Re: Where 3ACPx(x) and other crts originally used

Colin Herbert

You are asking a question which is opposite to that usually asked; "I have a "XXX" scope which is missing its CRT, can anyone tell me what it used"? I'm afraid that Peter Keller's book makes no mention of the 3ACP11 but I would guess it was made by Dumont and might have been used in of Dumont's scopes.

There were a couple of pages of addenda to the above-mentioned book which were posted on this forum by Dennis Tillman, IIRC. Some of the references therein might be of use - or not.


-----Original Message-----
From: [] On Behalf Of Mark Vincent
Sent: 11 May 2021 22:58
Subject: [TekScopes] Where 3ACPx(x) and other crts originally used

I have three NOX 3ACP11s and some other scope type crts that I cannot find
where they were originally used in. I have looked online for makes, model
numbers, etc. for several years. I cannot find anything. I do NOT mean the
modern clocks using crts. A site to get the specs is
Other crts with 1-5 and a few others larger than 5 as the first JEDEC crt
numbers would be nice to know what they were originally used in. Dumont,
Sylvania, E.T.C., etc were some makers of these types. I know other
countries had their own numbers. Some had flying leads instead of a base.
Some have a ring on the neck with pins facing the same way as the socket at
the end instead of the neck pins. The two I asked about last year, with
photos, would be nice to know what they were originally in. Some numbers
are multigun types.

It would be nice to build a scope with these numbers or find an original
and fully restore it. I do not know the maximum frequency the one I
mentioned above would go.The length of the wires to the plates and
capacitance would be the main factor for ft.

Would some of the "unusual" numbers be too hard to drive in the X and Y
direction, spot size too great, innards not being as tight in tolerance,
etc. to be in commercial or lab grade that Tek., H/P, etc did not decide to
use these other numbers? The ones I am asking about are not the ones for
high frequencies, say above 100mc. I know a 3WPx(x) is used in the 310/A
and 315 and few early models used ones like 5CPx(x), 5XPx(x).

I may be asking things that are obvious to some.


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