Corby, Thanks very much for this advice. It turned out the spare unit was quite OK after all. It's installed as I type, and the 5061A is locked beautifully and showing the same freq as the Z3815A GPSDO on a HP 5345 counter. A check of the "flop" parameters shows the Cs tube is nice & healthy and all's right with the world!!!
The unit had been running with the mode switch in the "Cs off" position for a couple of years so the tube was well and truly pumped down. The ion current was very close to zero. I have a Shera controller circuit built into the unused battery compartment so most of the time it runs as a GPSDO but I like to exercise the Cesium from time to time too. Thanks again Corby and everyone else who suggested ways to get it going again. Morris PS: my 5345 counter does not have the GPIB option so I can't do things like Allen plots. If anyone happens to have a junker with a GPIB card available I'd love to hear about it. > From: corby d dawson <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] 5061A ion pump P/S problem > To: [email protected] > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset=us-ascii > > Morris, > > You implied that you tested the spare module on the bench. > > You must connect the -side of the supply to the case of the module as > well as the pin. (this occurs in the unit by its connection to the > chassis) > > If you don't the supply floats and you will only read about 1/2 the > voltage out. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
