[TenTec] Model 1220 frequency jump fix

[wb2vuf@qsl.net (Bwana Bob)]

A strange problem with my 1220: When using repeater offsets, release the
PTT and instead of going back to the receive frequency, the rig goes to
the input (transmit frequency). Key the radio again and it may shift
another 600 kHz lower. Only cure is to recycle power.

I tried another mic and had the problem less frequency. I suspected
contact bounce on the PTT line was fouling up the processor. I added a 1
uf cap across the PTT line to debounce it, but it had no effect. Then I
tired squirting Deoxit into the PTT switches on both microphones and
that cured the problem. 

Does anyone know of another fix for this? I may try a bigger cap across
the PTT line, although with the cleaned PTT contacts, its working fine
now.


                                73,

                                Bob WB2VUF