[sdiy] [OT] Name that tube ==> I've got the answer

[Alex Stettler]

Hello everyone!


I've got an exact solution for your tube question:

This is a Schulz-Phelps ion gauge tube. They have some special properties by
which they could be indentified:

-closer spaced electrodes than in mostly used Bayard-Alpert ion gauge tube.
-The collector electrode (the outer, anode-like electrode) has a bigger
surface.
 the Bayard-Alpert gauge tube has only a wire grid around the filament as
collector.
 The Schulz-Phelps type has mostly sheet metal as collector (as could be
seen in the picture)

Schulz-Phelps gauge tubes are used in the lower fine down to the upper high
vacuum range.
For high down to ultra high vacuum, the Bayard-Alpert type is used.

Because of the closer spaced electrodes, the bigger collector surface and
some other physical processes I don't understand exactly, the Schulz-Phelps
gauge tube already generates a current directly related to pressure in the
higher pressure ranges than a Bayard-Alpert tube.

If you have some other high vacuum related questions please ask.
But offlist please, as high vacuum is only needed for keeping tubes at work
in any sort of tube-synth ;-)

I'm very interested in high vacuum technology and related stuff. I've
already done a lot of experiments with electronics/high voltage in high
vacuum with my home built / surplus scientific equipment.
Further I got a lot of high vacuum knowledge from the assistant of our
cleanroom-lab in the engineering school.

Kind regards,
Alex


-----Original Message-----
From: owner-synth-diy at dropmix.xs4all.nl
[mailto:owner-synth-diy at dropmix.xs4all.nl]On Behalf Of alex dickey
Sent: Tuesday, August 12, 2003 10:17 PM
To: synth-diy at dropmix.xs4all.nl
Subject: RE: [sdiy] [OT] Name that tube



> > http://www.seanet.com/~tpaddock/public/tube0187a.jpg
> > http://www.seanet.com/~tpaddock/public/tube0185a.jpg
> > http://www.seanet.com/~tpaddock/public/tube0184a.jpg
> >
> > Any idea what this thing is?

i dunno, but i'll bet ashcroft's tommy chong task force are gonna want to
talk with you.

alex