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1968 Decca CTV22C: Dual Standard CTV

 
crustytv
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Introduction

 

The CTV22

I've had a shuffle about in the display room so as to make access easier for the repair. There's no chance of getting the whole TV into the workshop as the 26" Aphelion is still taking up space in there along with the Ferguson 3700 that is waiting for me to find the motivation to install its new 25" CRT and then Ferguson 3703 which is having its PSU repaired on the PCB bench.

What I will likely do is remove the Decca's chassis to the work bench for close visual inspection, any remedial repairs can be performed there prior to refitting to the cabinet for power application.

The Decca in position, easy access to front and rear, space on top for the scope when needed.

ctv22c-3.jpg

Background

The chassis was designated the “Battersea” the CTV22 is a Dual Standard, Hybrid Colour, however although the chassis is almost identical to my Decca CTV25, The CTV22C does away with valve EHT Generation by using a much safer solid state tripler for EHT. Decca also released this version of the chassis for the CTV25 as can be seen below.

example.jpg

Why Rare?

Well hardly any 22" dual standard hybrid CTV's were made, even fewer are known to have survived and some are just plain extinct! Sets released in time for the launch of colour in 67 were either 19" or 25". 22" duals came the following year and only made for a very short run, I think one year. Once all the channels went colour around 69, manufacturers eagerly switched to the simpler single standard, you'll find lots of S/S 22".

Only 5 manufacturers bothered with 22" duals, this 22″ Decca is one of those super rare examples of what was probably one of the last Dual standard colour hybrids. It filled the short gap between the Decca CTV25 and the much loved Decca Bradford. As I mentioned at the start, you will be hard pressed to find any 22" CTV duals as there were not many manufactured in this period, in fact  there were only five others.

The only other 22″ colour dual standards were made by :-

  • Bush CTV174D
  • Murphy CV2210D
  • Philips G22K503
  • Stella ST2211
The Sets Current Condition

The original I.F. panel had been robbed long ago to fix another set.  The original tuner suffering the same fate, the good news being the set came with a bag that contained another tuner and IF panel. Also in the intervening two years since I acquired this set, I've managed to gather some spares to maintain the CTV25 and CTV22.

Other observations

There’s loose and cut wires all over the set and one or two just laying on the chassis who knows where they come from, a lot to contend with just with them. There's a split Mullard VA8650, a wire disconnected from the scan coils and what looks to be the degauss plug floating. There’s no single switch to change standards, it operates on channel change/micro switches, there’s a Bowden cable and a solenoid which again is all disconnected. One of the fuses is missing on the power pack. Other than that everything seems to be OK with no apparent missing components or cracked PCB’s. All the control knobs were missing but thankfully I have quite a stock of CTV knobs and the correct ones were found.

At this stage I’ve no idea how it all goes back together, thankfully I have the full Decca workshop maintenance manual that covers the CTV25 & CTV19.

ctv22c-1.jpg

There is a section covering the version of the CTV25 (shown at the top of this page) that had the tripler chassis, the same one as used in this CTV22 except it used a slightly different convergence panel. I also have my CTV25 for some of the similar references.

The cabinet was scrapped down and re-oiled which can be seen below now looks in top condition.

Further Photos

The cabinet after some elbow grease and refinishing came up a treat

ctv22c-2.jpgctv22c-4.jpg

Replacement knobs were found from stock

ctv22c-5.jpg

Wide Chassis view of the CTV22 &CTV25

  • ctv22c-a.jpg
    For Comparison, above is the CTV22 chassis, the CTV25 (below) with full thermionic EHT generation. Note: the IF panel on the CTV sits on the chassis behind the luminance, whereas on the CTV22 its sits on a runner to the left hand side
  • ctv25.jpg

All those loose and cut wires................... waa_gif

ctv22c-b.jpgctv22c-c.jpgctv22c-d.jpgctv22c-e.jpgctv22c-f.jpgctv22c-g.jpgctv22c-h.jpg

Next Steps

Scan the maintenance manual for the library so those that wish to follow along can do so.

But first things first, get the B&K out and test the tube, if its a dud then its a non starter as I don't have a spare 22" in stock.

More to follow.............. Including the panel transistor, valve and diode line-up/functions

ReplyQuote
Topic starter Posted : 09/01/2017 5:06 pm
Nuvistor
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It has got to be a good CRT, let's hope sothumb_gif.

I had looked through your online collection and the Decca was the only D/S 22inch I could find, so unless you had another hidden it was going to be this.

Just to show how slow I can be, Andrew I have just realised the FFSS connectiondunce_gif.

Looking forward to the story.

Frank

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Posted : 09/01/2017 5:55 pm
PYE625
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It will be a good set to get back to working condition again.

I have used Letraset in the past to repair missing or worn sections of print on control icons... I notice some inevitable wear of some of the writing on the Decca control panel, but at this stage, probably the least of things to occupy the mind with !

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Posted : 09/01/2017 6:41 pm
crustytv
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PYE625 said
I have used Letraset in the past to repair missing or worn sections of print on control icons... I notice some inevitable wear of some of the writing on the Decca control panel, but at this stage, probably the least of things to occupy the mind with !  

Absolutely no wear on the writing Andrew, the flash has made it look that way. I will take a better photo when I have time

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Topic starter Posted : 09/01/2017 6:52 pm
PYE625
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Chris said

Absolutely no wear on the writing Andrew, the flash has made it look that way. I will take a better photo when I have time  

Good news Chris, and the cabinet looks like new now. Teak often comes up good with a little TLC. thumb_gif

It was 300gns when new, I wonder what that would be equivalent in today's value.....hmm_gif

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Posted : 09/01/2017 6:56 pm
Marc
 Marc
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Hi Chris,

Fingers crossed for the CRT and then onto what looks like a fun repair, I'm looking forward to your progress and no doubt inevitable antics !

Marc.

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Posted : 09/01/2017 7:45 pm
crustytv
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Back on topic, the CRT is probably the worst I've come across.

On occasion I've had lowish emission on one or two guns, never all three and never as bad as this!

I could give it a tickle but I think this is a non starter, I've had it cooking on the B&K and rather than seeing emission rising hoping the cathode/s might recover, the emission is dropping off even more. A tickle I think would likely strip whats left, if it did mange to recover after a bop I seriously doubt it would last very long.

Considering the mess the sets in, it seems to have been treated to a rough and hard life. When a tube turns up and one will one day, I'll pick up the story once again, sorry for the anti climax.

crtbad.jpg

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Topic starter Posted : 09/01/2017 9:55 pm
Nuvistor
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Chris said
Back on topic, the CRT is probably the worst I've come across.

On occasion I've had lowish emission on one or two guns, never all three and never as bad as this!

 

Only one word but I don't swear, well not on this forumnuts_gif

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Posted : 09/01/2017 10:23 pm
Cathovisor
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Mod note.

Nice though the discussion about what FFRR/FFSS stood for is, can we keep it on topic about the TV set, please. As a new thread has been started by Nuvistor on this matter, I've moved the relevant posts there.

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Posted : 10/01/2017 12:02 am
Nuvistor
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Out of interest is the a label on the CRT with make and country of origin.

Frank

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Posted : 10/01/2017 12:52 am
PYE625
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Chris said 

Considering the mess the sets in, it seems to have been treated to a rough and hard life. When a tube turns up and one will one day, I'll pick up the story once again, sorry for the anti climax.

  

That is a shame Chris, but no need to apologise.....these things are sent to try us nuts_gif

I was thinking you could  try giving it a serious bop and it may give enough time for the tube to see the anniversary date.... Worth a try?

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Posted : 10/01/2017 8:38 am
Cathovisor
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What I am about to suggest may be tantamount to heresy in some people's minds, but... there are a lot more Bradford chassis sets out there than Battersea chassis sets. If a 22" Bradford should turn up, it should be bought and cannibalised?

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Posted : 10/01/2017 12:42 pm
Nuvistor
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Cathovisor said
What I am about to suggest may be tantamount to heresy in some people's minds, but... there are a lot more Bradford chassis sets out there than Battersea chassis sets. If a 22" Bradford should turn up, it should be bought and cannibalised?  

I don't have a problem with that, indeed it could be any suitable 22inch set that is not a rare model.

Frank

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Posted : 10/01/2017 2:18 pm
The_Teleman
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Is this a standard 22 inch CRT A56-120X ? If so I might be able to locate one for you 

chris

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Posted : 10/01/2017 3:28 pm