Audio circuit squeal!!!

[jetman]

It's a Galaxy 44hp. When I turn up the volume, you can hear an unstable squeal start to build up. Was wondering if anyone has seen similar issues and can remember their fix. Doesn't happen in PA or FM mode.

 

[Robb]

Have you tried cleaning the vol pot with some pot cleaner yet?

Does the shaft on that pot have any play/wobble?

 

[fourstringburn]

I imagine it does it only with the talk back volume on and using an external speaker. Turning the talk back off is the simple way to fix it. Do you really need to hear yourself?

Other than that, move your external speaker further away or what worked with me with the same issue in a mobile install was to put a ball cap over the external speaker. This worked without muffling the audio much.

 

[BBB]

Talk Back = Feedback. Don't run it except to set your reverb, then turn it all the way down or off. If its locked on, disable it. If you want to listen to your output audio, get a separate walkie talkie CB and a set of totally sealed head phones.

Sometimes RF feed back can be cured by adding Snap on Ferrites (or chokes as they're sometimes referred to) just clipped on right were the mic cable goes into the radio. I wish I had a dollar for every time I preached that OTA and it helped someone. Search up "Ferrites Snap On" on Amazon. This site will not let me paste those links.

If your VSWR is too high, you could experience feed back. This can be checked with an SWR meter and should be below 3 when keyed with the mic gain all the way down.

A voltage sag or low current power situation can cause similar audio problems. Is your power supply up to snuff? A 3 amp supply may not be enough.