[Test-Equipment] Looking for HP quartz oscillator schematic

[Carl Walker]

Greetings, all. I'm looking for schematics or component information on an HP 
00195-6013 crystal oscillator. This is one of the dark blue rectangular units 
that HP used as the reference in many of the early cesium standards, and 
possibly in the 105 series of quartz standards. The unit I have is dated 
5477, and is Series 1144A.

The one I've got has no oven at present; the "meter" output causes the oven 
monitor meter to pin at all times, and the oscillator is about 70 Hz high in 
frequency, and does not change given time to warm up. I pulled the end cap 
off the unit to reveal the PCB - and the 1/2 watt resistor near the 2N1701 
and 2N3053 has definitely seen better days; at some point, all the smoke has 
escaped from this device. There's also what appears to be a molded choke to 
the left of the power transistors - at the center and opposite edge of the 
board - that has also run a wee-bit too warm. I can't identify the intended 
value of either of these components.

If someone has data on this unit, or has one that's out in the open where the 
end cap can be removed without too much trouble, I'd be much obliged if you 
could pass along what the values of these devices are supposed to be. If 
you've got a schematic, that would be great - and would probably help in 
bringing this unit back to life (but if worse comes to worse, I can always 
take it apart a little further and trace the circuit out, provided I can find 
the original values for the smoky components). If a photo of the board would 
help in pinpointing the components in question, I can take one and send it 
along.

Thanks again,

-Carl, WA1RAJ