[time-nuts] ancient OCXO info on HP 05110-6043 needed

Rex rexa at sonic.net
Tue Dec 27 18:17:05 EST 2011

The description sounds the same as the crystal oven in a 5245L counter. 
Part number for one I have is 5243A-69A. I suspect the operation may be 
the same if you can find docs for the 5245 counter. The crystal is 1 MHz 
and the oscillator circuit was external to the oven unit connected 
through the 4 feed throughs. There is a thermistor bridge in the oven 
and a heater resistor connected through the ribbon cable.

On 12/26/2011 12:19 PM, ed breya wrote:
> While looking for something in my OCXO department I ran across this 
> old piece from the 1960s. I had saved it from an HP5110 synthesizer 
> carcass years ago, but only the crystal oven unit remained - no 
> oscillator or control circuits.
> Just thought I'd ask here if anyone has info or a source of a 5110 
> manual that may have enough info to see what the rest of the circuitry 
> was, and if it's worth fixing or reusing. The part is HP 05110-6043. I 
> don't recall ever seeing anything about this oldie anywhere.
> It's a cylindrical type, about 2.25" OD, and 5" long, with four teflon 
> feedthroughs on the side for the crystal circuit connections. Also out 
> the side runs a light gauge ribbon cable with six lines black, green, 
> orange, blue, gray, and red, presumably for the heater circuitry.  On 
> the side near the far end is a small plug cap, presumably covering a 
> temperature adjustment pot or thermostat. The crystal itself is huge, 
> mounted inside a vacuum tube envelope. Judging by the size of the 
> crystal and the big mica caps with it, I'd guess it's 1 MHz.
> Ed

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