View Full Version : Roundie RCA Monitor on ETF


Eric H
09-19-2007, 01:14 AM
Have you guys seen this yet?

http://www.earlytelevision.org/rca_tm21.html

Wowie Kazowie, look at the innards on that thing!
I count 12 can caps on one chassis alone, I'd hate to recap it!

cbenham
09-19-2007, 02:35 AM
This is the only 21 inch round tube monitor RCA Broadcast made with a full I&Q Decoder. I used to have one and it was a great way to heat the living room and watch TV in the winter!

stromberg6
09-19-2007, 04:50 PM
That is one to almost die for. The power supply is spectacular looking. Love to see a schematic of this beauty!
Kevin

Sandy G
09-19-2007, 05:44 PM
Wonder if it still works ?....

fujifrontier
09-19-2007, 09:34 PM
*sigh*

mr_fixer
09-19-2007, 11:47 PM
When I was a teenager I had a Conrac that looked like that. except green paint. Wish i had it now. :tears:

cbenham
09-20-2007, 02:17 PM
When I was a teenager I had a Conrac that looked like that. except green paint. Wish i had it now. :tears:

I'm not sure of the relationship between Conrac and RCA, but many of their tube type monitors from the 50s and 60s are *identical* which makes me wonder if
RCA designed the earliest ones and Conrac then took over and built them for themselves and RCA?

On a few, the service manuals are identical except for the covers and the part numbers.
Anybody have more information on this point?

julianburke
09-20-2007, 05:32 PM
I have one of these that is complete and working. The one shown is missing the large front door that hides the controls and is beautiful because it has the famous large diecast RCA logo that says "RCA COLOR TELEVISION". It also weighs about 300 lbs! Julian

fujifrontier
09-20-2007, 09:20 PM
big is beautiful.... i love the RCA "Colour Television" and "Television Tape" logos, like the ones you're talking about

Steve Hoffman
09-20-2007, 09:26 PM
How would the picture quality on the monitor differ from the commercial sets of the day? More intense, brighter? More accurate, etc.?

fujifrontier
09-20-2007, 09:30 PM
i bet they were probably the same.

not like today....

does anyone know what the font they used for the "Television" was?

old_tv_nut
09-20-2007, 11:46 PM
How would the picture quality on the monitor differ from the commercial sets of the day? More intense, brighter? More accurate, etc.?

The monitor would have full DC restoration, while the consumer set would not. The high voltage would be regulated more closely than on a consumer set, meaning the raster geometry would not change with beam current. [Later pro monitors had a separate HV supply and horizontal sweep - I do not know what was in this one.] The monitor MAY have had the white point set to Illuminant C if the owner was careful and had the proper equipment, but the consumer set definitely would be set much bluer. The monitor may have had color matrix adjustments rather than fixed resistors - don't know without seeing a schematic. Also do not know if the monitor had any more elaborate convergence circuits.

The picture tube on this monitor has the greenish color typical of sulfide phosphors, which means it would not have NTSC primaries, but would have the same primaries as consumer sets. Much later, SMPTE would adopt the "C" (for Conrac) phosphors as a standard, which were not NTSC either.

Dave A
09-21-2007, 09:05 AM
The closest font is called Raceway. Lot's o' places to download it for a few bucks. I have used it and it tends to spread waaay out when used.

Dave A

Pete Deksnis
09-21-2007, 03:11 PM
Is there a schematic for this guy? It would be interesting to compare the IQ-based chroma circuits with those in the CT-100.

Steve McVoy
09-21-2007, 03:31 PM
I have the manual for the TM-21. I'll scan it and post it soon.

stromberg6
09-21-2007, 06:18 PM
Thank You Steve
Kevin

John Folsom
09-21-2007, 06:54 PM
The first versions of the TM-21 used the 21AXP22 CRT. Later viersions used the 21CYP22, and still later the ,21F types. I imagine not many or any survived with the 21AXP22 or 21CYP22 tubes, they would have all been converted to the later "better/brighter" CRTs. TV stations tended to run the monitors a lot, and kept them on service for a long time.