The OCXO in my 8566B was 75 Hz out and died shortly thereafter...
I found a source of NOS OCXOs - Quest Components part?OSC92-51B-10MHZ fitted my particular 8566B.? They claim to still have a few.? They'll cost $25 (minimum line item) plus shipping... a bargain compared to other sources.
I bought some extras and have been checking them out.? The latest has settled down to 9.999 999 97 MHz compared to my GPSDO after running for a couple of months.
On Tue, Feb 22, 2022 at 6:10 PM Ed Breya via <edbreya=[email protected]> wrote:
One more quick thing - be sure the 10 MHz reference is OK, whether it's the internal OCXO, or an external source. I've had many failures of the internal reference (all oven failures) on the 8566 over the years. I've mentioned this here a number of times, and my opinion that the OCXO placement was a very poor choice, thermally speaking. It's right in the main air plenum that distributes cooling air for the whole unit, so it gets the best cooling of all, making its oven work very hard whenever the unit is running. The 8568 in contrast, has its (same model) OCXO nice and toasty, isolated in a front corner compartment.
If the reference is off frequency just a little bit - like due to oven failure - the whole system can't lock and operate.
