Old school 2970 won't rx when cold

[Harley3315]

I have an old school 2970 that doesn't like to rx in the cold temps up here in northwestern IL.
I would think that after 10 or so mins of the truck warming up this wouldn't be an issue but this one takes probably 20-30 mins to warm up enough to hear anything yet it transmits fine any ideas where to look?
Maybe 10 volt caps or something like that?

 

[sp5it]

VCO issue. Measure it's voltage when cold and when warmed up and operating.
Come back with result.

 

[Harley3315]

What should normal vfo voltage be 5 volts or so when working?

 

[144inBama]