[R-390] R-390 PTO Warmup Time

[SCOTT Barry]

While I know the manual states that the receiver should be allowed to 
warm up (30 minutes?), I wonder how long it should take for the PTO to 
stabilize.  I have the PTO out and monitoring the frequency from cold 
and it takes quite a while to stabilize - maybe 15 or 20 minutes.

It climbs until it reaches a certain frequency and then starts very 
slowly up and down a few hundred Hz before settling down to a reasonably 
stable frequency.  Before I took it out, I was seeing end-to-end about 
1,000,001.5 kc so I thought it may need a touch-up on that; however, I 
don't think I had let it warm up sufficiently because if I let it warm 
up a good while, it is much closer to 1,000,000kc end-to-end 
(approximately 1,000,000.300kc), hence my wondering about warmup time.

Any thoughts on this?  Would running the oven for about 10 minutes and 
then turning it off help stabilize it faster?

Thanks,
Barry - N4BUQ