[1000mp] Cooling fan causes buzz in transmit audio on Mark V

[Pete Smith]

At 08:56 AM 10/25/02 -0400, you wrote:
>It looks like whenever the cooling fan in my Mark V runs, it
>causes a buzz in the transmit audio.  It happens with a MD-100
>and Heil Goldline.  The only connections to the radio are:
>Antenna, mike, external speaker and earth ground.  Does anyone
>else have this problem and/or a fix?  Just starting to trace out
>the fan circuitry in the service manual to see if some by-pass
>caps or shielding of the fan wires might be needed.

This may be too easy, but is it possible that you're running too much 
compression?  My Mark 5 fan makes quite a lot of acoustic noise, and it 
isn't hard to imagine a microphone picking it up if the gain were high enough.


73, Pete N4ZR
Sometimes a tower is just a tower