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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: How Many Chronometers?
From: Gary LaPook
Date: 2009 Sep 15, 17:34 -0700
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From: Gary LaPook
Date: 2009 Sep 15, 17:34 -0700
I remember when I first got involved with radios back in the '60s that I coveted a high end radio that had an "oven" to keep the oscillator crystal at a constant temperature to keep the radio frequency from drifting as the crystal changed temperature. I now think, however, that that was mainly "a self inflicted wound" due to the tubes (valves) in the radios having "heaters" to "boil off" electrons from the cathodes in order to make the tubes function which caused the radios to change temperature a lot and to run quite hot. The young guys won't remember waiting for a radio to "warm up" before it would start working but us old timers will remember the orange glow coming out of the back of the radio from the glow of the "heaters" in each tube. I clearly remember warming my hands on cold nights over the hot radio. I now wonder if the much less extreme swings of temperature that would be expected in a wrist watch, or by a watch kept in an insulated box below decks, would make a large change in the watch crystals' resonant frequency affecting their rates in any significant way. So I have decided to extend my experiment. I have just placed all thee watches in my freezer which is at -7º right now (along with the recording thermometer) and will see what the rates are after three weeks and I will report back then. gl --- On Tue, 9/15/09, Werner Luehmann <wksj.luehmann@t-online.de> wrote:
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