[R-390] 2nd osc again

dog agfa at hughes.net
Tue Jul 23 10:15:05 EDT 2019


Thanks guys. I did check for 2 max tuning points on the osc caps, I knew 
that much from other experience. Not sure I checked them all, but the 
majority of them have 2 peaks and they are not right next to each other 
so I don't think there's an issue there. I was surprised that tuning 
T401 resulted in such a difference in some of the RF tuning though. I'll 
go through all the xtals and make sure there's no outliers. Other thing 
I can do which I did on the other RX is pull each xtal out, clean the 
pins and sockets and give them a bit of de-ox. May or may not help. But 
I think I'm getting close, but I wish I had some better 6AK5's. I don't 
think any of the tubes will come up to the -4.5VDC as a minimum across 
all the bands but like I said there are also some -10V in there too. At 
least the majority of the RF was not mis-tuned to a large degree. Only 1 
or 2 of the RF slugs were way off.




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