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How to eliminate noise on COMM 1 (GNS430W)

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Mike Whisky

Joined: 05 Jun 2006
Posts: 336
Location: Switzerland

Posted: Mon Apr 21, 2014 2:41 am Post subject: How to eliminate noise on COMM 1 (GNS430W)

Hi 

I have now 60h on my -10 and suffer of bad noise of my COMM 1 GNS430W.

It is constantly receiving loud noise only when the engine is running. Often it is ok on my home frequency 122.15 but permanently noise is present on 124.xxx frequencies.

The COMM 1 is connected to a belly mounted Comant C-122 antenna which is attached by screws and nut plates. The antenna came with a cork gasket which I used.

Here are my set of questions. The radio receives fine when engine is not running, so I guess that grounding of antenna or cabling should not be the cause of the issue. What could be the potential source of the noise? How can I identify it?



I took all electric circuits one by one off-line without success.



Any ideas are appreciated



Thanks

Mike

_________________
RV-10 builder (flying)
#511

jmjones2000(at)mindspring
Guest

Posted: Mon Apr 21, 2014 3:07 am Post subject: How to eliminate noise on COMM 1 (GNS430W)

Sounds like it is a shielding issue.  Make sure that you use shielded ground and antenna wires.  The shield should be grounded on just one side, not both (either antenna side or radio side). 

On Apr 21, 2014, at 2:41 AM, Mike Whisky <rv-10(at)wellenzohn.net> wrote:



 	  Quote: 	
		   

 

 Hi 

 I have now 60h on my -10 and suffer of bad noise of my COMM 1 GNS430W.

 It is constantly receiving loud noise only when the engine is running. Often it is ok on my home frequency 122.15 but permanently noise is present on 124.xxx frequencies.

 The COMM 1 is connected to a belly mounted Comant C-122 antenna which is attached by screws and nut plates. The antenna came with a cork gasket which I used.

 Here are my set of questions. The radio receives fine when engine is not running, so I guess that grounding of antenna or cabling should not be the cause of the issue. What could be the potential source of the noise? How can I identify it?

 

 I took all electric circuits one by one off-line without success.

 

 Any ideas are appreciated

 

 Thanks

 Mike

 

 --------

 RV-10 builder (flying, test phase)

 #511

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=422182#422182

rnewman(at)tcwtech.com
Guest

Posted: Mon Apr 21, 2014 3:25 am Post subject: How to eliminate noise on COMM 1 (GNS430W)

Mike.    Have you tried pulling the field breaker on the alternator so you are running on battery power only?     If so, then it would appear you are a problem with the magnetos generating noise.  If the problem goes away when you turn off the alternator then we are chasing an issue with respect to the alternator and it's regulator.  



One point if note,  there are squelch setting deep in the set-up menu of the gns series.  I remember making tweaks to it on my glastar many years ago.    Now with respect to the rv-10, I have dual gns-430w, each with a belly mount c-122 antenna and I did use the cork gaskets.   All works as advertised, I never have a communication issue with the radios on any frequency. 



Bob Newman 

N541RV

Tcwtech.com



Sent from my iPhone



 	  Quote: 	
		   On Apr 21, 2014, at 6:41 AM, "Mike Whisky" <rv-10(at)wellenzohn.net> wrote:

 

 

 

 Hi 

 I have now 60h on my -10 and suffer of bad noise of my COMM 1 GNS430W.

 It is constantly receiving loud noise only when the engine is running. Often it is ok on my home frequency 122.15 but permanently noise is present on 124.xxx frequencies.

 The COMM 1 is connected to a belly mounted Comant C-122 antenna which is attached by screws and nut plates. The antenna came with a cork gasket which I used.

 Here are my set of questions. The radio receives fine when engine is not running, so I guess that grounding of antenna or cabling should not be the cause of the issue. What could be the potential source of the noise? How can I identify it?

 

 I took all electric circuits one by one off-line without success.

 

 Any ideas are appreciated

 

 Thanks

 Mike

 

 --------

 RV-10 builder (flying, test phase)

 #511

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=422182#422182

carl.froehlich(at)verizon
Guest

Posted: Mon Apr 21, 2014 4:39 am Post subject: How to eliminate noise on COMM 1 (GNS430W)

There are several issues that can cause the problem you describe.  This last

week I fixed a similar problem on an RV-8A - an antenna connector on the

feed line was bad.  A bad connector can still allow the radio to receive.



As you don't say this is a problem on Comm #2 and this problem just

appeared, below are some thoughts to isolate the root issue:

- swap Comm #1 and Comm #2 antennas to see if the problem moves.  If so you

have either bad connectors, some other antenna feed line issue or a bad

antenna (not likely).  I use an MFJ antenna analyzer to verify antenna

health.

- swap out your 430 with someone else's 430 - if the problem goes away the

issue is inside your 430.  As Bob suggests this might be a simple squelch

setting.



If the above checks do not change the symptoms then start looking at the

things not checked.  This would include tray connections and magneto control

cabling (must be shielded wire and grounded per standard magneto wiring

practice).  If you did something right before this issue started, that would

also be a place to look.



Carl



--

Mike Whisky

Joined: 05 Jun 2006
Posts: 336
Location: Switzerland

Posted: Mon Apr 21, 2014 4:42 am Post subject: Re: How to eliminate noise on COMM 1 (GNS430W)

 	  jmjones2000(at)mindspring wrote: 	
		  Sounds like it is a shielding issue.  Make sure that you use shielded ground and antenna wires.  The shield should be grounded on just one side, not both (either antenna side or radio side). 



I am using RG-400 and BNC connectors. The shield is grounded on both ends. It's the first time I hear that it should be grounded only on one side! Can someone confirm. 

Mike

 

 

 

 

 

 

 



	
[/quote]

_________________
RV-10 builder (flying)
#511

flysrv10(at)gmail.com
Guest

Posted: Mon Apr 21, 2014 6:37 am Post subject: How to eliminate noise on COMM 1 (GNS430W)

The base of your antenna must have a good ground. I never use the cork gasket. 



Also ALL ground connections on your radios must go to a separate ground bus, directly connected to the battery. No airframe grounding of any kind. 



Do not archive. 



Rob Kermanj

Sent from my iPhone



 	  Quote: 	
		   On Apr 21, 2014, at 6:41 AM, "Mike Whisky" <rv-10(at)wellenzohn.net> wrote:

 

 

 

 Hi 

 I have now 60h on my -10 and suffer of bad noise of my COMM 1 GNS430W.

 It is constantly receiving loud noise only when the engine is running. Often it is ok on my home frequency 122.15 but permanently noise is present on 124.xxx frequencies.

 The COMM 1 is connected to a belly mounted Comant C-122 antenna which is attached by screws and nut plates. The antenna came with a cork gasket which I used.

 Here are my set of questions. The radio receives fine when engine is not running, so I guess that grounding of antenna or cabling should not be the cause of the issue. What could be the potential source of the noise? How can I identify it?

 

 I took all electric circuits one by one off-line without success.

 

 Any ideas are appreciated

 

 Thanks

 Mike

 

 --------

 RV-10 builder (flying, test phase)

 #511

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=422182#422182

Kellym

Joined: 10 Jan 2006
Posts: 1705
Location: Sun Lakes AZ

Posted: Mon Apr 21, 2014 6:37 am Post subject: How to eliminate noise on COMM 1 (GNS430W)

You are correct. Antenna cable is NOT one of the places that shielding 

is terminated to ground at only one end.

There are opportunities for a bad shield connection with coax. An 

earlier suggestion to swap antenna cables between Com 1 and Com 2 is a 

good one to see if it is the cable(does problem move between coms or 

not?). Likewise, if possible to either borrow another matching radio to 

see if it does it also, or to put your radio in someone ele's plane to 

see if the problem goes with the radio. All no/lo-cost tests.

Magnetos/electronic ignition and alternator system are two prime 

candidates for noise generation. Easy to eliminate the alternator noise 

by pulling field and main breakers.



On 4/21/2014 5:42 AM, Mike Whisky wrote:

 	  Quote: 	
		   

 jmjones2000(at)mindspring wrote:

> Sounds like it is a shielding issue.  Make sure that you use shielded ground and antenna wires.  The shield should be grounded on just one side, not both (either antenna side or radio side).

>

> I am using RG-400 and BNC connectors. The shield is grounded on both ends. It's the first time I hear that it should be grounded only on one side! Can someone confirm.

> Mike

>

> On Apr 21, 2014, at 2:41 AM, Mike Whisky  wrote:

>>   

>>   

>>   Hi

>>   I have now 60h on my -10 and suffer of bad noise of my COMM 1 GNS430W.

>>   It is constantly receiving loud noise only when the engine is running. Often it is ok on my home frequency 122.15 but permanently noise is present on 124.xxx frequencies.

>>   The COMM 1 is connected to a belly mounted Comant C-122 antenna which is attached by screws and nut plates. The antenna came with a cork gasket which I used.

>>   Here are my set of questions. The radio receives fine when engine is not running, so I guess that grounding of antenna or cabling should not be the cause of the issue. What could be the potential source of the noise? How can I identify it?

>>   

>>   I took all electric circuits one by one off-line without success.

>>   

>>   Any ideas are appreciated

>>   

>>   Thanks

>>   Mike

>>   

>>   --------

>>   RV-10 builder (flying, test phase)

>>   #511

>>   

>>   

>>   

>>   

>>   Read this topic online here:

>>   

>>   http://forums.matronics.com/viewtopic.php?p=422182#422182

>>   

>>   

>>   

>>   

>>   

>>   

>>   

>>   

>>   

>>   

>>

>>



 --------

 RV-10 builder (flying, test phase)

 #511





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=422188#422188

_________________
Kelly McMullen
A&P/IA, EAA Tech Counselor # 5286
KCHD

Mike Whisky

Joined: 05 Jun 2006
Posts: 336
Location: Switzerland

Posted: Mon Apr 21, 2014 10:17 am Post subject: Re: How to eliminate noise on COMM 1 (GNS430W)

I do have one common ground for everything at the firewall. It works fine for my COMM 2 (SL30). I will follow your advice and switch off field and then EI/Magneto. The ground of measuring connectivity of the antenna ground base against the structure has been positive. In order to switch antenna cable I need to make a male-male and one female-female coax as the connectors are just the other way around. But I do have now a pretty good idea to eliminate at least some potential sources. I'll keep you updated of the outcome.



Thanks

Michael

_________________
RV-10 builder (flying)
#511

Kellym

Joined: 10 Jan 2006
Posts: 1705
Location: Sun Lakes AZ

Posted: Mon Apr 21, 2014 12:36 pm Post subject: How to eliminate noise on COMM 1 (GNS430W)

The gasket is there to prevent moisture from getting to the connection 

and inside the airframe. It does NOT inhibit grounding. If you don't use 

the gasket then you need a good RTV or Proseal bead to seal the base of 

the antenna from the weather.

Grounding happens between the attach screws and the riveted nutplates, 

not from skin to antenna contact.

As long as a common ground point is used it does not matter whether 

there is a wire conductor back to the battery or the airframe is used on 

metal aircraft like the RV-10. Only things like intercoms, mike and 

headset jacks need a floating ground to prevent ground loops.



On 4/21/2014 7:36 AM, Rob Kermanj wrote:

 	  Quote: 	
		   



 The base of your antenna must have a good ground. I never use the cork gasket.



 Also ALL ground connections on your radios must go to a separate ground bus, directly connected to the battery. No airframe grounding of any kind.



 Do not archive.



 Rob Kermanj

 Sent from my iPhone



> On Apr 21, 2014, at 6:41 AM, "Mike Whisky" <rv-10(at)wellenzohn.net> wrote:

>

> 

>

> Hi

> I have now 60h on my -10 and suffer of bad noise of my COMM 1 GNS430W.

> It is constantly receiving loud noise only when the engine is running. Often it is ok on my home frequency 122.15 but permanently noise is present on 124.xxx frequencies.

> The COMM 1 is connected to a belly mounted Comant C-122 antenna which is attached by screws and nut plates. The antenna came with a cork gasket which I used.

> Here are my set of questions. The radio receives fine when engine is not running, so I guess that grounding of antenna or cabling should not be the cause of the issue. What could be the potential source of the noise? How can I identify it?

>

> I took all electric circuits one by one off-line without success.

>

> Any ideas are appreciated

>

> Thanks

> Mike

>

> --------

> RV-10 builder (flying, test phase)

> #511

>

>

> Read this topic online here:

>

> http://forums.matronics.com/viewtopic.php?p=422182#422182

>

>

_________________
Kelly McMullen
A&P/IA, EAA Tech Counselor # 5286
KCHD

Mike Whisky

Joined: 05 Jun 2006
Posts: 336
Location: Switzerland

Posted: Wed Apr 30, 2014 12:56 pm Post subject: Re: How to eliminate noise on COMM 1 (GNS430W)

Now this one is getting interesting. 

I measured the RG-400 antenna cable and found on the antenna side that on the female BNC connector the shield and the center pin are somehow  connected, which shouldn't be the case. 

The weird thing however is, that if I measure the cable from the other side the shield and the center pin are not connected?! I tested this several times and measured connectivity of the shields on both sides which is positiv. 

Does anyone have an idea what's going on?



Thanks

Mike

_________________
RV-10 builder (flying)
#511

philperry9

Joined: 23 Nov 2011
Posts: 381

Posted: Wed Apr 30, 2014 3:14 pm Post subject: How to eliminate noise on COMM 1 (GNS430W)

Are you disconnecting it from the radio while you are checking continuity?



If it's connected to the radio, it will show a dead short when checked from the other end.



Phil



Sent from my iPhone



On Apr 30, 2014, at 3:56 PM, "Mike Whisky" <rv-10(at)wellenzohn.net> wrote:






Now this one is getting interesting. 

I measured the RG-400 antenna cable and found on the antenna side that on the female BNC connector the shield and the center pin are somehow  connected, which shouldn't be the case. 

The weird thing however is, that if I measure the cable from the other side the shield and the center pin are not connected?! I tested this several times and measured connectivity of the shields on both sides which is positiv. 

Does anyone have an idea what's going on?



Thanks

Mike



--------

RV-10 builder (flying)

#511





Read this topic online here:



http://forums.matronics.com/viewtopic.php?p=422616#422616

Mike Whisky

Joined: 05 Jun 2006
Posts: 336
Location: Switzerland

Posted: Thu May 01, 2014 10:38 am Post subject: Re: How to eliminate noise on COMM 1 (GNS430W)

Yes it was disconnected.

_________________
RV-10 builder (flying)
#511

carl.froehlich(at)verizon
Guest

Posted: Thu May 01, 2014 11:25 am Post subject: How to eliminate noise on COMM 1 (GNS430W)

If so, this pretty well narrows it down to a bad connector (braid sometimes

shorts, sometimes not).  Try mechanically agitating (wiggling) the connector

at each end and see if you can make the short go away.



Carl



--

jdriggs49(at)msn.com
Guest

Posted: Thu May 01, 2014 11:27 am Post subject: How to eliminate noise on COMM 1 (GNS430W)

I get a lot of static on my Garmin 430 and on the SL-40 when the transmitting person keys their mike. Only then. Sometimes its so loud its hard to understand them. I've tried all kinds of squelch settings to no avail. Any ideas to help me??

 	  Quote: 	
		   Subject: Re: How to eliminate noise on COMM 1 (GNS430W)

 From: rv-10(at)wellenzohn.net

 Date: Thu, 1 May 2014 11:38:30 -0700

 To: rv10-list(at)matronics.com

 --> RV10-List message posted by: "Mike Whisky" <rv-10(at)wellenzohn.net>

 Yes it was disconnected.

 --------

 RV-10 builder (flying)

 #511

 Read this topic online here:

 http://forums.matronics.com/viewtopic.php?p=422683#422683

====

aerosport1

Joined: 07 Nov 2007
Posts: 231

Posted: Thu May 01, 2014 11:43 am Post subject: How to eliminate noise on COMM 1 (GNS430W)

One thing to check is that your headset plugs are isolated from any metal that is conductive/aluminum or carbon fiber. I had the same

Problem and it was my rear head set jacks. The isolator washers were the problem. I would at least check all the headset jacks for proper

Isolation.

 

 

Geoff Combs



 

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Danny Riggs

Sent: Thursday, May 01, 2014 3:27 PM

To: rv10-list(at)matronics.com

Subject: RE: Re: How to eliminate noise on COMM 1 (GNS430W)

 

I get a lot of static on my Garmin 430 and on the SL-40 when the transmitting person keys their mike. Only then. Sometimes its so loud its hard to understand them. I've tried all kinds of squelch settings to no avail. Any ideas to help me??

 	  Quote: 	
		   Subject: Re: How to eliminate noise on COMM 1 (GNS430W)

 From: rv-10(at)wellenzohn.net (rv-10(at)wellenzohn.net)

 Date: Thu, 1 May 2014 11:38:30 -0700

 To: rv10-list(at)matronics.com (rv10-list(at)matronics.com)

 

 --> RV10-List message posted by: "Mike Whisky" <rv-10(at)wellenzohn.net (rv-10(at)wellenzohn.net)>

 

 Yes it was disconnected.

 

 --------

 RV-10 builder (flying)

 #511

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=422683#422683

 

 

 

 

 

 

 

====

 

 

 


	


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_________________
Geoff Combs
RV-10 QB N829GW
Flying 500 hrs
40033

jdriggs49(at)msn.com
Guest

Posted: Thu May 01, 2014 12:29 pm Post subject: How to eliminate noise on COMM 1 (GNS430W)

I will do that. Thanks Geoff!!

From: g.combs(at)aerosportmodeling.com

To: rv10-list(at)matronics.com

Subject: RE: Re: How to eliminate noise on COMM 1 (GNS430W)

Date: Fri, 2 May 2014 15:39:40 -0400

One thing to check is that your headset plugs are isolated from any metal that is conductive/aluminum or carbon fiber. I had the same

Problem and it was my rear head set jacks. The isolator washers were the problem. I would at least check all the headset jacks for proper

Isolation.

Geoff Combs

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Danny Riggs

Sent: Thursday, May 01, 2014 3:27 PM

To: rv10-list(at)matronics.com

Subject: RE: Re: How to eliminate noise on COMM 1 (GNS430W)

I get a lot of static on my Garmin 430 and on the SL-40 when the transmitting person keys their mike. Only then. Sometimes its so loud its hard to understand them. I've tried all kinds of squelch settings to no avail. Any ideas to help me??

 	  Quote: 	
		   Subject: Re: How to eliminate noise on COMM 1 (GNS430W)

 From: rv-10(at)wellenzohn.net (rv-10(at)wellenzohn.net)

 Date: Thu, 1 May 2014 11:38:30 -0700

 To: rv10-list(at)matronics.com (rv10-list(at)matronics.com)

 --> RV10-List message posted by: "Mike Whisky" <rv-10(at)wellenzohn.net (rv-10(at)wellenzohn.net)>

 Yes it was disconnected.

 --------

 RV-10 builder (flying)

 #511

 Read this topic online here:

 http://forums.matronics.com/viewtopic.php?p=422683#422683

====

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Mike Whisky

Joined: 05 Jun 2006
Posts: 336
Location: Switzerland

Posted: Mon Aug 25, 2014 12:53 pm Post subject: Re: How to eliminate noise on COMM 1 (GNS430W)

I just wanted to give you an update on my noise issue. Following the advice on de-activating one system after the other I was able to narrow it down to the nav lights. Long story short Aeroleds did sent me new ones and the noise is gone. Great customer service!

Regards

Michael

_________________
RV-10 builder (flying)
#511

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