[EMAIL PROTECTED] said the following on 10/10/2007 02:17 PM: > In a message dated 10/10/2007 11:13:21 Pacific Daylight Time, [EMAIL > PROTECTED] > writes: > >> We first built a small proportional heater circuit that we could shove >> in next to the crystal, and that worked OK. We finally found a source >> for thermistors spot welded to a spring clip that would mount snugly >> directly to the crystal case. With 12 volts applied, these heated the >> crystals very nicely. With the heaters, we were able to keep the >> systems running year round with about 1/10 the service calls. > > Hi John, > > interesting anecdote! > > Would you know if the thermistors are still available? Who made them?
We bought them as a replacement part from Yaesu USA. This data is 10 years or more old, but here you go: Part Name Yaesu Part Number Murata Part Number Posistor G9090019 PTH507A01BG330N020 They used to be about $7.00 each. Yaesu's parts-order phone number at the time was (800) 255-9237. I'm not sure if there's another source for the Murata part; back then, we couldn't find one. Amazingly, I still have a web page documenting all that we learned about those cursed radios, including the schematic of our original homebrew heater design: http://www.febo.com/hamdocs/d4art.html. The quality of the heater schematic isn't very good, but it's all I have. John _______________________________________________ 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.
