I recently got a HP55300A on ebay for parts. It works fine but runs on 48V. I am going to install a AC supply inside and also place a fan on the top for cooling. I hope the air flow will not cool the OCXO too much. I am also looking for documentation. I have the User manual but am looking for the Programming Manual. Thanks Gary Neilson K5DSR

Hi At normal room temperatures, you simply can not run enough air past the OCXO to “cool it to much”. The OCXO heater will simply put out a bit more power as you increase the air flow. That’s not to say that the performance will improve any as the OCXO is quickly following any twitch or bump in the room temperature. Bob > On Nov 20, 2016, at 9:41 AM, Gary Neilson <gary@deepskyridge.com> wrote: > > I recently got a HP55300A on ebay for parts. It works fine but runs on 48V. > > I am going to install a AC supply inside and also place a fan on the top for cooling. > > I hope the air flow will not cool the OCXO too much. > > I am also looking for documentation. I have the User manual but am looking for the Programming Manual. > > Thanks > > Gary Neilson > > K5DSR > > _______________________________________________ > 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.

When I was testing the E1938A I used to run the environmental test chamber up to 85 degrees C, let the unit stabilize for a while, and then dump liquid nitrogen into the chamber to go to -55 degrees C in something like 2 minutes. The temperature inside the crystal oven fluctuated maybe a millidegree and the frequency fluctuated maybe 5 parts in 10^-12 during this event. IE, you don't need to worry about a fan blowing on your OCXO, if it is any good. Rick On 11/20/2016 6:41 AM, Gary Neilson wrote: > I recently got a HP55300A on ebay for parts. It works fine but runs on 48V. > > I am going to install a AC supply inside and also place a fan on the > top for cooling. > > I hope the air flow will not cool the OCXO too much. > > I am also looking for documentation. I have the User manual but am > looking for the Programming Manual. > > Thanks > > Gary Neilson > > K5DSR > > _______________________________________________ > 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. > >