Those are not “eye tubes”, they are counter tubes. You can see the numbers around each tube. Probably an early EPUT counter. 73 – Mike

Mike B. Feher, N4FS

89 Arnold Blvd.

Howell NJ 07731

848-245-9115

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of CL in NC via Milsurplus
Sent: Wednesday, September 14, 2022 10:56 AM
To: Milsurplus <[email protected]>
Subject: [Milsurplus] In the 'What is this' category

I do not know if this picture will post or not.  On the show, The Big Bang Theory, in the backgrounds of the apartments of the primary scientist characters are all kinds of electronic gadgets.  I saw one I had never noticed before.  It is a 4 or 6 inch rack panel, has two silver handles, on on each side, it appears to have 4 eye tubes across the front, and several knobs along the bottom and sides.   I attached the pic, but as I said, don't know if it will work  I tried to crop it and focus it as best I could.  There was a mod monitor in QST or the Handbook years ago that used 2 eye tubes for an indication of mod percent from 85% to overmod,  and that is the first thing I thought of, perhaps a commercial version.

Charlie, W4MEC in NC