RCI 2970 SCRATCHY AUDIO

[TonyV225]

I have a 2970 I just picked up its not the DX its an orange faced older model. The problem is the thing has really scratchy audio no matter what mic is put on it I tried the stock one a d104 desk mic aswell as the m6b handheld sadeltas turners cobra they all have a distorted scratchy sound its pretty bad now theres a switch on it to turn off the internal amplifier and when you do that it clears up now Im thinking by the way it sounds its as if rf is getting into the audio circuit have any of you seen this or heard a 2970 do this? Ill send it out if I cantfigure it out its no big deal but I just want to clear it up so I can run it it will make a nice extra 10 meter unit. Any help or ideas appreciated....Tony

 

[ExitThirteen]

Quick question, is the audio scratchy at lower mic gain, or does it clear up? If it's scratchy at low and high mic gain, it could possibly be a dirty relay, or an impedance mismatch caused by one of the finals on the amp board either being weak or faulty.

Check all components on the amp board, make sure nothing's burnt, make sure all solder joints are solid. Is the cover over the amp board still in place, and all wires are in good shape, no kinks, cuts, or broken shields? If so, I don't think the dirty audio would be caused by an RF bleedover problem, I'd check the relay and finals.

Hope this helps you get going in the right direction.

-Exit

 

[W5LZ]

That "scratchy" name is a sort of 'lump them all together' type phrase, is used for a lot of things that really aren't 'scratchy' audio. I honestly don't know of any way to distinguish between audio problems without hearing it. But, in general, any 'scratchy' sound is usually the product of a bad connection of some type. ExitThirteen's suggestion is the way (at least one of them) to find the 'problem'.
- 'Doc

 

[TonyV225]

Im thinking its in the amp section though because when I turn the internal amp off via an added switch it clears right up and if you monitor on another rig as your keying the mic and talking SSB you can switch the amp on and the distortion sounding audio kicks in or takes effect allthough I never tried it on AM . Well Im busy till tuesday so Ill tear it down then and see if I cant figure it out but its deffinately when its under load through the amplifier section so this should be fun lol. Anyways Ill just send it out if need be and have it all done up I know this clarifiers not cut either so if I really want that done Ill do it also but these have the shift abillity so that takes care of that issue anyways. but this audi is a must to fix. So if anything Ill find someone good with these chassis radios and have it all tuned and realligned maybe even a speach processor if its worth doing. I want to use this for 10 meters. Thanks for the suggestions......Tony