[Kenwood] TS-940S: AF Tune control operation unstable (oscillation at some points) - advice?

[k3ac at aol.com]

OK Dave - Great!  It's always nice when a problem is easily resolved like that. I AM a CW operator and the 940 filtering is so good using the VBT, etc, that I rarely used the AF TUNE (so had a feeling it was a corrosion issue).


enjoy/73,Bob, K3ACIn a message dated 12/3/2018 7:13:17 AM Eastern Standard Time, wb0gaz at yahoo.com writes:
As it turns out, that WAS the problem! 
The original owner since new was a phone op, I never used it before, and after rotating the control through range about 20 times, the problem disappeared.
Thanks!
Dave
--------------------------------------------On Sun, 12/2/18,  <k3ac at aol.com> wrote:
Subject: Re: [Kenwood] TS-940S: AF Tune control operation unstable (oscillation at some points) - advice?To: wb0gaz at yahoo.com, kenwood at mailman.qth.netDate: Sunday, December 2, 2018, 10:52 PM


Dave - well, theAF Tune pot on the 940 is not used very often (at least Idon't recall using it much when I had my 940 onCW)  so I suspect (at least an initial step) that itmay have developed some corrosion internally. Are you ableto get to it at all without removing front panel? If so,might be worth shooting a little Caig FaderLube (not DeOxit)inside and working the control to see if that improves theinstablity/oscillation. Getting to the opening of the caseunder the solder terminals can be difficult but you may beable to get a thin straw-like applicator close enough to getsome of the lube inside.

Bob,K3AC


In a message dated 12/2/2018 10:35:40 PM Eastern StandardTime, kenwood at mailman.qth.net writes:



Have TS-940 S/N 7M range. In CW mode, with AFTune button active, adjusting the AF Tune control results insome apparent oscillation or similar instability. There is atunable gain/level peak (I think normal operation; I'dnot ever tried that control before on a TS-940), however,rotating the control across the range also producesunstable, sharp (and fairly loud) audio tone artifacts atsome points.

Advice request - does this sound familiar toanyone? I'll have to open it up anyway for another issue(the backup battery is also now dead), but would like avoidreinventing the troubleshooting wheel if this is otherwise aknown type of issue.

Thanks,

Davewb0gaz at yahoo.com______________________________________________________________Kenwood mailing listHome: http://mailman.qth.net/mailman/listinfo/kenwoodHelp: http://mailman.qth.net/mmfaq.htmPost: mailto:Kenwood at mailman.qth.net

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