anyone knowing of these were used in most early color tv stations?? The tube count is high, complicated set. Used very good color demodulaion and other advanced circuits? Henry kloss used one of these when he was designing the advent videobeam. It shows his lab setup with this monitor, screen size is adjusted to look like a rectangular picture, but screen is definate roundie and cabinet the same. Station indicator is projected in large white numbers w/ black background from square window above crt. Does anyone have one besides the museum?? Color reproduction must be excellent. For ultra accurate NTSC color?

There are 5 surviving TM-21s that we know of, 4 with collectors and one at the Early Television Museum.

Good to hear you chime in, That saba projection unit is coool. I wish more american sets were beautiful like that. Here's pic of kloss in lab while using monitor round screen
size shortened top and bottom probaly to mimic 4:3 for videobeam screen validating with henry kloss at the controls. Person working at advent said theses were for accurate NTSC referencing. Click on green arrows to see pic enlarged when popped up.

The number above the screen was a piece of plastic to indicate the source (camera number), as this was a studio monitor with baseband composite input (no tuner). The "underscan" operation shown in the picture was selectable with a switch to show the complete image without corner cutoff. Part of the complication of studio monitors was to maintain linearity and convergence when in both underscan and "normal" modes.

I have an RCA TM-21 monitor. I don't know if it is registered with the archives yet-thought I have done that. I may get it fired up when the weather breaks. I have a GE PE350 camera sitting on top of it. Geeze it weighs a ton along with everything else I have! Julian

No, Julian, I didn't have your TM-21 in the database. I'll add it. Is it A, B, C, or D?

Julian, which cRT does you monitor have in it? 21AXP22, 21CYP22 or other?

You must be kidding?? I had one of those beasts when I went to high school.

Maybe I should have kept it. It's very possible that my monitor ended up in the hands of a collector. How interesting..... and it was CLEAN, too.

Well, you can't keep everything.

I'm thinking my TM 21 has a 21FJP22 in it. I also believe it was replaced in 1978 because of the warranty sticker on it. It is in my warehouse and will try to remember to look at it again and see which series it is and double check the numbers. It's a nice one and all complete with a beautiful front door.

There were 3 of those several years ago at Apex in Sun Valley... They were rusty and beat-up, but maybe I'll go see if they're still there. Next to them was a complete RCA film chain from the late 50s or early 60s.

Charles

Do I remember right that RCA only put the best of the best production CRT's in these? I wonder how they culled them.

Dave A

There is a 21 inch color CRT in Dave Johnson's stuff that looks just like a 21AXP22. It is labeled 1819P22. I was told that it was a specially selected 21AXP22 for use in monitors. Does anyone know if this is true?

the setup chart for the B&K tester
http://bkprecision.com/download/documentation/100-CRT.pdf
shows the same settings for both

When I did transfers on the film chain at Compact Video in Burbank, CA in the early 70's, they used a roundie monitor. I asked and was told that it was a specially selected, optimal picture tube. The date would seem late for a 21AXP22, however, the practice would suggest that it would have been part of monitor manufacture.

Later, there were hi-res (supposedly) versions of the 21FJP22... I have one in my Zenith, which if I recall, is a HR21GVP22. I've heard of a military number for 21" roundie tubes, which might be this 1819P22... I wonder if SgtRob might be able to ring in on this?

Charles

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I have an all-glass non-faceplate 21 incher out of a test jig which has a type # starting with 18__. I've been told the test tubes were factory seconds; maybe the 1800 series designation in general was used on commerical/industrial equipment.

Later, there were hi-res (supposedly) versions of the 21FJP22... I have one in my Zenith, which if I recall, is a HR21GVP22. I've heard of a military number for 21" roundie tubes, which might be this 1819P22... I wonder if SgtRob might be able to ring in on this?

Charles

Very interesting - I never heard of hi-res roundies. Can you put a magnifier on it and another tube and measure the difference?

My TM-21D manual specs a 21FJP22 tube. As soon as I get three neighbor kids and a block and tackle to move mine from the corner it is in, I will look at the tube.

Dave A

Did they ever make ones with a finer dot pitch than the normal 21" CRT?

No.

If anyone has a TM-21D and would like an original RCA manual for it (MI-40226-D) they are welcome to contact me. I have one I'd like to give to a good home.

I can use that book as I have two of these monitors and lost mine in the fire. Please contact me! Julian Burke 865 567 eight nine six zero.

We had 3 of the 21" color monitors in our color remote unit at KTLA used as a control room for our color studio. This was in the 60's. Still used them after rectangular monitors came in to use. This allowed directors to make sure images weren't cut off on all the roundies still in use. Also many commercial producers would request an RCA color monitor on the studio floor to check the quality of the color image. This as opposed to the consumer sets w/modulators we normally used.

-Steve D.

That monitor was a very well designed monitor. We used one on a TRT1B RCA VTR, which we converted to a high band system. That TRT1B was wonderful with its heterodyne color system, for wonky color tapes. We owned the only High band TRT1b in the USA

A 1957 advertisement.

https://visions4netjournal.files.wordpress.com/2017/05/img_5307.jpg

https://visions4netjournal.files.wordpress.com/2017/05/img_5308.jpg

Does a schematic exist for this monitor? They mention stabilized circuits using feedback, and looking at chassis pictures on the ETF it is clear 6AS7/6080 power regulator tubes are employed (likely for B+ regulation)....I'd really like to see what they did in this set VS their consumer offerings to make it more stable.

This should be readable. See link: https://visions4netjournal.com/2017/05/10/1661/

https://visions4netjournal.files.wordpress.com/2017/05/img_5310.jpg


http://wp.me/p8dob6-qN