[Elecraft] RFI in audio chain

[Joe Subich, W4TV]

> You have now eliminated the problem from causes in your station
> layout and the antenna/feedline to the K3 - as the complete same
> using the 730 works fine. True?

Not true ... the Icom uses an electret mic, not the dynamic Audio-
Technica.  If the microphone is wired correctly, the issue is in
the antenna system and probably requires improved common mode
decoupling.  Air wound solenoidal chokes are not sufficient in
the most intractable cases *like elevated verticals*.

Replace the elevated vertical with a dummy load.  If the RFI is
eliminated, the problem is in the antenna system.

73,

   ... Joe, W4TV


On 11/24/2015 7:00 AM, Bill wrote:
> 1. I have printed out Joe's directions and placed them in the K3 file -
> for future reference.
> 2. Is you K3's chassis connector OK - loose ground?
> 3. Have a proper ground from the K3 to your station ground?
> 4. You are using the same feedline to test the K3 as used to test the
> 730? If not - do so. Everything needs to be eliminated.
>
> You have now eliminated the problem from causes in  your station layout
> and the antenna/feedline to the K3 - as the complete same using the 730
> works fine. True? Then the problem is with the K3 or something attached
> to it.
>
> 5. Disconnect everything from it except power, antenna, and mic. Test
> it. All clear - the RF is coming in on something other than the mic
> (plugged into the K3). Problem still there?
> 6. At this point, try an alternate mic and see if it works. If it works
> good - the problem is the mic/mic wire/connector. If it does not and you
> still have RFI - walk away for a while and cool down.
>
> Just a few simple steps that would apply to any radio in a similar
> situation.
>
> Bill W2BLC K-Line
>
>
>
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