1963 RCA CTC-12 Ainsworth (Australian)

[old_coot88]

It's probably preachin' to the choir again, but can't be sed often enough. Always re-flow the two ground stakes on the far right-hand end of the chroma board, to keep the heaters lit on the two 6GU7 tubes (possibly 6FQ7s).
When those heaters go out, the CRT grids swing 'waay positive, driving the beam current into an avalanche condition, severely stressing the 3A3, flyback, and H out tube.
This applies to the CTC-12, 15, 16, 17, and 25 chassies.

(in the CTC-19 and all its derivitives, the DC coupling to the CRT grids was eliminated).

[Fairlane500skyliner]

Originally Posted by BRC2000

Hi Chris
I think this is a CTC15 as I have what looks like the same chassis on my bench at the moment.
In 1963 the 14 F 615 MU cost £292 in the UK. I have the documentation for the CTC15 625 NTSC 4.43Mz plus the PAL mod if you need it.
Keith

Thanks for that! I was wondering, as I was told it was a CTC-12 (and it the cabinet looks like one from Google), but the circuit diagram has "CTC-15" on it.

Chris

[Fairlane500skyliner]

Originally Posted by old_coot88

It's probably preachin' to the choir again, but can't be sed often enough. Always re-flow the two ground stakes on the far right-hand end of the chroma board, to keep the heaters lit on the two 6GU7 tubes (possibly 6FQ7s).
When those heaters go out, the CRT grids swing 'waay positive, driving the beam current into an avalanche condition, severely stressing the 3A3, flyback, and H out tube.
This applies to the CTC-12, 15, 16, 17, and 25 chassies.

(in the CTC-19 and all its derivitives, the DC coupling to the CRT grids was eliminated).

Thank you for that! I'll definitely keep this in mind when I get the set in my hands. Are there any other common faults with these sets that I should look for?

Chris

[AndrewM]

It was not known if the RMIT training set had survived and I was very surprised when it turned up on Ebay. I'm glad it's ended up going to a collector so it should be around for a few more years to come.

I had first heard about this set a few years back. The story I had heard was it was used to train colour TV technicians in the early 1970's. It's history prior to RMIT I don't know.

The back of the set states it was made for the UK market so presumably it had a 6.5 MHz sound IF that was modified locally to our 5.5MHz sound IF. The photos of the set don't show the PAL decoder sub-chassis. Is it missing?

[miniman82]

If so, it should be fairly easy to duplicate the chassis. I know how much fun it can be to remake missing circuits, just look at what we had to go through to get this CPA (similar to PAL) set working again:

http://earlytelevision.org/rca_cpa_restoration.html

[ceebee23]

This is a very important set ..possibly one of the extremely few, if not the only remaining roundie set in Australia .. and it opens the whole RCA PAL set question up? How many sets were made ..where did they go? Where are they now?

[Fairlane500skyliner]

Originally Posted by ceebee23

This is a very important set ..possibly one of the extremely few, if not the only remaining roundie set in Australia .. and it opens the whole RCA PAL set question up? How many sets were made ..where did they go? Where are they now?

I emailed a good friend and fellow collector about this set, and got this response:

"We had a 1960's RCA colour set at the college where I work, it would have been slightly earlier than this one, but was gone by the time I started work. I do have its service manual, stepdown transformer and pattern generator though. There were colour sets in Australia in the 60's for the purpose of teaching and studio training. As Australia decided on PAL in 1968, most of the old NTSC sets were imported prior to that year."

Chris

[Fairlane500skyliner]

Originally Posted by AndrewM

It was not known if the RMIT training set had survived and I was very surprised when it turned up on Ebay. I'm glad it's ended up going to a collector so it should be around for a few more years to come.

I had first heard about this set a few years back. The story I had heard was it was used to train colour TV technicians in the early 1970's. It's history prior to RMIT I don't know.

The back of the set states it was made for the UK market so presumably it had a 6.5 MHz sound IF that was modified locally to our 5.5MHz sound IF. The photos of the set don't show the PAL decoder sub-chassis. Is it missing?

You can rest assured that it's in a good home now! I believe it was used by Channel 7 television studios in Melbourne prior to RMIT, presumably as some sort of PAL vs. NTSC test set (given that it wasn't converted to PAL until it ended up with the RMIT). The PAL decoder is still there, though needs a little work.

Chris

[Alastair E]

When I was in college around 30 odd years ago, There was a 'roundie' in the corner of the electronics lab.

The lecturer said it was a Philips, but it didnt look like any Philips Ive ever seen before--or since. Looked a bit like some of your RCA roundie chassis...

A steel chassis full of valves, a metal black box on the right hand side and this fixed to a front wooden board that sorta held the round CRT, and front trim etc....

Lecturer (Who was quite a character) said it was--his words--'Never Twice The Same Colour' meaning NTSC and 110V, VHF Tuner and that it didn't work.....

Cant remember much more about it--but who knows, Swansea College being what Swansea College is--Its probably still there! Maybe I should pay a call there.....

--This set may somehow be related to the time when colour standards were being investigated by both Australia and UK....

[Sandy G]

Can't wait to see it restored to its former glory, displaying the "Glorious Lollipop Color" Roundies are famous for. A well-set up roundie-and a LOT of them never really were- is truly a sight to behold. Ya done GOOD !

[Fairlane500skyliner]

When I was in college around 30 odd years ago, There was a 'roundie' in the corner of the electronics lab.

The lecturer said it was a Philips, but it didnt look like any Philips Ive ever seen before--or since. Looked a bit like some of your RCA roundie chassis...

A steel chassis full of valves, a metal black box on the right hand side and this fixed to a front wooden board that sorta held the round CRT, and front trim etc....

Lecturer (Who was quite a character) said it was--his words--'Never Twice The Same Colour' meaning NTSC and 110V, VHF Tuner and that it didn't work.....

Cant remember much more about it--but who knows, Swansea College being what Swansea College is--Its probably still there! Maybe I should pay a call there.....

--This set may somehow be related to the time when colour standards were being investigated by both Australia and UK....

I reckon it's definitely a lead worth following up! Roundies outside North America aren't exactly common beasties.

Can't wait to see it restored to its former glory, displaying the "Glorious Lollipop Color" Roundies are famous for. A well-set up roundie-and a LOT of them never really were- is truly a sight to behold. Ya done GOOD !

So am I! Except I'm not going to post the usual "Wizard of Oz" photograph... More like "King of the Hill"..!

[wa2ise]

Originally Posted by Fairlane500skyliner

I'm not going to post the usual "Wizard of Oz" photograph......

The wizard: "Ignore that man behind the curtain, he's the IT guy working on the servers."

[Fairlane500skyliner]

Originally Posted by Alastair E

When I was in college around 30 odd years ago, There was a 'roundie' in the corner of the electronics lab.

The lecturer said it was a Philips, but it didnt look like any Philips Ive ever seen before--or since. Looked a bit like some of your RCA roundie chassis...

A steel chassis full of valves, a metal black box on the right hand side and this fixed to a front wooden board that sorta held the round CRT, and front trim etc....

Lecturer (Who was quite a character) said it was--his words--'Never Twice The Same Colour' meaning NTSC and 110V, VHF Tuner and that it didn't work.....

Cant remember much more about it--but who knows, Swansea College being what Swansea College is--Its probably still there! Maybe I should pay a call there.....

--This set may somehow be related to the time when colour standards were being investigated by both Australia and UK....

Did it look like this 1964 Philips 21KX102A?

http://www.oldtechnology.net/k4.html

[Aussie Bloke]

Just caught your thread, I am a vintage colour TV enthusiast from Australia myself and am always amazed to see roundies popping up in the land down under! To my knowledge there's been experimentation of colour television in Australia throughout the 60s so there will be a handful of roundies kicking around here. I know the Sydney Powerhouse Museum has an EMI 204 vidicon colour camera chain which includes a roundie monitor. Anyways I hope all goes well with your restoration on your roundie!