[GreenKeys] Re: RATTS

[jhhaynes at earthlink.net]

An additional problem I have observed in the field with Kenwood radios
and feeding the audio tones into the mic plug on the front panel is the
appearance of a spurious tone.  I have always been able to get rid of
it by using an isolation transformer between the computer or modem and
the mic plug.  Kenwood radios have a separate ground wire for the low
side of the mic that is different from the ground wire used for the PTT
line.

The problem seems to be RF related, as it shows up when power is 
increased.  I don't know what causes it; I only know how to fix it.
Kenwood radios have a low level mic, so I use the 1000:8 ohm little
transformer you can get from Radio Shack.  If that is too much stepdown
you can use half the primary.  Or use their 1:1 transformer.


-- 

jhhaynes at earthlink dot net