John, You can manually de-gas the ionizer and oven filaments. It looks like you had already brought the oven up to temp so just work on the ionizer. You can bring the voltage up slowly and keep watch on the ion pump current so it does not get too high. Once you have got it up to the rated voltage and the pump current is low you can bring up the oven. You do not need to provide the RF to test and see if the tube has a response. Once you have the oven and ionizer up and running and applied a DC C-field current, (I'd have to look up the current you need), the adjustable mass spectrometer voltage (the ionizer supply floats on this), and the -2000VDC EM voltage you can apply a 1/2 zeeman frequency signal to the flop coil and while adjusting the freq and voltage look for the peak. Once you see it adjust the mass spectrometer voltage (max +18VDC) for a peak. If you see the peaks during this portion you can then remove the 1/2 zeeman frequency signal and start trying to input some RF. Good Luck! Corby ____________________________________________________________ Click here to learn more about nursing jobs. http://thirdpartyoffers.juno.com/TGL2141/fc/PnY6rw2bVNXskC2QqZapymUmiigw1hCMYMFBPyE8ZaGYNuZa5smqt/

Actually your earlier advice proved golden. I believe I've been able to verify that the tube is at least within throwing distance of its factory spec (see test results at http://www.ke5fx.com/cs.htm including the configuration details). I haven't tried playing with the low-frequency test coil at all but it doesn't appear that it'll be necessary to mess with it. Much appreciate the help. Any objection to posting copies of your two emails on the web page? -- john, KE5FX > John, > > You can manually de-gas the ionizer and oven filaments. > > It looks like you had already brought the oven up to temp so just work on > the ionizer. > > You can bring the voltage up slowly and keep watch on the ion pump > current so it does not get too high. > > Once you have got it up to the rated voltage and the pump current is low > you can bring up the oven. > > You do not need to provide the RF to test and see if the tube has a > response. > > Once you have the oven and ionizer up and running and applied a DC > C-field current, > > (I'd have to look up the current you need), the adjustable mass > spectrometer voltage > > (the ionizer supply floats on this), and the -2000VDC EM voltage you can > apply a 1/2 zeeman frequency > > signal to the flop coil and while adjusting the freq and voltage look for > the peak. Once you see it > > adjust the mass spectrometer voltage (max +18VDC) for a peak. > > If you see the peaks during this portion you can then remove the 1/2 > zeeman frequency signal > > and start trying to input some RF. > > Good Luck! > > Corby