Background Tone (noise)

[snowyriver]

Recently I started hearing a sound when I transmit that sounds like feedback.  It started out barely audible and got worse to the point that I was unreadable to others.  Reception was fine.  I know this smacks of some kind of a ground problem and have been chasing that theory.  But....as I was messing with the grounds with the Master on, I heard the same tone, which worsened when I transmitted.  I turned off the right screen and it got quieter, turned off the left one and it went away totally.  Now I'm wondering what this means.  Anyone had a similar issue with their Skyview?  I'm up to date with versions.  Thanks,  Craig

 

[s19flyer]

I had the same issue. Not skyview but just in case.

Using Lightspeed headset and I had turned the volume up all the way on them and was adjusting the audio level with the radio. This caused feedback when transmitting. Turned them down to 50% and problem solved.

 

[Raymo]

How are your screens ground compared to your audio equipment?

My screens use the common ground point at the firewall while the audio equipment has an intermediate ground that then ties into the firewall with an 18g wire. This keeps the ground differential between all the audio equipment the same and avoid ground loops through other equipment grounds.

 

[n456ts]

Is it a humm like noise, or a ear piercing like noise? I have suggestions on finding ground loops if that would help (Not sure if that's relevant to post).

 

[jakej]

I just had a 'noise' problem with an RV when the RH taxi light was turned on, turn it or #2 Com off & noise went away.

In this case the solution was to clean ( nothing else was done) the headset plugs & the 'noise' disappeared. Go figure, those electron critters do weird things sometimes. Oh well, at least I couldn't blame the equipment or installation.
It didn't cost much to fix either ;D

 

[vlittle]

I just had a 'noise' problem with an RV when the RH taxi light was turned on, turn it or #2 Com off  & noise went away.

In this case the solution was to clean ( nothing else was done) the headset plugs & the 'noise' disappeared.  Go figure, those electron critters do weird things sometimes.  Oh well, at least I couldn't blame the equipment or installation.
It didn't cost much to fix either  ;D

Oxide films (corrosion) on electrical contacts act as diodes and will rectify RF signals. This rectification demodulates the RF and is audible as noise. In the olden days, we used a crystal of Galena (lead ore) and a piece of wire called a cat's whisker to make a crystal radio set that required no external power....same principal.

Also, the electronics in ANR headsets will do the same thing.. even when unpowered and unplugged! I can hear the ticks from my transponder this way, no connections required.

Vern