[time-nuts] Old crystal

[vilgotch1 at gmail.com]

They might be for an older version of the 5110A. Mine has a packaged 5 MHz
TXCO like the one in the early 5061A. That 5100A/5110A combo was a real show
stopper when it came out. Mine still works nicely when I switch it on but
it's not really practical for most purposes. It does all the frequency
synthesis from  about 0.01 Hz to 49.99999999 MHz by algebraic methods with
no PLLs. There's a digital interface that allows computer control presumably
for early work on fast frequency hopping etc, 

I have a couple of functioning HP 524 series vacuum tube counters and they
both have ovenised octal based vacuum mounted crystals that look like the
ones in the pics. One is 100 Kc and the other 1 Mc with a vacuum tube
regenerative divider to get down to 100 Kc. It has a couple of neon bulbs in
a relaxation oscillator arrangement to kick start the divider when you
switch it on!

Morris


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I just took a quick look. I have four of these ovens, definitely marked for
the HP5110A. One is partly disassembled so the crystal can be pulled. It
looks very much like the one in the picture that Jeremy put up. There are
two quite large mica caps mounted on a disc-shaped board along with the
crystal's (two) soldered leads. That's all that goes inside the oven. The
envelope definitely looks like an octal tube type, and the crystal is
double-convex - you can see it edge-on, or tell by looking at your
reflection from either side. The surfaces appear to be gold plated. The bulb
of this one appears marked with "35" and "01" 
(or"10").

So, if you look up the HP51110A, you'll find a workable oscillator circuit.

Ed