1963 RCA CTC-12 Ainsworth (Australian)
 

Good morning all,

I was extremely lucky recently to cross something (for $450!) off the very top of my "wanted list", and subsequently something I thought I'd never see in the flesh - a 1960s colour roundie. More specifically, this set is a 1963 RCA 213G18 EX, imported from Canada and converted to the Australian ~240v 50Hz & PAL systems. :thmbsp:

The cataract on this set put bidders off, which was quite lucky. However, that creates a minor challenge for me, worsened by the fact that this is probably the only "Roundie" in Australia, and also the vast expense if I were to import a replacement CRT. No matter how strong or weak the CRT is, I'd still like to repair the cataract so it's displayable (as it will probably be a while before I could afford to purchase and import a replacement tube if this one were to be weak, gassy or otherwise faulty).

I know that there are various methods using heat, but I've also heard of a method where you place the CRT face-down in a shallow pan of water, which I assume saturates the PVA to the point that it breaks down or loses adhesion on the safety glass? Does anyone have any experience with that method, or any other methods that don't include using a heat gun, heat lamps or hot wire on what is essentially a fragile glass bomb? :no:

I'm definitely thinking it's a CTC-12, and possibly called an RCA "Ainsworth", according to the webpage below. I'm curious though, if the "EX" in the model number (213G18 EX) indicates that it's for EXport?

http://rec.antiques.radio-phono.nark...ervice-manuals

A friend of mine has picked this set up from the seller, as I'm about a 40 hour round trip away. I will be picking it soon though, and will post some more information and photos when I do so. I'll also try and scan a copy of the diagrams detailing the conversions, which I'll post on here and Facebook.

Thank you in advance,

Chris :)

Has anyone ever tried strong fishing string.. Sorta saw back and forth from end to end and let the string cut into the glue while the tube is under the hot sun?

I've heard of people using piano wire, heated up by a Variac or something. I want to stay away from methods that involve heating the "glass bomb" though, as I can't replace the CRT or safety glass as easily as collectors in North America can.

Chris

That cataract is so bad it may just fall off once the tube is removed!

I soaked a safety glass off a tube last year, it was on a NOS rebuilt tube and was still tightly bonded but the safety glass had been cracked. It took a few weeks to get it all off but I figured it was worth the time so I wouldn't risk imploding it with heat.

I'm hoping you're right about the cataract! :scratch2:

I've also attached the documentation the seller emailed me, including the modified tube line-up and the PAL decoder.

Chris

hot wire will not, have not tried fishing line, but doubt it, the bonding agent can be VERY tough. I say very since I have come across some that were tougher than others. There are two types.

Green around the edges, is a oily messy kind that can but cut thru with safety wire (no need to heat). It more like a stiff jello, messy but not hard to cut thru.

white around the edges, Much tougher, can be rock hard or rubbery either way will not respond the hot wire (red hot will not effect it, I tried it). best bet on those is just to get soak the face in water ( I used a small plastic kiddie pool) about 4" deep to make sure you get under the glass. Remove the plastic tape around the edge to allow the water better access.

do this for as long as you can, I did one for a couple months, longer the better.

the idea is to get the bonding agent more of a rubbery consistency. After this you dig out chunks around the perimeter mount the tube in a support structure (a large stable round can like a garbage can) and leave it out in the sun on a hot day. in Florida summer days are in the 90's (air temp) for hours, in the sun things get hotter. using small wood wedges (like wood clothespins) inserted around the perimeter (where the chuck where dug out) you "gently" tap these wedges in to exert upward pressure all around the lens. The key is to go slow you just tap the wedges in until the make light contact with a little upward pressure. Too much and you break the glass making removal much more of a problem. The sun heat and the light pressure take time to work so you just make sure the wedges are snug and walk away for 30 min, come back see if any are loose, if so lightly tap them in until just snug (from pressing up on the lens). then walk away.

based on the look of yours it looks like soaking in for a week just to soften up the part that has already come loose will be enough time in the water. then dig out some chunks and begin the process described above.

The key is not to rush the upward pressure. Oh and make sure the can the CRT is resting in will not tip over.

Here's an indepth discussion about cataract removal from a few years back here on VK. It also includes a number of pictures and lots of hands on experiences.

http://www.videokarma.org/showthread.php?t=250651

wow .. an Aussie roundie... history of set would be fascinating? A rare beastie indeed? Aussie tuner? When was it converted to PAL???? what a find!!!!! Good luck with the cataract!

The history seems to be a little unclear, but this is what I've pieced together -

It's earliest known history is at the Channel 7 television studio in Melbourne, before it then ended up at the Royal Melbourne Institute of Technology (RMIT) as some sort of test set. The seller said that it was converted to PAL at the RMIT, so that brings it's history at Ch. 7 into question, as it sounds like it was an NTSC test set at the time. I would say that this set is possibly one of the original colour sets that were experiementally used to see which system Australia would adopt (PAL vs NTSC).

When I have the time, I'm going to email both the RMIT and Ch. 7 studios to see if either have any more background information on this set. Either way, this is an awesome piece of Australian history. :thmbsp:


Thank you for that link! There's some helpful discusison there, so I'll have to see what happens when this set arrives.

Chris

In the 60s Channel 7 showed colour tv off at a number of venues including the Royal Exhibition Buildings in Melbourne (It was part of a "expo" of the future.)

A colour studio and a wall of sets showing colour programming ... I remember seeing The Flinstones... were on display.

As I was all of 12 at the time ...the terms PAL and NTSC were unknown to me.. all I remember was being disappointed they were showing cartoons not live action programming.

It is possible this set was one used in the display.

Wow - certainly rare and worthy of full effort to restore. Hope the CRT shows some life.

From the rear cover photo, it appears the set was manufactured at RCA Victor Montreal for RCA Great Britain. Hence it appears the set was routed through the UK to Australia. Very interesting.

I imagine the set arrived in Australia with NTSC colour demodulation and was subsequently converted to a full delay line PAL decoder? Where is the PAL decoder modification located?

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

I was going to say that myself at the first glance of the chassis---it is NOT a "normal" ctc-12,. they had an octal H-out put tube and a focus rect tube in the cage. But I was afraid if I did say something...people would bitch at me.

I hope not! I was going to say the same thing. It is a CTC15. Like it or not.
The schematic, shows the world of difference, between the two. :scratch2:

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).

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

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? :scratch2:

Chris

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?

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

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

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

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....

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 !

I reckon it's definitely a lead worth following up! Roundies outside North America aren't exactly common beasties. :scratch2:


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

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

Did it look like this 1964 Philips 21KX102A?

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

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!