I have a few similar thermostats, which were sold in the 70ies by KVG Germany under their P/N XT-1. The manufacturer was Northern Engineering. The oven comprises an Octal type tube socket, in the interior there are two sockets for two "HC-6/U" style crystals. The temperature control is by a bi-metal switch in series with the heater coil, which is a resistor wire wound around the cylindrical body. I had measured the temperature stability those days, the test report is still in the box ;) The thermal hysteresis of the bi-metal switch causes a periodic temperature change within 0.3 K, which is not too bad.
Best regards Bernd DK1AG www.axtal.com -----Ursprüngliche Nachricht----- Von: time-nuts [mailto:[email protected]] Im Auftrag von Dave M Gesendet: Samstag, 11. April 2015 00:48 An: Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] Vintage Crystal Oven Thanks George, I used to work in a Motorola 2-way shop. The only heated ovens that Motorola used were the 6.3V thermostatically controlled ovens. Those were used in the old tube-style units. When they went solid-state, they used TXCOs in both base and mobile units. However, I'll check them out. Never know, there might be something useful there. Cheers, Dave M George Dubovsky wrote: > I'm not sure I remember the exact one you are describing, but in the > last month or so, there was a fellow selling crystal ovens on QTH.com. > I think they were from land-mobile service, like Motorola base > stations or some such. That's another place to search. > > 73, > > geo - n4ua > > On Fri, Apr 10, 2015 at 12:37 PM, Dave M <[email protected]> > wrote: > >> Years ago, (70s maybe) I came across an empty crystal oven. I know I >> have it in one of the storage containers of old stuff in my garage, >> but I can't find it. It was a proportional oven, but was otherwise >> an empty shell, so you could put your own circuitry inside >> (oscillator, voltage reference, etc.). Several small wires came out >> of it for power, temperature adjustment, e.g. Physical size was in >> the neighborhood of 1.5x1.5x3 inches. >> As I remember, it was manufactured by one of the major crystal >> manufacturers of the day (e.g., Knight, Bliley, etc.) >> >> Does anyone remember these ovens? I'd surely like to get my hands on >> a couple or three to play with. I search the net & Ebay occasionally >> for them, but so far, no hits. >> >> Dave M _______________________________________________ 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.
