Solid State Roundies, Have There Ever Been Any? - Videokarma.org TV - Video

NowhereMan 1966 · #1 11-14-2006, 06:42 PM

All,

I'm not sure where to ask this, but were there any solid state roundie color TV's ever made? Also, what was considered the first all solid state color TV?

Chuck, the curious.

DE KA3WRW

blue_lateral · #2 11-14-2006, 07:16 PM

I'll start this by sayinng "I dunno"....

However I think the answer is no. 1965 was the last year for major roundie sales as far as I know. there were some later ones, Philco I think in 1967, and even a new(!) RCA in 1968 that had a different chassis. I think that was a ctc-20. These were tube sets.

I think the first all solid-state color set was the original Motorola Quasar "works in a drawer" from 1966 or 67. These had rectangular tubes.

John

Chad Hauris · #3 11-14-2006, 07:18 PM

The last round sets were made in about 1970 by Magnavox and maybe Philco. These were considered at that time the economy models, just using up the stocks of the old CRT's so they didn't use the expensive solid state chassis in them...the last Philco round did have some solid state components such as in the IF stages I believe.

Randy Bassham · #4 11-14-2006, 07:43 PM

Quote:

Originally Posted by Chad Hauris

The last round sets were made in about 1970 by Magnavox and maybe Philco. These were considered at that time the economy models, just using up the stocks of the old CRT's so they didn't use the expensive solid state chassis in them...the last Philco round did have some solid state components such as in the IF stages I believe.

I was working for the Magnavox dealer here and unboxed the last of the Round Screen sets that came in in 1970, we probably had one or two on the floor for sometime after that, nobody wanted them. They were gawd-awful sets with the T939 series string chassis that couldn't have produced a good picture if it was located inside of the transmitter. The first all solid state Magnavox was the T979 chassis and could only be bought with the 25V tubes, IIRC it was introduced as a 1973 model. I think Chad's right, no company would have used something as passe as an old round screen on an all new chassis, by this time it was out with the old and round screen CRT's were not something to be bragged about.

Chad Hauris · #5 11-14-2006, 08:06 PM

I wonder if it would be possible to create a solid state round set by using a chassis from a solid state delta gun set? I have some salvaged working late 1970's RCA chassis from sets that had bad CRT's,.plus several round sets with bad flybacks,etc. I guess one of the problems might be the yoke inductance would not match up and perhaps the HV from the solid state chassis would be too high.

kx250rider · #6 11-15-2006, 01:29 AM

Quote:

Originally Posted by Chad Hauris

I wonder if it would be possible to create a solid state round set by using a chassis from a solid state delta gun set? I have some salvaged working late 1970's RCA chassis from sets that had bad CRT's,.plus several round sets with bad flybacks,etc. I guess one of the problems might be the yoke inductance would not match up and perhaps the HV from the solid state chassis would be too high.

Shouldn't be a problem! Just think about a test jig... They have various ballast resistors & coils to correct the yoke inductance for any chassis. The gun voltages are all the same among most delta gun sets. High voltage; 25KV should be no problem on a 21" round tube. I'd try it with a Chromacolor II chassis

Charles

bgadow · #7 11-15-2006, 12:30 PM

I have a roundie test jig that was used by the repairman until probably sometime in the nineties, maybe later. Not perfect, as there is a note inside about vertical issues (foldover?) when used with a rectangular chassis. If you look in Sams for solid state sets they often have a note stating that the HV may exceed the ratings of some test jigs, causing x-ray problems. But I'm sure all that could be worked around.

I had once looked through the Sams to see which was the last roundie in there and it was the Magnavox. I didn't realize it was series-string, though. Wow-that was cheap. The Philco looked to be more substantial. Lots of store brand roundies late, too, like Airline & Truetone.

Up in the attic I have a late model Admiral solid state chassis, Era II maybe? Looks to be complete. Someday I'm going to have to have some fun with that thing. When I was having trouble a couple years ago with a CTC-31 I thought seriously about swapping in that chassis.

David Roper · #8 11-15-2006, 05:27 PM

1970 roundie seems almost as much an anachronism as a 1957 rectangular color set. And what do they have in common? Series string!

Sandy G · #9 11-15-2006, 05:43 PM

Roundie CRTs were a laughable anachronism in the brave new world of 1970-Little better than throwaway items. But who amongst us TV guys wouldn't LOVE to have a couple brand spankin' new in the box stashed away somewhere ?

Chad Hauris · #10 11-15-2006, 06:36 PM

I would like to try the solid state chassis on the round tube...could anyone tell me what the inductance difference is between the typical tube type and solid state yoke coils? It seems as though the solid state set would likely use a lower impedence. The target round sets for the conversion would be CTC-15's and 16's with bad flybacks.
I know some of the RCA's used a 31 KV HV...the "donor" chassis I would like to try are from 25V" delta gun RCA's of about 1979 (like a CTC-92 or so)

Bobby Brady · #11 11-16-2006, 10:31 PM

Quote:

Originally Posted by Randy Bassham

I was working for the Magnavox dealer here and unboxed the last of the Round Screen sets that came in in 1970, we probably had one or two on the floor for sometime after that, nobody wanted them. They were gawd-awful sets with the T939 series string chassis that couldn't have produced a good picture if it was located inside of the transmitter. The first all solid state Magnavox was the T979 chassis and could only be bought with the 25V tubes, IIRC it was introduced as a 1973 model. .

I am surprised to learn a roundie was produced for '70 . I had the impression '68 was the last year a roundie set was made.

Is it possibile any company made a roundie color even later than '70?

Thanks

Carmine · #12 11-17-2006, 08:32 AM

You guys should stop playing God with television sets! If there were ever supposed to be solid-state roundies, they would have come about naturally, not as a result of your playing around with mother nature!

What's next, cloning people to be your slaves on trash-night to walk up and down the streets looking for vintage electronic gear!

jpdylon · #13 11-17-2006, 09:09 AM

Quote:

Originally Posted by Carmine

What's next, cloning people to be your slaves on trash-night to walk up and down the streets looking for vintage electronic gear!

hmmmm....might speed up the search process a bit

southernguy · #14 11-17-2006, 11:46 PM

I think this subject has come up before on here. It would be interesting to see something like a solid state roundie come to life and what process would be involed to make it work properly.

Charlie · #15 11-19-2006, 12:08 AM

I have a Philco roundie with 10 transistors and 17 tubes... chassis 19MT79. The Sams for it is dated 4/69... so perhaps the set is from late-68 or early-69. Mainly, there are 4 transistors in the tuner and 6 on the IF/video/agc board. Everything else that follows is tube.

The set is not running, although I have cleaned up the chassis and replaced a few parts. I've finish it sooner or later. Too many other irons in the fire at the moment. Another interesting feature about this set is it uses a tuning indicator tube... the bar type... not the eye type.