[time-nuts] HP5061B Ion Current

https://www.febo.com/pipermail/time-nuts/2017-March/104374.html I posted another HP cesium beam tube patent at http://gonascent.com/papers/hp/hp5061/US3387130.pdf . It covers the formation of the cesium beam and should be of interest. We now have over a month of operation on our first HP5061B

[time-nuts] HP5061B Ion Current

https://www.febo.com/pipermail/time-nuts/2017-March/104374.html The patent that I posted at http://gonascent.com/papers/hp/US3323008.pdf has many interesting facts about the cesium beam tube. It says that the temperature of the cesium oven is 65° C. I researched the vapor pressure of cesium at

[time-nuts] HP5061B Ion Current

Things to be careful about! "I think the final vacuum improvement can be achieved more quickly if the cesium oven is on." The outgassing in a tube that has been off for an extended time is almost all from the oven filaments and the ionizer filament. The metal surfaces are virtual "sponges" and

Re: [time-nuts] HP5061B Ion Current

I am listening and learning. Great point on the HV supplies. When I look at the supplies I believe they are soldered cans. Is that correct? Further had not thought about the ionizer. Skips pictures of the CBT tube clearly shows a popped ionizer. There are two oven controllers AC or the DC

Re: [time-nuts] HP5061B Ion Current

John makes a good point about the ionizer filament has anyone done a 'slow start' system for the Ionizer filament? I.e. Limit the inrush current as is done for expensive high power transmitting tubes? > On Mar 21, 2017, at 9:44 PM, Donald E. Pauly wrote: > > It

[time-nuts] HP5061B Ion Current

It looks like that there is about 10% hysteresis on the cesium trip off/on. That may not be enough to prevent cycling on and off. I may not have made it clear but instability in the +3,500 voltage makes a big difference in the threshold ion current required for activation. If it fades it can

[time-nuts] HP5061B Ion Current

If you cannot get the ion current below 50ua or so after a week at 5kV then you are out of luck. Most likely you have resistive deposits on the ion pump insulator. If you can get the tube to give a decent SN at those levels then you can run with the alarm circuit bypassed. I have run tubes a

Re: [time-nuts] HP5061B Ion Current

https://www.febo.com/pipermail/time-nuts/2017-March/104374.html I could not figure out why the A15 Ion Current monitor would not let the cesium oven turn on with ion current under 25 uA. At the time we had no way of measuring the +3,500 ion pump supply. We bought some 200 Meg resistors and made

Re: [time-nuts] HP5061B Ion Current

trojancow...@gmail.com said: > We will discuss our findings if there is interest. This is time-nuts. Of course there is interest. What fraction of the old/dead tubes are "gassy"? -- These are my opinions. I hate spam. ___ time-nuts mailing

Re: [time-nuts] HP5061B Ion Current

Donald welcome to the group. If a units been off a long time and it sure sounds like thats the case it may take quite a while like a month or so for the unit to remove all of the "Stuff" that has out gassed. So be patient and let the pump do its job. After it does lower and my fingers are crossed.

Re: [time-nuts] HP5061B Ion Current

Do a search of the list and a few other sites. there is a LOT of information on what challenges one can have. And a lot of the information is practical. As for as pumping a tube down, it took me pretty much a day + a whole weekend, but it did go down to what was scribbled on the door, and now

[time-nuts] HP5061B Ion Current

This is my first post. I just bought a non-working HP5061B on eBay for $350. My old boss KB7APQ in Salt Lake City and I are working on it. It came in from the Philipines in October of 2015 and was diagnosed with a bad physics package in March 2016 by AllTest in New Jersey. We initially found