A aviation & planes forum. AviationBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AviationBanter forum » rec.aviation newsgroups » Soaring
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Radio Squelch - Electrical Noise Problems



 
 
Thread Tools Display Modes
  #1  
Old June 12th 18, 05:29 AM posted to rec.aviation.soaring
Maxx Ruff[_2_]
external usenet poster
 
Posts: 5
Default Radio Squelch - Electrical Noise Problems

I'm trying to sort out electrical noise upsetting many of my clubs radios.

I’ve had moderate but inconsistent results with separating radio wiring
and
use of ferrite beads.

Does anyone know of any on-line info / guides to reduce squelch problems?
(Especially with regard to squelch being upset by electrical noise from
chargers, voltage converters, digital instruments and data wiring).

The problem with cockpit devices causing the need for more aggressive
radio squelch setting seems to be getting worse. Winding up the squelch is

easier than minimising the ‘interference’ but I feel it’s like using
earplugs
instead of fixing a noisy wheel bearing.

I’ve seen and used lots of useful suggestions scattered through numerous

topics on RAS and a sprinkling of possible electrical noise fixes on
Google. I
would really appreciate a pointer to good info and any ‘golden rules’.


Max


Ads
  #2  
Old June 12th 18, 07:28 AM posted to rec.aviation.soaring
Wyll Surf Air
external usenet poster
 
Posts: 21
Default Radio Squelch - Electrical Noise Problems

If there is a specific voltage converter that seems to be spitting out a lot of noise you might try wrapping it in tin foil. That has worked for me in the past.
  #3  
Old June 12th 18, 11:39 AM posted to rec.aviation.soaring
Chris Wedgwood[_2_]
external usenet poster
 
Posts: 35
Default Radio Squelch - Electrical Noise Problems

On Tuesday, June 12, 2018 at 5:30:06 AM UTC+1, Maxx Ruff wrote:
I'm trying to sort out electrical noise upsetting many of my clubs radios..

I’ve had moderate but inconsistent results with separating radio wiring
and
use of ferrite beads.

Does anyone know of any on-line info / guides to reduce squelch problems?
(Especially with regard to squelch being upset by electrical noise from
chargers, voltage converters, digital instruments and data wiring).

The problem with cockpit devices causing the need for more aggressive
radio squelch setting seems to be getting worse. Winding up the squelch is

easier than minimising the ‘interference’ but I feel it’s like using
earplugs
instead of fixing a noisy wheel bearing.

I’ve seen and used lots of useful suggestions scattered through numerous

topics on RAS and a sprinkling of possible electrical noise fixes on
Google. I
would really appreciate a pointer to good info and any ‘golden rules’.


Max


It would be helpful to detail what you've done, what equipment is there, etc..
  #4  
Old June 12th 18, 12:08 PM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 29
Default Radio Squelch - Electrical Noise Problems

If you can identify which device(s) are the primary culprit, installing a capacitor across the power leads to that device may cut the unwanted noise. Google “low pass filter” and you’ll find good info..
  #5  
Old June 12th 18, 12:13 PM posted to rec.aviation.soaring
Martin Gregorie[_6_]
external usenet poster
 
Posts: 83
Default Radio Squelch - Electrical Noise Problems

On Mon, 11 Jun 2018 23:28:23 -0700, Wyll Surf Air wrote:

If there is a specific voltage converter that seems to be spitting out a
lot of noise you might try wrapping it in tin foil. That has worked for
me in the past.


A cheap source of efficient 12v - 5v converters is to buy 'USB cigar
lighter chargers' from Ebay, throw away the plastic case and solder power
leads onto the 12v side of the PCB. However, these often produce RF noise
because they use a high frequency chopper circuit. I use them, of course,
since they are cheap and easy to find but I mount them inside a small
metal, rather than plastic, box and fit ferrite cores to both 12v and 5v
leads close to the box. I have no noise problems if they're used this way.

The only serious interference noise problem I've had was from a
mechanical T&B. Ferrite cores made no difference to it. The cure was to
fit a "12v interference suppression capacitor" across its its power
leads. These are special purpose polyester film capacitors. Mouser, among
others, sell them or a search using the term shown above will find many
sources, including fleabay.


--
Martin | martin at
Gregorie | gregorie dot org
  #6  
Old June 12th 18, 02:17 PM posted to rec.aviation.soaring
PAGA
external usenet poster
 
Posts: 29
Default Radio Squelch - Electrical Noise Problems

With the help of a good avionics friend, we recently found that some of the little GPS pucker did interfere with my radio when powered (and connected to a Kobo), while other models (we switched to a dongle) didn’t.

It took a long systematic one by one elimination test, turning on and off one device at a time. One source of static can be your phone(s) obviously, so your testing must include those. Once you find the culprit the solution is probably simple or already explained by some of the pros above who know electronic better.

Good luck,
686
  #7  
Old June 12th 18, 02:24 PM posted to rec.aviation.soaring
Dave Nadler
external usenet poster
 
Posts: 1,282
Default Radio Squelch - Electrical Noise Problems

On Tuesday, June 12, 2018 at 12:28:25 AM UTC-6, Wyll Surf Air wrote:
you might try wrapping it in tin foil. That has worked for me in the past.


https://tinyurl.com/y7o8rnpy
  #8  
Old June 12th 18, 03:20 PM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 1
Default Radio Squelch - Electrical Noise Problems


It would be helpful to detail what you've done, what equipment is there, etc..


Generally I try to modify the wiring to be as close as possible to John DeRosa's excellent presentations. I haven't found much on the topic of radio interference on his or any other website but would be happy to be corrected.

I've checked for voltage drops to the instruments, cleaned and tightened terminal blocks, grounding, fuses and connectors, separated Radio wiring as best I can (both physically and electrically), placed split ferrites on power, spr and mic/ptt leads to radio. Looped (twice) power wiring to the flarm through ferrite rings, clipped split ferrites on data leads to FLARM display and card readers if present.
I find that the first minute after the Master switch has been turned on is the noisiest, I assume things are initializing during this period. The Flarms seem to be the "primary culprits". A handheld radio confirms this.
The noise is stronger on some frequencies than others, 122.7 Mhz is moderately quieter than frequencies above 130 Mhz.
Should I try a ferrite on the Flarm GPS antenna or will this mess up the GPS?
Also, is a ferrite on the radio antenna cable a really, really bad idea?

I have assumed it is better to run both positive and ground wires to an instrument through the same ferrite OR would it be better to have a ferrite for each wire? Would it be better to have no ferrite on the radio ground so that its chassis is 'closer to RF ground'. Sigh.
I haven't tried a "12v interference suppression capacitor" yet, will order some. Will also order some copper foil to wrap around the flarms (or possibly to make a hat
  #9  
Old June 12th 18, 03:46 PM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 252
Default Radio Squelch - Electrical Noise Problems

I have to agree with PAGA.
It took almost a whole day but taking all units off line and adding them back one at a time identified what system was the source. Then it was a couple hours using ferrite devices to kill the noise. It was amazing to me how specific the positioning of the ferrite device on a wire/cable needed to be. Just moving the ferrite an inch back and forth on a wire/cable made a difference. Eventually, all became good in the world again.
  #10  
Old June 12th 18, 04:19 PM posted to rec.aviation.soaring
Maxx Ruff[_2_]
external usenet poster
 
Posts: 5
Default Radio Squelch - Electrical Noise Problems

At 10:39 12 June 2018, Chris Wedgwood wrote:

It would be helpful to detail what you've done, what equipment is

there,
etc


I generally try to modify wiring to comply with John DeRosa's excellent
presentations. I haven't found much on his or any other website about
radio interference but would be pleased to be corrected.

http://aviation.derosaweb.net/presentations/#wiring

I have checked for poor batteries, undersized cables, loose or voltage
drops on connectors, fuses, circuit breakers, switches, terminal blocks
and earthing.
I've separated (physically and electrically) as best as reasonably
possible, the wiring of the radio from other wiring.
I've placed solid ferrites on power wiring to the radio and each
instrument.
I've put split ferrites on data, display, memory card and radio mic/spr/
ptt cables.
I took the ferrites back off the memory card cables as I seemed to have
more trouble with the cards while the ferrites were present (but this
may have been caused by people corrupting the cards in a mac pc).

The ' primary culprit' often seems to be the Flarm, especially during the
first minute after the master switch is turned on when everything is
initializing. A hand held radio seems to confirm this. The interference
seems to be worse at higher frequencies with 122.7Mhz being a bit
better than above 130Mhz.

I haven't tried "a 12v interference suppression capacitor" across the
radio leads, will order some. Also ordering some copper foil to wrap
around the flarms (or to make a protective hat)

I'm not sure if its a good idea to clip a ferrite onto the flarm GPS
antenna lead or the radio antenna lead, suggestions are welcome.

 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Dittel radio squelch [email protected] Soaring 42 October 7th 16 04:31 PM
Noise Problem. Both Comms Breaking Squelch Lancair IV-P Flyer Owning 26 April 3rd 08 09:57 PM
Noise Problem. Both Comms Breaking Squelch MikeMl Home Built 10 April 3rd 08 09:57 PM
Static/Squelch Noise in Radio Kensandyeggo Home Built 2 April 13th 06 09:00 PM
Radio "Squelch-type" Noise Kensandyeggo Owning 7 April 12th 06 07:20 PM


All times are GMT +1. The time now is 02:55 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright 2004-2018 AviationBanter.
The comments are property of their posters.