[GreenKeys] GreenKeys Digest, Vol 99, Issue 39

[DR HOUSE]

> This would make a lot of sense.  The the 83 in the tube tester has
a military spec socket and a tube holder to keep it in place.
Also the instructions remind you via a sticker to always turn the
tester on with the line adjustment all the way counterclockwise

Thanks John,
Don

    Data sheets for early 82 tubes from the Cunningham Tube Company
do suggest a "base down" mounting.  But this is in the context of
"only a socket making very good filament contact and capable of
carrying 3 amperes continuously should be used".  Bear in mind
that early electronic connectors were very unreliable.

http://www.datasheetking.com/indexdl/Scans-008/Scans-00177151.pdf

    The RCA data sheet for the 83 tube does not call for base-down
mounting.

http://www.ronnierice.com/ebay/83%20RCA%20Tube/rca_83.pdf

    The "high end audio" guys suggest a 1-hour warmup on the filament,
in the base-down position, before applying high voltage for the first
time.

    If you can't find an 83, you can substitute a 5U4GB, which has
better specs, the same filament voltage and current, and no mercury.

http://www.hifitubes.nl/weblog/wp-content/rca-5u4gb.pdf

That was the standard power rectifier of the tube era, and
can rectify 1A at up to 1500V.  You can still get new 5U4GB tubes.
You'll have to replace the 4-pin socket with an octal socket,
and change the pinout.

Then you can get a solid-state 5U4 plug-compatible replacement.

http://tubedepot.com/ssr.html

All this is an overly complex way to get 120VDC at 60mA.

				John Nagle

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