This should be fun (RCA TM-10 15GP22 monitor)

[old_tv_nut]

Originally Posted by Phil Nelson

The CRT is stamped 15GP22 (and PAR under that, whatever PAR means).

Unless somebody knows what PAR means, we could guess - here's mine:
Production Acceptance Run (?)

[Pete Deksnis]

Originally Posted by old_tv_nut

Unless somebody knows what PAR means, we could guess - here's mine:
Production Acceptance Run (?)

Interesting guess. Phil: is there a date code on the 15GP22? The earliest known by me is the fourth week of 1954. If this tube is earlier it could be quite a significant 15G.

Pete

[Phil Nelson]

All I can see is the CRT neck at this stage. Nothing else printed on the glass of the neck. On the base it says Made in U.S.A. 5-22.

I just noticed that someone wrote in pencil on the bottoms of two guns. One says 5/13, the other has an asterisk drawn on it.

Phil Nelson

[Pete Deksnis]

Some 15G's have production id numbers etched inside, but I've never seen pencil before. No contamination issues apparently.

Yes, it's a 'new' 15G. Not many around with 1955 date codes. As was speculated before, this may be either selected or, considering the inside dates, custom built for a TM-10.

Pete

[Phil Nelson]

So, the date code is something like year-week (5-22 being 1955, 22nd week)?

It didn't occur to me that the penciled numbers would also be a date code.

If I get some time later, I can look inside for etched codes.

Phil Nelson

P.S. New is good for me, from a customer standpoint. The last thing I want to buy is the first example (of anything) off the assembly line

[kvflyer]

Originally Posted by Phil Nelson

So, the date code is something like year-week (5-22 being 1955, 22nd week)?

...

That would be my guess too...

[Pete Deksnis]

Originally Posted by Phil Nelson

So, the date code is something like year-week (5-22 being 1955, 22nd week)?

That is so -- for RCA in the fifties. What ticks me off is when, in the next decade, RCA went to letter date codes for their 7- and 9-pin tubes.

As some of you know, I am slowly working on a 1956 Philco model 22D5102 color set with the TV-233 chassis. In the set, a Philco-branded, SYLVANIA-built 6AW8A date code -- for the 30th week of 1958 -- is "58 30", with the 58 stamped above the 30. However, a PHILCO-built 6M3 damper in the same set is stamped "249". I speculate based upon the history of the TV-123 in question that it stands for the 49th week of 1962.

Pete

[Phil Nelson]

Working at my usual snail's pace, I have gotten as far as easing the monitor onto its (protected!) face, so's to remove the CRT and get a peek at the nether bits. Looks pretty clean and unmolested underneath. I like that orderly layout.

After counting electrolytics (46) in the parts list, I decided to make a spreadsheet for ordering parts and keeping track of things that I replace.

Phil Nelson