In article ,
Tom Dean wrote:

I have a Yaesu FT200M which I have installed in my truck for the purpose
of transmitting an APRS signal on 144.390. Each time I set the radio on
this frequency, turn the radio off and then back on, the frequency
changes to 144.385. Turn it off and on again and it tunes to 144.380,
etc., etc.

Tom-

I suggest you use a memory channel preset to 144.390. If memory
channels are tunable, look for a setting to turn that feature off.

It is possible your frequency adjust knob is set right at the point
where it changes frequency. This could be purely random, or could be
due to a defective rotary encoder.

Another possibility might be that the radio has a CMOS battery that is
getting weak.

Fred
K4DII