On 2 Oct 2014 07:10, "Magnus Danielson" <mag...@rubidium.dyndns.org> wrote: > > David, > > The character of starting high/low and then stabilize some 5-30 min later is typical of oven oscillators. Underdamped ovens have been seen before, I have even seen one on the brink of oscillation.
Thank you. Do you know the likely cause of the somewhat odd behaviour between about 150 and 220 s? This eBay auction, which someone posted http://m.ebay.com/itm/151256172424 says it's the high stability oscillator for an HP 8753D or 8753ES. I checked the part number at parts.keysight.comand it would appear it is the same as used in my VNA and several other microwave VNAs. That said, I have noticed a few errors on parts.agilent.com, one of which resulted in me buying the wrong part. I was later warned by Agilent not to trust the accuracy too much, especially on older equipment. It is better to check with them before making purchases. But they have a very helpful parts service that does make every effort to sort out what parts are. They spent quite some time finding out what connectors were on am obsolete cable for me. > TCXO will not have the same wide range, as it compensate for the temperature. This answers my original curiosity now - did I have an OCXO or TCXO. Although I am not going to bother, as it will be easier and more accurate to feed the VNA from a rubidium or GPS locked TCXO/OCXO, it would probably be possible to buy one of those off of eBay and replace the OCXO with a better one. Then stick it in my VNA - I would not want to modify the original one. There have some rather small double oven OCXOs on eBay recently for very little money. From the earlier comments about this oscillator, it would appear its specification is quite poor for an OCXO. > Cheers, > Magnus Thank you. Dave _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
