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Forum 141

ITT CK505

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colourmaster
(@colourmaster)
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Hi  everyone, my next restoration project is a 20" itt colour which was their first chassis to use an in line crt . This set came from Ipswich as well . It uses the CVC20 chassis and is housed in a cabinet the same style as the CVC9 hybrid.

Regards.

Gary.

Forum 142

 
Posted : 10/03/2017 3:20 am
Nuvistor
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The first ITT sets we sold, only faults I can remember them having was the frame output transistors and an occasional tripler. No doubt I fixed other faults on them but that info is lost in time.

Nice set and they had a good picture.

Frank

 
Posted : 10/03/2017 7:24 am
colourmaster
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Hi Frank

We sold the cvc25/32 where I worked . It was the usual thing in that the 90degree chassis was more reliable than the 110degree version. The only problem I face so far is that I have no service manual.

Regards.

Gary.

 
Posted : 10/03/2017 8:27 am
crustytv
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colourmaster said
The only problem I face so far is that I have no service manual.

Regards.

Gary.  

Hi Gary,

That's the beauty of being a member of Radios-TV, almost all our members service data needs can and are met.

Give me a couple of days to get the whole thing scanned ( I need to make some progress top light on my Baird) but if in the meantime you need and particular circuit snippet uploaded to your thread, I can do a quick ad-hoc scan of that part to get you going

ittman.jpg

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Posted : 10/03/2017 8:45 am
colourmaster
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Hi Chris, that's great many thanks. In the meantime I'll have a go at it . My memory might come flooding back .

Regards.

Gary.

 
Posted : 10/03/2017 9:43 am
colourmaster
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Hi everyone, I've made a start on this set today . Looking inside it looks in good condition so I switched on and was rewarded with a good colour picture but the width is lacking abit . The control has no effect so the E/W transistor must be   open circuit, I seem to remember them failing. Also the line sync was lost but was put right with a new TBA920 ic. As it was running it's now developed an agc fault .that will be in the IF can . The chassis is a CVC20/2 . I'll wait until I can obtain some service information so that's it for now.

Regards.

Gary

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Posted : 11/03/2017 1:53 pm
Nuvistor
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One problem I do remember with these sets was the inductors in the line time base being noisy, line whistle, not at 15khz but they rattled and it could be loud. I think, not sure now, but ITT suggested wood glue, the white stuff, to quieten them down. Did the inductors/transformers get dry joints on the PCB or am I  thinking of other TV's?

 

When I look back there is so much I have forgotten about most of the TV's, radios etc that were bread and butter repairs.

Frank

 
Posted : 11/03/2017 2:52 pm
sideband
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This was quite common in a lot of sets and was normally caused, as you say, by an inductor rattling away somewhere in the line stage (or in the case of the Philips G11, the mains input choke). It was a harmonic that usually caused the rattle which is why it always sounded lower than the line whistle. Araldite was a popular solution or, if you were out in the field and had 20 jobs to do, a matchstick wedged into the winding could provide a worthwhile reduction in the noise.....!

 
Posted : 11/03/2017 3:00 pm
Katie Bush
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Is this the thing we used to call a "transductor"? - Three windings side by side on two 'E' shaped ferrite yokes in a glued together face-to-face configuration and half submerged in a potting compound with eight (or was it twelve?) legs protruding from below.

(trying to find a picture)

 
Posted : 11/03/2017 3:11 pm
Nuvistor
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 "transductor"

I don't remember that term, but has from previous post, a lot lost in the mists of time.

 

Nice little fun  pamphlet from TDK on inductors.

http://www.global.tdk.com/news_center/publications/inductors_world/pdf/aaa60300.pdf

Frank

 
Posted : 11/03/2017 3:22 pm
Katie Bush
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Hi Frank,

I was led to believe the word "transductor" is compounded from "transformer" and "inductor" - being neither, and both at the same time.

 
Posted : 11/03/2017 3:28 pm
Nuvistor
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From Wikipedia 

AC through one winding, DC through the other winding and vary the DC current to vary the reactance.

Frank

 
Posted : 11/03/2017 3:35 pm
Katie Bush
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Hi Frank,

Yep, I saw that link earlier, but what I was looking for was a picture - best way to positively identify the device we're discussing here.

 
Posted : 11/03/2017 3:47 pm
Cathovisor
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First instance of transductors I met were the devices used to provide AFC in some pre-war press button EMI radios. 

 
Posted : 11/03/2017 4:11 pm
Katie Bush
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Cathovisor said
First instance of transductors I met were the devices used to provide AFC in some pre-war press button EMI radios.   

Correct me if I'm wrong but didn't the good old rotary dial telephone, GPO type 700 and the like, use a form of transductor to superimpose voice modulation (AC) onto the DC of the connected exchange line?

 
Posted : 11/03/2017 4:20 pm
Cathovisor
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You're not thinking of the ASTIC, are you?

(Anti-Side Tone Induction Coil)

 
Posted : 11/03/2017 9:17 pm
Katie Bush
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Hi Mike,

Could well have been. It's been a while (25~30 years) since I last played at restoring classic telephones. Nowadays, I prefer them to just 'plug 'n play'.

 
Posted : 11/03/2017 10:07 pm
The_Teleman
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Hi Gary , nice set & good to see it working ,just a thought on the line sync fault I seem to remember the suflex capacitor on the line osc pcb causing the demise of the TBA920 

great progress 

Chris 

 
Posted : 12/03/2017 12:24 pm
crustytv
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Service data for the ITT CVC20-2 chassis can now be found in the data library

CrustyTV Television Shop: Take a virtual tour
Crusty's TV/VCR Collection: View my collection
Crustys Youtube Channel: My stuff
Crusty's 70s Lounge: Take a peek

 
Posted : 18/03/2017 2:37 pm
colourmaster
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Hi Chris many thanks for that . Now I can continue the restoration. Regards. Gary.

 
Posted : 18/03/2017 4:47 pm
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