[sdiy] [OT] Name that tube

[metasonix]

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

Eimac IG35 vacuum gauge. 

Just literally a 35T power triode with intubation. 

It measures vacuum by the triode's AC gain--the harder
the vacuum, the higher the voltage gain (or, for very high vacuum,
there is an inverted-triode connection that can be a very sensitive
indication of residual gas). 

WWII surplus, thus the Navy marking.

Tantalum anode, platinum-plated grid, thoriated tungsten filament,
borosilicate glass.

The green color in the glass around the seals is uranium--it makes
the glass stronger there.

Collectible. Not made in 50 years or more.
About $20 worth of platinum in it. Don't trash it.

>This is a Schulz-Phelps ion gauge tube.
>-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)

Nice guess, but wrong! You looked that up somewhere...

ETI still makes all kinds of gauges--Bayard, Schulz, Pirani, triode, etc etc...
www.etigauges.com/ion12.html

Next?



uncle eric
metasonix.com