[R-390] Testing the 2nd osc, swapping xtals

[dog]

Alan,

Thanks for taking a look at the circuit for me. Right now the discrete 
component exchange of the xtals sounds like a project, except maybe in 
the case of the few where I have really low voltage. It would be a 
project to do them all but maybe substituting one or 2 may be viable. I 
have a good supply of newer dipped mica caps and may be able to replace 
the feedback caps for the osc and also the 5000pf bypass caps and maybe 
any other thing that seems obvious. I bought a lot of 4700pf 1KV quite a 
while ago thinking of replacing a lot of them but never got around to 
it, there's a lot of them, especially in the IF. I did notice yesterday 
after the rx warmed up good, the voltages wandered around a bit. About 
an hour into it, the osc voltage dropped down significantly (maybe 5 to 
4 V) and then as it warmed up it slowly increased again, but not to the 
peak I had at about an hour into it. Not sure if that's the tube or 
components, but it also may be worth investigating. I've got about 5 
tubes I can substitute, plus the 2 in the 1st osc position for both rx.  
Right now both of them seem to be operating about the same 2nd osc 
voltage wise but of course there are distinct variations per MC. I'll 
also attempt to de-ox the bandswitch after a bit of cleaning, but it 
doesn't seem noisy or erratic at all. Right now both RXs seem to vary 
from a low of less than 2V to a max of 8. I wonder what they were when new.

I don't know why I'm doing this in the middle of mowing season, I should 
have been working on this either in last week's heat or last winter. 
Evasion I suppose.

Dave N3DT