Thanks as always. The difference is only about .5 to 1.5 kc. So I guess the rig is aging well. It's not so much a bother as much as me being hypersensitive about my TR-4's operation. I love my Drakes. And after starting a fire in one while trying to tune it up... I just try to watch everything and want to keep it on the air. I just love putting out a couple of hundred watts barefoot. Actually I love everything about them.
Great list... always helpful. KB8NXO On Mon, Oct 18, 2010 at 1:15 PM, Garey Barrell <[email protected]> wrote: > Richard - > > This is function of the aging of the BAND oscillator crystals. The > crystals were originally specified as +/- 0.003% tolerance, which is about > +/- 550 Hz for the 40M crystal, and up to about +/- 1.2 kHz for the 10M > crystal. So when new, the typical variation could be up to +/- 1 kHz, or > one skirt division. However, crystals 'age' over time, and the frequencies > change at seemingly random rates and directions. Most that I am familiar > with tend to drift UP in frequency, but this is not always the case. The > aging rate varies, but typically runs 6 - 8 ppm per year, or 60 - 80 ppm for > ten years. This translates to ~1.2 kHz for the 18.1 MHz 40M crystal. Forty > years means ~ 4.8 kHz..... > > IF it bothers you too much, you can buy a new set of BAND crystals from > International Crystal Mfrs, specify 0.001% tolerance, and 'fix' it! :-) > > 73, Garey - K4OAH > Glen Allen, VA > > Drake 2-B, 2-C/2-NT, 4-B, C-Line& > TR-4/C Service Supplement CDs > <www.k4oah.com> > > > > Richard Palmer wrote: > >> Should I have to calibrate my tuning skirt every time I change bands or is >> this indicative of an alignment needed? >> >> (sorry about all the rookie questions but I am a rookie) >> >> Thanks >> KB8NXO >> >> > > _______________________________________________ > Drakelist mailing list > [email protected] > http://mailman.zerobeat.net/mailman/listinfo/drakelist > >
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