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ITT/KB SV-049

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PYE625
(@pye625)
Famed V-Ratter Registered

Way back in 1974-5 my parents were able to replace the then aging GEC Elektra dual-standard set with a nice 24inch ITT VC200 set kindly handed down from my nan when she bought a new colour ITT CVC5 set. In 1977 when my parents rented our first colour set, the VC200 was passed on to an aunt of mine. She replaced it with a colour set in the early 80's and since then, I know not the rest of the set's history.

It has now been my good fortune to secure an ITT VC200 set, albeit a 20inch, for £6. It is at this moment in the safe hands of Marc and will hopefully in due course be winging it's way down to Cambridgeshire, along with the CRT, by the very kind help from Mike (Cathovisor).

Marc has been brilliant in not only collecting a CRT for me, but this set also. He has also taken a few pic's of the set and has tested it's tube as well.

Here below then are Marc's photo's....

itt 05
itt 04
itt 03
itt 02
itt 01
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Topic starter Posted : 15/09/2018 2:33 pm
PYE625
(@pye625)
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One thing in particular that caught my attention in Marc's first photo was a box of Quality Street just to the right of the set..... ?  But somehow I think these are not included ! 

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Topic starter Posted : 15/09/2018 2:43 pm
Marc
 Marc
(@marc)
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Posted by: PYE625

One thing in particular that caught my attention in Marc's first photo was a box of Quality Street just to the right of the set..... ?  But somehow I think these are not included ! 

They aren't included for me either say's my missus, boohoo ☹  

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Posted : 15/09/2018 4:01 pm
Red_to_Black
(@red_to_black)
Noble V-Ratter Registered
Posted by: PYE625

It is at this moment in the safe hands of Marc and will hopefully in due course be winging it's way down to Cambridgeshire, along with the CRT, by the very kind help from Mike (Cathovisor).

Marc has been brilliant in not only collecting a CRT for me, but this set also. He has also taken a few pic's of the set and has tested it's tube as well.  ?  ?

Here below then are Marc's photo's....

This is the forums nicest attribute, it shows the nicer side of human nature and it is really good to see fellow enthusiasts helping each other out.

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Posted : 15/09/2018 5:23 pm
Jayceebee
(@jayceebee)
Noble V-Ratter Registered

Very nice Andrew, am I right in thinking that with the VC200 video is applied to the grid of the CRT instead if the cathode

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Posted : 15/09/2018 8:32 pm
PYE625
(@pye625)
Famed V-Ratter Registered

Cheers John, yes it is indeed grid modulated....I have been reading LLJ's November 1973 article from the Vrat data library.

Well worth downloading for some interesting reading..... as all his articles are.

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Topic starter Posted : 15/09/2018 9:06 pm
Jayceebee
(@jayceebee)
Noble V-Ratter Registered

Thanks, I didn't realise it was in the library. I had been looking for it on American Radio history but couldn't find it, I didn't think the article was as early as that somehow.

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Posted : 15/09/2018 9:35 pm
Focus Diode
(@focus)
Honorable V-Ratter Registered

The last time I saw a VC200 was back in the 1980s. Not many appear to have survived but probably sold in much lower numbers than the earlier VC1-53s.

Well done for securing the set. I'd hoped someone here would.

The CVC5 parentage is clear to see! Looking forward to hearing how you get on with it.

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Posted : 15/09/2018 10:16 pm
Boingy
(@boingy)
Trusted V-Ratter Registered

I can remember working on a few of these sets. All pretty straightforward in the line o/p stage, with the usual suspects. I did have my fair share of duff LOPTs, though.

It's a good find, Andrew. Fingers crossed, it shouldn't give you too much trouble.

I might have time next month to help you get it home, if that's any help to you. It would be nice to meet up with some more ratters 🙂

All the best,

Tony

Happy days!

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Posted : 15/09/2018 11:28 pm
Terry
(@terrykc)
Famed V-Ratter Rest in Peace

We had several hundred of the later VC207 (I think) sets - the one with the varicap tuner - at the Stock Exchange for use on our cable TV system. Of course, the UHF tuner had to be replaced by our special VHF tuner.

Another provider had previously experimented with an earlier version of the chassis by bolting a Labgear Televerta on the back to translate the VHF channels to UHF but it didn't work as the Televerta drifted considerably at switch on and took quite a time to stabilise so, OK in a domestic situation where it could be left running contentiously but useless  in an office environment where it was fed from the set's on/off switch. 

Another problem was severe patterning on one channel, sometimes more. We had about half a dozen of these sets running on the bench and I switched one off for some reason and was surprised to see the patterning disappear on the adjacent set!  I assumed it was coming from the Televerta, so I disconnected it and turned the set on again and the interference returned! After a bit of detective work with an LMS, I determined that the 1st IF stage was the problem. 

Now LLJ refers to a problem with the VC200 where the grounded base pre-amp oscillates at UHF (I don't even remember if the VC207 still retained this pre-amp)  - but this was definitely the first IF stage.

Looking at the set after I got the can off, something struck me as odd. I looked at the schematic and then at the set and I would imagine that, if there'd been any observers present, they would have seen a broad grin on my face at this point! The schematic shows a ferrite bead on the base lead of the transistor, although I note that this doesn't appear on LLJ's schematic.

Have you ever seen white ferrite? No, me neither! However this set had a white bead on the transistor's base lead!

It was one of those ceramic beads like those you find on the element connections in a Henley Solon iron and, of course, after I fitted a black ferrite bead(!) the set was as clean as I whistle.

I phoned ITT at Footscray and told them what I'd found and it was something they had never come across. However, I was told, these sets were made in Portugal and Portugal didn't use UHF at the time, so they would never have seen it!

 

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Posted : 16/09/2018 5:01 pm
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PYE625
(@pye625)
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It is with great delight that today the marvellous Mike (Cathovisor) brings down this TV set, along with a replacement CRT for a Defiant set of mine, from Marc up in Wakefield. Marc kindly collected the items for me a short time ago. Thanks guy's

I placed the CRT to one side as I was keen to see the ITT set. It is an SV-049 from November 1972 sporting the VC205 chassis. I cleaned and hoovered out the dust and below are some pictures from around the chassis.

itt 15
itt 14
itt 13
itt 12
itt 11
itt 10
itt 09
itt 08
itt 07
itt 06

Mod Note: New thread merged with original thread, makes sense to keep it all in one thread rather than having two.

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Topic starter Posted : 18/10/2018 8:22 pm
Marc
 Marc
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You're welcome Andrew

Looks a darn sight cleaner in the back of that ITT/KB now

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Posted : 18/10/2018 8:22 pm
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PYE625
(@pye625)
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After a general look over the chassis for any obvious defects or dangers, I decided to apply mains via a 15 watt lamp with a valve removed to break the heater circuit so as to allow a gradual build up of HT to reform the capacitors. This was probably not needed as the previous owner of the set had already powered it up, but I wanted to be safe.

Anyway, all seemed to be ok as the lamp quickly dimmed and HT was present. I replaced the valve and applied power via a 200w lamp this time. After a short time, sound was heard then a raster appeared on the screen. I tuned in the set and received good sound and a rolling picture. Adjustment of the vertical hold varied the rate, but it is not possible to lock the frame.

Investigation will therefore begin in this area of the chassis. However, before I do that, I will remove the mains RF by-pass capacitor from the mains switch area. I rather could do without this going bang !

First light then, and we are rolling.

IMG 4827 50
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Topic starter Posted : 18/10/2018 8:22 pm
Cathovisor
(@cathovisor)
Illustrious V-Ratter Registered

N-n-nineteen, looking at the serial number designations!

Yes, that has been from Wakefield to home then to Stamford and Wansford before going to Holwell and on to you all in 24 hours!

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Posted : 18/10/2018 8:22 pm
PYE625 liked
crustytv
(@crustytv)
Vrat Founder Admin
Posted by: PYE625

It is an SV-049 from November 1972 sporting the VC205 chassis.

The VC205 is basically a VC200, the VC205 only differs in as much as the sound I.F amplifier and discriminator are on an I.C. and new video stage.

Data for the VC200 is already in the library and I will scan the mod update sheet to cover the addition of the I.C. and new video cct.

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Posted : 18/10/2018 8:31 pm
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crustytv
(@crustytv)
Vrat Founder Admin

VC205 enhancement data now available in the data library

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Posted : 18/10/2018 9:06 pm
PYE625
(@pye625)
Famed V-Ratter Registered

Thanks Chris (And for merging the two threads. I had forgotten about the one I previously started!)

A minor improvement was made by simply replacing the PCL805 frame output valve, but this is clearly not the real culprit as the frame hold is fully at one end of its travel to achieve lock. Furthermore, correct height and linearity cannot be obtained. So tomorrow afternoon, some proper fault-finding here is required.

Aside from that, it is looking to be a great set indeed !

IMG 4842 50
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Topic starter Posted : 18/10/2018 9:08 pm
Nuvistor
(@nuvistor)
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Those mixed dielectric capacitors across the mains did go with a bang, we didn’t really have anything much better at the time.

 

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Posted : 18/10/2018 9:15 pm
colourmaster
(@colourmaster)
Reputable V-Ratter Registered

Hi Andrew

That looks a nice clean set you have there  I have the last version with the varicap tuner. We had a few of the  RGD versions on rental and found them to be very reliable.

Regards. 

Gary. 

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Posted : 18/10/2018 9:18 pm
PYE625
(@pye625)
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Thanks Gary

I have temporarily snipped the mixed dielectric cap out of circuit now that full mains is being applied Frank. I am not quite ready for an early Guy Fawkes experience.

As a matter of interest, it looks like there are several mixed dielectric capacitors dotted about plus one or two black Callins electrolytics. For instance, C82 in the PCL805 cathode circuit is a Callins 100uf...… Hmm I wonder....

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Topic starter Posted : 18/10/2018 9:20 pm
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