test data for tv7d/u and Hickok 539c
- Thread starter yewhlock
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audiodyssey
A Journey without end...
TV-7d/u = HS53481 FIL=6.3V BIAS=12 RANGE=D (I think the minimum is 38)
However, these tubes can't be accurately tested on the TV-7 with the plate voltages the TV-7 provides. You are going to see the fuse light pretty brightly with stronger kt88's...that's them sucking the life out of your tester =)
However, these tubes can't be accurately tested on the TV-7 with the plate voltages the TV-7 provides. You are going to see the fuse light pretty brightly with stronger kt88's...that's them sucking the life out of your tester =)
Jim McShane
Well-Known Member
Just for the record...
I test KT-88/6550 tubes on my TV-7 just fine. It should be said that I use a solid state sub for the 83 tube. But I never get any fuse lamp action to speak of. And while it's true that like almost any other tester, the TV-7s don't put "normal" plate and/or screen voltages on the tube, it tests the KT-88 as well as it tests any other tube. I have modified my TV-7B to be able to read plate current and voltage of a tube under test.
When you read plate voltages on a TV7 keep in mind there is very little filtering of the supply (IIRC just a .0027 uf cap) so the meter you use to measure needs to be up to the task.
Also, the fuse bulb glowing is not an indication of a problem, it's just an indication that the tester is drawing heavier current. It doesn't do any harm whatsoever to the tester.
With the SS "83" in place I can even test 6336 tubes on the TV-7 - I just start with a low line voltage setting and bring it up slowly as the tube warms and the heater current falls.
If you are having problems with KT-88 testing you might want to check the condition of your 83. The SS devices offer lower impedance than even a healthy 83 though - and you eliminate 2.5 amps of heater current and the resultant heat "under the hood".
