Today's Message Index:
----------------------
1. 04:27 AM - Re: Garmin 430 Intercom Connections (Ralph E. Capen)
2. 08:02 AM - Re: Garmin 430 Intercom Connections (Tim Andres)
3. 08:19 AM - Re: Garmin 430 Intercom Connections (Jared Yates)
4. 08:49 AM - Re: Garmin 430 Intercom Connections (Tim Andres)
5. 10:31 AM - Re: Frequency problem update (Dale Medendorp)
6. 11:50 AM - Re: Frequency problem update (Kelly McMullen)
7. 01:33 PM - Re: Frequency problem update (Robert L. Nuckolls, III)
8. 02:06 PM - Question about monitoring output in two alternator configuration (Dan Charrois)
9. 02:29 PM - Re: Frequency problem update (don van santen)
10. 02:53 PM - Re: Question about monitoring output in two alternator configuration (Eric Page)
11. 03:16 PM - 12v vs 14v System? (Roger Evenson)
12. 03:40 PM - Re: Question about monitoring output in two alternator configuration (Dan Charrois)
13. 04:22 PM - Re: Question about monitoring output in two alternator configuration (Eric Page)
14. 05:26 PM - Re: Frequency problem update (danielj.billingsley@yahoo.com)
15. 05:31 PM - Re: Question about monitoring output in two alternator configuration (Dan Charrois)
16. 06:50 PM - Re: Frequency problem update (Kelly McMullen)
17. 07:06 PM - Re: Frequency problem update (Bill Maxwell)
18. 07:15 PM - Re: Question about monitoring output in two alternator configuration (Robert L. Nuckolls, III)
19. 07:19 PM - Re: Frequency problem update (Robert L. Nuckolls, III)
20. 07:21 PM - Re: Question about monitoring output in two alternator configuration (Robert L. Nuckolls, III)
21. 08:42 PM - Re: 12v vs 14v System? (user9253)
Message 1
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| Subject: | Re: Garmin 430 Intercom Connections |
Justin,
I have a 420W (cousin to the 430W) and a PS Engineering PMA7000MS - so I think
I may be wearing the 'been there, done-that' t-shirt.
I didn't use the 420W intercom function - I wired to the audio panel intercom function.
I wired pins 7, 19, 6, 4, and 18 (should be the same for the 430W) to the audio
panel (not the PM1000 II - but you have the circuit origins from the 420W) -
works fins!
Remember to isolate your headset connections from ground with the 'stepped' washers
if you're installing in a conductive airframe.
Ralph
-----Original Message-----
>From: Justin Jones <jmjones2000@mindspring.com>
>Sent: Feb 12, 2015 1:57 AM
>To: aeroelectric-list@matronics.com
>Subject: AeroElectric-List: Garmin 430 Intercom Connections
>
>
>I am digging through manuals trying to understand how to hook up my simple setup.
I have a Garmin 430W (with nav and com) and a PS Engineering PM1000 II 4
place intercom. My goal is to be able to transmit and receive VHF communications,
listen to the Ident of the Navaids when tuned, and have it connected to the
4 place intercom.
>
>The Garmin Manual shows
>
>Com Mic Key
>
>Intercom Mic Hi
>
>Com Mic Audio Hi
>
>500 Com Audio Hi
>
>Com Mic Audio Lo
>
>500 Com Mic Audio Lo
>
>
>The PS Engineering Audio Panel has the following connections for the Aircraft
Radio
>
>A/C Radio phone Audio hi
>A/C Radio phone Audio Lo
>
>A/C Radio PTT
>
>A/C Mic Audio Lo
>A/C Mic Audio Hi
>
>
>Why does Garmin list an Intercom Mic Hi pin? I assume this doesnt get connected
if an external intercom is used.
>
>Does the "A/C Radio PTT get connected to the Com Mic Key or to the ?
>
>The manual says 500 COM AUDIO is the summation of the COM receiver audio, COM
sidetone audio, and Intercom MIC audio. Why have the com Com Mic Audio connections
if the 500 Com Mic audio includes all the listed inputs?
>
>Thoughts?
>
>I am going crosseyed trying to figure all this out.
>
>Thanks
>
>Justin
>
>
Message 2
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| Subject: | Re: Garmin 430 Intercom Connections |
The two companies use a little different lingo for audio connections, once you
figure that out its simple. I can send you an interconnect between a 430 and a
PSE 5000 audio panel, that may help sort out the different nomenclature.
One issue, you have no audio mixer with that intercom, or a way to select audio
sources. I don't think you can simply tie them together and turn them up and
down as needed.
Tim
> On Feb 11, 2015, at 10:57 PM, Justin Jones <jmjones2000@mindspring.com> wrote:
>
>
> I am digging through manuals trying to understand how to hook up my simple setup.
I have a Garmin 430W (with nav and com) and a PS Engineering PM1000 II 4
place intercom. My goal is to be able to transmit and receive VHF communications,
listen to the Ident of the Navaids when tuned, and have it connected to
the 4 place intercom.
>
> The Garmin Manual shows
>
> Com Mic Key
>
> Intercom Mic Hi
>
> Com Mic Audio Hi
>
> 500 Com Audio Hi
>
> Com Mic Audio Lo
>
> 500 Com Mic Audio Lo
>
>
>
> The PS Engineering Audio Panel has the following connections for the Aircraft
Radio
>
> A/C Radio phone Audio hi
> A/C Radio phone Audio Lo
>
> A/C Radio PTT
>
> A/C Mic Audio Lo
> A/C Mic Audio Hi
>
>
> Why does Garmin list an Intercom Mic Hi pin? I assume this doesnt get connected
if an external intercom is used.
>
> Does the "A/C Radio PTT get connected to the Com Mic Key or to the ?
>
> The manual says 500 COM AUDIO is the summation of the COM receiver audio, COM
sidetone audio, and Intercom MIC audio. Why have the com Com Mic Audio connections
if the 500 Com Mic audio includes all the listed inputs?
>
> Thoughts?
>
> I am going crosseyed trying to figure all this out.
>
> Thanks
>
> Justin
>
>
>
>
>
>
>
>
>
>
>
>
>
Message 3
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| Subject: | Re: Garmin 430 Intercom Connections |
I'd be interested to hear if there is a way to get VHF Nav audio without additional
hardware. I don't have an audio panel, so I routed it to one of the channels
on the audio iso amp, which also consolidates EFIS audio and entertainment.
> On Feb 12, 2015, at 11:00, Tim Andres <tim2542@sbcglobal.net> wrote:
>
>
>
> The two companies use a little different lingo for audio connections, once you
figure that out its simple. I can send you an interconnect between a 430 and
a PSE 5000 audio panel, that may help sort out the different nomenclature.
> One issue, you have no audio mixer with that intercom, or a way to select audio
sources. I don't think you can simply tie them together and turn them up and
down as needed.
> Tim
>
>
>
>
>
>
>> On Feb 11, 2015, at 10:57 PM, Justin Jones <jmjones2000@mindspring.com> wrote:
>>
>>
>> I am digging through manuals trying to understand how to hook up my simple setup.
I have a Garmin 430W (with nav and com) and a PS Engineering PM1000 II
4 place intercom. My goal is to be able to transmit and receive VHF communications,
listen to the Ident of the Navaids when tuned, and have it connected to
the 4 place intercom.
>>
>> The Garmin Manual shows
>>
>> Com Mic Key
>>
>> Intercom Mic Hi
>>
>> Com Mic Audio Hi
>>
>> 500 Com Audio Hi
>>
>> Com Mic Audio Lo
>>
>> 500 Com Mic Audio Lo
>>
>>
>>
>> The PS Engineering Audio Panel has the following connections for the Aircraft
Radio
>>
>> A/C Radio phone Audio hi
>> A/C Radio phone Audio Lo
>>
>> A/C Radio PTT
>>
>> A/C Mic Audio Lo
>> A/C Mic Audio Hi
>>
>>
>> Why does Garmin list an Intercom Mic Hi pin? I assume this doesnt get connected
if an external intercom is used.
>>
>> Does the "A/C Radio PTT get connected to the Com Mic Key or to the ?
>>
>> The manual says 500 COM AUDIO is the summation of the COM receiver audio, COM
sidetone audio, and Intercom MIC audio. Why have the com Com Mic Audio connections
if the 500 Com Mic audio includes all the listed inputs?
>>
>> Thoughts?
>>
>> I am going crosseyed trying to figure all this out.
>>
>> Thanks
>>
>> Justin
>
>
>
>
>
Message 4
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| Subject: | Re: Garmin 430 Intercom Connections |
Possibly you can use the music in, but it's not intended for that and may not be
the correct impedance or functionality. A simple select audio switch might work,
but now you can't monitor comm while your listening to Nav. Otherwise I think
you will have to use an audio mixer. Someone sells an inexpensive mixer
for EAB, don't recall who. But now you've got two separate boxes to mount and
wire, it might be simpler to pony up and put in an audio panel. A good used one
won't be much more than the two boxes you need now.
Good luck
Tim
> On Feb 12, 2015, at 8:20 AM, Jared Yates <email@jaredyates.com> wrote:
>
>
> I'd be interested to hear if there is a way to get VHF Nav audio without additional
hardware. I don't have an audio panel, so I routed it to one of the channels
on the audio iso amp, which also consolidates EFIS audio and entertainment.
>
>
>
>> On Feb 12, 2015, at 11:00, Tim Andres <tim2542@sbcglobal.net> wrote:
>>
>>
>>
>> The two companies use a little different lingo for audio connections, once you
figure that out its simple. I can send you an interconnect between a 430 and
a PSE 5000 audio panel, that may help sort out the different nomenclature.
>> One issue, you have no audio mixer with that intercom, or a way to select audio
sources. I don't think you can simply tie them together and turn them up and
down as needed.
>> Tim
>>
>>
>>
>>
>>
>>
>>> On Feb 11, 2015, at 10:57 PM, Justin Jones <jmjones2000@mindspring.com> wrote:
>>>
>>>
>>> I am digging through manuals trying to understand how to hook up my simple
setup. I have a Garmin 430W (with nav and com) and a PS Engineering PM1000 II
4 place intercom. My goal is to be able to transmit and receive VHF communications,
listen to the Ident of the Navaids when tuned, and have it connected to
the 4 place intercom.
>>>
>>> The Garmin Manual shows
>>>
>>> Com Mic Key
>>>
>>> Intercom Mic Hi
>>>
>>> Com Mic Audio Hi
>>>
>>> 500 Com Audio Hi
>>>
>>> Com Mic Audio Lo
>>>
>>> 500 Com Mic Audio Lo
>>>
>>>
>>>
>>> The PS Engineering Audio Panel has the following connections for the Aircraft
Radio
>>>
>>> A/C Radio phone Audio hi
>>> A/C Radio phone Audio Lo
>>>
>>> A/C Radio PTT
>>>
>>> A/C Mic Audio Lo
>>> A/C Mic Audio Hi
>>>
>>>
>>> Why does Garmin list an Intercom Mic Hi pin? I assume this doesnt get connected
if an external intercom is used.
>>>
>>> Does the "A/C Radio PTT get connected to the Com Mic Key or to the ?
>>>
>>> The manual says 500 COM AUDIO is the summation of the COM receiver audio, COM
sidetone audio, and Intercom MIC audio. Why have the com Com Mic Audio connections
if the 500 Com Mic audio includes all the listed inputs?
>>>
>>> Thoughts?
>>>
>>> I am going crosseyed trying to figure all this out.
>>>
>>> Thanks
>>>
>>> Justin
>>
>>
>>
>>
>>
>
>
>
>
>
Message 5
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| Subject: | Re: Frequency problem update |
Since the problem is sensitive to frequency (ground vs tower) I suspect the
antenna or the way it's mounted, in which case the ferrite might be the
best solution.
Dale
Message 6
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| Subject: | Re: Frequency problem update |
The frequency sensitivity relates to the fact that RF feedback is
occurring. I had this problem in a previous aircraft, which I eventually
traced back to a cold solder joint on the RG-58 BNC coax connector at
the radio. It worked fine on frequencies below 123.0, and as the
frequency went higher it would give off a feedback squeal when the mike
was keyed. New coax with properly crimped BNC connectors eliminated the
problem. Ferrite beads just mask the problem.
On 2/12/2015 11:30 AM, Dale Medendorp wrote:
>
> Since the problem is sensitive to frequency (ground vs tower) I
> suspect the antenna or the way it's mounted, in which case the ferrite
> might be the best solution.
>
> Dale
>
> *
>
>
> *
Message 7
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| Subject: | Re: Frequency problem update |
At 13:49 2015-02-12, you wrote:
>
>The frequency sensitivity relates to the fact that RF feedback is
>occurring. I had this problem in a previous aircraft, which I
>eventually traced back to a cold solder joint on the RG-58 BNC coax
>connector at the radio. It worked fine on frequencies below 123.0,
>and as the frequency went higher it would give off a feedback squeal
>when the mike was keyed. New coax with properly crimped BNC
>connectors eliminated the problem. Ferrite beads just mask the problem.
Yes. By definition, a transmission line with strong
standing waves (high SWR) may become a poor transmission
line and a better antenna. Since the 'distance' from
peak to peak on a standing wave is defined by the operating
frequency, the degree with which a degraded transmission
line radiates (or receives) is a function of the frequency
of interest.
In one case, the operator reported relief from the
effects by simply shortening a coax. He put a new
connector on one end and decided to cut away some
extra slack. The connector replaced was a 'good' one
but the frequency of interest moved off to another
value. He didn't discover the 'other' bad connector
until later under different circumstances.
Ferrites over a radiating line WILL reduce the
effects . . . but it does nothing to correct the
underlying issue . . . which may still have deleterious
effect on system performance.
Bad transmission lines can affect reception too
but these are often more difficult to observe.
In the final analysis, it's difficult to beat
antenna installations with track records unless
you're going to visit a capable RF lab and have
any 'new idea' in antennas evaluated by-the-numbers.
Bob . . .
Message 8
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| Subject: | Question about monitoring output in two alternator |
configuration
Hi everyone.
I have an electrical system with dual alternators (primary and backup) and have
a question with regards to monitoring their output current. My EFIS has the
capability of monitoring each output separately, but considering that the alternators
are wired such that only one can be on at a time, I'm not a big fan of
this, since I don't want to get used to the view of an alternator output always
reading zero during normal operation - it desensitizes a person in noticing
if there ever is a real problem. (I used to fly a Mooney that had a red gear
warning light always on when the gear were up, by terrible design. You get really
used to seeing a red light always on, and then completely ignore it).
Instead, I'd rather have the EFIS just provide a display showing a single output
of either alternator - whichever is producing current. What seems to me to
be a simple way of achieving this would be to just tie the output of each alternator
to the same side of the shunt (the terminal opposite that going to the
contactor). Then, it would seem to me as though the shunt would just measure
the combined output of both alternators, which in effect would be just the output
of the alternator that's currently active. But when I asked the EFIS manufacturer
about this, they implied that this wouldn't be the "right way" to do
it - instead, I should use a hall sensor and pass both wires through it.
But I can't understand why using the shunt in this manner wouldn't work (other
than the shunt becoming a single point of failure if it should blow like a fuse).
Can anyone provide any advice on this? Thanks!
Dan
---
Dan Charrois
President, Syzygy Research & Technology
Phone: 780-961-2213
Message 9
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| Subject: | Re: Frequency problem update |
Bob,
Over the years that I have followed this list I recall you saying "check
your coax connections". I might be having a senior moment, but I can not
remember you ever telling us how to check them. Is continuity all we are
looking for on the conductor and the shield but not shorted together?
On Feb 12, 2015 1:40 PM, "Robert L. Nuckolls, III" <
nuckolls.bob@aeroelectric.com> wrote:
> nuckolls.bob@aeroelectric.com>
>
> At 13:49 2015-02-12, you wrote:
>
>> kellym@aviating.com>
>>
>> The frequency sensitivity relates to the fact that RF feedback is
>> occurring. I had this problem in a previous aircraft, which I eventually
>> traced back to a cold solder joint on the RG-58 BNC coax connector at the
>> radio. It worked fine on frequencies below 123.0, and as the frequency went
>> higher it would give off a feedback squeal when the mike was keyed. New
>> coax with properly crimped BNC connectors eliminated the problem. Ferrite
>> beads just mask the problem.
>>
>
> Yes. By definition, a transmission line with strong
> standing waves (high SWR) may become a poor transmission
> line and a better antenna. Since the 'distance' from
> peak to peak on a standing wave is defined by the operating
> frequency, the degree with which a degraded transmission
> line radiates (or receives) is a function of the frequency
> of interest.
>
> In one case, the operator reported relief from the
> effects by simply shortening a coax. He put a new
> connector on one end and decided to cut away some
> extra slack. The connector replaced was a 'good' one
> but the frequency of interest moved off to another
> value. He didn't discover the 'other' bad connector
> until later under different circumstances.
>
> Ferrites over a radiating line WILL reduce the
> effects . . . but it does nothing to correct the
> underlying issue . . . which may still have deleterious
> effect on system performance.
>
> Bad transmission lines can affect reception too
> but these are often more difficult to observe.
> In the final analysis, it's difficult to beat
> antenna installations with track records unless
> you're going to visit a capable RF lab and have
> any 'new idea' in antennas evaluated by-the-numbers.
>
>
> Bob . . .
>
>
Message 10
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| Subject: | Re: Question about monitoring output in two alternator |
configuration
Does the EFIS offer an adjustable millivolts-per-ampere setting for the alternator
current display? If so, you should be able to use any shunt that suits your
load with no problem -- just match the EFIS setting to the shunt's specification.
If this setting is fixed in the EFIS software, you'd have to use a shunt
that matched it exactly (or build a circuit to scale the shunt output to match
what the EFIS expects).
Based on the EFIS manufacturer's comment, it almost sounds like the EFIS is designed
to use a Hall effect sensor. Is a particular part specified in the installation
manual, or did the guy you talked to suggest one? If you can use a Hall
sensor, it would eliminate breaks in the heavy wires, save you four crimp
operations, and eliminate a failure mode in those wires.
Eric
On Feb 12, 2015, at 2:05 PM, Dan Charrois <dan@syz.com> wrote:
> ...I'd rather have the EFIS just provide a display showing a single output of
either alternator - whichever is producing current. What seems to me to be a
simple way of achieving this would be to just tie the output of each alternator
to the same side of the shunt (the terminal opposite that going to the contactor).
Then, it would seem to me as though the shunt would just measure the
combined output of both alternators, which in effect would be just the output
of the alternator that's currently active. But when I asked the EFIS manufacturer
about this, they implied that this wouldn't be the "right way" to do it -
instead, I should use a hall sensor and pass both wires through it.
>
> But I can't understand why using the shunt in this manner wouldn't work (other
than the shunt becoming a single point of failure if it should blow like a fuse).
Message 11
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| Subject: | 12v vs 14v System? |
Is there any practical difference between a 12v and a 14v system?
At the airport, the question came up whether my Standard VR166 voltage regulator
(12volt?) was appropriately rated for my system and it was suggested this regulator
might not be right for a '14 volt system'.
"Did I have a 12v. or a 14v. battery?" Looked at the Odyssey docs and of course,
it's a 12 volt battery (and there are no 14 volt batteries in the Aircraft Spruce
catalog!).
My battery is an Odyssey PC-680, listed as a 12 volt battery. All batteries listed
in the catalog are listed as either 12 (if not 24v).
Starter is a Skytec, listed as 12 volt. All starters are listed as 12v.
Alternator is an L40 from B and C. It's listed as 14 volt. Some manufacturers list
theirs as 12v; some as 14v.
Regulator is a Standard VR166. 12 volt? Some voltage regulators are listed as 12v;
some manufacturers list as 14v; even saw one listed as 14.2v.
My assumption has always been that some manufacturers list their equipment as 14v.
and some at 12v., but that's just an artifact, and there's no practical difference.
Am I correct?
Thanks, Roger.
"For I know the plans I have for you," declares the Lord, "plans to prosper you
and not to harm you, plans to give you hope and a future." Jeremiah 29:11
Message 12
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| Subject: | Re: Question about monitoring output in two alternator |
configuration
> Does the EFIS offer an adjustable millivolts-per-ampere setting for the alternator
current display? If so, you should be able to use any shunt that suits
your load with no problem -- just match the EFIS setting to the shunt's specification.
If this setting is fixed in the EFIS software, you'd have to use a shunt
that matched it exactly (or build a circuit to scale the shunt output to
match what the EFIS expects).
Good question - I'm not sure if it's adjustable (Advanced Flight Systems) - their
manual talks about setting the zero point, but not if the mV/A is adjustable.
I was just planning on using the shunt that came with the EFIS, since I have
it already... and it should already be appropriately sized.
>
> Based on the EFIS manufacturer's comment, it almost sounds like the EFIS is designed
to use a Hall effect sensor. Is a particular part specified in the installation
manual, or did the guy you talked to suggest one? If you can use a
Hall sensor, it would eliminate breaks in the heavy wires, save you four crimp
operations, and eliminate a failure mode in those wires.
It can use either (or both) a Hall effect or a shunt. The shunt came with it,
but the Hall effect sensor is an additional cost, which is why I was figuring
on just using the shunt it came with. Though minimizing breaks in the heavy
wires, as well as a potential failure mode, is certainly worth considering. Of
course, the next question I'd have for them is whether their hall effect sensor
is big enough to accommodate both alternator B-leads..
Thanks for your response!
Dan
---
Dan Charrois
President, Syzygy Research & Technology
Phone: 780-961-2213
Message 13
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| Subject: | Re: Question about monitoring output in two alternator |
configuration
On Feb 12, 2015, at 3:38 PM, Dan Charrois <dan@syz.com> wrote:
> Good question - I'm not sure if it's adjustable (Advanced Flight Systems) - their
manual talks about setting the zero point, but not if the mV/A is adjustable.
I was just planning on using the shunt that came with the EFIS, since I
have it already... and it should already be appropriately sized.
Hilarious. They ship the EFIS a with a shunt, then tell their customers that using
the shunt isn't the right way to set it up. Customer support by Laurel &
Hardy.
Eric
do not archive
Message 14
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| Subject: | Re: Frequency problem update |
Bob, Thanks for the good information. To answer a previous question you had
...The antenna IS mounted inside of the vertical stab. I did not put a grou
nd plane on it but rather (as mentioned earlier) took the ground to the tub
e frame. The only reason I configured it this way was because a buddy with
the same Kitfox model mounted it this way and it has performed for him very
well. With my Ham background, I knew the ideal install would be with that
ground plane, however, fitting a ground plane of any size perpendicular to
the antenna is not possible where the antenna is currently at. The antenna
itself is not accessible...only the connections to it. I have been using a
headset that has ANR capability, but I was using it without the ANR. Every
time I turned the ANR feature on, I got the same RF noise. I was hoping tha
t the new Bose headset would work but it is the same issue. The ferrite bea
d trick has made it operational, but like you said it is only masking the i
ssue. I suppose I will end up mounting an antenna behind the turtledeck wit
h a proper ground plane for the fix. Thanks to all who assisted with this p
roblem.Dan B.=C2-
From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
To: aeroelectric-list@matronics.com
Sent: Thursday, February 12, 2015 2:28 PM
Subject: Re: AeroElectric-List: Frequency problem update
s.bob@aeroelectric.com>
At 13:49 2015-02-12, you wrote:
om>
>
>The frequency sensitivity relates to the fact that RF feedback is
>occurring. I had this problem in a previous aircraft, which I
>eventually traced back to a cold solder joint on the RG-58 BNC coax
>connector at the radio. It worked fine on frequencies below 123.0,
>and as the frequency went higher it would give off a feedback squeal
>when the mike was keyed. New coax with properly crimped BNC
>connectors eliminated the problem. Ferrite beads just mask the problem.
=C2- =C2- Yes. By definition, a transmission line with strong
=C2- =C2- standing waves (high SWR) may become a poor transmission
=C2- =C2- line and a better antenna. Since the 'distance' from
=C2- =C2- peak to peak on a standing wave is defined by the operating
=C2- =C2- frequency, the degree with which a degraded transmission
=C2- =C2- line radiates (or receives) is a function of the frequency
=C2- =C2- of interest.
=C2- =C2- In one case, the operator reported relief from the
=C2- =C2- effects by simply shortening a coax. He put a new
=C2- =C2- connector on one end and decided to cut away some
=C2- =C2- extra slack. The connector replaced was a 'good' one
=C2- =C2- but the frequency of interest moved off to another
=C2- =C2- value. He didn't discover the 'other' bad connector
=C2- =C2- until later under different circumstances.
=C2- =C2- Ferrites over a radiating line WILL reduce the
=C2- =C2- effects . . . but it does nothing to correct the
=C2- =C2- underlying issue . . . which may still have deleterious
=C2- =C2- effect on system performance.
=C2- =C2- Bad transmission lines can affect reception too
=C2- =C2- but these are often more difficult to observe.
=C2- =C2- In the final analysis, it's difficult to beat
=C2- =C2- antenna installations with track records unless
=C2- =C2- you're going to visit a capable RF lab and have
=C2- =C2- any 'new idea' in antennas evaluated by-the-numbers.
=C2- Bob . . .
-
S -
-
=C2- =C2- =C2- =C2- =C2- -Matt Dralle, List Admin.
Message 15
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| Subject: | Re: Question about monitoring output in two alternator |
configuration
To clarify (especially for those who may be looking to this thread in the future),
they ship the EFIS with a shunt, and for a single alternator setup, it's a
perfectly good and reliable method of monitoring the current generated by it.
Their system supports either/and/or. Where they suggested the hall effect sensor
is only for cases like mine with a backup alternator where they suggest
it's a better way of a single point measurement from two different sources. I've
had a very good experience with their customer support - I'm just trying to
see if I'm missing anything critical as to why a shunt wouldn't be equally effective.
Dan
> On 2015-Feb-12, at 5:16 PM, Eric Page <edpav8r@yahoo.com> wrote:
>
>
> On Feb 12, 2015, at 3:38 PM, Dan Charrois <dan@syz.com> wrote:
>> Good question - I'm not sure if it's adjustable (Advanced Flight Systems) -
their manual talks about setting the zero point, but not if the mV/A is adjustable.
I was just planning on using the shunt that came with the EFIS, since I
have it already... and it should already be appropriately sized.
>
> Hilarious. They ship the EFIS a with a shunt, then tell their customers that
using the shunt isn't the right way to set it up. Customer support by Laurel
& Hardy.
>
---
Dan Charrois
President, Syzygy Research & Technology
Phone: 780-961-2213
Message 16
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| Subject: | Re: Frequency problem update |
It is NOT the location or lack of ground plane causing the feedback. It
is most likely one of the coax connections.
On 2/12/2015 6:25 PM, danielj.billingsley@yahoo.com wrote:
> Bob, Thanks for the good information. To answer a previous question
> you had...The antenna IS mounted inside of the vertical stab. I did
> not put a ground plane on it but rather (as mentioned earlier) took
> the ground to the tube frame. The only reason I configured it this way
> was because a buddy with the same Kitfox model mounted it this way and
> it has performed for him very well. With my Ham background, I knew the
> ideal install would be with that ground plane, however, fitting a
> ground plane of any size perpendicular to the antenna is not possible
> where the antenna is currently at. The antenna itself is not
> accessible...only the connections to it. I have been using a headset
> that has ANR capability, but I was using it without the ANR. Every
> time I turned the ANR feature on, I got the same RF noise. I was
> hoping that the new Bose headset would work but it is the same issue.
> The ferrite bead trick has made it operational, but like you said it
> is only masking the issue. I suppose I will end up mounting an antenna
> behind the turtledeck with a proper ground plane for the fix. Thanks
> to all who assisted with this problem.
> Dan B.
> ****
Message 17
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| Subject: | Re: Frequency problem update |
Once you solve the feedback problem, you will then likely start finding
occasions when your signal cannot be heard by another aircraft on
certain bearings, or that aircraft will only hear a weak signal. That
will be caused by your antenna's mounting position, being partially
shielded by the fin frame etc. When you think of it, an antenna mounted
within the tubing frame of the aircraft, even in the fin, is essentially
an antenna mounted in a Faraday Cage.
Bill
On 13/02/2015 1:48 PM, Kelly McMullen wrote:
> <kellym@aviating.com>
>
> It is NOT the location or lack of ground plane causing the feedback.
> It is most likely one of the coax connections.
>
> On 2/12/2015 6:25 PM, danielj.billingsley@yahoo.com wrote:
>> Bob, Thanks for the good information. To answer a previous question
>> you had...The antenna IS mounted inside of the vertical stab. I did
>> not put a ground plane on it but rather (as mentioned earlier) took
>> the ground to the tube frame. The only reason I configured it this
>> way was because a buddy with the same Kitfox model mounted it this
>> way and it has performed for him very well. With my Ham background, I
>> knew the ideal install would be with that ground plane, however,
>> fitting a ground plane of any size perpendicular to the antenna is
>> not possible where the antenna is currently at. The antenna itself is
>> not accessible...only the connections to it. I have been using a
>> headset that has ANR capability, but I was using it without the ANR.
>> Every time I turned the ANR feature on, I got the same RF noise. I
>> was hoping that the new Bose headset would work but it is the same
>> issue. The ferrite bead trick has made it operational, but like you
>> said it is only masking the issue. I suppose I will end up mounting
>> an antenna behind the turtledeck with a proper ground plane for the
>> fix. Thanks to all who assisted with this problem.
>> Dan B.
>> ****
>
>
Message 18
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| Subject: | Re: Question about monitoring output in two alternator |
configuration
At 16:05 2015-02-12, you wrote:
Hi everyone.
I have an electrical system with dual alternators (primary and
backup) and have a question with regards to monitoring their output
current. My EFIS has the capability of monitoring each output
separately, but considering that the alternators are wired such that
only one can be on at a time, I'm not a big fan of this, since I
don't want to get used to the view of an alternator output always
reading zero during normal operation - it desensitizes a person in
noticing if there ever is a real problem. (I used to fly a Mooney
that had a red gear warning light always on when the gear were up, by
terrible design. You get really used to seeing a red light always
on, and then completely ignore it).
But 'zero' in a standby alternator is significant. What
is the likelihood of loosing a standby alternator AND
the main alternator between two pre-flight tests?
Instead, I'd rather have the EFIS just provide a display showing a
single output of either alternator - whichever is producing
current. What seems to me to be a simple way of achieving this would
be to just tie the output of each alternator to the same side of the
shunt (the terminal opposite that going to the contactor). Then, it
would seem to me as though the shunt would just measure the combined
output of both alternators, which in effect would be just the output
of the alternator that's currently active. But when I asked the EFIS
manufacturer about this, they implied that this wouldn't be the
"right way" to do it - instead, I should use a hall sensor and pass
both wires through it.
But I can't understand why using the shunt in this manner wouldn't
work (other than the shunt becoming a single point of failure if it
should blow like a fuse).
It would . . . but perhaps hooking neither alternator
to the EFIS is a better plan. Your alternator's output
is a KNOWN quantity that is, by design, loaded no
heavier than original design goals. As long as
your low voltage light is not flashing, all is
right with the universe . . . irrespective of
any reading you might observe for the alternator.
Similarly, should main alternator fail then the
standby alternator should be loaded no greater
than its capability to keep the bus at 12.5 to 13.0
volts. Again, the voltmeter for one bus is your
primary statement of electrical system health
for flight ops.
Attaching both alternators to a single shunt
forces both output paths to share circuitry.
If you'd like to have these paths be totally
independent of each other, be circuit protected
with a device appropriate to alternator size,
-OR- (as in Z-12/8) have the two alternators
drive different parts of the system, then
the two wires through a hall sensor is the
preferred architecture.
Bob . . .
Message 19
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| Subject: | Re: Frequency problem update |
At 16:27 2015-02-12, you wrote:
>Bob,
>Over the years that I have followed this list I
>recall you saying "check your coax
>connections". I might be having a senior moment,
>but I can not remember you ever telling us how
>to check them. Is continuity all we are looking
>for on the conductor and the shield but not shorted together?
Certainly do the continuity check. Then, my favorite is the
twist and tug test. The most common failure at the coax
connector is loss of integrity at the shield. In the
legacy solder-and-clamp connectors (UG-88) it was really
easy fabricate a bad joint. With the crimp on connectors,
a badly adjusted stripper can damage wires such that
they are mechanically weakened.
With either connector, a substantial torque moment
on the cable as it enters the back of the connector
should produce ZERO perceived motion.
Bob . . .
Message 20
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| Subject: | Re: Question about monitoring output in two alternator |
configuration
Hilarious. They ship the EFIS a with a shunt, then tell their
customers that using the shunt isn't the right way to set it
up. Customer support by Laurel & Hardy.
One shunt per alternator is how it was
done for the last century or so . . . still
works good. Tying two alternators to the
same shunt raises questions about the
loss of independence/redundancy of the
two systems.
Bob . . .
Message 21
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| Subject: | Re: 12v vs 14v System? |
> Is there any practical difference between a 12v and a 14v system?
No, they are nominally the same. A fully charged 12 volt lead acid battery measures
about 13 volts. A voltage regulator for a 12 volt battery is set at about
14.2 volts. A voltage regulator set at 13 volts would keep a battery from
discharging but would not charge a battery that needs to be charged.
> there's no practical difference. Am I correct?
Yes
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=438296#438296
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