On the 3CX-6000A7? triode, the tube is 1st? hi-pot tested? between the anode and grid (and a temp short between grid and cathode).? ?Then the polarity is reversed.? ?Leakage should be < 5 ua? in both cases.? On a 3CX-6000A7, a good tube will hi pot test to 25 kv. (On a 3CX-3000A7, it should hi-pot test to 20 kv.? A? good? 3-500Z? should hi-pot test to > 12 kv)
Then the? tube is hi-pot tested between the grid and cathode (and a temp short between the grid? and anode).? ?Then the polarity is reversed.? A good? 3CX-6000A7? should hi-pot test to 5 kv? (same 5 kv with the smaller? 3CX-3000A7).The hi-pot tester has to be a DC type...and also incorporate current limiting.? ?It's an invaluable tool.? It's also used to test vac caps, (fixed and variable, glass and ceramic), vac relays, connectors, disc caps, doorknob caps, and coax connectors, and also cables...and anything else you can think of.? It just saves a lot of grief..... knowing that the parts you installed meet spec.
(I use the small, compact hi-pot tester sold by Tom Rauch, W8JI, through his business, CTR engineering.? It's a 0-15 kv DC unit, and incorporates dual current limiting.? It operates on anything from 12-18 vdc.? ?That comes in handy for a hamfest, etc.? The unit also has a red led on it to depict leakage current.? ?I use a Fluke 87 DVM, in series with the return leg, for a more accurate reading of leakage current.? ?Both methods work).
