I think that these pages can help you: http://www.timeok.it/wp-content/uploads/2015/09/First-aid-when-you-buy-an-hp5065A-v-1.2.pdf http://www.timeok.it/wp-content/uploads/2015/09/First-aid-II-when-you-buy-an-hp5065A-v-1.0.pdf Luciano From "time-nuts" time-nuts-bounces@febo.com To "time-nuts" time-nuts@febo.com Cc Date Sun, 25 Sep 2016 18:42:50 -0700 Subject [time-nuts] HP 5065A questions Hello time-nuts, I have recently had the opportunity to play with an HP 5065A rubidium standard and have some questions. This unit has been powered down for quite a long time, it appears to be almost working. I can see both the 137Hz and second harmonic signals but they seem very low. In the manual (the one from KO4BB.com) in section 3.9 (pg 3-1) there is a procedure to apply a 1A current through the TEC until the 2nd harmonic comes back (due to cell flooding). 1. What the heck is rubidium cell flooding, and how does the TEC in the 5065A fix this problem? None of the -many- rubidium oscillators that I have been inside before has a TEC, and I have never seen the subject addressed. The manual suggests that it may take several weeks at the 1A current to fix the problem (normal operation of the 5065A applies .7V across the TEC). 2. When the coarse oscillator control is swept across 5Mhz (open loop) the 137Hz ERROR signal swings about +/-8 on the meter. This seems low (and may be related to this flooding issue). Just wondering what others have seen on their units? 3. On page 5-15 of the manual it says to adjust A7R29 for a 2nd harmonic voltage of 4V at A14(1). In the section on A14 on page 8-61 the table states that the normal A14(1) voltage is 8V. So which is it? Granted the 2nd harmonic won't extinguish the CONTINUOUS light until it falls to less than about 1.1V. I'm also curious about the level of the 60MHz signal feeding the Rb cell. This unit has several volts of RF, which appears to be plenty, but just wondering if anyone has any baseline information. Also, any hints about the care and feeding of the HP 5065A would be welcome. Thanks in advance. Regards, Skip Withrow _______________________________________________ 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.

Thanks for the link to those handy documents, Luciano. I have a serial 1420A that I plan on resurrecting once my lab is built. Since seeing the capacitor warning, I checked it just now and sure enough, 1 capacitor had vomited on the PCB, so I've removed it and cleaned the PCB ready for replacing all the suspect caps in the future. My one has H89 option installed, and a extra output at 4.433MHZ = PAL TV subcarrier frequency. So I suspect that is what option H89 is. Cheers, Andy On 26/09/2016, at 6:58 PM, timeok wrote: > > I think that these pages can help you: > http://www.timeok.it/wp-content/uploads/2015/09/First-aid-when-you-buy-an-hp5065A-v-1.2.pdf > http://www.timeok.it/wp-content/uploads/2015/09/First-aid-II-when-you-buy-an-hp5065A-v-1.0.pdf > > Luciano >