Hi Kurt, A good (or at least gas free) 4-1000A should exhibit less that a uA of leakage up to 20KV. Check it cold. Also ensure that the glass is clean prior to the test. 73 & Good afternoon, Marv WC6W -- "Kurt Lacko" <uncrichie@comcast.net> wrote: I have a 4-1000 tube of questionable origin. I don't have an amplifier to test it and before asking someone to drop it in their amp I want to test as best I can first. My Hi Pot setup goes to 10KV. What voltage should I be able to go to (grid/anode)and what would be an acceptable leakage (in micro amps)at that voltage? Should this test be with or without energized filaments? Anything else I should do or know about. Thanks in advance, Kurt... _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps ________________________________________________________________________ Try Juno Platinum for Free! Then, only $9.95/month! Unlimited Internet Access with 1GB of Email Storage. Visit http://www.juno.com/value to sign up today!