Scott wrote:
I'm trying to download a copy of the manual, but at the rate it's
downloading, I may have it by Tuesday, April 27th.....2013!

Anyhow...does anyone have a copy of how to set the timebase oscillator
frequency? I measure the signal coming out the back of the counter
(with another counter) at 10.000066 MHz. I adjusted the "coarse tune"
adjustment on the back of the unit and this is as close as it gets to
10.000000 MHz, so I assume there must be some other adjustment
somewhere...I took off both covers, but any adjustment control is not
blatantly obvious....

Scott
N0EDV

Scott,
I've seen the oven temperature control circuit more likely to cause this
type of problem. The fact that the oscillator is working eliminates a lot of
circuitry.

Before you do any more adjusting, do this:
Check that the oven temperature control circuit is working. Check to see if
the collector of Q1 is in the ballpark of about -21 volts. That point
should start out (cold oven) at around -5 volts or so, and go toward -21
volts as the oven warms up. If it stays at the lower voltage, you have a
problem with either Q1 or one of the transistors on the oven control assy
A25. That same reasoning goes if the voltage at Q1 collector starts out and
stays at -35 volts or so.
An extreme cause would be that of the oven heater being open. In that case,
the oven assembly is bad, and will need to be replaced. You can attempt ot
disassemble the oven and repair the heater, but it's iffy. One of the temp
sensor components inside the oven might be bad as well.
If the oven and the oven control is OK, that means that the oscillator is
out of tune. That could be caused by the crystal itself, of one of the
capacitors inside the oven.

I have an operable oven assembly that we could make a deal on, but since I
recently moved from Florida to Alabama and don't have a shop area yet, it's
still in storage. If you can wait for a couple of months, I could dig it
out for you. You might look on Ebay for an oven; I've seen them offerred
there, but not often.

--
David
dgminala at mediacombb dot net