[time-nuts] 8566B with Ovenaire 10Mhz oven.

J. L. Trantham jltran at att.net
Wed May 29 17:16:56 EDT 2013


I have been inside two different variants of the Ovenaire oscillators but
not the one you describe.

One was defective due to a low output amplitude, solved by changing a
resistor in the amplifier on the oscillator board, and the other was
defective by virtue of being off frequency, resolved by opening the unit,
cleaning the dust out (from the Styrofoam insulation), spinning the trim pot
for the temperature control back and forth and putting it back where it
started, then adjusting the piston capacitor on the oscillator board.

Can you post a picture?

Have you looked at the output with a scope?


-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Mark C. Stephens
Sent: Wednesday, May 29, 2013 5:45 AM
To: time-nuts at febo.com
Subject: [time-nuts] 8566B with Ovenaire 10Mhz oven.

I have recently obtained the holy grail for me - an 8566B.
They are rare as hens teeth in Australia!

I have a 8568B as well and my phase noise floor is somewhere way down there
on that machine ;)

However it appears the internal 10Mhz reference had died on the new (old)

I haven't room on the bench due to 5 things going at once so I ran it up on
the kitchen table for the benefit of the kids - they are going to inherit
all this junk I guess :p

I didn't plug an external standard in to check the rest of circuitry because
that's down in the workshop.
Perhaps I need a house standard output in the lounge? ;)

Hmm Anyway, did some quick checks and I think the voltages are all there,
but my manual has the 10811 oven assembly which the Pin outs are completely

Anyone spied a 8566B manual with the Ovenaire OSC-49-61C connections?
Or even just the connections so  I can work on the Ovenaire on the bench.

The output has a 10Mhz SMB on the right side and a row of six feed through
caps on the left.
Bottom to top

1.       Black

2.       Orange

3.       Purple

4.       Red

5.       Black

6.       Linked to pin 5.

I guess It won't be too hard to work out by tracing the circuit but I like
to leave the innards of these things undisturbed as much as possible.


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