[Heathkit] IM-25 problems

[Edward B Richards]

Hi Guys;

I have 2 of subject TVOM's. I like them because they have more scales
than most VTVM's; 9 voltage, 7 resistance and 11 current. The low voltage
scales (.5 & .15) are handy for nulling SSB carriers and neutralizing
transmitters during alignment. They can be battery powered, a feature
that I have not used yet. They also have separate switches for the
voltage, resistance and current ranges, with a function switch to select
which one is being used. That way you don't have to change the voltage
range to read resistance, etc.

The problem is that both of them drift. I have to keep taking them apart
and re-calibrating the functions. They also drift during the first hour
of use. Does anyone have a cure for this? maybe a voltage regulator for
the AC power supply? Anything that would make them more stable. Thanks
and 73.

Ed Richards K6UUZ