Date: Thu Apr 12 20:38:57 2007

Author: Tim Cook

Subject: Re: Wanted: Tubes for old Sargent-Welch e/m apparatus

If you look at the Sargent Welch link below you'll see they are out of
stock but will be available. We just received some after a lengthy wait.
I always thought Electro Technique Products was the manufacturer. I'm
skeptical that Tel-atomic was ever involved. If you order one, be sure
to test it right away. Sometimes they are defective with dim beams, or
the pin geometry is bad enough that you can't take data,

You can see a picture of the tube on our web site, at . I believe The description is
in error in calling it Specific Charge of electron apparatus. We're
trying to get time to change it to "charge to mass ratio of the electron

Tim Cook, Ariz. State

-----Original Message-----
From: [] On
Behalf Of Scott Shelley
Sent: Thursday, April 12, 2007 9:08 AM
Subject: Re: [tap-l] Wanted: Tubes for old Sargent-Welch e/m apparatus

>I never quite got our conclusion:
>Is it true that there is currently no source for either the new tubes
>or for re-conditioning the old tubes?

Here's the result from the research I've done:

I called Sargent-Welch and spoke with the buyer for the tubes specified
on page 773 of their 2006-2007 catalogue as:
"Replacement Tube for Older Model of e/m apparatus", part number WL0623.
Also mentioned is that these are replacement tubes for the WL0623B
(My apparatuses are WL0623A - does anyone know if this is different?)

Sargent-Welch couldn't give me any information on these tubes (not a
photo or even their diameter), so he had me call their supplier of this
part, which happens to be Tel-Atomic.

I spoke to a gentleman at Tel-Atomic who knew of the tubes I'm seeking,
but assured me that they're no longer made (at least not by Tel-Atomic).