giffen Marr wrote:
>
>> <GAMarr@Charter.Net
>> >
>>
>> I am planning on using the cheapest ELT available to meet the FAR 91
>> Requirements and a 406 PLB. The current cost of ELT's meeting the 406
>> requirements are out of sight as compared to the 121.5 units. The
>> other
>> advantage is the PLB is not much larger then a cell phone as
>> compared to the
>> ELT. Only advantage to the ELT is the battery life may be longer
>> then the
>> PLB.
>>
>> Giff Marr
>> LIV-P/Mistral 65%
>>
>> -----Original Message-----
>> From: owner-aeroelectric-list-server@matronics.com
>> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
>> AeroElectric-List Digest Server
>> Sent: Friday, January 11, 2008 1:56 AM
>> To: AeroElectric-List Digest List
>> Subject: AeroElectric-List Digest: 14 Msgs - 01/10/08
>>
>> *
>>
>> =================================================
>> Online Versions of Today's List Digest Archive
>> =================================================
>>
>> Today's complete AeroElectric-List Digest can also be found in
>> either of the
>> two Web Links listed below. The .html file includes the Digest
>> formatted in
>> HTML for viewing with a web browser and features Hyperlinked Indexes
>> and
>> Message Navigation. The .txt file includes the plain ASCII version
>> of the
>> AeroElectric-List Digest and can be viewed with a generic text
>> editor such
>> as Notepad or with a web browser.
>>
>> HTML Version:
>>
>>
>> http://www.matronics.com/digest/digestview.php?Style=82701&View=html&Chapter
>> 08-01-10&Archive=AeroElectric
>>
>> Text Version:
>>
>>
>> http://www.matronics.com/digest/digestview.php?Style=82701&View=txt&Chapter
>> 2008-01-10&Archive=AeroElectric
>>
>>
>> ===============================================
>> EMail Version of Today's List Digest Archive
>> ===============================================
>>
>>
>> ----------------------------------------------------------
>> AeroElectric-List Digest Archive
>> ---
>> Total Messages Posted Thu 01/10/08: 14
>> ----------------------------------------------------------
>>
>>
>> Today's Message Index:
>> ----------------------
>>
>> 1. 05:17 AM - Re: Strobe discharge pop-pop-pop (Ralph E. Capen)
>> 2. 06:19 AM - Re: Question about Annunciating Lights (Brett
>> Ferrell)
>> 3. 09:16 AM - Re: Cheaper 406mhz plb alternative? (David
>> Chalmers)
>> 4. 10:08 AM - Re: Odd ICOM IC-A200 Power/Ground Instructions ()
>> 5. 12:18 PM - Re: Rotax 914 capacitor (Robert L. Nuckolls, III)
>> 6. 01:02 PM - Re: Shielded Wire (Robert L. Nuckolls, III)
>> 7. 02:56 PM - Re: Shielded Wire (Eric M. Jones)
>> 8. 05:19 PM - Re: XM radio power cord (Robert L. Nuckolls, III)
>> 9. 05:41 PM - Re: Strobe discharge pop-pop-pop (Robert L.
>> Nuckolls,
>> III)
>> 10. 06:01 PM - Re: Question about Annunciating Lights (Robert L.
>> Nuckolls, III)
>> 11. 06:10 PM - Re: Cheaper 406mhz plb alternative? (Steve Thomas)
>> 12. 06:12 PM - Re: Audio panel #inputs vs #sources (Robert L.
>> Nuckolls,
>> III)
>> 13. 06:36 PM - Re: XM radio power cord (Dale Ensing)
>> 14. 09:20 PM - Re: Question about Annunciating Lights
>> (Fiveonepw@aol.com)
>>
>>
>>
>> ________________________________ Message 1
>> _____________________________________
>>
>>
>> Time: 05:17:08 AM PST US
>> From: "Ralph E. Capen" <recapen@earthlink.net>
>> Subject: Re: AeroElectric-List: Strobe discharge pop-pop-pop
>>
>>
>> I'll be trying it outside soon and with the engine later - I'm almost
>> thinking the engine will drown it out...
>>
>> -----Original Message-----
>>> From: Ken <klehman@albedo.net>
>>> Sent: Jan 9, 2008 11:45 PM
>>> To: aeroelectric-list@matronics.com
>>> Subject: Re: AeroElectric-List: Strobe discharge pop-pop-pop
>>>
>>>
>>> Ralph
>>> Have you tried it outside? My radio picks it up when in a metal
>>> hangar
>>> but not when outside. My intercom picks up a little as well via power
>>> supply or ground but hardly noticeable with the engine idling. So it
>>> might not be worth pursuing. The chapter on noise and grounding may
>>> be
>>> helpful. And if it is still noticeable a cheap automotive radio power
>>> filter on the strobe power supplies also helped in my case.
>>> Ken
>>>
>>> Ralph E. Capen wrote:
>>>>
>>>> I'm doing some system testing and I can hear a very slight pop each
>>>> time my
>> strobes discharge through my headset. It doesn't break the squelch or
>> prevent me from hearing the radios - or stereo for that matter. No
>> whining
>> on the charge cycles and I gotta listen carefully to catch the pop -
>> but
>> it's there.
>>>>
>>>> Is this strictly due to the high-voltage discharge in a 12V system?
>>>> Is there
>> something I can due to get rid of this? Or should I take gladness
>> that it's
>> faint, doesn't interfere, it's as good as it gets, have a coke and a
>> smile
>> and.......?
>>>>
>>>> Ralph
>>>
>>>
>>
>>
>> ________________________________ Message 2
>> _____________________________________
>>
>>
>> Time: 06:19:33 AM PST US
>> From: Brett Ferrell <bferrell@123mail.net>
>> Subject: RE: AeroElectric-List: Question about Annunciating Lights
>>
>>
>> I made my panel out of Honeywell microswitches. It's not really a
>> cheap
>> way, but the results are nice, and it's fairly straight-forward,
>> with "dead
>> face"
>> (labels so you KNOW the lamp is out, because it cannot be read unless
>> illuminated from behind). I also built a push-to-test circuit.
>>
>> http://www.velocityxl.com/Electrical.htm
>> (just the pictures)
>> http://www.velocityxl.com/annunciator.JPG
>> http://www.velocityxl.com/press_to_test.JPG
>> http://www.velocityxl.com/IMAGES2/GRT3.JPG
>>
>> I bought mine from these folks http://www.fmw411.com/
>>
>> Brett
>>
>> Quoting Carl Morgan <zk-vii@rvproject.gen.nz>:
>>
>>> I took Mark's work as a basis, and this is what I ended up with....
>>>
>>> Close up:
>>> http://www.rvproject.gen.nz/photos/2007-06/Web_Img_9760.jpg
>>>
>>> http://www.rvproject.gen.nz/dailylog/dailylog_2007-07-28.html the
>>> final look,
>>>
>>>
>>> http://www.rvproject.gen.nz/dailylog/dailylog_2007-06-18.html and
>>> http://www.rvproject.gen.nz/dailylog/dailylog_2007-06-19.html for
>>> some
>>> of the fabrication process.
>>>
>>> Just another possible source of ideas.
>>>
>>> Carl
>>>
>>> --
>>> Carl Morgan - ZK-VII - RV 7A - Inspection next Tue!
>>> http://www.rvproject.gen.nz/
>>> -----Original Message-----
>>> From: owner-aeroelectric-list-server@matronics.com
>>> [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of
>>> Fiveonepw@aol.com
>>> Sent: 10 January 2008 18:14
>>> To: aeroelectric-list@matronics.com
>>> Subject: Re: AeroElectric-List: Question about Annunciating Lights
>>>
>>>
>>> Here's another take on rollin' yer own:
>>>
>>>
>>> http://websites.expercraft.com/n51pw/index.php?
>>> q=log_entry&log_id=5126
>>>
>>> Click on fotos for bigger view and Next Entry>> for more info
>>> (several
>>> pages) including wiring diagram, part #s etc...
>>>
>>> From The PossumWorks in TN
>>> Mark Phillips
>>>
>>>
>>> ----------------------------------------------------------------------
>>> ------
>>> --
>>> Start the year off right. Easy ways to stay in shape in the new
>>> year.
>>>
>>>
>>> 10:16
>>>
>>
>>
>> ________________________________ Message 3
>> _____________________________________
>>
>>
>> Time: 09:16:46 AM PST US
>> From: "David Chalmers" <david@ChalmersFamily.com>
>> Subject: Re: AeroElectric-List: Cheaper 406mhz plb alternative?
>>
>> There's a good review here http://www.equipped.org/SPOT_ORSummer2007.htm
>>
>>
>> On 1/9/08, Charlie England <ceengland@bellsouth.net> wrote:
>>>
>>> ceengland@bellsouth.net>
>>>
>>> Anyone know any details about this product?
>>>
>>> http://www.findmespot.com/explorespot/spotmessenger.aspx
>>>
>>> IF it's using the public SARSAT satellites, maybe it would still work
>>> after the 1st mandatory subscription lapses. (Still be a lot cheaper
>>> than typical PLBs with built in GPS.)
>>>
>>> Charlie
>>>
>>>
>>
>> ________________________________ Message 4
>> _____________________________________
>>
>>
>> Time: 10:08:56 AM PST US
>> From: <gmcjetpilot@yahoo.com>
>> Subject: AeroElectric-List: Re: Odd ICOM IC-A200 Power/Ground
>> Instructions
>>
>> Tim the 18 awg and 10 amp fuse is the broad brush approach, one size
>> fits
>> all. Yes its overkill. You could use a smaller awg wire and fuse. Also
>> sometimes people gang off of existing 10 amp CB's and therefore
>> 18 awg is the correct wire size. I used 5 amp and stayed with the 18
>> awg
>> because I had it; A short run of 20 awg would work fine. They're just
>> covered their bases.
>>
>> Notice 13.8 volts spec? You can take some IR loss with a 14.3-14.5
>> volt
>> buss.
>>
>> The wire diagram clearly shows ONE power and ONE ground with a daisy
>> chain
>> or jumpers. Sorry have no idea what he's talking about. TWIST?
>> Really. May
>> be this is new and it does help but I am stumped. I went with one
>> wire for
>> power and ground. George
>>
>> If you find a 100% answer why, email me please, thanks
>>
>> PS Its a great radio but instructions are lousy.
>>
>>
>>> From: Tim Lewis <Tim_Lewis@msm.umr.edu>
>>> Subject: AeroElectric-List: Odd ICOM IC-A200 Power/Ground
>>> Instructions
>>
>>
>>> The ICOM IC-A200 (VHF Comm radio) installation instruction
>>
>>
>> (http://www.aeroelectric.com/Installation_Data/Icom_ICA200_Installation_Manu
>> al.pdf)
>>
>>> depicts a 10 amp breaker, and tells the installer to "Use
>>> 2 pairs of #18 AWG wires for power and power grounding wiring."
>>> This
>>> struck me as odd, since a single 18 AWG wire is normally used with a
>>> 10 amp breaker, and since the IC-A200 is rated to draw only
>>> 2.6 amps (during transmit).
>>
>>> I called ICOM tech support and spoke to Mike, who told me that I
>>> should
>>> indeed use two 18 AWG wires for power and two 18 AWG wires for
>>> ground,
>>> and that the two wires should be twisted together "to reduce
>>> interference". He further recommended twisting the end of the two
>>> wires together, aided by solder, and crimping this assembly into the
>>> supplied Molex terminal.
>>
>>> I expressed some skepticism about the efficacy of twisting two 12V
>>> power wires together to reduce interference. I was unable to elicit
>>> an explanation of the mechanism by which the alleged interference
>>> reduction was to be achieved. I was also unable to elicit an
>>> explanation of why it should take two 18AWG wires in parallel to
>>> supply 2.6 Amps (peak) to a radio. I elected not to engage Mike in a
>>> discussion of the advisability of crimping a connector to a soldered
>>> wire.
>>
>>> Does anybody have insight into reasoning or experience that lends
>>> credibility to the idea that two 18 AWG wires should be used for
>>> power
>>> (and two for
>>> ground) in an ICOM IC-A200 radio installation?
>>
>>> Thanks,
>>> Tim Lewis
>>
>>
>> ---------------------------------
>> Never miss a thing. Make Yahoo your homepage.
>>
>> ________________________________ Message 5
>> _____________________________________
>>
>>
>> Time: 12:18:54 PM PST US
>> From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
>> Subject: Re: AeroElectric-List: Rotax 914 capacitor
>>
>>
>> At 12:13 PM 1/9/2008 -0800, you wrote:
>>
>>>
>>> Hi All,
>>> B&C offer a couple different capacitors, 10,000uF @50VDC and
>>> 47,000uF
>>> @16VDC. Is one of these appropriate for use on the Rotax alternator?
>>> Thanks, Kevin
>>
>>
>> This is not a really critical capacitor with
>> respect to value but 16v is bit low for
>> a rating. 25V or more is the target. Furhter,
>> the "rule of thumb" for sizing is 1,000 uF per
>> amp of alternator output so the 10KuF/50v is
>> pretty good for the SD-8. Your system would
>> be better served by 20KuF/25V or larger.
>>
>> Bob . . .
>>
>> ----------------------------------------)
>> ( . . . a long habit of not thinking )
>> ( a thing wrong, gives it a superficial )
>> ( appearance of being right . . . )
>> ( )
>> ( -Thomas Paine 1776- )
>> ----------------------------------------
>>
>>
>> ________________________________ Message 6
>> _____________________________________
>>
>>
>> Time: 01:02:10 PM PST US
>> From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
>> Subject: Re: AeroElectric-List: Shielded Wire
>>
>>
>> At 06:12 AM 1/10/2008 -0800, you wrote:
>>
>>>
>>> Bob:
>>>
>>> Maybe this is a little clearer:
>>>
>>> All the wires in the wing are shielded.
>>
>>
>> ?Why?
>>
>>
>>> The wire used is MIL-DTL-27500TG2T14. That particular one is
>>> 12AWG, two
>>> conductor, twisted pair, shielded and sheathed. The unshielded
>>> version
>>> was not available without special order and long lead time. The
>>> weight
>>> difference between shielded and unshielded was 2.75lbs for 1,000 feet
>>> so I got the shielded version.
>>>
>>> There are no manufacturer's recommendations per se. Sizing for loads
>>> was done as per AC43-13-2A based on the power consumption rating
>>> for each
>> load.
>>>
>>> All power loads have a power lead and a return lead. The sensors
>>> have
>>> how ever many wires are required by the sensor.
>>>
>>> Ignoring connectors, fuses, switches, ground buss etc, all power
>>> loads
>>> were to be routed as follows:
>>>
>>> Power lead: Bat(+) -to- Load.
>>> Return lead: Load -to- Bat (-) and, Load -to- Airframe (at
>>> Local
>>> Ground) -to- Bat (-)
>>> Shielding: - Bat(-) -to- Airframe (at Local Ground)
>>>
>>> I can't find where I read it but something led me to believe that if
>>> you were going to use shielded wire it was OK to do it the way I did.
>>
>> I'm not sure I'm interpreting you words into an
>> accurate schematic of your architecture but since
>> the use of shielding where shielding adds no value,
>> then exactly how you wire it has no significance
>> with respect to performance.
>>
>>
>>> So, given that I am going to use the wire I have, that I am going to
>>> run a return lead for all power loads and that I want to hook up the
>>> shielding on the wire, what is the correct way to do it?
>>>
>>> Regarding the return lead, I'm pretty clear that the return lead
>>> should
>>> not be grounded at the Bat (-) and at a Local ground. Quote from
>>> your
>> response:
>>>
>>> " One and only one ground . . . local is probably fine
>>> but not both places . . ."
>>>
>>> No problem changing it but why is it such a bad thing to do it that
>>> way.
>>> Using the landing light as an example. What harm does it cause to
>>> ground it locally and also run a lead back to the bat (-). Why is
>>> that
>>> worse than only grounding locally and the corollary, why is that not
>>> better than only running the lead back to the bat (-). Is the same
>>> applicable to the strobe's power unit and the fuel pump. Would it be
>>> the same for something like a flap actuator motor.
>>
>> My personal goals for system design are to achieve
>> the desired level of performance with a minimum of
>> parts and minimized $time$ to acquire/install/maintain.
>>
>> You appear to be asking advice for doing things that
>> I would not choose to do because they do not add
>> value under the design goals stated. Doing doesn't
>> necessarily degrade performance but it's certain
>> not to enhance it. Are there risks for venturing outside
>> the simple ideas that support conventional wisdom?
>> Difficult to predict but probably not.
>>
>>
>>> Regarding the shielding: I'm less clear on this. Removing the local
>>> ground from the return lead will also take the shielding out of the
>>> ground path from the Load to the Bat(-). But what about grounding
>>> the
>> shielding itself.
>>> Again using the landing light as an example, what is the difference
>>> between grounding at both ends and grounding only at the Bat(-). Is
>>> the same applicable to the strobe's power unit, fuel pump and flap
>>> motor.
>>>
>>> Looking forward to your explanations.
>>
>> A detailed trek through the physics from which
>> conventional wisdom and common practices evolved
>> is beyond the scope of what I can do here on
>> the List. I did a short-course on noise propagation
>> issues and solutions a few years ago at Hawker-
>> Beech . . . and that was a 4-hour, Power-Point
>> presentation.
>>
>> Suffice it to say that if my mental image
>> for what you've described is correct,
>> then there is no reason to expect degradation
>> of performance and no reason to expect an
>> enhancement of performance. I.e, shielding
>> added without specific noise propagation
>> problems to be solved only adds to weight
>> of the airplane and cost of ownership. It
>> follows then that I have no advice based
>> on physics to offer for "doing it right".
>>
>> Bob . . .
>>
>>
>> ________________________________ Message 7
>> _____________________________________
>>
>>
>> Time: 02:56:00 PM PST US
>> Subject: AeroElectric-List: Re: Shielded Wire
>> From: "Eric M. Jones" <emjones@charter.net>
>>
>>
>> Okay, cut this message out and punch three holes into it and stick
>> it into
>> your book. This is the cat's meow on coaxial cable shielding and
>> grounding
>> from Kimmel Gerke Associates. I hope they balance my liberal use of
>> their
>> stuff with the free advertising given here.
>>
>> http://www.emiguru.com/kgb/sum1996.htm Kimmel Gerke Bullets.
>>
>> "For many designers, cables and connectors are an afterthought.
>> After all,
>> they just connect things together, right? But cables and connectors
>> are
>> major entry and exit points for EMI into and out of electronic
>> systems. They
>> act as "hidden antennas" for radiated energy, and "hidden conduits"
>> for
>> conducted energy.
>>
>>
>> "In fact, cables and connectors are so important, they are the often
>> the
>> first things we check out when troubleshooting EMI problems in a
>> system.
>> Here are a few thoughts on cable and connector design for EMI.
>> Trade off shielding for filtering. If you don't filter I/O
>> interfaces, then
>> you must assume that the highest frequencies inside the unit will
>> end up on
>> the cable wires. (Or you must assume the cables will intercept the
>> highest
>> frequencies and bring them into the unit.)
>>
>> "Just because that RS-232 interface is only operating in the
>> kilobaud range
>> doesn't stop higher frequencies from hitching a "free ride" on the
>> cables.
>> We've solved many radiated problems (emissions and immunity) by adding
>> simple filters to interfaces that were only supposed to carry "slow"
>> or "low
>> frequency" signals.
>>
>> "The alternate to filtering the cables is shielding the cables. We
>> generally
>> prefer to filter slower cables, since it's usually more cost
>> effective and
>> easier to maintain EMI integrity.
>>
>> "Ground the cable shield. If you do decide to use shielded cables,
>> then the
>> immediate question becomes how best to ground the cable shield. The
>> correct
>> method depends on both threat frequencies and circuit impedance
>> levels.
>>
>> "For problem frequencies below 10 kHz [audio], the preferred
>> approach is to
>> ground one only one end of the shield. This is to prevent "ground
>> loop"
>> coupling from the cable shield to the inner wires. This is
>> particularly
>> important for preventing 60 Hz coupling into low level/high impedance
>> circuits used in audio or instrumentation systems.
>>
>> "Unfortunately, this is exactly the wrong thing to do for high
>> frequency
>> threats.
>> For most RF situations [above 10 kHz], the preferred approach is to
>> ground
>> both ends of the cable shield, to minimize coupling at the open end
>> due to
>> standing wave effects. So what do you do if both threats exist? You
>> can
>> ground one end with a small capacitor (1,000- 10,000 pf typical) or
>> you can
>> use two shields
>> - one grounded on one end, and the other grounded on both ends. In the
>> latter case, the shields must be insulated from each other.
>>
>> "One more case where both ends must be grounded is the low frequency/
>> low
>> impedance case, where magnetic fields are the major culprit. In this
>> case,
>> the strategy is to minimize "loop size" by providing an adjacent
>> return path
>> for noise currents. This is often necessary in electrical sub-
>> stations,
>> where large 60 Hz magnetic fields exist due to the high current
>> levels. Most
>> of the time, however, single point grounding at low frequencies is the
>> preferred approach.
>>
>> "Use Care With Connector Terminations. This is extremely important for
>> shielded cables with EMI threats above about 1 MHz. Poor joints (or
>> worse,
>> "pigtail" connections from the shield to the connector) are a
>> leading cause
>> EMI-induced failures on shielded cables. We've seen 20 dB increases in
>> emissions, and 10 fold reductions in ESD immunity due to poor
>> connections.
>> (Remember, with a 1 nsec edge rate, ESD is a 300 MHz EMI problem.)
>>
>> "To maintain high frequency cable shield integrity, you need a
>> circumferential bond between the cable shield and the connector
>> shell. In
>> addition you need full metal-to-metal between the mating connectors.
>> Finally, you need a solid connector-to-chassis connection. One
>> problem we
>> often see here is with chassis connectors that overlap connector
>> cutouts.
>> The imprecise fit creates a slot that very effectively couples high
>> frequency energy directly to/from the cable shield. Think in terms
>> of a
>> garden hose -you need a very tight connection at the faucet, or else
>> it
>> leaks.
>>
>> "What About The Cable Shield Itself? Yes, this is a valid concern,
>> but only
>> after you have addressed the connector termination issues. For
>> frequencies
>> below about 10 MHz, most cable shielding materials behave about the
>> same,
>> and provide very respectable amounts of shielding. For frequencies
>> above
>> about 10 MHz, however, the cable construction becomes important. Loose
>> single braids become increasingly leaky, so above 10 MHz, you may
>> need high
>> density braid shields. Double braids work very well here, as do
>> braid over
>> Mylar cable shields. For high frequencies, both shields should be
>> connected
>> together. "
>>
>> --------
>> Eric M. Jones
>> www.PerihelionDesign.com
>> 113 Brentwood Drive
>> Southbridge, MA 01550
>> (508) 764-2072
>> emjones@charter.net
>>
>>
>> Read this topic online here:
>>
>> http://forums.matronics.com/viewtopic.php?p=157322#157322
>>
>>
>> ________________________________ Message 8
>> _____________________________________
>>
>>
>> Time: 05:19:04 PM PST US
>> From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
>> Subject: Re: AeroElectric-List: XM radio power cord
>>
>>
>> At 06:06 PM 1/9/2008 -0500, you wrote:
>>
>>> <densing@carolina.rr.com>
>>>
>>> A question regarding an XM Express radio that I use in the airplane
>>> and
>>> in the car.
>>>
>>> The power cord for the XM radio has a cigarette lighter type plug, is
>>> about three feet long with a mini coaxial plug on the radio end.
>>> Clamped on the cord are two cylinder shaped plastic devices (for lack
>>> of a better descriptive word). There is one on the cig. liter plug
>>> end
>>> and another smaller one on the radio end.
>>> The wire used in the power cord is very stiff and difficult to keep
>>> organized and out of the way. I would like to substitute another
>>> power
>>> cord that is coiled and stretchy. Much easier to manage and keep
>>> neat.
>>> What are the devices clamped on the cord and what is their function?
>>> What will be the impact if I used a power cord without the devices.
>>
>> I suspect these are ferrite noise filters which
>> are commonly added to commercial products for the
>> for the purpose of reducing conducted electro-magnetic
>> interference between devices connected with the cable.
>>
>> See:
>>
>> http://www.aeroelectric.com/Pictures/Filters/Ferrite_EMI_Filter_2.jpg
>>
>> http://www.aeroelectric.com/Pictures/Filters/Ferrite_EMI_Filter.jpg
>>
>> If the devices you're seeing are similar in nature, then
>> it's probable that your device will FUNCTION if fitted
>> with a cord that does not have the filters.
>>
>> But like any non-qualified device use in the airplane,
>> you should be cognizant of potential for interference
>> from the XM radio . . . whether filtered or not. Do some
>> tests and be ready to turn the radio OFF anytime another
>> radio system seems not to behave as expected.
>>
>> Bob . . .
>>
>>
>> ----------------------------------------)
>> ( . . . a long habit of not thinking )
>> ( a thing wrong, gives it a superficial )
>> ( appearance of being right . . . )
>> ( )
>> ( -Thomas Paine 1776- )
>> ----------------------------------------
>>
>>
>> ________________________________ Message 9
>> _____________________________________
>>
>>
>> Time: 05:41:58 PM PST US
>> From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
>> Subject: Re: AeroElectric-List: Strobe discharge pop-pop-pop
>>
>>
>> At 01:36 PM 1/9/2008 -0500, you wrote:
>>
>>> <recapen@earthlink.net>
>>>
>>> I'm doing some system testing and I can hear a very slight pop each
>>> time my strobes discharge through my headset. It doesn't break the
>>> squelch or prevent me from hearing the radios - or stereo for that
>>> matter. No whining on the charge cycles and I gotta listen carefully
>>> to catch the pop
>>> - but it's there.
>>>
>>> Is this strictly due to the high-voltage discharge in a 12V
>>> system? Is
>>> there something I can due to get rid of this? Or should I take
>>> gladness that it's faint, doesn't interfere, it's as good as it gets,
>>> have a coke and a smile and.......?
>>
>> When you think about the physics of what's going
>> on inside a xenon flash-tube, it has a great deal
>> in common with a lightning strike. As we all know,
>> a lighting strike can be "felt" both in terms of
>> magnetic and electrostatic effects, both of which
>> have the ability to radiate some distance and/or
>> couple to conductors.
>>
>> What you're hearing is the broad spectrum, radiated
>> noise coming directly from the confines of the ionized
>> gasses in the tube when it fires.
>>
>> When we put the first strobes on Cessna single-engine
>> airplanes in the 60's, there was a lot of fuss about
>> this mini-strike being heard in the ADF receivers.
>> We tried some glass with conductive coatings (reduced
>> light output) and fine-mesh screen wire (really hard to
>> work with).
>>
>> Somebody finally noted that, "Bee, when you're tuned to
>> a station that was strong enough to be useable for either
>> listening or navigating, the "pop" was imperceptible
>> and effects on navigation nil."
>>
>> Chances are that in flight, you're going to discover
>> the same thing. Now, if it does turn out to be a problem,
>> you'll need to repeat the same experiments we tried 40
>> years ago and perhaps some new ones. I'm aware of no
>> current tricks of the trade that would a apply.
>>
>> Bob . . .
>>
>>
>> ________________________________ Message 10
>> ____________________________________
>>
>>
>> Time: 06:01:33 PM PST US
>> From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
>> Subject: Re: AeroElectric-List: Question about Annunciating Lights
>>
>>
>> At 12:54 PM 1/9/2008 -0500, you wrote:
>>
>>> Bob, it would help if you also added these pictures to the article...
>>>
>>> Bret Smith
>>> RV-9A "Fuselage"
>>> Blue Ridge, GA
>>
>>
>> Done. Thanks!
>>
>>
>>>> A fine piece of work! I've preserved this data in
>>>> an excerpt of the websit and posted it to:
>>>>
>>>> http://aeroelectric.com/articles/Roll_your_own_Annunicator_Panel.pdf
>>>
>>> Bob . . .
>>>
>>> ----------------------------------------)
>>> ( . . . a long habit of not thinking )
>>> ( a thing wrong, gives it a superficial )
>>> ( appearance of being right . . . )
>>> ( )
>>> ( -Thomas Paine 1776- )
>>> ----------------------------------------
>>>
>>
>>
>> ________________________________ Message 11
>> ____________________________________
>>
>>
>> Time: 06:10:07 PM PST US
>> From: Steve Thomas <lists@stevet.net>
>> Subject: Re: AeroElectric-List: Cheaper 406mhz plb alternative?
>>
>> As far as 406MHz ELT goes, I currently have an ACK installed in my
>> not-
>> yet-flying Glasair. This unit is not a 406 MHz unit. With the
>> demise of
>> satellite tracking on 121.5, I wrote to ACK to ask if they had any
>> plans to
>> release a 406 unit. The reply was that, yes, they have one under
>> development. It is an exact replacement for the 121.5 unit, uses
>> the same
>> remote head, and uses easy to replace, commercially available
>> batteries (I
>> don't remember what kind, but they were not Alkaline). I don't
>> remember the
>> price exactly, but it was half of what the lowest price alternative
>> was.
>> They said to keep watching their web site and expected it to be
>> available
>> within the first half of this year.
>>
>>
>> On Jan 10, 2008, at 9:01 AM, David Chalmers wrote:
>>
>>> There's a good review here
>>> http://www.equipped.org/SPOT_ORSummer2007.htm
>>>
>>>
>>> On 1/9/08, Charlie England <ceengland@bellsouth.net> wrote:
>>>>
>>>
>>> Anyone know any details about this product?
>>>
>>> http://www.findmespot.com/explorespot/spotmessenger.aspx
>>>
>>> IF it's using the public SARSAT satellites, maybe it would still work
>>>
>>>
>>
>>
>> ________________________________ Message 12
>> ____________________________________
>>
>>
>> Time: 06:12:17 PM PST US
>> From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
>> Subject: Re: AeroElectric-List: Audio panel #inputs vs #sources
>>
>>
>> At 11:16 AM 1/9/2008 -0500, you wrote:
>>
>>> <recapen@earthlink.net>
>>>
>>> Folks,
>>>
>>> I have three inputs that should be 'unswitched':
>>> AOA warning
>>> Traffic Alert
>>> AF3400EM Engine monitor
>>>
>>> My audio panel (PS Engineering PMA7000MS) has two unswitched inputs.
>>> Can I tie two of the sources to one input? I think there would
>>> only be
>>> an issue if they both went off at teh same time.
>>> Alternatively, I can put the third to a switched input and leave the
>>> switch on.
>>
>> Put 100 ohm resistors in series with EACH of the three output
>> before bringing them together whether switched or not. See:
>>
>> http://aeroelectric.com/articles/Rev11/18Audio_R11.pdf
>>
>> Bob . . .
>>
>>
>> ________________________________ Message 13
>> ____________________________________
>>
>>
>> Time: 06:36:13 PM PST US
>> From: "Dale Ensing" <densing@carolina.rr.com>
>> Subject: Re: AeroElectric-List: XM radio power cord
>>
>>
>> Thank you Bob. The 'devices' on the power cord look just like the
>> ferrite
>> filters in the pictures. And thanks for the alert to possible
>> interference
>> to other radio systems in the airplane.
>> Dale
>>
>>> At 06:06 PM 1/9/2008 -0500, you wrote:
>>>
>>>> <densing@carolina.rr.com>
>>>>
>>>> A question regarding an XM Express radio that I use in the airplane
>>>> and in the car.
>>>>
>>>> The power cord for the XM radio has a cigarette lighter type plug,
>>>> is
>>>> about three feet long with a mini coaxial plug on the radio end.
>>>> Clamped on the cord are two cylinder shaped plastic devices (for
>>>> lack
>>>> of a better descriptive word). There is one on the cig. liter plug
>>>> end
>>>> and another smaller one on the radio end.
>>>> The wire used in the power cord is very stiff and difficult to keep
>>>> organized and out of the way. I would like to substitute another
>>>> power
>>>> cord that is coiled and stretchy. Much easier to manage and keep
>>>> neat.
>>>> What are the devices clamped on the cord and what is their function?
>>>> What will be the impact if I used a power cord without the devices.
>>>
>>> I suspect these are ferrite noise filters which
>>> are commonly added to commercial products for the
>>> for the purpose of reducing conducted electro-magnetic
>>> interference between devices connected with the cable.
>>>
>>> See:
>>>
>>> http://www.aeroelectric.com/Pictures/Filters/Ferrite_EMI_Filter_2.jpg
>>>
>>> http://www.aeroelectric.com/Pictures/Filters/Ferrite_EMI_Filter.jpg
>>>
>>> If the devices you're seeing are similar in nature, then
>>> it's probable that your device will FUNCTION if fitted
>>> with a cord that does not have the filters.
>>>
>>> But like any non-qualified device use in the airplane,
>>> you should be cognizant of potential for interference
>>> from the XM radio . . . whether filtered or not. Do some
>>> tests and be ready to turn the radio OFF anytime another
>>> radio system seems not to behave as expected.
>>>
>>> Bob . . .
>>
>>
>> ________________________________ Message 14
>> ____________________________________
>>
>>
>> Time: 09:20:38 PM PST US
>> From: Fiveonepw@aol.com
>> Subject: Re: AeroElectric-List: Question about Annunciating Lights
>>
>>
>> In a message dated 01/10/2008 8:21:26 AM Central Standard Time,
>> bferrell@123mail.net writes:
>>
>>
>> I made my panel out of Honeywell microswitches.
>>
>>>>>
>> Slick! Where were these back when I needed 'em?! Nice work-
>>
>> Mark
>> do not archive
>>
>>
>> **************Start the year off right. Easy ways to stay in shape.
>> http://body.aol.com/fitness/winter-exercise?NCID=aolcmp00300000002489
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
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If you want satellites locked in, consider getting your amateur radio
license (ham) and then start carrying (or install) a Tiny Track (or
something similar).
http://www.byonics.com/tinytrak/
And use it to keep your position updated via APRS:
http://www.googleaprs.com/
Then people will have a way to see your flight is/was going.
I wonder if ADS-B is going to support something similar.
Regards,
Matt-
> <frank.hinde@hp.com>
>
> Indeed, and you can always activate it when you know you are going down.
> In fact I wonder how reliable the G switches are in the case of ELT's
> anyway...121.5 ELTs are notoriously innefective but the 406 units will
> still have the same kind of G switch technology I would presume, how well
> do they work?
>
> Indeed my Wife is briefed to do exactly this...if the engine quits have
> the PLB in your hands and be ready to activate.
>
> As to Steve Fosset I thought he just a had a 121.5 ELT and the same thing
> on a fancy wristwatch I doubt if that was a full 406 unit with a 5W
> transmit signal (remember that 121.5's only have a 50mW signal I
> believe)...This is supposed to be enough power to get out from under tree
> cover ect.
>
> Personally I want the satellites to have a lock on me BEFORE we hit the
> ground.
>
> Frank rv7a
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Steve
> Thomas
> Sent: Friday, January 11, 2008 8:22 AM
> To: aeroelectric-list@matronics.com
> Subject: AeroElectric-List: Re: ELT/PLB
>
>
> Well, a PLB may be less expensive, but it presumes that you are conscious
> when you need to activate it. Or that you will successfully regain
> consciousness before, well, you know. Steve Fausset had a personal PLB -
> didn't do him any good at all. Just a thought.
>
>
> On Jan 11, 2008, at 7:24 AM, Giffen Marr wrote:
>
>> --> <GAMarr@Charter.Net
>> >
>>
>> I am planning on using the cheapest ELT available to meet the FAR 91
>> Requirements and a 406 PLB. The current cost of ELT's meeting the 406
>> requirements are out of sight as compared to the 121.5 units. The
>> other advantage is the PLB is not much larger then a cell phone as
>> compared to the ELT. Only advantage to the ELT is the battery life may
>> be longer then the PLB.
>>
>> Giff Marr
>> LIV-P/Mistral 65%
>>
>> -----Original Message-----
>> From: owner-aeroelectric-list-server@matronics.com
>> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
>> AeroElectric-List Digest Server
>> Sent: Friday, January 11, 2008 1:56 AM
>> To: AeroElectric-List Digest List
>> Subject: AeroElectric-List Digest: 14 Msgs - 01/10/08
>>
>> *
>>
>> =================================================
>> Online Versions of Today's List Digest Archive
>> =================================================
>>
>> Today's complete AeroElectric-List Digest can also be found in either
>> of the two Web Links listed below. The .html file includes the Digest
>> formatted in HTML for viewing with a web browser and features
>> Hyperlinked Indexes and Message Navigation. The .txt file includes
>> the plain ASCII version of the AeroElectric-List Digest and can be
>> viewed with a generic text editor such as Notepad or with a web
>> browser.
>>
>> HTML Version:
>>
>>
>> http://www.matronics.com/digest/digestview.php?Style=82701&View=html&C
>> hapter
>> 08-01-10&Archive=AeroElectric
>>
>> Text Version:
>>
>>
>> http://www.matronics.com/digest/digestview.php?Style=82701&View=txt&Ch
>> apter
>> 2008-01-10&Archive=AeroElectric
>>
>>
>> ===============================================
>> EMail Version of Today's List Digest Archive
>> ===============================================
>>
>>
>> ----------------------------------------------------------
>> AeroElectric-List Digest Archive
>> ---
>> Total Messages Posted Thu 01/10/08: 14
>> ----------------------------------------------------------
>>
>>
>> Today's Message Index:
>> ----------------------
>>
>> 1. 05:17 AM - Re: Strobe discharge pop-pop-pop (Ralph E. Capen)
>> 2. 06:19 AM - Re: Question about Annunciating Lights (Brett
>> Ferrell)
>> 3. 09:16 AM - Re: Cheaper 406mhz plb alternative? (David
>> Chalmers)
>> 4. 10:08 AM - Re: Odd ICOM IC-A200 Power/Ground Instructions ()
>> 5. 12:18 PM - Re: Rotax 914 capacitor (Robert L. Nuckolls, III)
>> 6. 01:02 PM - Re: Shielded Wire (Robert L. Nuckolls, III)
>> 7. 02:56 PM - Re: Shielded Wire (Eric M. Jones)
>> 8. 05:19 PM - Re: XM radio power cord (Robert L. Nuckolls, III)
>> 9. 05:41 PM - Re: Strobe discharge pop-pop-pop (Robert L.
>> Nuckolls,
>> III)
>> 10. 06:01 PM - Re: Question about Annunciating Lights (Robert L.
>> Nuckolls, III)
>> 11. 06:10 PM - Re: Cheaper 406mhz plb alternative? (Steve Thomas)
>> 12. 06:12 PM - Re: Audio panel #inputs vs #sources (Robert L.
>> Nuckolls,
>> III)
>> 13. 06:36 PM - Re: XM radio power cord (Dale Ensing)
>> 14. 09:20 PM - Re: Question about Annunciating Lights
>> (Fiveonepw@aol.com)
>>
>>
>>
>> ________________________________ Message 1
>> _____________________________________
>>
>>
>> Time: 05:17:08 AM PST US
>> From: "Ralph E. Capen" <recapen@earthlink.net>
>> Subject: Re: AeroElectric-List: Strobe discharge pop-pop-pop
>>
>>
>> I'll be trying it outside soon and with the engine later - I'm almost
>> thinking the engine will drown it out...
>>
>> -----Original Message-----
>>> From: Ken <klehman@albedo.net>
>>> Sent: Jan 9, 2008 11:45 PM
>>> To: aeroelectric-list@matronics.com
>>> Subject: Re: AeroElectric-List: Strobe discharge pop-pop-pop
>>>
>>>
>>> Ralph
>>> Have you tried it outside? My radio picks it up when in a metal
>>> hangar but not when outside. My intercom picks up a little as well
>>> via power supply or ground but hardly noticeable with the engine
>>> idling. So it might not be worth pursuing. The chapter on noise and
>>> grounding may be helpful. And if it is still noticeable a cheap
>>> automotive radio power filter on the strobe power supplies also
>>> helped in my case.
>>> Ken
>>>
>>> Ralph E. Capen wrote:
>>>>
>>>> I'm doing some system testing and I can hear a very slight pop each
>>>> time my
>> strobes discharge through my headset. It doesn't break the squelch or
>> prevent me from hearing the radios - or stereo for that matter. No
>> whining on the charge cycles and I gotta listen carefully to catch the
>> pop - but it's there.
>>>>
>>>> Is this strictly due to the high-voltage discharge in a 12V system?
>>>> Is there
>> something I can due to get rid of this? Or should I take gladness
>> that it's faint, doesn't interfere, it's as good as it gets, have a
>> coke and a smile and.......?
>>>>
>>>> Ralph
>>>
>>>
>>
>>
>> ________________________________ Message 2
>> _____________________________________
>>
>>
>> Time: 06:19:33 AM PST US
>> From: Brett Ferrell <bferrell@123mail.net>
>> Subject: RE: AeroElectric-List: Question about Annunciating Lights
>>
>>
>> I made my panel out of Honeywell microswitches. It's not really a
>> cheap way, but the results are nice, and it's fairly straight-forward,
>> with "dead face"
>> (labels so you KNOW the lamp is out, because it cannot be read unless
>> illuminated from behind). I also built a push-to-test circuit.
>>
>> http://www.velocityxl.com/Electrical.htm
>> (just the pictures)
>> http://www.velocityxl.com/annunciator.JPG
>> http://www.velocityxl.com/press_to_test.JPG
>> http://www.velocityxl.com/IMAGES2/GRT3.JPG
>>
>> I bought mine from these folks http://www.fmw411.com/
>>
>> Brett
>>
>> Quoting Carl Morgan <zk-vii@rvproject.gen.nz>:
>>
>>> I took Mark's work as a basis, and this is what I ended up with....
>>>
>>> Close up:
>>> http://www.rvproject.gen.nz/photos/2007-06/Web_Img_9760.jpg
>>>
>>> http://www.rvproject.gen.nz/dailylog/dailylog_2007-07-28.html the
>>> final look,
>>>
>>>
>>> http://www.rvproject.gen.nz/dailylog/dailylog_2007-06-18.html and
>>> http://www.rvproject.gen.nz/dailylog/dailylog_2007-06-19.html for
>>> some of the fabrication process.
>>>
>>> Just another possible source of ideas.
>>>
>>> Carl
>>>
>>> --
>>> Carl Morgan - ZK-VII - RV 7A - Inspection next Tue!
>>> http://www.rvproject.gen.nz/
>>> -----Original Message-----
>>> From: owner-aeroelectric-list-server@matronics.com
>>> [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of
>>> Fiveonepw@aol.com
>>> Sent: 10 January 2008 18:14
>>> To: aeroelectric-list@matronics.com
>>> Subject: Re: AeroElectric-List: Question about Annunciating Lights
>>>
>>>
>>> Here's another take on rollin' yer own:
>>>
>>>
>>> http://websites.expercraft.com/n51pw/index.php?
>>> q=log_entry&log_id=5126
>>>
>>> Click on fotos for bigger view and Next Entry>> for more info
>>> (several
>>> pages) including wiring diagram, part #s etc...
>>>
>>> From The PossumWorks in TN
>>> Mark Phillips
>>>
>>>
>>> ---------------------------------------------------------------------
>>> -
>>> ------
>>> --
>>> Start the year off right. Easy ways to stay in shape in the new
>>> year.
>>>
>>>
>>> 10:16
>>>
>>
>>
>> ________________________________ Message 3
>> _____________________________________
>>
>>
>> Time: 09:16:46 AM PST US
>> From: "David Chalmers" <david@ChalmersFamily.com>
>> Subject: Re: AeroElectric-List: Cheaper 406mhz plb alternative?
>>
>> There's a good review here
>> http://www.equipped.org/SPOT_ORSummer2007.htm
>>
>>
>> On 1/9/08, Charlie England <ceengland@bellsouth.net> wrote:
>>>
>>> ceengland@bellsouth.net>
>>>
>>> Anyone know any details about this product?
>>>
>>> http://www.findmespot.com/explorespot/spotmessenger.aspx
>>>
>>> IF it's using the public SARSAT satellites, maybe it would still work
>>> after the 1st mandatory subscription lapses. (Still be a lot cheaper
>>> than typical PLBs with built in GPS.)
>>>
>>> Charlie
>>>
>>>
>>
>> ________________________________ Message 4
>> _____________________________________
>>
>>
>> Time: 10:08:56 AM PST US
>> From: <gmcjetpilot@yahoo.com>
>> Subject: AeroElectric-List: Re: Odd ICOM IC-A200 Power/Ground
>> Instructions
>>
>> Tim the 18 awg and 10 amp fuse is the broad brush approach, one size
>> fits all. Yes its overkill. You could use a smaller awg wire and fuse.
>> Also sometimes people gang off of existing 10 amp CB's and therefore
>> 18 awg is the correct wire size. I used 5 amp and stayed with the 18
>> awg because I had it; A short run of 20 awg would work fine. They're
>> just covered their bases.
>>
>> Notice 13.8 volts spec? You can take some IR loss with a 14.3-14.5
>> volt buss.
>>
>> The wire diagram clearly shows ONE power and ONE ground with a daisy
>> chain or jumpers. Sorry have no idea what he's talking about. TWIST?
>> Really. May
>> be this is new and it does help but I am stumped. I went with one wire
>> for power and ground. George
>>
>> If you find a 100% answer why, email me please, thanks
>>
>> PS Its a great radio but instructions are lousy.
>>
>>
>>> From: Tim Lewis <Tim_Lewis@msm.umr.edu>
>>> Subject: AeroElectric-List: Odd ICOM IC-A200 Power/Ground
>>> Instructions
>>
>>
>>> The ICOM IC-A200 (VHF Comm radio) installation instruction
>>
>>
>> (http://www.aeroelectric.com/Installation_Data/Icom_ICA200_Installatio
>> n_Manu
>> al.pdf)
>>
>>> depicts a 10 amp breaker, and tells the installer to "Use
>>> 2 pairs of #18 AWG wires for power and power grounding wiring."
>>> This
>>> struck me as odd, since a single 18 AWG wire is normally used with a
>>> 10 amp breaker, and since the IC-A200 is rated to draw only
>>> 2.6 amps (during transmit).
>>
>>> I called ICOM tech support and spoke to Mike, who told me that I
>>> should indeed use two 18 AWG wires for power and two 18 AWG wires for
>>> ground, and that the two wires should be twisted together "to reduce
>>> interference". He further recommended twisting the end of the two
>>> wires together, aided by solder, and crimping this assembly into the
>>> supplied Molex terminal.
>>
>>> I expressed some skepticism about the efficacy of twisting two 12V
>>> power wires together to reduce interference. I was unable to elicit
>>> an explanation of the mechanism by which the alleged interference
>>> reduction was to be achieved. I was also unable to elicit an
>>> explanation of why it should take two 18AWG wires in parallel to
>>> supply 2.6 Amps (peak) to a radio. I elected not to engage Mike in a
>>> discussion of the advisability of crimping a connector to a soldered
>>> wire.
>>
>>> Does anybody have insight into reasoning or experience that lends
>>> credibility to the idea that two 18 AWG wires should be used for
>>> power (and two for
>>> ground) in an ICOM IC-A200 radio installation?
>>
>>> Thanks,
>>> Tim Lewis
>>
>>
>> ---------------------------------
>> Never miss a thing. Make Yahoo your homepage.
>>
>> ________________________________ Message 5
>> _____________________________________
>>
>>
>> Time: 12:18:54 PM PST US
>> From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
>> Subject: Re: AeroElectric-List: Rotax 914 capacitor
>>
>>
>> At 12:13 PM 1/9/2008 -0800, you wrote:
>>
>>>
>>> Hi All,
>>> B&C offer a couple different capacitors, 10,000uF @50VDC and 47,000uF
>>> @16VDC. Is one of these appropriate for use on the Rotax alternator?
>>> Thanks, Kevin
>>
>>
>> This is not a really critical capacitor with
>> respect to value but 16v is bit low for
>> a rating. 25V or more is the target. Furhter,
>> the "rule of thumb" for sizing is 1,000 uF per
>> amp of alternator output so the 10KuF/50v is
>> pretty good for the SD-8. Your system would
>> be better served by 20KuF/25V or larger.
>>
>> Bob . . .
>>
>> ----------------------------------------)
>> ( . . . a long habit of not thinking )
>> ( a thing wrong, gives it a superficial )
>> ( appearance of being right . . . )
>> ( )
>> ( -Thomas Paine 1776- )
>> ----------------------------------------
>>
>>
>> ________________________________ Message 6
>> _____________________________________
>>
>>
>> Time: 01:02:10 PM PST US
>> From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
>> Subject: Re: AeroElectric-List: Shielded Wire
>>
>>
>> At 06:12 AM 1/10/2008 -0800, you wrote:
>>
>>>
>>> Bob:
>>>
>>> Maybe this is a little clearer:
>>>
>>> All the wires in the wing are shielded.
>>
>>
>> ?Why?
>>
>>
>>> The wire used is MIL-DTL-27500TG2T14. That particular one is
>>> 12AWG, two
>>> conductor, twisted pair, shielded and sheathed. The unshielded
>>> version
>>> was not available without special order and long lead time. The
>>> weight
>>> difference between shielded and unshielded was 2.75lbs for 1,000 feet
>>> so I got the shielded version.
>>>
>>> There are no manufacturer's recommendations per se. Sizing for loads
>>> was done as per AC43-13-2A based on the power consumption rating
>>> for each
>> load.
>>>
>>> All power loads have a power lead and a return lead. The sensors
>>> have
>>> how ever many wires are required by the sensor.
>>>
>>> Ignoring connectors, fuses, switches, ground buss etc, all power
>>> loads
>>> were to be routed as follows:
>>>
>>> Power lead: Bat(+) -to- Load.
>>> Return lead: Load -to- Bat (-) and, Load -to- Airframe (at
>>> Local
>>> Ground) -to- Bat (-)
>>> Shielding: - Bat(-) -to- Airframe (at Local Ground)
>>>
>>> I can't find where I read it but something led me to believe that if
>>> you were going to use shielded wire it was OK to do it the way I did.
>>
>> I'm not sure I'm interpreting you words into an
>> accurate schematic of your architecture but since
>> the use of shielding where shielding adds no value,
>> then exactly how you wire it has no significance
>> with respect to performance.
>>
>>
>>> So, given that I am going to use the wire I have, that I am going to
>>> run a return lead for all power loads and that I want to hook up the
>>> shielding on the wire, what is the correct way to do it?
>>>
>>> Regarding the return lead, I'm pretty clear that the return lead
>>> should
>>> not be grounded at the Bat (-) and at a Local ground. Quote from
>>> your
>> response:
>>>
>>> " One and only one ground . . . local is probably fine
>>> but not both places . . ."
>>>
>>> No problem changing it but why is it such a bad thing to do it that
>>> way.
>>> Using the landing light as an example. What harm does it cause to
>>> ground it locally and also run a lead back to the bat (-). Why is
>>> that
>>> worse than only grounding locally and the corollary, why is that not
>>> better than only running the lead back to the bat (-). Is the same
>>> applicable to the strobe's power unit and the fuel pump. Would it be
>>> the same for something like a flap actuator motor.
>>
>> My personal goals for system design are to achieve
>> the desired level of performance with a minimum of
>> parts and minimized $time$ to acquire/install/maintain.
>>
>> You appear to be asking advice for doing things that
>> I would not choose to do because they do not add
>> value under the design goals stated. Doing doesn't
>> necessarily degrade performance but it's certain
>> not to enhance it. Are there risks for venturing outside
>> the simple ideas that support conventional wisdom?
>> Difficult to predict but probably not.
>>
>>
>>> Regarding the shielding: I'm less clear on this. Removing the local
>>> ground from the return lead will also take the shielding out of the
>>> ground path from the Load to the Bat(-). But what about grounding
>>> the
>> shielding itself.
>>> Again using the landing light as an example, what is the difference
>>> between grounding at both ends and grounding only at the Bat(-). Is
>>> the same applicable to the strobe's power unit, fuel pump and flap
>>> motor.
>>>
>>> Looking forward to your explanations.
>>
>> A detailed trek through the physics from which
>> conventional wisdom and common practices evolved
>> is beyond the scope of what I can do here on
>> the List. I did a short-course on noise propagation
>> issues and solutions a few years ago at Hawker-
>> Beech . . . and that was a 4-hour, Power-Point
>> presentation.
>>
>> Suffice it to say that if my mental image
>> for what you've described is correct,
>> then there is no reason to expect degradation
>> of performance and no reason to expect an
>> enhancement of performance. I.e, shielding
>> added without specific noise propagation
>> problems to be solved only adds to weight
>> of the airplane and cost of ownership. It
>> follows then that I have no advice based
>> on physics to offer for "doing it right".
>>
>> Bob . . .
>>
>>
>> ________________________________ Message 7
>> _____________________________________
>>
>>
>> Time: 02:56:00 PM PST US
>> Subject: AeroElectric-List: Re: Shielded Wire
>> From: "Eric M. Jones" <emjones@charter.net>
>>
>>
>> Okay, cut this message out and punch three holes into it and stick
>> it into
>> your book. This is the cat's meow on coaxial cable shielding and
>> grounding
>> from Kimmel Gerke Associates. I hope they balance my liberal use of
>> their
>> stuff with the free advertising given here.
>>
>> http://www.emiguru.com/kgb/sum1996.htm Kimmel Gerke Bullets.
>>
>> "For many designers, cables and connectors are an afterthought.
>> After all,
>> they just connect things together, right? But cables and connectors
>> are
>> major entry and exit points for EMI into and out of electronic
>> systems. They
>> act as "hidden antennas" for radiated energy, and "hidden conduits"
>> for
>> conducted energy.
>>
>>
>> "In fact, cables and connectors are so important, they are the often
>> the
>> first things we check out when troubleshooting EMI problems in a
>> system.
>> Here are a few thoughts on cable and connector design for EMI.
>> Trade off shielding for filtering. If you don't filter I/O
>> interfaces, then
>> you must assume that the highest frequencies inside the unit will
>> end up on
>> the cable wires. (Or you must assume the cables will intercept the
>> highest
>> frequencies and bring them into the unit.)
>>
>> "Just because that RS-232 interface is only operating in the
>> kilobaud range
>> doesn't stop higher frequencies from hitching a "free ride" on the
>> cables.
>> We've solved many radiated problems (emissions and immunity) by adding
>> simple filters to interfaces that were only supposed to carry "slow"
>> or "low
>> frequency" signals.
>>
>> "The alternate to filtering the cables is shielding the cables. We
>> generally
>> prefer to filter slower cables, since it's usually more cost
>> effective and
>> easier to maintain EMI integrity.
>>
>> "Ground the cable shield. If you do decide to use shielded cables,
>> then the
>> immediate question becomes how best to ground the cable shield. The
>> correct
>> method depends on both threat frequencies and circuit impedance
>> levels.
>>
>> "For problem frequencies below 10 kHz [audio], the preferred
>> approach is to
>> ground one only one end of the shield. This is to prevent "ground
>> loop"
>> coupling from the cable shield to the inner wires. This is
>> particularly
>> important for preventing 60 Hz coupling into low level/high impedance
>> circuits used in audio or instrumentation systems.
>>
>> "Unfortunately, this is exactly the wrong thing to do for high
>> frequency
>> threats.
>> For most RF situations [above 10 kHz], the preferred approach is to
>> ground
>> both ends of the cable shield, to minimize coupling at the open end
>> due to
>> standing wave effects. So what do you do if both threats exist? You
>> can
>> ground one end with a small capacitor (1,000- 10,000 pf typical) or
>> you can
>> use two shields
>> - one grounded on one end, and the other grounded on both ends. In the
>> latter case, the shields must be insulated from each other.
>>
>> "One more case where both ends must be grounded is the low frequency/
>> low
>> impedance case, where magnetic fields are the major culprit. In this
>> case,
>> the strategy is to minimize "loop size" by providing an adjacent
>> return path
>> for noise currents. This is often necessary in electrical sub-
>> stations,
>> where large 60 Hz magnetic fields exist due to the high current
>> levels. Most
>> of the time, however, single point grounding at low frequencies is the
>> preferred approach.
>>
>> "Use Care With Connector Terminations. This is extremely important for
>> shielded cables with EMI threats above about 1 MHz. Poor joints (or
>> worse,
>> "pigtail" connections from the shield to the connector) are a
>> leading cause
>> EMI-induced failures on shielded cables. We've seen 20 dB increases in
>> emissions, and 10 fold reductions in ESD immunity due to poor
>> connections.
>> (Remember, with a 1 nsec edge rate, ESD is a 300 MHz EMI problem.)
>>
>> "To maintain high frequency cable shield integrity, you need a
>> circumferential bond between the cable shield and the connector
>> shell. In
>> addition you need full metal-to-metal between the mating connectors.
>> Finally, you need a solid connector-to-chassis connection. One
>> problem we
>> often see here is with chassis connectors that overlap connector
>> cutouts.
>> The imprecise fit creates a slot that very effectively couples high
>> frequency energy directly to/from the cable shield. Think in terms
>> of a
>> garden hose -you need a very tight connection at the faucet, or else
>> it
>> leaks.
>>
>> "What About The Cable Shield Itself? Yes, this is a valid concern,
>> but only
>> after you have addressed the connector termination issues. For
>> frequencies
>> below about 10 MHz, most cable shielding materials behave about the
>> same,
>> and provide very respectable amounts of shielding. For frequencies
>> above
>> about 10 MHz, however, the cable construction becomes important. Loose
>> single braids become increasingly leaky, so above 10 MHz, you may
>> need high
>> density braid shields. Double braids work very well here, as do
>> braid over
>> Mylar cable shields. For high frequencies, both shields should be
>> connected
>> together. "
>>
>> --------
>> Eric M. Jones
>> www.PerihelionDesign.com
>> 113 Brentwood Drive
>> Southbridge, MA 01550
>> (508) 764-2072
>> emjones@charter.net
>>
>>
>> Read this topic online here:
>>
>> http://forums.matronics.com/viewtopic.php?p=157322#157322
>>
>>
>> ________________________________ Message 8
>> _____________________________________
>>
>>
>> Time: 05:19:04 PM PST US
>> From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
>> Subject: Re: AeroElectric-List: XM radio power cord
>>
>>
>> At 06:06 PM 1/9/2008 -0500, you wrote:
>>
>>> <densing@carolina.rr.com>
>>>
>>> A question regarding an XM Express radio that I use in the airplane
>>> and
>>> in the car.
>>>
>>> The power cord for the XM radio has a cigarette lighter type plug, is
>>> about three feet long with a mini coaxial plug on the radio end.
>>> Clamped on the cord are two cylinder shaped plastic devices (for lack
>>> of a better descriptive word). There is one on the cig. liter plug
>>> end
>>> and another smaller one on the radio end.
>>> The wire used in the power cord is very stiff and difficult to keep
>>> organized and out of the way. I would like to substitute another
>>> power
>>> cord that is coiled and stretchy. Much easier to manage and keep
>>> neat.
>>> What are the devices clamped on the cord and what is their function?
>>> What will be the impact if I used a power cord without the devices.
>>
>> I suspect these are ferrite noise filters which
>> are commonly added to commercial products for the
>> for the purpose of reducing conducted electro-magnetic
>> interference between devices connected with the cable.
>>
>> See:
>>
>> http://www.aeroelectric.com/Pictures/Filters/Ferrite_EMI_Filter_2.jpg
>>
>> http://www.aeroelectric.com/Pictures/Filters/Ferrite_EMI_Filter.jpg
>>
>> If the devices you're seeing are similar in nature, then
>> it's probable that your device will FUNCTION if fitted
>> with a cord that does not have the filters.
>>
>> But like any non-qualified device use in the airplane,
>> you should be cognizant of potential for interference
>> from the XM radio . . . whether filtered or not. Do some
>> tests and be ready to turn the radio OFF anytime another
>> radio system seems not to behave as expected.
>>
>> Bob . . .
>>
>>
>> ----------------------------------------)
>> ( . . . a long habit of not thinking )
>> ( a thing wrong, gives it a superficial )
>> ( appearance of being right . . . )
>> ( )
>> ( -Thomas Paine 1776- )
>> ----------------------------------------
>>
>>
>> ________________________________ Message 9
>> _____________________________________
>>
>>
>> Time: 05:41:58 PM PST US
>> From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
>> Subject: Re: AeroElectric-List: Strobe discharge pop-pop-pop
>>
>>
>> At 01:36 PM 1/9/2008 -0500, you wrote:
>>
>>> <recapen@earthlink.net>
>>>
>>> I'm doing some system testing and I can hear a very slight pop each
>>> time my strobes discharge through my headset. It doesn't break the
>>> squelch or prevent me from hearing the radios - or stereo for that
>>> matter. No whining on the charge cycles and I gotta listen carefully
>>> to catch the pop
>>> - but it's there.
>>>
>>> Is this strictly due to the high-voltage discharge in a 12V
>>> system? Is
>>> there something I can due to get rid of this? Or should I take
>>> gladness that it's faint, doesn't interfere, it's as good as it gets,
>>> have a coke and a smile and.......?
>>
>> When you think about the physics of what's going
>> on inside a xenon flash-tube, it has a great deal
>> in common with a lightning strike. As we all know,
>> a lighting strike can be "felt" both in terms of
>> magnetic and electrostatic effects, both of which
>> have the ability to radiate some distance and/or
>> couple to conductors.
>>
>> What you're hearing is the broad spectrum, radiated
>> noise coming directly from the confines of the ionized
>> gasses in the tube when it fires.
>>
>> When we put the first strobes on Cessna single-engine
>> airplanes in the 60's, there was a lot of fuss about
>> this mini-strike being heard in the ADF receivers.
>> We tried some glass with conductive coatings (reduced
>> light output) and fine-mesh screen wire (really hard to
>> work with).
>>
>> Somebody finally noted that, "Bee, when you're tuned to
>> a station that was strong enough to be useable for either
>> listening or navigating, the "pop" was imperceptible
>> and effects on navigation nil."
>>
>> Chances are that in flight, you're going to discover
>> the same thing. Now, if it does turn out to be a problem,
>> you'll need to repeat the same experiments we tried 40
>> years ago and perhaps some new ones. I'm aware of no
>> current tricks of the trade that would a apply.
>>
>> Bob . . .
>>
>>
>> ________________________________ Message 10
>> ____________________________________
>>
>>
>> Time: 06:01:33 PM PST US
>> From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
>> Subject: Re: AeroElectric-List: Question about Annunciating Lights
>>
>>
>> At 12:54 PM 1/9/2008 -0500, you wrote:
>>
>>> Bob, it would help if you also added these pictures to the article...
>>>
>>> Bret Smith
>>> RV-9A "Fuselage"
>>> Blue Ridge, GA
>>
>>
>> Done. Thanks!
>>
>>
>>>> A fine piece of work! I've preserved this data in
>>>> an excerpt of the websit and posted it to:
>>>>
>>>> http://aeroelectric.com/articles/Roll_your_own_Annunicator_Panel.pdf
>>>
>>> Bob . . .
>>>
>>> ----------------------------------------)
>>> ( . . . a long habit of not thinking )
>>> ( a thing wrong, gives it a superficial )
>>> ( appearance of being right . . . )
>>> ( )
>>> ( -Thomas Paine 1776- )
>>> ----------------------------------------
>>>
>>
>>
>> ________________________________ Message 11
>> ____________________________________
>>
>>
>> Time: 06:10:07 PM PST US
>> From: Steve Thomas <lists@stevet.net>
>> Subject: Re: AeroElectric-List: Cheaper 406mhz plb alternative?
>>
>> As far as 406MHz ELT goes, I currently have an ACK installed in my
>> not-
>> yet-flying Glasair. This unit is not a 406 MHz unit. With the
>> demise of
>> satellite tracking on 121.5, I wrote to ACK to ask if they had any
>> plans to
>> release a 406 unit. The reply was that, yes, they have one under
>> development. It is an exact replacement for the 121.5 unit, uses
>> the same
>> remote head, and uses easy to replace, commercially available
>> batteries (I
>> don't remember what kind, but they were not Alkaline). I don't
>> remember the
>> price exactly, but it was half of what the lowest price alternative
>> was.
>> They said to keep watching their web site and expected it to be
>> available
>> within the first half of this year.
>>
>>
>> On Jan 10, 2008, at 9:01 AM, David Chalmers wrote:
>>
>>> There's a good review here
>>> http://www.equipped.org/SPOT_ORSummer2007.htm
>>>
>>>
>>> On 1/9/08, Charlie England <ceengland@bellsouth.net> wrote:
>>>>
>>>
>>> Anyone know any details about this product?
>>>
>>> http://www.findmespot.com/explorespot/spotmessenger.aspx
>>>
>>> IF it's using the public SARSAT satellites, maybe it would still work
>>>
>>>
>>
>>
>> ________________________________ Message 12
>> ____________________________________
>>
>>
>> Time: 06:12:17 PM PST US
>> From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
>> Subject: Re: AeroElectric-List: Audio panel #inputs vs #sources
>>
>>
>> At 11:16 AM 1/9/2008 -0500, you wrote:
>>
>>> <recapen@earthlink.net>
>>>
>>> Folks,
>>>
>>> I have three inputs that should be 'unswitched':
>>> AOA warning
>>> Traffic Alert
>>> AF3400EM Engine monitor
>>>
>>> My audio panel (PS Engineering PMA7000MS) has two unswitched inputs.
>>> Can I tie two of the sources to one input? I think there would
>>> only be
>>> an issue if they both went off at teh same time.
>>> Alternatively, I can put the third to a switched input and leave the
>>> switch on.
>>
>> Put 100 ohm resistors in series with EACH of the three output
>> before bringing them together whether switched or not. See:
>>
>> http://aeroelectric.com/articles/Rev11/18Audio_R11.pdf
>>
>> Bob . . .
>>
>>
>> ________________________________ Message 13
>> ____________________________________
>>
>>
>> Time: 06:36:13 PM PST US
>> From: "Dale Ensing" <densing@carolina.rr.com>
>> Subject: Re: AeroElectric-List: XM radio power cord
>>
>>
>> Thank you Bob. The 'devices' on the power cord look just like the
>> ferrite
>> filters in the pictures. And thanks for the alert to possible
>> interference
>> to other radio systems in the airplane.
>> Dale
>>
>>> At 06:06 PM 1/9/2008 -0500, you wrote:
>>>
>>>> <densing@carolina.rr.com>
>>>>
>>>> A question regarding an XM Express radio that I use in the airplane
>>>> and in the car.
>>>>
>>>> The power cord for the XM radio has a cigarette lighter type plug,
>>>> is
>>>> about three feet long with a mini coaxial plug on the radio end.
>>>> Clamped on the cord are two cylinder shaped plastic devices (for
>>>> lack
>>>> of a better descriptive word). There is one on the cig. liter plug
>>>> end
>>>> and another smaller one on the radio end.
>>>> The wire used in the power cord is very stiff and difficult to keep
>>>> organized and out of the way. I would like to substitute another
>>>> power
>>>> cord that is coiled and stretchy. Much easier to manage and keep
>>>> neat.
>>>> What are the devices clamped on the cord and what is their function?
>>>> What will be the impact if I used a power cord without the devices.
>>>
>>> I suspect these are ferrite noise filters which
>>> are commonly added to commercial products for the
>>> for the purpose of reducing conducted electro-magnetic
>>> interference between devices connected with the cable.
>>>
>>> See:
>>>
>>> http://www.aeroelectric.com/Pictures/Filters/Ferrite_EMI_Filter_2.jpg
>>>
>>> http://www.aeroelectric.com/Pictures/Filters/Ferrite_EMI_Filter.jpg
>>>
>>> If the devices you're seeing are similar in nature, then
>>> it's probable that your device will FUNCTION if fitted
>>> with a cord that does not have the filters.
>>>
>>> But like any non-qualified device use in the airplane,
>>> you should be cognizant of potential for interference
>>> from the XM radio . . . whether filtered or not. Do some
>>> tests and be ready to turn the radio OFF anytime another
>>> radio system seems not to behave as expected.
>>>
>>> Bob . . .
>>
>>
>> ________________________________ Message 14
>> ____________________________________
>>
>>
>> Time: 09:20:38 PM PST US
>> From: Fiveonepw@aol.com
>> Subject: Re: AeroElectric-List: Question about Annunciating Lights
>>
>>
>> In a message dated 01/10/2008 8:21:26 AM Central Standard Time,
>> bferrell@123mail.net writes:
>>
>>
>> I made my panel out of Honeywell microswitches.
>>
>>>>>
>> Slick! Where were these back when I needed 'em?! Nice work-
>>
>> Mark
>> do not archive
>>
>>
>> **************Start the year off right. Easy ways to stay in shape.
>> http://body.aol.com/fitness/winter-exercise?NCID=aolcmp00300000002489
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
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Get the PLB that works when it is turned them on when you leave home
and turned them off when you get back. The object is that some one
knows where you are all the time when it is on. Nice for the wife at
home. Real time monitoring is the state of the art and the cost is
minimal. An ELT only works when you crash.
Read about Spot PL device.
Paul
================
At 08:22 AM 1/11/2008, you wrote:
>
>Well, a PLB may be less expensive, but it presumes that you are
>conscious when you need to activate it. Or that you will successfully
>regain consciousness before, well, you know. Steve Fausset had a
>personal PLB - didn't do him any good at all. Just a thought.
>
>
>On Jan 11, 2008, at 7:24 AM, Giffen Marr wrote:
>
>>
>>I am planning on using the cheapest ELT available to meet the FAR 91
>>Requirements and a 406 PLB. The current cost of ELT's meeting the 406
>>requirements are out of sight as compared to the 121.5 units. The
>>other
>>advantage is the PLB is not much larger then a cell phone as
>>compared to the
>>ELT. Only advantage to the ELT is the battery life may be longer
>>then the
>>PLB.
>>
>>Giff Marr
>>LIV-P/Mistral 65%
>>
>>-----Original Message-----
>>From: owner-aeroelectric-list-server@matronics.com
>>[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
>>AeroElectric-List Digest Server
>>Sent: Friday, January 11, 2008 1:56 AM
>>To: AeroElectric-List Digest List
>>Subject: AeroElectric-List Digest: 14 Msgs - 01/10/08
>>
>>*
>>
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>> ----------------------------------------------------------
>> AeroElectric-List Digest Archive
>> ---
>> Total Messages Posted Thu 01/10/08: 14
>> ----------------------------------------------------------
>>
>>
>>Today's Message Index:
>>----------------------
>>
>> 1. 05:17 AM - Re: Strobe discharge pop-pop-pop (Ralph E. Capen)
>> 2. 06:19 AM - Re: Question about Annunciating Lights (Brett
>>Ferrell)
>> 3. 09:16 AM - Re: Cheaper 406mhz plb alternative? (David
>>Chalmers)
>> 4. 10:08 AM - Re: Odd ICOM IC-A200 Power/Ground Instructions ()
>> 5. 12:18 PM - Re: Rotax 914 capacitor (Robert L. Nuckolls, III)
>> 6. 01:02 PM - Re: Shielded Wire (Robert L. Nuckolls, III)
>> 7. 02:56 PM - Re: Shielded Wire (Eric M. Jones)
>> 8. 05:19 PM - Re: XM radio power cord (Robert L. Nuckolls, III)
>> 9. 05:41 PM - Re: Strobe discharge pop-pop-pop (Robert L.
>>Nuckolls,
>>III)
>> 10. 06:01 PM - Re: Question about Annunciating Lights (Robert L.
>>Nuckolls, III)
>> 11. 06:10 PM - Re: Cheaper 406mhz plb alternative? (Steve Thomas)
>> 12. 06:12 PM - Re: Audio panel #inputs vs #sources (Robert L.
>>Nuckolls,
>>III)
>> 13. 06:36 PM - Re: XM radio power cord (Dale Ensing)
>> 14. 09:20 PM - Re: Question about Annunciating Lights
>>(Fiveonepw@aol.com)
>>
>>
>>
>>________________________________ Message 1
>>_____________________________________
>>
>>
>>Time: 05:17:08 AM PST US
>>From: "Ralph E. Capen" <recapen@earthlink.net>
>>Subject: Re: AeroElectric-List: Strobe discharge pop-pop-pop
>>
>>
>>I'll be trying it outside soon and with the engine later - I'm almost
>>thinking the engine will drown it out...
>>
>>-----Original Message-----
>>>From: Ken <klehman@albedo.net>
>>>Sent: Jan 9, 2008 11:45 PM
>>>To: aeroelectric-list@matronics.com
>>>Subject: Re: AeroElectric-List: Strobe discharge pop-pop-pop
>>>
>>>
>>>Ralph
>>>Have you tried it outside? My radio picks it up when in a metal
>>>hangar
>>>but not when outside. My intercom picks up a little as well via power
>>>supply or ground but hardly noticeable with the engine idling. So it
>>>might not be worth pursuing. The chapter on noise and grounding may
>>>be
>>>helpful. And if it is still noticeable a cheap automotive radio power
>>>filter on the strobe power supplies also helped in my case.
>>>Ken
>>>
>>>Ralph E. Capen wrote:
>>>>
>>>>I'm doing some system testing and I can hear a very slight pop each
>>>>time my
>>strobes discharge through my headset. It doesn't break the squelch or
>>prevent me from hearing the radios - or stereo for that matter. No
>>whining
>>on the charge cycles and I gotta listen carefully to catch the pop -
>>but
>>it's there.
>>>>
>>>>Is this strictly due to the high-voltage discharge in a 12V system?
>>>>Is there
>>something I can due to get rid of this? Or should I take gladness
>>that it's
>>faint, doesn't interfere, it's as good as it gets, have a coke and a
>>smile
>>and.......?
>>>>
>>>>Ralph
>>
>>
>>________________________________ Message 2
>>_____________________________________
>>
>>
>>Time: 06:19:33 AM PST US
>>From: Brett Ferrell <bferrell@123mail.net>
>>Subject: RE: AeroElectric-List: Question about Annunciating Lights
>>
>>
>>I made my panel out of Honeywell microswitches. It's not really a
>>cheap
>>way, but the results are nice, and it's fairly straight-forward,
>>with "dead
>>face"
>>(labels so you KNOW the lamp is out, because it cannot be read unless
>>illuminated from behind). I also built a push-to-test circuit.
>>
>>http://www.velocityxl.com/Electrical.htm
>>(just the pictures)
>>http://www.velocityxl.com/annunciator.JPG
>>http://www.velocityxl.com/press_to_test.JPG
>>http://www.velocityxl.com/IMAGES2/GRT3.JPG
>>
>>I bought mine from these folks http://www.fmw411.com/
>>
>>Brett
>>
>>Quoting Carl Morgan <zk-vii@rvproject.gen.nz>:
>>
>>>I took Mark's work as a basis, and this is what I ended up with....
>>>
>>>Close up:
>>>http://www.rvproject.gen.nz/photos/2007-06/Web_Img_9760.jpg
>>>
>>>http://www.rvproject.gen.nz/dailylog/dailylog_2007-07-28.html the
>>>final look,
>>>
>>>
>>>http://www.rvproject.gen.nz/dailylog/dailylog_2007-06-18.html and
>>>http://www.rvproject.gen.nz/dailylog/dailylog_2007-06-19.html for
>>>some
>>>of the fabrication process.
>>>
>>>Just another possible source of ideas.
>>>
>>>Carl
>>>
>>>--
>>>Carl Morgan - ZK-VII - RV 7A - Inspection next Tue!
>>>http://www.rvproject.gen.nz/
>>> -----Original Message-----
>>> From: owner-aeroelectric-list-server@matronics.com
>>>[mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of
>>>Fiveonepw@aol.com
>>> Sent: 10 January 2008 18:14
>>> To: aeroelectric-list@matronics.com
>>> Subject: Re: AeroElectric-List: Question about Annunciating Lights
>>>
>>>
>>> Here's another take on rollin' yer own:
>>>
>>>
>>>http://websites.expercraft.com/n51pw/index.php? q=log_entry&log_id=5126
>>>
>>> Click on fotos for bigger view and Next Entry>> for more info
>>>(several
>>>pages) including wiring diagram, part #s etc...
>>>
>>> From The PossumWorks in TN
>>> Mark Phillips
>>>
>>>
>>>----------------------------------------------------------------------
>>>------
>>>--
>>> Start the year off right. Easy ways to stay in shape in the new
>>>year.
>>>
>>>
>>>10:16
>>
>>
>>________________________________ Message 3
>>_____________________________________
>>
>>
>>Time: 09:16:46 AM PST US
>>From: "David Chalmers" <david@ChalmersFamily.com>
>>Subject: Re: AeroElectric-List: Cheaper 406mhz plb alternative?
>>
>>There's a good review here http://www.equipped.org/SPOT_ORSummer2007.htm
>>
>>
>>On 1/9/08, Charlie England <ceengland@bellsouth.net> wrote:
>>>
>>>ceengland@bellsouth.net>
>>>
>>>Anyone know any details about this product?
>>>
>>>http://www.findmespot.com/explorespot/spotmessenger.aspx
>>>
>>>IF it's using the public SARSAT satellites, maybe it would still work
>>>after the 1st mandatory subscription lapses. (Still be a lot cheaper
>>>than typical PLBs with built in GPS.)
>>>
>>>Charlie
>>
>>________________________________ Message 4
>>_____________________________________
>>
>>
>>Time: 10:08:56 AM PST US
>>From: <gmcjetpilot@yahoo.com>
>>Subject: AeroElectric-List: Re: Odd ICOM IC-A200 Power/Ground
>>Instructions
>>
>>Tim the 18 awg and 10 amp fuse is the broad brush approach, one size
>>fits
>>all. Yes its overkill. You could use a smaller awg wire and fuse. Also
>>sometimes people gang off of existing 10 amp CB's and therefore
>>18 awg is the correct wire size. I used 5 amp and stayed with the 18
>>awg
>>because I had it; A short run of 20 awg would work fine. They're just
>>covered their bases.
>>
>> Notice 13.8 volts spec? You can take some IR loss with a 14.3-14.5
>>volt
>>buss.
>>
>>The wire diagram clearly shows ONE power and ONE ground with a daisy
>>chain
>>or jumpers. Sorry have no idea what he's talking about. TWIST?
>>Really. May
>>be this is new and it does help but I am stumped. I went with one
>>wire for
>>power and ground. George
>>
>> If you find a 100% answer why, email me please, thanks
>>
>> PS Its a great radio but instructions are lousy.
>>
>>
>>>From: Tim Lewis <Tim_Lewis@msm.umr.edu>
>>>Subject: AeroElectric-List: Odd ICOM IC-A200 Power/Ground
>>>Instructions
>>
>>
>>>The ICOM IC-A200 (VHF Comm radio) installation instruction
>>
>>
>>(http://www.aeroelectric.com/Installation_Data/Icom_ICA200_Installation_Manu
>> > al.pdf)
>>
>>>depicts a 10 amp breaker, and tells the installer to "Use
>>>2 pairs of #18 AWG wires for power and power grounding wiring."
>>>This
>>>struck me as odd, since a single 18 AWG wire is normally used with a
>>>10 amp breaker, and since the IC-A200 is rated to draw only
>>>2.6 amps (during transmit).
>>
>>>I called ICOM tech support and spoke to Mike, who told me that I
>>>should
>>>indeed use two 18 AWG wires for power and two 18 AWG wires for
>>>ground,
>>>and that the two wires should be twisted together "to reduce
>>>interference". He further recommended twisting the end of the two
>>>wires together, aided by solder, and crimping this assembly into the
>>>supplied Molex terminal.
>>
>>>I expressed some skepticism about the efficacy of twisting two 12V
>>>power wires together to reduce interference. I was unable to elicit
>>>an explanation of the mechanism by which the alleged interference
>>>reduction was to be achieved. I was also unable to elicit an
>>>explanation of why it should take two 18AWG wires in parallel to
>>>supply 2.6 Amps (peak) to a radio. I elected not to engage Mike in a
>>>discussion of the advisability of crimping a connector to a soldered
>>>wire.
>>
>>>Does anybody have insight into reasoning or experience that lends
>>>credibility to the idea that two 18 AWG wires should be used for
>>>power
>>>(and two for
>>>ground) in an ICOM IC-A200 radio installation?
>>
>>>Thanks,
>>>Tim Lewis
>>
>>
>>---------------------------------
>>Never miss a thing. Make Yahoo your homepage.
>>
>>________________________________ Message 5
>>_____________________________________
>>
>>
>>Time: 12:18:54 PM PST US
>>From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
>>Subject: Re: AeroElectric-List: Rotax 914 capacitor
>>
>>
>>At 12:13 PM 1/9/2008 -0800, you wrote:
>>
>>>
>>>Hi All,
>>>B&C offer a couple different capacitors, 10,000uF @50VDC and
>>>47,000uF
>>>@16VDC. Is one of these appropriate for use on the Rotax alternator?
>>>Thanks, Kevin
>>
>>
>> This is not a really critical capacitor with
>> respect to value but 16v is bit low for
>> a rating. 25V or more is the target. Furhter,
>> the "rule of thumb" for sizing is 1,000 uF per
>> amp of alternator output so the 10KuF/50v is
>> pretty good for the SD-8. Your system would
>> be better served by 20KuF/25V or larger.
>>
>> Bob . . .
>>
>> ----------------------------------------)
>> ( . . . a long habit of not thinking )
>> ( a thing wrong, gives it a superficial )
>> ( appearance of being right . . . )
>> ( )
>> ( -Thomas Paine 1776- )
>> ----------------------------------------
>>
>>
>>________________________________ Message 6
>>_____________________________________
>>
>>
>>Time: 01:02:10 PM PST US
>>From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
>>Subject: Re: AeroElectric-List: Shielded Wire
>>
>>
>>At 06:12 AM 1/10/2008 -0800, you wrote:
>>
>>>
>>>Bob:
>>>
>>>Maybe this is a little clearer:
>>>
>>>All the wires in the wing are shielded.
>>
>>
>> ?Why?
>>
>>
>>>The wire used is MIL-DTL-27500TG2T14. That particular one is
>>>12AWG, two
>>>conductor, twisted pair, shielded and sheathed. The unshielded
>>>version
>>>was not available without special order and long lead time. The
>>>weight
>>>difference between shielded and unshielded was 2.75lbs for 1,000 feet
>>>so I got the shielded version.
>>>
>>>There are no manufacturer's recommendations per se. Sizing for loads
>>>was done as per AC43-13-2A based on the power consumption rating
>>>for each
>>load.
>>>
>>>All power loads have a power lead and a return lead. The sensors
>>>have
>>>how ever many wires are required by the sensor.
>>>
>>>Ignoring connectors, fuses, switches, ground buss etc, all power
>>>loads
>>>were to be routed as follows:
>>>
>>> Power lead: Bat(+) -to- Load.
>>> Return lead: Load -to- Bat (-) and, Load -to- Airframe (at
>>>Local
>>>Ground) -to- Bat (-)
>>> Shielding: - Bat(-) -to- Airframe (at Local Ground)
>>>
>>>I can't find where I read it but something led me to believe that if
>>>you were going to use shielded wire it was OK to do it the way I did.
>>
>> I'm not sure I'm interpreting you words into an
>> accurate schematic of your architecture but since
>> the use of shielding where shielding adds no value,
>> then exactly how you wire it has no significance
>> with respect to performance.
>>
>>
>>>So, given that I am going to use the wire I have, that I am going to
>>>run a return lead for all power loads and that I want to hook up the
>>>shielding on the wire, what is the correct way to do it?
>>>
>>>Regarding the return lead, I'm pretty clear that the return lead
>>>should
>>>not be grounded at the Bat (-) and at a Local ground. Quote from
>>>your
>>response:
>>>
>>>" One and only one ground . . . local is probably fine
>>> but not both places . . ."
>>>
>>>No problem changing it but why is it such a bad thing to do it that
>>>way.
>>>Using the landing light as an example. What harm does it cause to
>>>ground it locally and also run a lead back to the bat (-). Why is
>>>that
>>>worse than only grounding locally and the corollary, why is that not
>>>better than only running the lead back to the bat (-). Is the same
>>>applicable to the strobe's power unit and the fuel pump. Would it be
>>>the same for something like a flap actuator motor.
>>
>> My personal goals for system design are to achieve
>> the desired level of performance with a minimum of
>> parts and minimized $time$ to acquire/install/maintain.
>>
>> You appear to be asking advice for doing things that
>> I would not choose to do because they do not add
>> value under the design goals stated. Doing doesn't
>> necessarily degrade performance but it's certain
>> not to enhance it. Are there risks for venturing outside
>> the simple ideas that support conventional wisdom?
>> Difficult to predict but probably not.
>>
>>
>>>Regarding the shielding: I'm less clear on this. Removing the local
>>>ground from the return lead will also take the shielding out of the
>>>ground path from the Load to the Bat(-). But what about grounding
>>>the
>>shielding itself.
>>>Again using the landing light as an example, what is the difference
>>>between grounding at both ends and grounding only at the Bat(-). Is
>>>the same applicable to the strobe's power unit, fuel pump and flap
>>>motor.
>>>
>>>Looking forward to your explanations.
>>
>> A detailed trek through the physics from which
>> conventional wisdom and common practices evolved
>> is beyond the scope of what I can do here on
>> the List. I did a short-course on noise propagation
>> issues and solutions a few years ago at Hawker-
>> Beech . . . and that was a 4-hour, Power-Point
>> presentation.
>>
>> Suffice it to say that if my mental image
>> for what you've described is correct,
>> then there is no reason to expect degradation
>> of performance and no reason to expect an
>> enhancement of performance. I.e, shielding
>> added without specific noise propagation
>> problems to be solved only adds to weight
>> of the airplane and cost of ownership. It
>> follows then that I have no advice based
>> on physics to offer for "doing it right".
>>
>> Bob . . .
>>
>>
>>________________________________ Message 7
>>_____________________________________
>>
>>
>>Time: 02:56:00 PM PST US
>>Subject: AeroElectric-List: Re: Shielded Wire
>>From: "Eric M. Jones" <emjones@charter.net>
>>
>>
>>Okay, cut this message out and punch three holes into it and stick
>>it into
>>your book. This is the cat's meow on coaxial cable shielding and
>>grounding
>>from Kimmel Gerke Associates. I hope they balance my liberal use of
>>their
>>stuff with the free advertising given here.
>>
>>http://www.emiguru.com/kgb/sum1996.htm Kimmel Gerke Bullets.
>>
>>"For many designers, cables and connectors are an afterthought.
>>After all,
>>they just connect things together, right? But cables and connectors
>>are
>>major entry and exit points for EMI into and out of electronic
>>systems. They
>>act as "hidden antennas" for radiated energy, and "hidden conduits"
>>for
>>conducted energy.
>>
>>
>>"In fact, cables and connectors are so important, they are the often
>>the
>>first things we check out when troubleshooting EMI problems in a
>>system.
>>Here are a few thoughts on cable and connector design for EMI.
>>Trade off shielding for filtering. If you don't filter I/O
>>interfaces, then
>>you must assume that the highest frequencies inside the unit will
>>end up on
>>the cable wires. (Or you must assume the cables will intercept the
>>highest
>>frequencies and bring them into the unit.)
>>
>>"Just because that RS-232 interface is only operating in the
>>kilobaud range
>>doesn't stop higher frequencies from hitching a "free ride" on the
>>cables.
>>We've solved many radiated problems (emissions and immunity) by adding
>>simple filters to interfaces that were only supposed to carry "slow"
>>or "low
>>frequency" signals.
>>
>>"The alternate to filtering the cables is shielding the cables. We
>>generally
>>prefer to filter slower cables, since it's usually more cost
>>effective and
>>easier to maintain EMI integrity.
>>
>>"Ground the cable shield. If you do decide to use shielded cables,
>>then the
>>immediate question becomes how best to ground the cable shield. The
>>correct
>>method depends on both threat frequencies and circuit impedance
>>levels.
>>
>>"For problem frequencies below 10 kHz [audio], the preferred
>>approach is to
>>ground one only one end of the shield. This is to prevent "ground
>>loop"
>>coupling from the cable shield to the inner wires. This is
>>particularly
>>important for preventing 60 Hz coupling into low level/high impedance
>>circuits used in audio or instrumentation systems.
>>
>>"Unfortunately, this is exactly the wrong thing to do for high
>>frequency
>>threats.
>>For most RF situations [above 10 kHz], the preferred approach is to
>>ground
>>both ends of the cable shield, to minimize coupling at the open end
>>due to
>>standing wave effects. So what do you do if both threats exist? You
>>can
>>ground one end with a small capacitor (1,000- 10,000 pf typical) or
>>you can
>>use two shields
>>- one grounded on one end, and the other grounded on both ends. In the
>>latter case, the shields must be insulated from each other.
>>
>>"One more case where both ends must be grounded is the low frequency/ low
>>impedance case, where magnetic fields are the major culprit. In this
>>case,
>>the strategy is to minimize "loop size" by providing an adjacent
>>return path
>>for noise currents. This is often necessary in electrical sub- stations,
>>where large 60 Hz magnetic fields exist due to the high current
>>levels. Most
>>of the time, however, single point grounding at low frequencies is the
>>preferred approach.
>>
>>"Use Care With Connector Terminations. This is extremely important for
>>shielded cables with EMI threats above about 1 MHz. Poor joints (or
>>worse,
>>"pigtail" connections from the shield to the connector) are a
>>leading cause
>>EMI-induced failures on shielded cables. We've seen 20 dB increases in
>>emissions, and 10 fold reductions in ESD immunity due to poor
>>connections.
>>(Remember, with a 1 nsec edge rate, ESD is a 300 MHz EMI problem.)
>>
>>"To maintain high frequency cable shield integrity, you need a
>>circumferential bond between the cable shield and the connector
>>shell. In
>>addition you need full metal-to-metal between the mating connectors.
>>Finally, you need a solid connector-to-chassis connection. One
>>problem we
>>often see here is with chassis connectors that overlap connector
>>cutouts.
>>The imprecise fit creates a slot that very effectively couples high
>>frequency energy directly to/from the cable shield. Think in terms
>>of a
>>garden hose -you need a very tight connection at the faucet, or else
>>it
>>leaks.
>>
>>"What About The Cable Shield Itself? Yes, this is a valid concern,
>>but only
>>after you have addressed the connector termination issues. For
>>frequencies
>>below about 10 MHz, most cable shielding materials behave about the
>>same,
>>and provide very respectable amounts of shielding. For frequencies
>>above
>>about 10 MHz, however, the cable construction becomes important. Loose
>>single braids become increasingly leaky, so above 10 MHz, you may
>>need high
>>density braid shields. Double braids work very well here, as do
>>braid over
>>Mylar cable shields. For high frequencies, both shields should be
>>connected
>>together. "
>>
>>--------
>>Eric M. Jones
>>www.PerihelionDesign.com
>>113 Brentwood Drive
>>Southbridge, MA 01550
>>(508) 764-2072
>>emjones@charter.net
>>
>>
>>Read this topic online here:
>>
>>http://forums.matronics.com/viewtopic.php?p=157322#157322
>>
>>
>>________________________________ Message 8
>>_____________________________________
>>
>>
>>Time: 05:19:04 PM PST US
>>From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
>>Subject: Re: AeroElectric-List: XM radio power cord
>>
>>
>>At 06:06 PM 1/9/2008 -0500, you wrote:
>>
>>><densing@carolina.rr.com>
>>>
>>>A question regarding an XM Express radio that I use in the airplane
>>>and
>>>in the car.
>>>
>>>The power cord for the XM radio has a cigarette lighter type plug, is
>>>about three feet long with a mini coaxial plug on the radio end.
>>>Clamped on the cord are two cylinder shaped plastic devices (for lack
>>>of a better descriptive word). There is one on the cig. liter plug
>>>end
>>>and another smaller one on the radio end.
>>>The wire used in the power cord is very stiff and difficult to keep
>>>organized and out of the way. I would like to substitute another
>>>power
>>>cord that is coiled and stretchy. Much easier to manage and keep
>>>neat.
>>>What are the devices clamped on the cord and what is their function?
>>>What will be the impact if I used a power cord without the devices.
>>
>> I suspect these are ferrite noise filters which
>> are commonly added to commercial products for the
>> for the purpose of reducing conducted electro-magnetic
>> interference between devices connected with the cable.
>>
>> See:
>>
>>http://www.aeroelectric.com/Pictures/Filters/Ferrite_EMI_Filter_2.jpg
>>
>>http://www.aeroelectric.com/Pictures/Filters/Ferrite_EMI_Filter.jpg
>>
>> If the devices you're seeing are similar in nature, then
>> it's probable that your device will FUNCTION if fitted
>> with a cord that does not have the filters.
>>
>> But like any non-qualified device use in the airplane,
>> you should be cognizant of potential for interference
>> from the XM radio . . . whether filtered or not. Do some
>> tests and be ready to turn the radio OFF anytime another
>> radio system seems not to behave as expected.
>>
>> Bob . . .
>>
>>
>> ----------------------------------------)
>> ( . . . a long habit of not thinking )
>> ( a thing wrong, gives it a superficial )
>> ( appearance of being right . . . )
>> ( )
>> ( -Thomas Paine 1776- )
>> ----------------------------------------
>>
>>
>>________________________________ Message 9
>>_____________________________________
>>
>>
>>Time: 05:41:58 PM PST US
>>From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
>>Subject: Re: AeroElectric-List: Strobe discharge pop-pop-pop
>>
>>
>>At 01:36 PM 1/9/2008 -0500, you wrote:
>>
>>><recapen@earthlink.net>
>>>
>>>I'm doing some system testing and I can hear a very slight pop each
>>>time my strobes discharge through my headset. It doesn't break the
>>>squelch or prevent me from hearing the radios - or stereo for that
>>>matter. No whining on the charge cycles and I gotta listen carefully
>>>to catch the pop
>>>- but it's there.
>>>
>>>Is this strictly due to the high-voltage discharge in a 12V
>>>system? Is
>>>there something I can due to get rid of this? Or should I take
>>>gladness that it's faint, doesn't interfere, it's as good as it gets,
>>>have a coke and a smile and.......?
>>
>> When you think about the physics of what's going
>> on inside a xenon flash-tube, it has a great deal
>> in common with a lightning strike. As we all know,
>> a lighting strike can be "felt" both in terms of
>> magnetic and electrostatic effects, both of which
>> have the ability to radiate some distance and/or
>> couple to conductors.
>>
>> What you're hearing is the broad spectrum, radiated
>> noise coming directly from the confines of the ionized
>> gasses in the tube when it fires.
>>
>> When we put the first strobes on Cessna single-engine
>> airplanes in the 60's, there was a lot of fuss about
>> this mini-strike being heard in the ADF receivers.
>> We tried some glass with conductive coatings (reduced
>> light output) and fine-mesh screen wire (really hard to
>> work with).
>>
>> Somebody finally noted that, "Bee, when you're tuned to
>> a station that was strong enough to be useable for either
>> listening or navigating, the "pop" was imperceptible
>> and effects on navigation nil."
>>
>> Chances are that in flight, you're going to discover
>> the same thing. Now, if it does turn out to be a problem,
>> you'll need to repeat the same experiments we tried 40
>> years ago and perhaps some new ones. I'm aware of no
>> current tricks of the trade that would a apply.
>>
>> Bob . . .
>>
>>
>>________________________________ Message 10
>>____________________________________
>>
>>
>>Time: 06:01:33 PM PST US
>>From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
>>Subject: Re: AeroElectric-List: Question about Annunciating Lights
>>
>>
>>At 12:54 PM 1/9/2008 -0500, you wrote:
>>
>>>Bob, it would help if you also added these pictures to the article...
>>>
>>>Bret Smith
>>>RV-9A "Fuselage"
>>>Blue Ridge, GA
>>
>>
>> Done. Thanks!
>>
>>
>>>> A fine piece of work! I've preserved this data in
>>>> an excerpt of the websit and posted it to:
>>>>
>>>>http://aeroelectric.com/articles/Roll_your_own_Annunicator_Panel.pdf
>>>
>>> Bob . . .
>>>
>>> ----------------------------------------)
>>> ( . . . a long habit of not thinking )
>>> ( a thing wrong, gives it a superficial )
>>> ( appearance of being right . . . )
>>> ( )
>>> ( -Thomas Paine 1776- )
>>> ----------------------------------------
>>
>>
>>________________________________ Message 11
>>____________________________________
>>
>>
>>Time: 06:10:07 PM PST US
>>From: Steve Thomas <lists@stevet.net>
>>Subject: Re: AeroElectric-List: Cheaper 406mhz plb alternative?
>>
>>As far as 406MHz ELT goes, I currently have an ACK installed in my
>>not-
>>yet-flying Glasair. This unit is not a 406 MHz unit. With the
>>demise of
>>satellite tracking on 121.5, I wrote to ACK to ask if they had any
>>plans to
>>release a 406 unit. The reply was that, yes, they have one under
>>development. It is an exact replacement for the 121.5 unit, uses
>>the same
>>remote head, and uses easy to replace, commercially available
>>batteries (I
>>don't remember what kind, but they were not Alkaline). I don't
>>remember the
>>price exactly, but it was half of what the lowest price alternative
>>was.
>>They said to keep watching their web site and expected it to be
>>available
>>within the first half of this year.
>>
>>
>>On Jan 10, 2008, at 9:01 AM, David Chalmers wrote:
>>
>>>There's a good review here
>>>http://www.equipped.org/SPOT_ORSummer2007.htm
>>>
>>>
>>>On 1/9/08, Charlie England <ceengland@bellsouth.net> wrote:
>>>
>>>Anyone know any details about this product?
>>>
>>>http://www.findmespot.com/explorespot/spotmessenger.aspx
>>>
>>>IF it's using the public SARSAT satellites, maybe it would still work
>>
>>
>>________________________________ Message 12
>>____________________________________
>>
>>
>>Time: 06:12:17 PM PST US
>>From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
>>Subject: Re: AeroElectric-List: Audio panel #inputs vs #sources
>>
>>
>>At 11:16 AM 1/9/2008 -0500, you wrote:
>>
>>><recapen@earthlink.net>
>>>
>>>Folks,
>>>
>>>I have three inputs that should be 'unswitched':
>>>AOA warning
>>>Traffic Alert
>>>AF3400EM Engine monitor
>>>
>>>My audio panel (PS Engineering PMA7000MS) has two unswitched inputs.
>>>Can I tie two of the sources to one input? I think there would
>>>only be
>>>an issue if they both went off at teh same time.
>>>Alternatively, I can put the third to a switched input and leave the
>>>switch on.
>>
>> Put 100 ohm resistors in series with EACH of the three output
>> before bringing them together whether switched or not. See:
>>
>>http://aeroelectric.com/articles/Rev11/18Audio_R11.pdf
>>
>> Bob . . .
>>
>>
>>________________________________ Message 13
>>____________________________________
>>
>>
>>Time: 06:36:13 PM PST US
>>From: "Dale Ensing" <densing@carolina.rr.com>
>>Subject: Re: AeroElectric-List: XM radio power cord
>>
>>
>>Thank you Bob. The 'devices' on the power cord look just like the
>>ferrite
>>filters in the pictures. And thanks for the alert to possible
>>interference
>>to other radio systems in the airplane.
>>Dale
>>
>>>At 06:06 PM 1/9/2008 -0500, you wrote:
>>>
>>>><densing@carolina.rr.com>
>>>>
>>>>A question regarding an XM Express radio that I use in the airplane
>>>>and in the car.
>>>>
>>>>The power cord for the XM radio has a cigarette lighter type plug,
>>>>is
>>>>about three feet long with a mini coaxial plug on the radio end.
>>>>Clamped on the cord are two cylinder shaped plastic devices (for
>>>>lack
>>>>of a better descriptive word). There is one on the cig. liter plug
>>>>end
>>>>and another smaller one on the radio end.
>>>>The wire used in the power cord is very stiff and difficult to keep
>>>>organized and out of the way. I would like to substitute another
>>>>power
>>>>cord that is coiled and stretchy. Much easier to manage and keep
>>>>neat.
>>>>What are the devices clamped on the cord and what is their function?
>>>>What will be the impact if I used a power cord without the devices.
>>>
>>> I suspect these are ferrite noise filters which
>>> are commonly added to commercial products for the
>>> for the purpose of reducing conducted electro-magnetic
>>> interference between devices connected with the cable.
>>>
>>> See:
>>>
>>>http://www.aeroelectric.com/Pictures/Filters/Ferrite_EMI_Filter_2.jpg
>>>
>>>http://www.aeroelectric.com/Pictures/Filters/Ferrite_EMI_Filter.jpg
>>>
>>> If the devices you're seeing are similar in nature, then
>>> it's probable that your device will FUNCTION if fitted
>>> with a cord that does not have the filters.
>>>
>>> But like any non-qualified device use in the airplane,
>>> you should be cognizant of potential for interference
>>> from the XM radio . . . whether filtered or not. Do some
>>> tests and be ready to turn the radio OFF anytime another
>>> radio system seems not to behave as expected.
>>>
>>> Bob . . .
>>
>>
>>________________________________ Message 14
>>____________________________________
>>
>>
>>Time: 09:20:38 PM PST US
>>From: Fiveonepw@aol.com
>>Subject: Re: AeroElectric-List: Question about Annunciating Lights
>>
>>
>>In a message dated 01/10/2008 8:21:26 AM Central Standard Time,
>>bferrell@123mail.net writes:
>>
>>
>>I made my panel out of Honeywell microswitches.
>>
>>Slick! Where were these back when I needed 'em?! Nice work-
>>
>>Mark
>>do not archive
>>
>>
>>**************Start the year off right. Easy ways to stay in shape.
>>http://body.aol.com/fitness/winter-exercise?NCID=aolcmp00300000002489
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
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I think it is more about making sure the PLB is actually transmitting while still
airborne....I believe the satalites can actually register the signal relatively
quickly but may not have the actual GPS coordinates locked in.
So making an assumption that you have say 2 minutes before you hit the ground and
in the worse case the PLB is destroyed (unlikely) , is that enough time time
to alert SAR?..I'm thinking you may not have gotten the accurate GPS lock but
a 2 square mile position (from triangulating the signal itself) is a whole lot
better than no position at all.
Your thoughts?
Frank
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Matt Prather
Sent: Friday, January 11, 2008 9:34 AM
Subject: RE: AeroElectric-List: Re: ELT/PLB
--> <mprather@spro.net>
If you want satellites locked in, consider getting your amateur radio license (ham)
and then start carrying (or install) a Tiny Track (or something similar).
http://www.byonics.com/tinytrak/
And use it to keep your position updated via APRS:
http://www.googleaprs.com/
Then people will have a way to see your flight is/was going.
I wonder if ADS-B is going to support something similar.
Regards,
Matt-
> <frank.hinde@hp.com>
>
> Indeed, and you can always activate it when you know you are going down.
> In fact I wonder how reliable the G switches are in the case of ELT's
> anyway...121.5 ELTs are notoriously innefective but the 406 units will
> still have the same kind of G switch technology I would presume, how
> well do they work?
Message 15
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Subject: | Question about Annunciating Lights |
I bought those ports but then read so much about Van's being the only ports
that were accurate that I put them on the shelf and installed Van's "rivet
ports".
Has anyone flown with the Safe-Air ports and found them to be as accurate as
Van's?
TIA
Allen Fulmer
RV7 wiring and avionics
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Peter
Laurence
Sent: Friday, January 11, 2008 8:03 AM
To: aeroelectric-list@matronics.com
Subject: Re: AeroElectric-List: Question about Annunciating Lights
For all of you that don't know, Mark makes a great static port!
Peter Laurence
Here's another take on rollin' yer own:
http://websites.expercraft.com/n51pw/index.php?q=log_entry&log_id=5126
Click on fotos for bigger view and Next Entry>> for more info (several
pages) including wiring diagram, part #s etc...
From The PossumWorks in TN
Mark Phillips
----------------------------------------------------------------------------
Start the year off right. Easy ways to stay in shape in the new year.
href="http://www.matronics.com/Navigator?AeroElectric-List">http://www.matro
nics.com/Navigator?AeroElectric-List
href="http://forums.matronics.com">http://forums.matronics.com
href="http://www.matronics.com/contribution">http://www.matronics.com/c
Message 16
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Subject: | Toggle switch tool |
Bob,
Some time ago someone mentioned a tool for tightening the nut on toggle
switches without scratching the painted panel surface. I suppose if it's a
hex nut on the switch, a deep socket wrench (9/16?) would work. However
some switches come with a knurled nut. Is there a tool for this? Can't
seem to find one at any of the on-line vendors I've tried. Probably because
I don't know what it's called. Any help is appreciated.
Bevan
RV7A wiring
Message 17
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Subject: | Re: Toggle switch tool |
Bevan,
I solved this issue by just buying 9/16" hex nuts. B&C Electrical sells spare
hex nuts, lock washers and anti-rotation washers for switches. I bought several
as replacements to any knurled nuts I had. I also figured I would need some
spare nuts and washers for those I will eventually drop on the floor and have
roll into inaccessible places.
FYI, it was the switches I got from SteinAir that came with knurled nuts. All
switches that I got from B&C came with hex nuts.
Good luck,
--------
David Gallagher
601 XL, tail and wings completed,
fueslage almost done. Working engine and electrical systems.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=157511#157511
Message 18
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Subject: | Annunicator panels |
> >
> >In the document you saved to your website, you're missing the building
> >pictures... which are very important and are in the bottom of the Van's
Air
> >Force thread
> >
> >Carlos
>
> Are you talking about the two shots that were forwarded to
> me by another reader? See reposted document with additions
> at:
>
> http://aeroelectric.com/articles/Roll_your_own_Annunicator_Panel.pdf
>
> Thanks for the heads-up!
>
> Bob . . .
You're welcome, sir!
Carlos
Message 19
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Subject: | Question about Annunciating Lights |
Mark,
That's actually better than what I was looking for!
I could buy those LED rectangles and mount them behind the reverse engraved
acrylic front and have exactly what I am looking for. Any idea on whether
the measurements on the rectangles are in mm?
Thank you for posting that information. You have solved my problem! Look
at that - its only January and already my list contribution has paid off.
Scott R. Shook
RV-7A (Building)
N696JS (Reserved)
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Fiveonepw@aol.com
Sent: Wednesday, 09 January, 2008 22:14
Subject: Re: AeroElectric-List: Question about Annunciating Lights
Here's another take on rollin' yer own:
http://websites.expercraft.com/n51pw/index.php?q=log_entry
<http://websites.expercraft.com/n51pw/index.php?q=log_entry&log_id=5126>
&log_id=5126
Click on fotos for bigger view and Next Entry>> for more info (several
pages) including wiring diagram, part #s etc...
>From The PossumWorks in TN
Mark Phillips
_____
Start the year off right. Easy
<http://body.aol.com/fitness/winter-exercise?NCID=aolcmp00300000002489>
ways to stay in shape in the new year.
Message 20
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|
I can't imagine that, if I'm having a critical emergency, that Im
going to say, "OK, two minutes before crashing, I'm going to activate
my PLB". Even remembering that it needs to be activated at all is
unlikely, given the amount of adrenaline that will be pumping through
your system. What do you do if you loose a prop, or have a door open
and can barely control the airplane? "Oh, yea, don't forget to
activate the PLB".
It's your airplane, and your emergency situation to plan for, so do
what suits you. As for me, even though automatic triggering functions
aren't perfect, I'll stick with an ELT that can be triggered both ways.
Steve
On Jan 11, 2008, at 10:12 AM, Hinde, Frank George (Corvallis) wrote:
> I think it is more about making sure the PLB is actually
> transmitting while still airborne....I believe the satalites can
> actually register the signal relatively quickly but may not have the
> actual GPS coordinates locked in.
>
> So making an assumption that you have say 2 minutes before you hit
> the ground and in the worse case the PLB is destroyed (unlikely) ,
> is that enough time time to alert SAR?..I'm thinking you may not
> have gotten the accurate GPS lock but a 2 square mile position (from
> triangulating the signal itself) is a whole lot better than no
> position at all.
>
> Your thoughts?
>
> Frank
Message 21
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I would certainly agree it depends upon your particular circumstances and having
automatic activation is better than not having it.
As for me I tend to fly to the outer regions of the USA only when accompanied by
my better half..Her sole job in an emergency is to get the antenna up and fingers
poised over the "On" button. So for me I think its a reasonable plan.
I still carry the PLB for short hops...a 200mph airplane can get an awfully long
way away in what seems like a short flight and for this a 406Mhz ELT would be
better.
Frank
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Steve Thomas
Sent: Friday, January 11, 2008 12:00 PM
Subject: Re: AeroElectric-List: Re: ELT/PLB
I can't imagine that, if I'm having a critical emergency, that Im going to say,
"OK, two minutes before crashing, I'm going to activate my PLB". Even remembering
that it needs to be activated at all is unlikely, given the amount of adrenaline
that will be pumping through your system. What do you do if you loose
a prop, or have a door open and can barely control the airplane? "Oh, yea,
don't forget to activate the PLB".
It's your airplane, and your emergency situation to plan for, so do what suits
you. As for me, even though automatic triggering functions aren't perfect, I'll
stick with an ELT that can be triggered both ways.
Steve
Message 22
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Subject: | Question about Annunciating Lights |
Hi Scott,
Finding the LED bars was a bit of a struggle..... some pointers that
might.... They are generically known as "LED Light Bars".
Some specific model numbers / sources:
Stanley MU02-2101 , DigiKey 404-1145-ND - I think that is what Mark used.
Kingston 404-1145-ND, Can be sourced from RS Components
Agilent HLCP-H100, not sure - but probably mouser
The other probably I had was I could get red of one type, yellow of a
different type and green of a third type from a different vendor!
I ended up paying a little more, but got all Kingston modules through RS
Components and are about 9mm x 19mm visible and sit in a 2x8 way DIL socket.
Regards,
Carl
--
Carl Morgan - ZK-VII - RV 7A
http://www.rvproject.gen.nz/
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Scott R.
Shook
Sent: 12 January 2008 08:51
To: aeroelectric-list@matronics.com
Subject: RE: AeroElectric-List: Question about Annunciating Lights
Mark,
Thats actually better than what I was looking for!
I could buy those LED rectangles and mount them behind the reverse
engraved acrylic front and have exactly what I am looking for. Any idea on
whether the measurements on the rectangles are in mm?
Thank you for posting that information. You have solved my problem! Look
at that - its only January and already my list contribution has paid off.
Scott R. Shook
RV-7A (Building)
N696JS (Reserved)
----------------------------------------------------------------------------
--
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Fiveonepw@aol.com
Sent: Wednesday, 09 January, 2008 22:14
To: aeroelectric-list@matronics.com
Subject: Re: AeroElectric-List: Question about Annunciating Lights
Here's another take on rollin' yer own:
http://websites.expercraft.com/n51pw/index.php?q=log_entry&log_id=5126
Click on fotos for bigger view and Next Entry>> for more info (several
pages) including wiring diagram, part #s etc...
From The PossumWorks in TN
Mark Phillips
----------------------------------------------------------------------------
--
Start the year off right. Easy ways to stay in shape in the new year.
http://www.matronics.com/contribution
18:09
Message 23
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Greetings Listers,
The airplane I'm building is intended for off airport operations. I
believe my most likely accident scenario is striking a an object close to
the ground. That will give me virtually no time to do anything before the
event is over. I consider the automatic activation feature manditory for my
anticipated mission profile.
Another subject I have seen almost no comment on is water operation
accidents and ELTs.
Raymond Julian
Kettle River, MN
"Hope for the best,
but prepare for the worst."
----- Original Message -----
From: "Hinde, Frank George (Corvallis)" <frank.hinde@hp.com>
Sent: Friday, January 11, 2008 2:27 PM
Subject: RE: AeroElectric-List: Re: ELT/PLB
> <frank.hinde@hp.com>
>
> I would certainly agree it depends upon your particular circumstances and
> having automatic activation is better than not having it.
>
> As for me I tend to fly to the outer regions of the USA only when
> accompanied by my better half..Her sole job in an emergency is to get the
> antenna up and fingers poised over the "On" button. So for me I think its
> a reasonable plan.
>
> I still carry the PLB for short hops...a 200mph airplane can get an
> awfully long way away in what seems like a short flight and for this a
> 406Mhz ELT would be better.
>
> Frank
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Steve
> Thomas
> Sent: Friday, January 11, 2008 12:00 PM
> To: aeroelectric-list@matronics.com
> Subject: Re: AeroElectric-List: Re: ELT/PLB
>
>
> I can't imagine that, if I'm having a critical emergency, that Im going to
> say, "OK, two minutes before crashing, I'm going to activate my PLB".
> Even remembering that it needs to be activated at all is unlikely, given
> the amount of adrenaline that will be pumping through your system. What
> do you do if you loose a prop, or have a door open and can barely control
> the airplane? "Oh, yea, don't forget to activate the PLB".
>
> It's your airplane, and your emergency situation to plan for, so do what
> suits you. As for me, even though automatic triggering functions aren't
> perfect, I'll stick with an ELT that can be triggered both ways.
>
> Steve
>
>
>
Message 24
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Subject: | Question about Annunciating Lights |
I used 14x16mm light bars for mine. Got red, green and yellow from Digikey
at ~$1.60 a piece. Link to red bar:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=404-1152-ND
Regards,
Greg Young
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Carl
Morgan
Sent: Friday, January 11, 2008 2:40 PM
Subject: RE: AeroElectric-List: Question about Annunciating Lights
Hi Scott,
Finding the LED bars was a bit of a struggle..... some pointers that
might.... They are generically known as "LED Light Bars".
Some specific model numbers / sources:
Stanley MU02-2101 , DigiKey 404-1145-ND - I think that is what Mark used.
Kingston 404-1145-ND, Can be sourced from RS Components
Agilent HLCP-H100, not sure - but probably mouser
The other probably I had was I could get red of one type, yellow of a
different type and green of a third type from a different vendor!
I ended up paying a little more, but got all Kingston modules through RS
Components and are about 9mm x 19mm visible and sit in a 2x8 way DIL socket.
Regards,
Carl
--
Carl Morgan - ZK-VII - RV 7A
http://www.rvproject.gen.nz/
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Scott R.
Shook
Sent: 12 January 2008 08:51
Subject: RE: AeroElectric-List: Question about Annunciating Lights
Mark,
That's actually better than what I was looking for!
I could buy those LED rectangles and mount them behind the reverse engraved
acrylic front and have exactly what I am looking for. Any idea on whether
the measurements on the rectangles are in mm?
Thank you for posting that information. You have solved my problem! Look
at that - its only January and already my list contribution has paid off.
Scott R. Shook
RV-7A (Building)
N696JS (Reserved)
Message 25
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Subject: | Re: Toggle switch tool |
At 10:51 AM 1/11/2008 -0800, you wrote:
>
>Bob,
>
>Some time ago someone mentioned a tool for tightening the nut on toggle
>switches without scratching the painted panel surface. I suppose if it's a
>hex nut on the switch, a deep socket wrench (9/16?) would work. However
>some switches come with a knurled nut. Is there a tool for this? Can't
>seem to find one at any of the on-line vendors I've tried. Probably because
>I don't know what it's called. Any help is appreciated.
Dave has already offered the same advice I would offer.
The knurled nuts are sexy looking but a B@#$@h to deal
with mechanically. Years ago I had a "knurled nut driver"
that had exactly the right diameter and numbers of teeth
to firmly engage those nuts. It did a nice job of getting
the nut tight without damaging the panel. However, as
years went buy, more manufacturers came out with almost-a-
clone of the nuts that had been something of a de-facto
standard part in the US. My tool was found not to fit
every knurled nut in the wild. I think I pitched it.
With regard to tools for tightening switch nuts:
There are some nice 9/16, hollow shaft nut drivers
by Craftsman an others that are already very smooth
(polished) and have no or minimal internal relief or
radius on the inside corners so that they'll get
good engagement on thin nuts.
I've taken el-cheeso nut drivers and/or deep sockets
and sanded the open ends flat with ever finer
paper with the last pass being with polish compound
on a buffing wheel. This tool will not mark your
panel adjacent to the nut you're working. Nowadays,
I'd probably chuck the socket in the lathe and use
Dremmel tools to finish the open end.
All my new panels are Lexan fronts so are quite
resistant to scratching but it's a good point of
craftsmanship to have a 9/16" tool specifically
tailored to this task.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
Message 26
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|
On the big scale I think the government is pushing this conversion (as
they are ADS-B) to enable better tracking on each GA aircraft. In the
end they will have a dozen ways to track, charge and identify everyone.
Can't wait.
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Hinde, Frank George (Corvallis)
Sent: Friday, January 11, 2008 1:12 PM
Subject: RE: AeroElectric-List: Re: ELT/PLB
--> (Corvallis)" <frank.hinde@hp.com>
I think it is more about making sure the PLB is actually transmitting
while still airborne....I believe the satalites can actually register
the signal relatively quickly but may not have the actual GPS
coordinates locked in.
So making an assumption that you have say 2 minutes before you hit the
ground and in the worse case the PLB is destroyed (unlikely) , is that
enough time time to alert SAR?..I'm thinking you may not have gotten the
accurate GPS lock but a 2 square mile position (from triangulating the
signal itself) is a whole lot better than no position at all.
Your thoughts?
Frank
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Matt
Prather
Sent: Friday, January 11, 2008 9:34 AM
Subject: RE: AeroElectric-List: Re: ELT/PLB
--> <mprather@spro.net>
If you want satellites locked in, consider getting your amateur radio
license (ham) and then start carrying (or install) a Tiny Track (or
something similar).
http://www.byonics.com/tinytrak/
And use it to keep your position updated via APRS:
http://www.googleaprs.com/
Then people will have a way to see your flight is/was going.
I wonder if ADS-B is going to support something similar.
Regards,
Matt-
> --> (Corvallis)"
> <frank.hinde@hp.com>
>
> Indeed, and you can always activate it when you know you are going
> down. In fact I wonder how reliable the G switches are in the case of
> ELT's anyway...121.5 ELTs are notoriously innefective but the 406
> units will still have the same kind of G switch technology I would
> presume, how well do they work?
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Subject: | Re: Toggle switch tool |
All:
Along the same lines does anyone know where you can get a tool that works on
the slotted knurled nuts that go on headphone jacks. I have seen one
before, but I have been looking for one for the past few years without luck.
Thanks
Mark
----- Original Message -----
From: "B Tomm" <fvalarm@rapidnet.net>
Sent: Friday, January 11, 2008 10:51 AM
Subject: AeroElectric-List: Toggle switch tool
>
> Bob,
>
> Some time ago someone mentioned a tool for tightening the nut on toggle
> switches without scratching the painted panel surface. I suppose if it's
a
> hex nut on the switch, a deep socket wrench (9/16?) would work. However
> some switches come with a knurled nut. Is there a tool for this? Can't
> seem to find one at any of the on-line vendors I've tried. Probably
because
> I don't know what it's called. Any help is appreciated.
>
> Bevan
> RV7A wiring
>
>
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The required 121.5Mhz ELT in the plane didn't do him any good, either.
I haven't checked lately on the price difference between PLBs & 406
ELTs. If there's a serious difference, remember we are supposed to be
homebuilt a/c experimenters. Ever looked at the G-switch on a typical
ELT? The ones I've seen are just a pivoting steel weight next to an
off-the-shelf miniature toggle switch.Get to work on that PLB. :-)
Charlie
Steve Thomas wrote:
>
> Well, a PLB may be less expensive, but it presumes that you are
> conscious when you need to activate it. Or that you will successfully
> regain consciousness before, well, you know. Steve Fausset had a
> personal PLB - didn't do him any good at all. Just a thought.
>
>
> On Jan 11, 2008, at 7:24 AM, Giffen Marr wrote:
>
>> <GAMarr@Charter.Net>
>>
>> I am planning on using the cheapest ELT available to meet the FAR 91
>> Requirements and a 406 PLB. The current cost of ELT's meeting the 406
>> requirements are out of sight as compared to the 121.5 units. The other
>> advantage is the PLB is not much larger then a cell phone as compared
>> to the
>> ELT. Only advantage to the ELT is the battery life may be longer then the
>> PLB.
>>
>> Giff Marr
>> LIV-P/Mistral 65%
>>
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Subject: | Re: Toggle switch tool |
X-mailer: Pegasus Mail for Windows (4.41)
From: "FLAGSTONE" <flagstone@cox.net>
Subject: Re: AeroElectric-List: Toggle switch tool
Date sent: Sat, 12 Jan 2008 03:33:28 -0800
Send reply to: aeroelectric-list@matronics.com
> Along the same lines does anyone know where you can get a tool that works on
> the slotted knurled nuts that go on headphone jacks. I have seen one
> before, but I have been looking for one for the past few years without luck.
Such as.....
http://tinyurl.com/35gujq
Jim Baker
580.788.2779
Elmore City, OK
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"On the big scale I think the government is pushing this conversion (as they
are ADS-B) to enable better tracking on each GA aircraft. In the end they
will have a dozen ways to track, charge and identify everyone.
Can't wait."
That's quite a pessimistic view. Anyone with something to hide will simply
not use whatever the technology is. I think the government desperately
needs to cut costs for searches that can easily exceed your lifetimes worth
of taxes. It may speed up the rescue process which may give you a better
chance of survival, but in the larger picture, it's about saving very large
amounts of money.
Bevan
RV7A wiring
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Subject: | Re: Question about Annunciating Lights |
8-)
do not archive
**************Start the year off right. Easy ways to stay in shape.
http://body.aol.com/fitness/winter-exercise?NCID=aolcmp00300000002489
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Subject: | Re: Question about Annunciating Lights |
In a message dated 01/11/2008 1:53:32 PM Central Standard Time,
sshook@cox.net writes:
Any idea on whether the measurements on the rectangles are in mm?
Here's the Digikey page with the LED modules- is gives dimensions in mm-
_http://digi-key.dirxion.com/Main.asp_ (http://digi-key.dirxion.com/Main.asp)
N-joy!
Mark
**************Start the year off right. Easy ways to stay in shape.
http://body.aol.com/fitness/winter-exercise?NCID=aolcmp00300000002489
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Subject: | Terminal Tool TT5000 |
Anyone used one of these:
http://www.averytools.com/pc-937-80-the-terminal-tool.aspx
It looks like it might be good for those heavy gauge wires.
Thanks,
Mike Cencula
RV-7A Fuse
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