At 11:38 AM -0800 12/11/07, Eric Fort wrote: >I'm looking for a fairly basic, relatively simple 10 Mhz PORTABLE >reference (probably quartz based) with enough stability over a period >of a week of outdoor temp extremes to keep a 47Ghz transmitter locked >within 100hz while mountaintop contesting. Suggestions are >appreciated. something that is small and ran off 12 volts dc (car >battery) would be a definite plus. > >Thanks, > >Eric
Eric, It's interesting to see all the suggestions. There are many ways to achieve this goal. It is always a good plan to use the existing environment to your advantage. However, the environment on a mountaintop is not exactly conducive to maintaining stability of an OCXO, so you have to look at the environment that *you* are living in. I assume that you will be on this mountaintop all week, and that you will have a source of warmth and fuel and electricity, and that you will be near the radio when doing your transmissions. Since your body will maintain its internal temperature at 37C, why not take advantage of that to keep your OCXO warm? I am thinking of an HP hockey puck oscillator, the E1938A or whatever it was that Rick Karlquist designed. It's apparently a very good oscillator. You could slip it into a pocket you would sew in your long johns in the armpit or groin area. That should keep it toasty-warm at all times. You can power it with a Li-ion battery pack kept in another pocket in not quite such a private area. You'd want to have about three of these battery packs on hand, one charging, one ready to go, and one in use. You'd also want the oscillator to have two power pack plugs with steering diodes built in, so you could do a hot swap of batteries. The result of all this is that the oscillator's temperature and power supply voltage would be nearly constant. Those are conducive to stability. The only unstable part of the environment is physical motion. Just sit still when you're transmitting! -- --David Forbes, Tucson, AZ http://www.cathodecorner.com/ _______________________________________________ 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.
