Fred, Thanks for the info. I suspect the piston capacitor is on the oscillator board, along with the crystal. I suspect the trim pot is on the oven assembly. At least that was the way it was on the OSC 49-38C I opened. I did not have the courage to separate the oven control board from the oven assembly either. You would need to disconnect two heating coils along with a TO220 type transistor from the board and assembly. I suspect the trim pot adjusts the temperature to be able to find the lowest temp-co point of the crystal but I do not know.
I would love to hear more about that circuit if anyone has ever 'autopsied' one. Joe -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Frederick Bray Sent: Saturday, May 11, 2013 10:43 PM To: [email protected] Subject: Re: [time-nuts] OXCO Issues -- Latest Okay, I thought that perhaps the heating element wasn't working, so I pulled the oven apart. In fact, the internal unit was warm and it got hot when I ran it for a couple minutes w/o the foam around it. All of the solder connections which I can see look good. I am not sure I want to try to remove the internal PC board. There are two adjustments visible once it is apart. One is a trimpot and the one that you can normally adjust with the case closed appears to be a piston type capacitor. It actually appears to be better constructed than I thought. I'll take a few pictures tomorrow for those who asked. Fred _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
