Today's Message Index:
----------------------
1. 06:36 AM - Re: RV-14 (Justin Jones)
2. 07:42 AM - Re: RV-14 (Robert L. Nuckolls, III)
3. 09:39 AM - Re: RV-14 (Ralph Finch)
4. 10:04 AM - Toroid beads ()
5. 10:41 AM - Re: Toroid beads (Tim Andres)
6. 10:54 AM - Re: Toroid beads (Dj Merrill)
7. 10:56 AM - Re: Toroid beads ()
8. 11:21 AM - Re: Toroid beads ()
9. 11:32 AM - Re: Toroid beads (Jim Kale)
10. 11:41 AM - Re: Toroid beads (Dj Merrill)
11. 12:10 PM - Re: Toroid beads ()
12. 12:19 PM - Re: Toroid beads (Tim Andres)
13. 12:21 PM - Re: Toroid beads (Ralph Finch)
14. 01:09 PM - Re: RV-14 (Peter Pengilly)
15. 02:18 PM - Re: RV-14 (Jeff Luckey)
16. 03:15 PM - Re: Toroid beads (Bill Maxwell)
17. 08:22 PM - Re: Toroid beads (Robert L. Nuckolls, III)
18. 08:42 PM - Re: RV-14 (Robert L. Nuckolls, III)
Message 1
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As far as your electrical architecture is concerned, you need to do a google search
for "The Aeroelectric Connection". The Z- diagrams are in the book and already
built to suit your specific application. As mentioned earlier, bob is the
author and has done a masterful job at putting the book and diagrams together.
Going from memory, you will be looking for either Z-13 or Z-14 for the dual
alternator schematic.
You have come to the right place for help! There are folks on here that are smarter
on this subject than I could ever imagine being.
Justin
> On Oct 23, 2014, at 21:11, Kelly McMullen <kellym@aviating.com> wrote:
>
>
> Have you priced your choices vs Dynon Skyview? Including annual database and
charts update cost?
> I think Dynon has been around giving excellent cost effective products and service
to the experimental market a lot longer than Garmin;
> but we all tend to think our choices are superior to other choices. ;-)
> IMHO the simplest way to reduce your electrical system needs and costs are to
go with single ship's battery,
> backup up battery for each EFIS screen, and dual ADAHRS,
> That is what I have done with my RV-10 with the following choices:
> Lycoming IO-540 with dual Bendix 1200 mags, Plane Power 60 amp alternator, Odyssey
PC-925 battery.
> Two Dynon Skyview D1000 screens each with their own backup battery, dual ADAHRS,
Dynon autopilot, dynon ADSB transponder and receiver
> PS Eng PS5000X audio panel
> GTN-650
> SL30.
> Dynon heated pitot/AOA.
>
> Granted the GTN200 was not available when I selected, and the G3X system was
priced much higher at the time.
> PMag still does not have a 6 cyl version, last I checked.
> Each Dynon EFIS is independently capable of controlling the autopilot servos,
each can use either ADAHRS,
> I am very comfortable with what i have for flying IFR, day or night.I may upgrade
one of my screens to touch, but it is not a priority.
> Since your PMags produce their own power, no dual bus electrical system needed.
As long as either of your selected EFIS can operate on a backup battery and
provide you enough time to get to VFR or on the ground and supply you the same
level of backup as having old mechanical instruments that are required under
91.205 c&d you should be fine.
> You will want to do a load analysis to see if 40 amps really is enough. While
my system is legitimately within the 80% of rated capacity with intermittent
use items not considered, with everything on it is very close to 60 amps, even
using LED nav and strobe systems.
> Owen Baker has done an excellent document on distilling the instrumentation required
by reg for IFR in amateur built experimentals, certainly contained in
archives of this list. Whether you want more than legal minimum is up to you and
how much electrical complexity you want.
>
>> On 10/23/2014 9:33 AM, Stoney Ware wrote:
>>
>> I am a first time builder and building a RV-14. I am trying to plan for the
electrical and backup system now. I will be flying IFR, when necessary. Here
is my potential configuration:
>>
>> Lycoming IO-390 with dual P-Mags & 40 Amp B&C Alternator (Purchased)
>>
>> G3X Dual Touchscreen Monitors
>>
>> GMC305 AutoPilot Console
>>
>> GTN650 GPS/Comm
>>
>> GTN200 Comm
>>
>> GMA 240 Audio Panel
>>
>> GTX 23 Transponder
>>
>> So two questions:
>>
>> What should I do for a backup in the case of a loss of the Garmin System?
>>
>> 1.Add a second ADAHRS and battery backup for the EFIS
>>
>> 2.Add a separate system, i.e. GRT Mini, TruTrak Gemini, Dynon D6
>>
>> 3.Use a portable backup like the Garmin 696 or 796?
>>
>> What about additional alternator?
>>
>> My knowledge and experience is only what I have read on-line in the last 6 months
and asking a lot of questions, but still very limited.
>>
>> Thanks,
>>
>> Stoney Ware
>>
>> *
>>
>>
>> *
>
>
>
>
>
Message 2
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> >>
> >> My knowledge and experience is only what I have read on-line in
> the last 6 months and asking a lot of questions, but still very limited.
> >>
> >> Thanks,
> >>
> >> Stoney Ware
Suggest you consider Z-13/8 architecture first . . . which
can be found here (along with it's cousins) . . .
http://tinyurl.com/5wxzn7
First you need to do a LOAD analysis . . . fancy
name for making a list of every electron-hungry
device on your airplane.
You then sort them into pigeon-holes categorized
for the various flight . . . with the one called
"Main Alternator Out" getting special attention.
Download a form from http://tinyurl.com/7jqypwj
and print three copies. One for each of the Z-13/8
busses, MAIN, ENDURANCE and BATTERY.
The goal is to ascertain exactly what your maximum
alternator loads are and under what conditions.
The special attention is for MAIN ALT OUT
where you'd like to get your loads down to
8A or less.
The point being that in the unlikely event
of main alternator failure, you can operate
enough electro-whizzies to conduct a comfortable
flight for as long as you have fuel aboard . . .
while holding battery energy in reserve.
Once you have the airport in sight, you can
turn on everything you'd like to light-up . . .
including the kitchen sink. This will be
possible because you've included routine
BATTERY MAINTENANCE in your to-do list
along with oil changes, checks for leaks,
tire wear, tire pressures, etc. etc.
Launching into ANY anticipated mission
KNOWING your energy requirements along
with energy availability offers a very
low risk adventure. But without need
for the added $maintenance$ of standby
batteries in the electro-whizzies normally
considered essential for continued
flight to airport of destination.
This offers an opportunity to craft an
electrical system with predictable endurance
exceeding duration of fuel on board.
Make sure that Z-13/8 is truly inadequate to
your anticipated needs and associated risks
before you launch into something like Z-14
(really suited to only a small percentage
of OBAM aircraft projects), . Bring your musings
here to the List . . .
Filling in the knowledge gaps after your
energy/mission studies are complete starts
with a copy of the book. Random-access,
low-energy paper available here . . .
http://tinyurl.com/cgr42l5
or byte-bound, battery-powered copy available
here . . .
http://tinyurl.com/cgr42l5
Bob . . .
Message 3
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I must disagree with the attitude here...that a proper backup system is too
complicated, so don't do it. The OP's mission is IFR, perhaps at night,
probably single-pilot and of course single-engine. That's already a complex
task which needs to be done right. In this case, "right" means having
backup electricity not from a perhaps tired aircraft battery and an EFIS
battery backup.
You must have an e-buss to quickly and easily shed unnecessary load. Once
you've acknowledged that complexity, adding a standby alternator, for
instance, is not much more difficult and is very prudent.
Studies Mr. Nuckolls' The Aeroelectric Connection book, continue to ask
questions here, and implement a backup system that reduces risks to your
comfort level, not because it's easier. Many people have done the Z-13 or
-14 system given in the book as Mr. Nuckolls has already done most of the
design work.
Ralph Finch
RV-9A
> >
>
> Primary backup is in fact ship's battery...Having a total of 3 batteries
> to test once a year is a whole lot simpler than trying to install dual
> electric buss with one or two alternators and one or two batteries that
> will power what besides you flight instruments?
>
Message 4
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Anyone got a part number (or spec) handy for the toroid beads that slide
over the RG-58/400 coax on our home made antennas?
-James
Message 5
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Subject: | Re: Toroid beads |
If you dont find any James let me know, I have a few left over.
Tim Andres
On Friday, October 24, 2014 10:23 AM, "berkut13@berkut13.com" <berkut13@berkut13.com>
wrote:
Anyone got a part number (or
spec) handy for the toroid beads that slide over the RG-58/400 coax on our home
made antennas?
-James
Message 6
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Subject: | Re: Toroid beads |
On 10/24/2014 01:03 PM, berkut13@berkut13.com wrote:
> *Anyone got a part number (or spec) handy for the toroid beads that
> slide over the RG-58/400 coax on our home made antennas?*
Radio Shack sells them (called Snap Choke Core):
http://www.radioshack.com/family/index.jsp?categoryId 32273&znt_campaign=Category_CMS&znt_medium=RSCOM&znt_source=CAT&znt_content=CT2032230
-Dj
--
Dj Merrill - N1JOV - VP EAA Chapter 87
Sportsman 2+2 Builder #7118 N421DJ - http://deej.net/sportsman/
Glastar Flyer N866RH - http://deej.net/glastar/
Message 7
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Subject: | Re: Toroid beads |
Will need them ongoing, I was really looking for a source.
Thanks though.
-James
From: Tim Andres
Sent: Friday, October 24, 2014 12:37 PM
Subject: Re: AeroElectric-List: Toroid beads
If you dont find any James let me know, I have a few left over.
Tim Andres
On Friday, October 24, 2014 10:23 AM, "berkut13@berkut13.com"
<berkut13@berkut13.com> wrote:
Anyone got a part number (or spec) handy for the toroid beads that slide
over the RG-58/400 coax on our home made antennas?
-James
Message 8
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Subject: | Re: Toroid beads |
Too big. Looking for source for the small ferrite "doughnuts" that slip
over the coax at the di-pole element split.
Shown here:
http://www.berkut13.com/com2_08.jpg
Thanks,
James
-----Original Message-----
From: Dj Merrill
Sent: Friday, October 24, 2014 12:53 PM
Subject: Re: AeroElectric-List: Toroid beads
On 10/24/2014 01:03 PM, berkut13@berkut13.com wrote:
> *Anyone got a part number (or spec) handy for the toroid beads that
> slide over the RG-58/400 coax on our home made antennas?*
Radio Shack sells them (called Snap Choke Core):
http://www.radioshack.com/family/index.jsp?categoryId 32273&znt_campa
ign=Category_CMS&znt_medium=RSCOM&znt_source=CAT&znt_content=CT20
32230
-Dj
Message 9
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You might try RST Engineering. It is the guy who writes the Kit Planes
Electronics articles. He normally sells them.
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
berkut13@berkut13.com
Sent: Friday, October 24, 2014 12:55 PM
Subject: Re: AeroElectric-List: Toroid beads
Will need them ongoing, I was really looking for a source.
Thanks though.
-James
From: Tim Andres <mailto:tim2542@sbcglobal.net>
Sent: Friday, October 24, 2014 12:37 PM
Subject: Re: AeroElectric-List: Toroid beads
If you dont find any James let me know, I have a few left over.
Tim Andres
On Friday, October 24, 2014 10:23 AM, "berkut13@berkut13.com
<mailto:berkut13@berkut13.com> " <berkut13@berkut13.com
<mailto:berkut13@berkut13.com> > wrote:
Anyone got a part number (or spec) handy for the toroid beads that slide
over the RG-58/400 coax on our home made antennas?
-James
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 10
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Subject: | Re: Toroid beads |
On 10/24/2014 02:19 PM, berkut13@berkut13.com wrote:
> Too big. Looking for source for the small ferrite "doughnuts" that slip
> over the coax at the di-pole element split.
>
> Shown here:
> http://www.berkut13.com/com2_08.jpg
Hi James, I think the ones from Radio Shack will perform the same job,
electrically.
Yes, they are physically bigger, but they do offer one that is the right
inside diameter size to fit around the coax. They just have a plastic
case around the ferrite that "snaps" in place. Makes them easy to
remove, too, without having to undo any soldering or crimping since they
are a split configuration.
You can remove the outer plastic shell and wrap them with something
smaller (tape, whatever) if the physical outside diameter is too big.
You can probably find the exact ones you are looking for at McMaster
Carr or some other online source, and someone else on the list might be
able to offer a specific reference.
-Dj
--
Dj Merrill - N1JOV - VP EAA Chapter 87
Sportsman 2+2 Builder #7118 N421DJ - http://deej.net/sportsman/
Glastar Flyer N866RH - http://deej.net/glastar/
Message 11
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Subject: | Re: Toroid beads |
No thanks! Last time I ordered from RST, it took 6 months of reminder
phone calls/emails to get it. I=99m not ever doing that
again...YMMV.
To keep this on track...I need specs and a distributor if possible.
http://www.mouser.com/catalog/catalogusd/647/1295.pdf
If the selection is nothing more than finding something that fits around
the coax, I would order from the =9CTOROIDAL FERRITE
BEADS=9D section.
-James
From: Jim Kale
Sent: Friday, October 24, 2014 1:32 PM
Subject: RE: AeroElectric-List: Toroid beads
You might try RST Engineering. It is the guy who writes the Kit Planes
Electronics articles. He normally sells them.
Message 12
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Subject: | Re: Toroid beads |
Those are much different than the ones I think James May be looking for. I have
no idea if they are suitable. RST once sold a kit with the small ferrite beads
that just fit the RG 58 and could easily be imbedded into a composite structure.
I think that is what he's looking for.
Tim
> On Oct 24, 2014, at 10:53 AM, Dj Merrill <deej@deej.net> wrote:
>
>
>> On 10/24/2014 01:03 PM, berkut13@berkut13.com wrote:
>> *Anyone got a part number (or spec) handy for the toroid beads that
>> slide over the RG-58/400 coax on our home made antennas?*
>
>
> Radio Shack sells them (called Snap Choke Core):
>
> http://www.radioshack.com/family/index.jsp?categoryId 32273&znt_campaign=Category_CMS&znt_medium=RSCOM&znt_source=CAT&znt_content=CT2032230
>
> -Dj
>
>
> --
> Dj Merrill - N1JOV - VP EAA Chapter 87
> Sportsman 2+2 Builder #7118 N421DJ - http://deej.net/sportsman/
> Glastar Flyer N866RH - http://deej.net/glastar/
>
>
>
>
Message 13
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Subject: | Re: Toroid beads |
Or your mileage won't vary. I keep seeing bitter complaints about RST total
lack of customer service. I'd for sure never order anything from him.
On Fri, Oct 24, 2014 at 12:08 PM, <berkut13@berkut13.com> wrote:
> No thanks! Last time I ordered from RST, it took 6 months of reminder
> phone calls/emails to get it. I'm not ever doing that again...YMMV.
>
Message 14
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Bob,
In my view Z13/8 has many advantages, but how would you handle the
start-up brown out problem? For example if an EFIS with integral engine
monitor is fitted it must be operational during engine start, but is
unlikely to endure the start-up low voltage transients. A second
alternator seems by far a better mitigation for main alternator failure
than a second battery, but I can't see any way around a small additional
battery to hold up the power for the EFIS/Engine Monitor (and perhaps
main Nav radio/GPS) during engine start.
What are your thoughts?
Peter
On 24/10/2014 15:41, Robert L. Nuckolls, III wrote:
> <nuckolls.bob@aeroelectric.com>
>
>
>> >>
>> >> My knowledge and experience is only what I have read on-line in
>> the last 6 months and asking a lot of questions, but still very limited.
>> >>
>> >> Thanks,
>> >>
>> >> Stoney Ware
>
> Suggest you consider Z-13/8 architecture first . . . which
> can be found here (along with it's cousins) . . .
>
> http://tinyurl.com/5wxzn7
>
> First you need to do a LOAD analysis . . . fancy
> name for making a list of every electron-hungry
> device on your airplane.
>
> You then sort them into pigeon-holes categorized
> for the various flight . . . with the one called
> "Main Alternator Out" getting special attention.
>
> Download a form from http://tinyurl.com/7jqypwj
> and print three copies. One for each of the Z-13/8
> busses, MAIN, ENDURANCE and BATTERY.
>
> The goal is to ascertain exactly what your maximum
> alternator loads are and under what conditions.
> The special attention is for MAIN ALT OUT
> where you'd like to get your loads down to
> 8A or less.
>
> The point being that in the unlikely event
> of main alternator failure, you can operate
> enough electro-whizzies to conduct a comfortable
> flight for as long as you have fuel aboard . . .
> while holding battery energy in reserve.
>
> Once you have the airport in sight, you can
> turn on everything you'd like to light-up . . .
> including the kitchen sink. This will be
> possible because you've included routine
> BATTERY MAINTENANCE in your to-do list
> along with oil changes, checks for leaks,
> tire wear, tire pressures, etc. etc.
>
> Launching into ANY anticipated mission
> KNOWING your energy requirements along
> with energy availability offers a very
> low risk adventure. But without need
> for the added $maintenance$ of standby
> batteries in the electro-whizzies normally
> considered essential for continued
> flight to airport of destination.
>
> This offers an opportunity to craft an
> electrical system with predictable endurance
> exceeding duration of fuel on board.
>
> Make sure that Z-13/8 is truly inadequate to
> your anticipated needs and associated risks
> before you launch into something like Z-14
> (really suited to only a small percentage
> of OBAM aircraft projects), . Bring your musings
> here to the List . . .
>
> Filling in the knowledge gaps after your
> energy/mission studies are complete starts
> with a copy of the book. Random-access,
> low-energy paper available here . . .
>
> http://tinyurl.com/cgr42l5
>
> or byte-bound, battery-powered copy available
> here . . .
>
> http://tinyurl.com/cgr42l5
>
>
> Bob . . .
>
>
Message 15
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I share Peter's concerns.
In fact, keeping the avionics alive during
crank is one of the criteria (among many others)
which led to this design.
See attached pdf.
-Jeff
On Friday, October 24, 2014 1:17 PM, Peter Pengilly <peter@sportingaero.com> wrote:
Bob,
In my view Z13/8 has many advantages, but how would you handle the
start-up brown out problem? For example if an
EFIS with integral engine
monitor is fitted it must be operational during engine start, but is
unlikely to endure the start-up low voltage transients. A second
alternator seems by far a better mitigation for main alternator failure
than a second battery, but I can't see any way around a small additional
battery to hold up the power for the EFIS/Engine Monitor (and perhaps
main Nav radio/GPS) during engine start.
What are your thoughts?
Peter
On 24/10/2014 15:41, Robert L. Nuckolls, III wrote:
> <nuckolls.bob@aeroelectric.com>
>
>
>> >>
>> >> My knowledge and experience is only what I have read on-line in
>> the last 6 months and asking a lot of questions, but still very
limited.
>> >>
>> >> Thanks,
>> >>
>> >> Stoney Ware
>
> Suggest you consider Z-13/8 architecture first . . . which
> can be found here (along with it's cousins) . . .
>
> http://tinyurl.com/5wxzn7
>
> First you need to do a LOAD analysis . . . fancy
> name for making a list of every electron-hungry
> device on your airplane.
>
> You then sort them into pigeon-holes categorized
> for the various flight . . . with the one called
> "Main Alternator Out" getting special attention.
>
> Download a form from http://tinyurl.com/7jqypwj
> and print three copies. One for
each of the Z-13/8
> busses, MAIN, ENDURANCE and BATTERY.
>
> The goal is to ascertain exactly what your maximum
> alternator loads are and under what conditions.
> The special attention is for MAIN ALT OUT
> where you'd like to get your loads down to
> 8A or less.
>
> The point being that in the unlikely event
> of main alternator failure, you can operate
> enough electro-whizzies to conduct a comfortable
> flight for as long as you have fuel aboard . . .
> while holding battery energy in reserve.
>
> Once you have the airport in sight, you can
> turn on everything you'd like to light-up . . .
> including the kitchen sink. This will be
> possible because
you've included routine
> BATTERY MAINTENANCE in your to-do list
> along with oil changes, checks for leaks,
> tire wear, tire pressures, etc. etc.
>
> Launching into ANY anticipated mission
> KNOWING your energy requirements along
> with energy availability offers a very
> low risk adventure. But without need
> for the added $maintenance$ of standby
> batteries in the electro-whizzies normally
> considered essential for continued
> flight to airport of destination.
>
> This offers an opportunity to craft an
> electrical system with predictable endurance
> exceeding duration of fuel on board.
>
> Make sure that Z-13/8 is truly inadequate to
>
your anticipated needs and associated risks
> before you launch into something like Z-14
> (really suited to only a small percentage
> of OBAM aircraft projects), . Bring your musings
> here to the List . . .
>
> Filling in the knowledge gaps after your
> energy/mission studies are complete starts
> with a copy of the book. Random-access,
> low-energy paper available here . . .
>
> http://tinyurl.com/cgr42l5
>
> or byte-bound, battery-powered copy available
> here . . .
>
> http://tinyurl.com/cgr42l5
>
>
> Bob . .
.
>
>
Message 16
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Subject: | Re: Toroid beads |
They are simply called "toroids", which describe their shape, Jim. They
come in various compositions, both ferite and iron, that vary in their
frequency responses. You will needneed a ferite composition effective at
VHF. Commonly available through ham radio suppliers, so should not be
too hard to find over there.
Bill
On 25/10/2014 5:19 AM, berkut13@berkut13.com wrote:
> Too big. Looking for source for the small ferrite "doughnuts" that
> slip over the coax at the di-pole element split.
> Shown here:
> http://www.berkut13.com/com2_08.jpg
> Thanks,
> James
> -----Original Message-----
> From: Dj Merrill
> Sent: Friday, October 24, 2014 12:53 PM
> To: aeroelectric-list@matronics.com
> Subject: Re: AeroElectric-List: Toroid beads
> On 10/24/2014 01:03 PM, berkut13@berkut13.com wrote:
> > *Anyone got a part number (or spec) handy for the toroid beads that
> > slide over the RG-58/400 coax on our home made antennas?*
> Radio Shack sells them (called Snap Choke Core):
> http://www.radioshack.com/family/index.jsp?categoryId 32273&znt_campaign=Category_CMS&znt_medium=RSCOM&znt_source=CAT&znt_content=CT2032230
> -Dj
> *
>
>
> *
Message 17
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Subject: | Re: Toroid beads |
At 12:03 PM 10/24/2014, you wrote:
>Anyone got a part number (or spec) handy for the toroid beads that
>slide over the RG-58/400 coax on our home made antennas?
>-James
These are so ineffectual as to make their 'benefits'
undetectable except by sophisticated test equipment
in the lab. Cessna produced thousands of airplanes with
coax brazenly attached to horizontal cat-whisker dipoles
with excellent results. Our resident physics PhD did a study
on these antennas back in '69 or so. This was before 'donuts
on the coax' became the 'buzz-phrase'. Back then the purists
were into 4:1 coax baluns . . . they took care of the 'worries'
about feeding an unbalanced coax with a balanced antenna . . .
but demonstrated a 3:1 SWR under the best condition.
Later, somebody tried the ferrite beads thing . . . not all
ferrites are made the same. You need a material that
exhibits low losses at the frequency of interest . . . 110
Mhz or thereabouts. Then it's useful to understand that
the EFFECTIVENESS of adding such magnetics to the feed line
varies as the SQUARE of the turns. So, 9 ferrites strung
along a coax offer performance on the order of three turns
of coax fed through a larger torroid.
The big question is: If you don't have a balun (coax
or ferrite), who would know? The answer is: nobody.
We're talking a receiving antenna excited with nano or
pico watts from a ground station. Further, the signal
is line of sight . . . seldom more than 50 miles from
ground station to airplane. A wet string with a gazillion
to one SWR would receive the signal.
If you'd really like to 'balance' things up, you
can build a 1:1 "Pawsey stub" balun from a piece of
scrap coax. See:
http://tinyurl.com/yytxwd3
I've built dozens of these and the work just fine
but as a VOR receive antenna, the benefits for having
installed it are not observable from the cockpit.
If you'd like to see an example of effective
ferrite decoupling of a badly mated antenna/feedline
condition, look at the "airwhip" vhf comm antenna
articles on the web. One poster took one apart to show
the ferrite torroid at the base with 4-5 turns of
coax through the core . . . 16 to 25 times the
effectiveness of a single core. Further, the material
from which this core is made is narrowly crafted for
the frequency of interest. Ferrites from Radio Shack
for noise mitigation are not even close.
My first choice: Hook the coax to the antenna 'bare
foot' and it will work fine.
Second choice; Build a 1:1 Pawsey stub balun.
Third choice; track down suitable torroids but use
larger ones that will allow multiple passes of
coax thorugh the center.
But understand that choices 2 an 3 are pretty much
a waste of time in terms of outcome.
Bob . . .
Message 18
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At 03:06 PM 10/24/2014, you wrote:
><peter@sportingaero.com>
>
>Bob,
>
>In my view Z13/8 has many advantages, but how would you handle the
>start-up brown out problem? For example if an EFIS with integral
>engine monitor is fitted it must be operational during engine start,
>but is unlikely to endure the start-up low voltage transients. A
>second alternator seems by far a better mitigation for main
>alternator failure than a second battery, but I can't see any way
>around a small additional battery to hold up the power for the
>EFIS/Engine Monitor (and perhaps main Nav radio/GPS) during engine start.
>
>What are your thoughts?
Brownout resets are not an architecture problem,
they're a radio problem. A radio that DOES NOT
conform to DO-160 guidelines for graceful recovery
after all manner of input power interruptions.
That capability is supposed to be internal to
the appliance, not external . . . and for good
reason. What's the poor C-172 owner supposed to
do when he wants to modernize his avionics but
doesn't want to climb the Everest-of-paperwork
necessary to modify the ship's certificated
electrical system?
My work with lithium cells has germinated some
ideas for very light, no moving parts, brownout
mitigation for appliances that suffer this malady.
I'm making some pretty startling discoveries . . .
startling because of what the suppliers of lithium
products don't choose to tell us for what ever
reasons.
Along those same lines of thought, it's still not
clear to me that the owner-operator of a brown-out
vulnerable instrumentation package is at any serious
risks for having one or more gizmos reboot after engine
start . . . yeah . . . we were to worship the oil
pressure gage . . . I remember reading those words
in my dad's copy of Sick and Rudder from his flight
school days in 1946.
But seriously, how many instances of 'failure to
build pressure' in the first 30 seconds of run
time were due to lubrication system failure that
warranted shut-down and investigation?Some airplanes
I've flow took a minute to develop full oil pressure
on the gage in very cold weather . . . in spite of
the fact that nothing was amiss in the engine.
Architecture should be crafted to optimize system
performance for all the equipment items needed to
accomplish the mission. But if some piece of equipment
fails to meet legacy goals for performance, I'm
more disposed to put the necessary band-aid on that
piece of equipment than to take an egg-beater to the
whole system.
Bob . . .
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