If you install the second unit, your 5061A still won't work. +20v at the sensor output will signal the ion current monitor to shut down the electron multiplier supply.
If you have some high-value resistors around, can you make up a test 200M resistor string? If so, see what happens when that's connected across 4 & 5 of the first 3500 v supply. However, even with the failure case you describe with the first unit, I'd expect your 5061A to still work at least for a short time. Do you have beam current? If not, you might have other problems as well. Check the voltage at A15 pin 4. You should have +18 v or so. If not, more troubleshooting is in order. The danger running without a working ion pump, though, is that at eventually you'll damage the electron multiplier. Bill Ezell ---------- They said 'Windows or better' so I used Linux. Morris Odell wrote: > Hi all, > > My 5061A has failed and I've isolated the problem to a faulty A18, the +3500 > volt ion pump power supply. > > The existing one has almost certainly has had the internal 200M resistor go > open as the output voltage is about 5 kV and it does not decay quickly when > the power is off. The output voltage to the current sensing circuit is 0. > > I have a replacement which I suspect is faulty - when energised from a +18 > volt source it only produces 2 kV which decays quickly and the sensor output > is +20 when the thing is unloaded. That 200M resistor may have gone low! Is > this one worth installing ie: will +2 kV pump enough ions? > > So I'm looking for a replacement or advice from anyone who may have > attempted to repair one. > > If anyone has a parts donor of course I'd be happy to pay appropriately > including shipping down here to Australia. > > Morris > > > _______________________________________________ > 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.
