Today's Message Index:
----------------------
1. 01:13 AM - Re: Question: can these wires be put in one wire bundle? (zwakie)
2. 06:45 AM - Re: Re: Question: can these wires be put in one wire bundle? (FLYaDIVE)
3. 10:42 AM - Re: Question: can these wires be put in one wire bundle? (Robert L. Nuckolls, III)
4. 10:52 AM - Re: Re: Question: can these wires be put in one wire bundle? (Robert L. Nuckolls, III)
5. 11:43 AM - Re: Re: Question: can these wires be put in one wire bundle? (FLYaDIVE)
6. 01:43 PM - Re: Re: Question: can these wires be put in one wire bundle? (Robert L. Nuckolls, III)
7. 02:22 PM - Re: Question: can these wires be put in one wire bundle? (zwakie)
8. 03:47 PM - Rear battery earthing structure (Neil Parkinson)
9. 04:23 PM - Re: Rear battery earthing structure (Robert L. Nuckolls, III)
10. 06:43 PM - Re: Re: Question: can these wires be put in one wire bundle? (Rick Beebe)
11. 09:02 PM - Re: Re: Question: can these wires be put in one wire bundle? (jim)
Message 1
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Subject: | Re: Question: can these wires be put in one wire bundle? |
BARRY CHECK 6 wrote:
> Keep the Transponder COAX out of the bundle. Run it as far away from ALL other
wires as possible and away from other COAX also.
Thanks Barry. I guess I should have mentioned that in my opening post: the radio
and transponder antennas are aft of the units, so both coax cables will not
be in the bundle.
--------
Marcel Zwakenberg
XS TG || 912ULS || PH-SBR
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=483671#483671
Message 2
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Subject: | Re: Question: can these wires be put in one wire |
bundle?
Oh, Marcel:
Some other tricks I do:
1 - I use Black and Red wire for primary B+ voltages.
2 - I twist the B+ wires - about 4 to 6 twists per inch. This helps in
keeping noise out of the system.
3 - Use shielded cables for Audio lines.
4 - Audio lines are Grounded ONLY at the source - Example: At the radio and
at the intercom.
5 - If you have two set of similar wires - Example: A RS232 from one
Nav/Comm and another Nav/Comm keep them apart and/or use shielded wires.
Side note: I have installed 4 sets of Garmin G5's. NOISE is a huge issue
with them. I use Toroids on the B+ hot wires, wrap them well, the more
wraps the better and ONLY on the B+ Positive wire.
Good NOISELESS Luck,
Barry
Message 3
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Subject: | Re: Question: can these wires be put in one wire |
bundle?
>My plan was to put all the wires for both units into a single wire
>bundle except for the mic, phone and ptt wires. In addition I plan
>of putting a single power and ground wire into this bundle,
>connecting to a separate fuseblock near the units in the back (of
>course, the AWG of these will be scaled upwards appropriately).
There are no noise problems associated
with bundling mixed signals. It's done
in the big birds all the time . . . even
the shielded wires. The whole reason for
shielding is to break the electro-static
coupling path between potential antagonist/
victim pairs.
Suggest you not put part of your bus structure
in the rear. Keep it simple, one fuse for each
protected feeder from the central bus structure
to each powered device. A combined ground for
all rear mounted devices works. We show this
'star' configuration grounding system in Figure
Z-15 with an extension to the instrument panel . . .
a second extension to rear mounted appliances
works too.
>I will also need to put two shielded audio cables back to front to
>connect into the AP60 audio mixer that is also in the back near the
>radio/xpdr units. I guess it's best to keep those separate from this
>bundle, but as these audio wries will be running sort of parallel to
>mentioned wire bundle what is the minimum distance between these two
>runs to avoid audio issues? Also: if my guess of keeping the audio
>wires separate is wrong, please let me know.
I would bundle all power and ground wires from panel
rearward together including the audio. Further, there
is no reason to route coax separately . . . the
signal isolation physics for shielding applies
to radio frequencies as it does for low level
audio.
Spent 40 years herding electrons in everything
from C150 to B400 and Learjets. There is vigorous
competition between the various system groups for
space, weight and volume on the airplane. Finding
placed to put things and wire it all up can be
challenging. Worries about mixed signals in
wire bundles is wwaaaayyy down on the list
of concerns. Proper design and qualification
of the appliances makes 'em installer/user
friendly. It's called electromagnetic compatibility
or EMC for short.
Bob . . .
Message 4
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Subject: | Re: Question: can these wires be put in one |
wire bundle?
At 08:44 AM 10/7/2018, you wrote:
>Oh, Marcel:
>
>Some other tricks I do:
>1 - I use Black and Red wire for primary B+ voltages.
>2 - I twist the B+ wires - about 4 to 6 twists
>per inch.=C2 This helps in keeping noise out of the system.
Noise from where to where?
>3 - Use shielded cables for Audio lines.
>4 - Audio lines are Grounded ONLY at the source
>- Example: At the radio and at the intercom.
Treat shields per manufacturer's installation instructions.
Shields are sometimes part of the energy management.
>5 - If you have two set of similar wires -
>Example: A RS232 from one Nav/Comm and another
>Nav/Comm keep them apart and/or use shielded wires.
There is no reason for doing this. If we attempted
to keep everythting separated behind the panel
of a King Air, it would look like a spider-web
as opposed to an organized, mechanically
secure installtion.
>Side note:=C2 I have installed 4 sets of Garmin
>G5's.=C2 NOISE is a huge issue with them.=C2 I use
>Toroids on the B+ hot wires, wrap them well, the
>more wraps the better and ONLY on the B+ Positive wire.
Noise from where to where? What is the nature
of the noise? Are these not a DO160
qualified system? Is the G5 the victim or
the antagonist?
Bob . . .
Message 5
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Subject: | Re: Question: can these wires be put in one wire |
bundle?
Bob:
On Sun, Oct 7, 2018 at 1:56 PM Robert L. Nuckolls, III <
nuckolls.bob@aeroelectric.com> wrote:
> At 08:44 AM 10/7/2018, you wrote:
>
> Oh, Marcel:
>
> Some other tricks I do:
> 1 - I use Black and Red wire for primary B+ voltages.
> 2 - I twist the B+ wires - about 4 to 6 twists per inch.=C3=82 This help
s in
> keeping noise out of the system.
>
>
> Noise from where to where?
>
Barry - When I know where the noise is coming from I attack the noise. In
the meantime I do what I can to prevent the noise from attacking the
system.
> 3 - Use shielded cables for Audio lines.
> 4 - Audio lines are Grounded ONLY at the source - Example: At the radio
> and at the intercom.
>
>
> Treat shields per manufacturer's installation instructions.
> Shields are sometimes part of the energy management.
>
> 5 - If you have two set of similar wires - Example: A RS232 from one
> Nav/Comm and another Nav/Comm keep them apart and/or use shielded wires.
>
>
> There is no reason for doing this.
>
Barry - There sure is! You do what you can where you can to keep the noise
down OR you are forced to live with it.
> If we attempted
> to keep everythting separated behind the panel
> of a King Air, it would look like a spider-web
> as opposed to an organized, mechanically
> secure installtion.
>
Barry - Spider Web. They are very organized. It's the Rat's Nest I
despise.
You keep separated what you can. You use shielded wire where you can. You
of course do not have to go weird in your actions.
But, the issue becomes a problem AFTER the wiring is complete and THEN you
find you have noise.
Then you scramble with capacitors, coils and filter networks - Maybe or
Maybe not being able to solve the problem ONLY to find proper wiring would
have eliminated the noise.
Why scramble for a band-aid instead of eliminating the problem?
> Side note:=C3=82 I have installed 4 sets of Garmin G5's.=C3=82 NOISE is
a huge
> issue with them.=C3=82 I use Toroids on the B+ hot wires, wrap them well
, the
> more wraps the better and ONLY on the B+ Positive wire.
>
>
> Noise from where to where? What is the nature
> of the noise? Are these not a DO160
> qualified system?
>
Barry - I do not know! They are a Garmin system (LCD Attitude Indicator,
ASI, VSI, HSI and they interface to Panel Mounted GPS & A/P) pretty much an
all glass panel.
https://www.garmin.com/en-US/blog/aviation/announcement-g5-electronic-fligh
t-instrument-as-dghsi-in-certificated-aircraft/
> Is the G5 the victim or
> the antagonist?
>
Barry - It is the VICTIM, as the G5 has a Noise Testing program built into
them.
The big issue of noise, is because it has a remote mounted Magnetometer.
Barry
>
Message 6
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Subject: | Re: Question: can these wires be put in one |
wire bundle?
>>Some other tricks I do:
>>1 - I use Black and Red wire for primary B+ voltages.
>>2 - I twist the B+ wires - about 4 to 6 twists
>>per inch.=C3=82=C2 This helps in keeping noise out of the system.
>
>=C2 Noise from where to where?
>
>Barry - When I know where the noise is coming
>from I attack the noise.=C2 In the meantime I do
>what I can to prevent the noise from attacking
>the system.
>Barry - There sure is!=C2 You do what you can
>where you can to keep the noise down OR you are forced to live with it.
You speak of 'the noise' . . . never met a
noise problem I couldn't whip . . . albeit
some were pretty bizarre. But in decades
of helping push certified iron down the
production line, not once have I encountered
a noise issue that was cured or would have
be prevented by:
Adding inductors to power lines of
a properly qualified appliance, twisting
any pairs of wires together, adding shielding
above or beyond that specified by the
manufacturer of the system or adding/increasing
separation of coaxes from other wires in
the airframe.
>Barry - Spider Web. They are very organized. It's the Rat's Nest I despise.
>You keep separated what you can. You use shielded wire where you can.
>You of course do not have to go weird in your actions.
>But, the issue becomes a problem AFTER the wiring is complete and THEN you
>find you have noise. Then you scramble with capacitors, coils and filter
>networks - Maybe or Maybe not being able to=C2 solve the problem ONLY to
>find proper wiring would have eliminated the noise.
I have never encountered a case of 'improper wiring'.
If moving a wire or adding an heretofore unspecified
shield, then there's something seriously wrong with
the selection of hardware.
I prefer to identify the victim, point of entry for
noise into that system. Identify the noise source.
Identify the propagation pathway. Then craft a
'fire-break' in that pathway to reduce interference
to acceptable levels.
>Why scramble for a band-aid instead of eliminating the problem?
But Barry,
>>Side note: I have installed 4 sets of Garmin G5's.
>>NOISE is a huge issue with them. I use Toroids on the B+ hot
>>wires, wrap them well, the more wraps the better and ONLY on the
>>B+ Positive wire.
>
> Noise from where to where? What is the nature
> of the noise? Are these not a DO160
> qualified system?
>
>Barry - I do not know! They are a Garmin system (LCD Attitude Indicator,
ASI,
>VSI, HSI and they interface to Panel Mounted GPS
>& A/P) pretty much an all glass panel.
>
><https://www.garmin.com/en-US/blog/aviation/announcement-g5-electronic-flig
ht-instrument-as-dghsi-in-certificated-aircraft/>https://www.garmin.com/en-U
S/blog/aviation/announcement-g5-electronic-flight-instrument-as-dghsi-in-cer
tificated-aircraft/
Okay, if these are going into TC ships, then they must
have been vetted for EMC.
If they succumb to some stimulus in an existing airframe,
the stimulus has to be much larger and/or of a nature
not anticipated by the folks who craft certification protocols.
If a filter was found necessary to protect
functionality of the Garmin system, how do you know
that the same antagonist isn't deleterious to other
systems? What was the core material used and number of
turns. What was the value of inductance added with
this filter (speaks to the spectrum of noise for which
his would be an effective filter). Are you sure that
the core 'packed with as many turns as possible' was
not saturated with the DC current flow through its
winding?
>
>Is the G5 the victim or
>the antagonist?
>
>Barry - It is the VICTIM, as the G5 has a Noise
>Testing program built into them.
>The big issue of noise, is because it has a remote mounted Magnetometer.
What does the G5 installation manual say about noise?
Remote magnetometers have been around for nearly a century
and yes, need to be thoughtfully installed
to avoid interference to its accuracy . . . but adding
inductance to the power supply line for an input qualified
to Mil-STD-704 stimulus would not be one of the factory
recommended fixes.
Bob . . .
Message 7
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Subject: | Re: Question: can these wires be put in one wire bundle? |
nuckolls.bob(at)aeroelect wrote:
>
> There are no noise problems associated
> with bundling mixed signals. It's done
> in the big birds all the time . . . even
> the shielded wires. The whole reason for
> shielding is to break the electro-static
> coupling path between potential antagonist/
> victim pairs.
>
That is how I understood it from the 'Conneciton, thanks for confirming.
nuckolls.bob(at)aeroelect wrote:
>
> Suggest you not put part of your bus structure
> in the rear. Keep it simple, one fuse for each
> protected feeder from the central bus structure
> to each powered device. A combined ground for
> all rear mounted devices works. We show this
> 'star' configuration grounding system in Figure
> Z-15 with an extension to the instrument panel . . .
> a second extension to rear mounted appliances
> works too.
>
I know star conifgurations are not ideal, but this is going to be an intermediate
solution until I have my new panel ready for installation. I thought for a
limiited time I should get away with it. Am I assuming wrong?
nuckolls.bob(at)aeroelect wrote:
>
> I would bundle all power and ground wires from panel
> rearward together including the audio.
>
Will do, thanks.
nuckolls.bob(at)aeroelect wrote:
>
> Further, there
> is no reason to route coax separately . . . the
> signal isolation physics for shielding applies
> to radio frequencies as it does for low level
> audio.
>
Point taken. In my case all coax runs more aft, so no issue there...
Thanks Bob for taking the time to answer my questions in detail, really appreciated!
Marcel
--------
Marcel Zwakenberg
XS TG || 912ULS || PH-SBR
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=483690#483690
Message 8
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Subject: | Rear battery earthing structure |
Hi Everybody.
Im building an RV8 with a rear battery location.
Can I please have some advice on the earthing structure . Can I just earth the
battery to the structure in the rear , then take it the common earth at the panel
? Or is it worth running some asw2 cable to earth the panel , or the engine
??
I will have some rear avionics equipment , should I run the earth from the panel
to these ? Or just tap of the structure locally ?
Im not sure when I start running into earth loop issues ??
Many thanks.
Neil.
Message 9
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Subject: | Re: Rear battery earthing structure |
At 05:46 PM 10/7/2018, you wrote:
>Parkinson <nwparkinson@btopenworld.com>
>
>Hi Everybody.
>
>I=99m building an RV8 with a rear battery location.
>
>Can I please have some advice on the earthing
>structure . Can I just earth the battery to the
>structure in the rear , then take it the common
>earth at the panel ? Or is it worth running some
>asw2 cable to earth the panel , or the engine ??
Ground battery locally
http://aeroelectric.com/Pictures/Batteries/Battery_Install_OBrien_3.jpg
http://aeroelectric.com/Pictures/Grounding/Local_Battery_Grounds_1.jpg
Install ground bus on firewall.
http://aeroelectric.com/Pictures/Grounding/Forest_of_Tabs_Ground_Kit.pdf
http://aeroelectric.com/Pictures/Grounding/gnd_bus.jpg
Run braided-flat-wire
from crankcase to firewall ground stud.
http://aeroelectric.com/Pictures/Grounding/Braided%20Copper%20Bond%20Straps.
jpg
>I will have some rear avionics equipment ,
>should I run the earth from the panel to these ?
>Or just tap of the structure locally ?
What kind of avionics? Anything with audio or digital
signal leads?
Bob . . .
Message 10
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Subject: | Re: Question: can these wires be put in one wire |
bundle?
On 10/7/2018 2:41 PM, FLYaDIVE wrote:
> Is the G5 the victim or
>
> the antagonist?
>
> Barry - It is the VICTIM, as the G5 has a Noise Testing program built
> into them.
> The big issue of noise, is because it has a remote mounted Magnetometer.
The GMU11 magnetometer is susceptible to noise, as I discovered. I ended
up rewiring my strobe lights before it would pass the interference test.
To be fair, I mounted the GMU11 in the tail (fiberglass plane) in the
spot where the Whelen powerpack used to live. I had replaced the Whelen
units with Aveo LED units but used the existing wire so it was spliced
right near the GMU 11. Also the shields were not contiguous out to the
lights. In the end I pulled new shielded wire from the lights directly
to the panel switch and that solved my interference problem. Perhaps if
I had located the magnetometer in the wing I wouldn't have had an issue.
But I don't think it's fair to say the G5 is susceptible to noise. By
their nature, magnetometers are sensitive beasts.
--Rick
Message 11
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Subject: | Re: Question: can these wires be put in one wire |
bundle?
Noise problems are sometimes present no matter how careful the builder has
been. That is why I read this forum, just to get ideas how to chase them.
When a friend ask me for ideas on how to find an intermittent source of
noise in his GlassStar, I gave him some ideas based on what I had learned
here. He had no luck and was just ready to give up when he accidently
noticed his HOBBS meter was running intermittently. He had a standard
arrangement where a switch in the oil pressure line turned on the HOBBS
meter so it recorded actual engine run time. When he replaced the oil
pressure switch that activated the HOBBS meter, the intermittent noise went
away. That was a total accidental situation. I doubt anyone would have
suspected a bad set of points in an oil pressure switch of causing the
problem.
You learn something new every day if you just pay attention to what you can
learn by other's experiences.
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
<owner-aeroelectric-list-server@matronics.com> On Behalf Of zwakie
Sent: Sunday, October 7, 2018 4:22 PM
Subject: AeroElectric-List: Re: Question: can these wires be put in one wire
bundle?
nuckolls.bob(at)aeroelect wrote:
>
> There are no noise problems associated
> with bundling mixed signals. It's done
> in the big birds all the time . . . even
> the shielded wires. The whole reason for
> shielding is to break the electro-static
> coupling path between potential antagonist/
> victim pairs.
>
That is how I understood it from the 'Conneciton, thanks for confirming.
nuckolls.bob(at)aeroelect wrote:
>
> Suggest you not put part of your bus structure
> in the rear. Keep it simple, one fuse for each
> protected feeder from the central bus structure
> to each powered device. A combined ground for
> all rear mounted devices works. We show this
> 'star' configuration grounding system in Figure
> Z-15 with an extension to the instrument panel . . .
> a second extension to rear mounted appliances
> works too.
>
I know star conifgurations are not ideal, but this is going to be an
intermediate solution until I have my new panel ready for installation. I
thought for a limiited time I should get away with it. Am I assuming wrong?
nuckolls.bob(at)aeroelect wrote:
>
> I would bundle all power and ground wires from panel
> rearward together including the audio.
>
Will do, thanks.
nuckolls.bob(at)aeroelect wrote:
>
> Further, there
> is no reason to route coax separately . . . the
> signal isolation physics for shielding applies
> to radio frequencies as it does for low level
> audio.
>
Point taken. In my case all coax runs more aft, so no issue there...
Thanks Bob for taking the time to answer my questions in detail, really
appreciated!
Marcel
--------
Marcel Zwakenberg
XS TG || 912ULS || PH-SBR
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=483690#483690
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