I just looked at eBay and most everything suitable is well over $200. -John
============ > The small Bertan modules in particular are extremely stable and > well-behaved. You get exactly the voltage that you program, accurate to > within about a tenth of a percent. No spikes, no drift, and no obnoxious > AF > whine like you get from the HP modules. > > The smaller ones are good for 500 uA, and the larger modules are good for > 2-5 mA depending on model. > > -- john, KE5FX > >> -----Original Message----- >> From: [email protected] [mailto:[email protected]]on >> Behalf Of J. Forster >> Sent: Sunday, January 17, 2010 8:00 AM >> To: Discussion of precise time and frequency measurement >> Subject: Re: [time-nuts] 4 KV Power Supply Recommendations >> >> >> The small modules are nice, but many PMT supplies do not go to 5 mA. 5 >> mA >> @ 4 KV is 20 Watts output, more at the input. That's a lot for a PMT >> supply. >> >> Also, remember that some supplies designed for gas lasers have a HV >> "kick" >> at startup that may go to 20-30 KV. >> >> -John >> >> ============== >> >> >> > >> >> Since it appears to be making some progress, I'd be tempted to just >> >> continue. The pump rate of an ion pump varies with the current, so it >> >> seems you are pumping, just somewhat more slowly than w/ the external >> >> supply, as long as you are not overloading the internal supply. >> >> >> >> If you don't have a lab supply, get an old transformer from some >> vaccum >> >> tube gear and use the HV secondary to drive a Cockroft-Walton >> multiplier >> >> to get to what you want. Pretty trivial to build these days. Put the >> >> primary on a Variac to adjust the voltage. >> >> >> >> BTW, a commercial supply at that voltage and current is going to cost >> >> several hundred dollars. >> > >> > The nicer Glassman rack-mounted supplies are spendy, but smaller HV >> > modules >> > for PMT and laser work are common and inexpensive. Go to eBay >> and search >> > for "<manufacturer> supply", where common manufacturers include Emco, >> > Bertan, Spellman, Fluke, and Glassman. E.g. item 220539685243 . >> These >> > smaller modules tend to sell for well under $100, and are handy to >> have >> > around. >> > >> > -- john, KE5FX >> >> >> >> _______________________________________________ >> 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. >> > > > _______________________________________________ > 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. > > _______________________________________________ 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.
