[SignalOne] CX11A warm up drift

[Bob Sullivan]

Bob,

I have two CX-11A's .. .one with the TCXO and one without. They both drift 
pretty much like what you have described. I live with it by simply letting 
the -11's warm up! I only mention this since a "new" TCXO" may not solve 
the drift problem.

Other than this somewhat irritating warm up drift the CX-11A's are 
certainly great fun to operate!

73, Bob
WØYVA
Personal site: http://www.isquare.com/personal_pages/ras-hardware.htm



At 01:32 PM 6/25/2007, RZaepfel at aol.com wrote:


>This list is for discussions regarding collecting, repair, use and sale of 
>Signal/One radios and accessories.
>
>Documentation on Signal/One radios can be found at 
>http://www.hamanuals.com and several other sites on the Web.
>
>.
>
>Greetings List!
>
>My CX11A (late production -- May 1981 according to Paul's reckoning)
>exhibits excessive warm up drift with concomitant readout inaccuracy. From 
>a  cold
>start the readout displays about 400 Hz high and slowly, over about 
>two  hours,
>comes to rest at the correct indication. The radio has the adjustable 10  MHz
>plug-in oscillator board and I know that the 10 MHz is moving with time and
>temperature. I experimented with a resistor glued to the 10 MHz crystal to 
>act
>as a rudimentary oven, it helps, but the drift continues. I replaced the +15
>and  -15 volt regulators recently and checked the synthesizer and bfo. They
>seem to  be at spec. The 34.2 MHz oscillator in the bfo box comes to rest
>quickly as the  oven warms to temperature. It's quite possible that silver 
>micas in
>the 10 MHz  oscillator are getting "old" and moving a bit with temperature
>change.
>
>Your thoughts and experiences are welcome. A TCXO would be a good
>acquisition. Should anyone on the List have a TCXO for the CX11A that they 
>wish  to
>sell, please contact me.
>
>Bob K4HJF
>
>
>
>
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