Tom, I don't have any FTS CS units but I would be suspicious that the 'ion pump voltage' of '0' really means that the ion pump current is 0. And, if so, I would be very suspicious of a dead HV supply or a shorted tube.
If it's anything like the HP units, you should be able to disconnect the CS tube from the HV supply and measure the HV supply directly from the connector on the chassis and, from the wire from the tube, measure the resistance from the HV wire on the tube to ground. On the HP units, HV should be about +3500 VDC and the resistance should be infinite. If the HV is absent, it's a HV supply problem and if the resistance shows a short, you might be able to 'open' it by using the HV supply to charge a HV capacitor then connect that to the tube (be careful, HV really can hurt you) and see if it might 'blow' open the short (I was able to do that to 'resurrect' an HP tube). Good luck. Joe -----Original Message----- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Tom Miller Sent: Tuesday, October 01, 2013 8:53 PM To: Tom Miller; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] FTS 4060 Cesium Time & Frequency Standard, Datum Update. I received the FTS 4060 unit and guess what - it does not work. So a few questions to the experts on this list- 1) How can I verify that the CBT is in fact bad? Is there any easy way to confirm the high voltage supplies are working short of pulling the CBT assembly out and making direct HV measurements? How about the other tube functions? There is no beam activity on meter 3 and the ion pump voltage is 0. 2) If it is a bad tube (likely), is there any way it can be rebuilt? Does anyone do such a thing? 3) Is there any source for used tubes? 4) If this is a dead end, is there any value in the rest of the unit? This one has the display clock and the 5 MHz and 100 kHz options. Or should I just bury it in the back yard and lick my wounds? Regards, Tom ----- Original Message ----- From: "Tom Miller" <tmil...@skylinenet.net> To: "Discussion of precise time and frequency measurement" <time-nuts@febo.com> Sent: Tuesday, September 24, 2013 7:10 PM Subject: [time-nuts] FTS 4060 Cesium Time & Frequency Standard, Datum While we are on Cs standards, is there technical information (service manual) available for the Datum FTS 4060 Cesium Time & Frequency Standard and its options? Thank you, Tom _______________________________________________ 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. _______________________________________________ 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. _______________________________________________ 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.