Siemens LGR 7641 specs

[litterbox99]

Siemens LGR 7641 tube specs.

A few years ago I purchased a HeNe tube & power supply kit.
It came with a Siemens 7641 tube, un-marked power brick
(3 1/4 x 1 1/4 x 3/4) and three 20k 3W metal oxide ballast resistors.

I powered it with a variable power supply (YH-305D) @ 12 vdc
This set up has worked fine for years.

Last time I powered it up, my bench supply glitched and jumped
to 49 VDC, it took me a second to shut it down. Fired it back up
and nothing. I'm, sure the brick is toast because it draws no
mA anymore and the tube wont lase.


Question 1

What are the voltage and current requirements for this tube ?

Question 2

Can you burn out a HeNe tube by too much voltage or amps ?

It doesn't glow when I hold it up to a plasma globe, but my 7631A's
do. I even tried using the supply that runs my 7631's (1750VDC,
5.0 mA) @ a ballast range of 60k-75k. Still no joy.

Guess I smoked them both ?

 

[ultimatekaiser]

you almost certainly destroyed the power supply, but it shouldnt affect the tube. though if it doesnt glow under RF it probably has no gas in it. it should glow against a plasma globe generally unless something is very wrong.