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Peter Wieck Peter Wieck is offline
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Default Restoring a TV-7/U Tube Tester

On Tuesday, October 24, 2017 at 1:29:53 AM UTC-4, wrote:
The type 83 can operate horizontally just fine, but in one plane, which the TV7 socket position does for you. Think filament sag as they heat up. In one direction, they will have more space so as not to touch the anodes.

Also, the link given for an 83 solid-state replacement will not work properly. You need to re-create the 15v drop the 83 has. Search for 83 replacements using zener diodes. These will work much more like an 83.


Three years late - but here you are. Welcome!

The link works fine from here.

You *do not* need to recreate anything special - the circuit as-given works just fine. As to Zeners, along the lines of William of Occam, eschew needless complexity.

When I replaced the 83 in my 539B, I used my calibration tubes (6L6 & 12AX7 & 80), I had taken readings with a good 83. With the drop-in replacement, the readings were within a couple of needle-widths. This did prove the concept.

Hickok put the two rectifier tubes on their sides for the space. That it works does not make it a good idea. The solid-state drop in neatly solves the problem and removes any doubt as to the efficacy of the 83. You pays you money, you takes you chances. These are not precision instruments at any level at all. They are useful to compare one tube to another, cull for obvious defects and failures and reasonably close matching if necessary. But, as always, the best test of any tube is the equipment it serves.

Peter Wieck
Melrose Park, PA