Thanks, I do not have a repair manual and I hate to abandon the signal generator after man years of positive use... Ulrich In a message dated 4/15/2016 9:14:21 P.M. Eastern Daylight Time, paulsw...@gmail.com writes:
Ulrich To your first question I am unaware of anyone that repairs them. Though there are many places that might, typical cal and repair shops. I have a sick 8662 also (age) and need to dig in. At least I know the board and the most likely issue. The yahoo user group has a lot of useful details. Regards Paul WB8TSL On Fri, Apr 15, 2016 at 7:08 PM, Dr. Ulrich Rohde via time-nuts <_time-nuts@febo.com_ (mailto:time-nuts@febo.com) > wrote: Thanks Sent from my iPhone On Apr 15, 2016, at 6:38 PM, "John Miles" <_john@miles.io_ (mailto:j...@miles.io) > wrote: >> My signal generator has a poor, intermittent power supply. The RF >> section is ok. Who can please tell me which company can and will fix these >> older >> but excellent generators? >> >> Thanks, Ulrich > > Have a look at the capacitors in the voltage divider that drives the bases of the switching transistors. There's a good chance that's your problem, and they probably need to be replaced even if not. 75-TVA1607 (Mouser p/n for Sprague TVA1607) works well. > > It would be nice to use 105C parts if you can find some, but the 85C TVA1607s have worked well for me in multiple 8662As over several years. > > The other likely suspect is one of the large screw-terminal electrolytics on the motherboard. The power supply can almost-but-not-quite start up when one of those is completely open. High ESR is very likely to cause intermittent operation. > > -- john, KE5FX > Miles Design LLC > > _______________________________________________ > time-nuts mailing list -- _time-nuts@febo.com_ (mailto:time-nuts@febo.com) > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- _time-nuts@febo.com_ (mailto:time-nuts@febo.com) To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.