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Marconi 4701. 2000 series colour. My greatest restoration p

 
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Marconi 4701. 2000 series colour. My greatest restoration p

Post by Till Eulenspiegel » Tue Dec 23, 2014 1:29 pm

I picked up this rather sad looking Marconi 2000 series colour set from Malc's on Saturday.
This set has had a lucky escape. Malc was planning to use the cabinet as a nesting box for his geese. Check out the pictures, this set is in a mighty rough state, one of the metal chassis parts is actually rusted away.
So, can I save this set, or, does it go back Malc's and become that nesting box?

The easiest part of the resto job will be gluing the cabinet back together.

Till Eulensiegel.
Attachments
4701 _0022.jpg
4701_0023.jpg
4701_0024.jpg
4701_0025.jpg

 
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Re: Marconi 4701. 2000 series colour. My greatest restorati

Post by slidertogrid » Tue Dec 23, 2014 2:30 pm

Crikey ! That does look rough! As to if it's saveable I would be inclined to see what the Tube is like before going any further . is it a 19" ?
If you decide to go ahead with the restoration I wish you the very best of luck :thumb I think you may need it! ttt:
Rich.

 
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Re: Marconi 4701. 2000 series colour. My greatest restorati

Post by Till Eulenspiegel » Tue Dec 23, 2014 2:31 pm

I've got the choice of two decoder boards. Unfortunately both have two damaged coils.
One is the 7.8Kc/s tuning which is located at the bottom left of the board. The other which I have not yet identified it's function is located at the middle left side of the PCB.

If I'm ever going to do anyhting with set I'm going to need the full service manual.

The set is now in the garden workshop. The good thing about the nineteen inch version of the 2000 series is that is not too heavy. About 60 pounds.

Till Eulenspiegel.
Attachments
4701_0027.jpg

 
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Re: Marconi 4701. 2000 series colour. My greatest restorati

Post by Till Eulenspiegel » Tue Dec 23, 2014 2:36 pm

slidertogrid wrote:Crikey ! That does look rough! As to if it's saveable I would be inclined to see what the Tube is like before going any further . is it a 19" ?
If you decide to go ahead with the restoration I wish you the very best of luck :thumb I think you may need it! ttt:
Rich.

Hi Rich,
I've restored loads of basket case TVs and radios but this has to be my greatest challenge ever!
The CRT is a 19". It might be a good idea to test it first.
I've been on the look out for a 19" 2000 for years. Anyway, something to look at over the hols.

Till Eulenspiegel.

 
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Re: Marconi 4701. 2000 series colour. My greatest restorati

Post by Till Eulenspiegel » Tue Dec 23, 2014 2:37 pm

ppppenguin wrote:The full manual is in the VRAT tech library.

Hi Jeffrey,
I'm gonna need it for this one.

Till Eulenspiegel.
Last edited by Till Eulenspiegel on Tue Dec 23, 2014 3:10 pm, edited 1 time in total.

 
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Re: Marconi 4701. 2000 series colour. My greatest restorati

Post by marc » Tue Dec 23, 2014 2:54 pm

Hi Till,

Flipping heck ! you've certainly got your work cut out with this one :ccf
I shall definitely be watching with interest. :aaq
Good luck with it.

Marc.

 
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Re: Marconi 4701. 2000 series colour. My greatest restorati

Post by Focus 2 » Tue Dec 23, 2014 4:22 pm

Not an impossible restoration if spare boards are available, however the rusted transistors are going to be a problem.
Should be a great project!

Cheers and the very best of luck,
Brian

 
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Re: Marconi 4701. 2000 series colour. My greatest restorati

Post by Till Eulenspiegel » Tue Dec 23, 2014 6:13 pm

Murphyv310 wrote:Rusted chassis!
MOT failure David. So your next skill to be learned is MIG welding.
You really though should have done a John Wakely, PLUG IT IN!


Hi Trevor,
I guess it'll never pass the MOT but it could used off-road in fields.

Till Eulenspiegel.

 
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Re: Marconi 4701. 2000 series colour. My greatest restorati

Post by Doz » Wed Dec 24, 2014 8:17 am

looks like it has been safely stored in a lake .... :aaj

 
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Re: Marconi 4701. 2000 series colour. My greatest restorati

Post by Tazman1966 » Wed Dec 24, 2014 10:30 am

Made Mr Rusty-Pye tame by comparison!

 
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Re: Marconi 4701. 2000 series colour. My greatest restorati

Post by Till Eulenspiegel » Wed Dec 24, 2014 10:41 am

Hi Taz,
I was going to mention Mr Rusty Pye. Perhaps I should introduce members of the other forum to the awfulnessness of the Marconi 4701. Why not call it "Mr Rusty Thorn".

Hi Doz, Not fished out of a lake, the set came out of Malc's garage. That's where the rusty Pye came from.

Till Eulenspiegel.

 
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Re: Marconi 4701. 2000 series colour. My greatest restorati

Post by malcscott » Wed Dec 24, 2014 11:52 am

Now only the rusty Ekco CT102 left in the garage. :ccf

 
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Re: Marconi 4701. 2000 series colour. My greatest restorati

Post by Till Eulenspiegel » Wed Dec 24, 2014 12:42 pm

Didn't get much done with the set this morning. Here's a few more photies of the set.
The cabinet is drying out and is starting to spring apart. No problem it'll just glue back together.
The CRT is not the original. It's a Mazda A49-191X which has has the rimband three for push-through presentation. The original tube would have been the Mazda CTA1950 which had the rimband 1, similar to the Mullard A49-11X.
I gave the chassis a good spray of WD40 which should drive out any moisture.
Don't expect this set to be finished very soon. It's gonna be one of those resto jobs that will drag out for a long, long time.
Serial number is 1046. The 19" CRT 2000 series TVs were introduced in 1968. Price £309.
A lot more expensive than the GEC 2028 which was a bargain at £259.00.
Incidently, has anyone ever seen the Sobell 1028, a re-badged version of the 2028. Or, the Baird 705?

Till Eulenspiegel.
Attachments
4701_0030.jpg
4701_0031.jpg
4701_0032.jpg

 
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Re: Marconi 4701. 2000 series colour. My greatest restorati

Post by freya » Wed Dec 24, 2014 2:21 pm

will you clamp the cabinet to prevent it warping when dried out ?

 
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Re: Marconi 4701. 2000 series colour. My greatest restorati

Post by Till Eulenspiegel » Wed Dec 24, 2014 2:55 pm

Hi Stephen,
I certainly will, but first the cabinet must be allowed to dry out completely.
The top looks as it is slightly warped, if it is too bad it's a simple matter just to make a new one.
With regard to the rusted metalwork. I did consider Meccano, but then I was looking at some wrecked LCD TVs and I'm sure some of the metal strips from one of those could be made to fit. At least we'll get something out of those useless things.

Till Eulenspiegel.

 
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Re: Marconi 4701. 2000 series colour. My greatest restorati

Post by Till Eulenspiegel » Wed Dec 24, 2014 4:09 pm

Hi Jeffrey,
If ever this set is made to work again I might consider equipping it with direct video and audio sockets. That's one advantage of having a fully isolated chassis.
The fact is of course, although the 2000 was the worlds first all transistor TV set, the circuits are quite straight forward. There is nothing in there to be scared of. Nevertheless, a very brave manufacturing project from a firm that knew every trick in the book about being profitable. I doubt if the company made any real money from the 2000 series CTV. Great prestige product though. Look at us, see how clever we are! The others are still fiddling about with old fashioned valves.
Another company that was good at making money was Ford of Britain. In 1961 the Classic was introduced, a great over-engineered creation with outrageous styling. The first and only car which was styled around the four headlamps, beautifully integrated into the front of the car. 110,000 were sold but they lost money selling it.

Till Eulenspiegel.

 
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Re: Marconi 4701. 2000 series colour. My greatest restorati

Post by Alastair » Wed Dec 24, 2014 5:17 pm

Eee gads--Thats a bit of an extreme state there! I guess Malc's Garage is a bit like mine--where it rains inside--even when its fine outside! :bba

Then again once all the dust and crud are off, it all it wont (!) look so bad.....
--You'll have it running well by this New Year, and I'll bet you'll be watching The Queen's Speech on it Next Christmas!

A49-11X Hmm, I seem to remember one of the old valve suppliers,-- Langrex I think--Still has stock of 'em, so all isnt lost if the CRT is stuffed.....

 
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Re: Marconi 4701. 2000 series colour. My greatest restorati

Post by Lloyd » Wed Dec 24, 2014 6:25 pm

Wow :ccf

That looks just a bit crusty! My Stella ST2049a looked a bit like that when I got it, except the cabinet is chipboard and has all swollen up and looks horrible! I did manage to get it going! Tube's rather dead though...

Good luck with the restoration! I'd love to get my hands on one of these!!

Regards,
Lloyd.

 
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Re: Marconi 4701. 2000 series colour. My greatest restorati

Post by Till Eulenspiegel » Wed Dec 24, 2014 6:31 pm

The EHT generator board is in very good condition. The series regulator transistor VT6 is in the service manual decribed as a type D1693. It has been replaced sometime ago with a 2N3055 which I reckon is a good service replacement. A number of the carbon resistors are out of tolerance and will need replacing.
I have replaced capacitors C2 and C8 which are both 140 microfarads @100volts with NOS "Lorlin" elcos. Lorlin seems to be another firm that has dissappeared. In the 1970s Thorn TVs were full of them.
CCL capacitors were rebranded as "Pye"

Till Eulenspiegel.
Attachments
4701_0033.jpg
4701_0034.jpg

 
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Re: Marconi 4701. 2000 series colour. My greatest restorati

Post by ntscuser » Wed Dec 24, 2014 6:45 pm

ppppenguin wrote:I think Thorn reckoned they were effectively stuffing a fiver (tenner?) into each 2000 set they sold.


Fifty!

On the plus side they avoided the problems associated with valves being mounted on printed circuit boards.

 
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Re: Marconi 4701. 2000 series colour. My greatest restorati

Post by Katie Bush » Thu Dec 25, 2014 12:55 am

Well,

I reckon if that's a viable project, then my N1700 and N1702 VCRs should be just as viable, given they in just about the same state of health, though no missing panels and no wooden cabinets to spring apart. :)

I'm going to watch this "TV series" and see how it turns out!

This project should have been done fourteen years ago though! - If you think about it. :aal

Marion

 
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Re: Marconi 4701. 2000 series colour. My greatest restorati

Post by Till Eulenspiegel » Thu Dec 25, 2014 2:43 am

Hi Marion,
This set is not in the shop, it's in the garden workshop. So the plan is to do something to it every morning before I leave the house to go to the shop. It's in a pretty rough state. However, I've got tough out this resto job to completion. Although I think we've got to accept the fact when the set is finally working it's not going to be the best 2000 CTV in town.

Till Eulenspiegel.

 
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Re: Marconi 4701. 2000 series colour. My greatest restorati

Post by Till Eulenspiegel » Thu Dec 25, 2014 5:08 pm

Today I removed the convergence panel for cleaning. It's in surprisingly good condition. A good application of Stardrops The Power Cleaner and hot water and it's looks as good as new.
Pictures to follow.
The main power supply assembly is missing and so is the regulator board. If replacements can't be found it's a simple matter to make replacements.
The wooden block upon which the mains transformer is mounted has come away. The transformer has to come out for testing anyway, but it'll need drying out first. Meanwhile the cabinet is disintegrating nicely.

Till Eulenspiegel.

 
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Re: Marconi 4701. 2000 series colour. My greatest restorati

Post by Till Eulenspiegel » Fri Dec 26, 2014 4:12 pm

Today, after a bit of a battle I managed to extract the audio and frame timebase board, it finally came out for inspection and testing. Once again it got the Stardrops treatment and it has cleaned up nicely. The two BD116 audio output transistors are rusty but should clean up OK. No corrosion on the two BD124 frame output transistors.
The good news is that Malc has all the other PCB assemblies for the set and I will collect them in the new year.

So after writing this I will return to the shed and attempt to remove the IF amplifier and luma boards.

Till Eulenspiegel.

 
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Re: Marconi 4701. 2000 series colour. My greatest restorati

Post by Doz » Fri Dec 26, 2014 4:36 pm

Alastair E wrote:Eee gads--Thats a bit of an extreme state there! I guess Malc's Garage is a bit like mine--where it rains inside--even when its fine outside! :bba

Then again once all the dust and crud are off, it all it wont (!) look so bad.....
--You'll have it running well by this New Year, and I'll bet you'll be watching The Queen's Speech on it Next Christmas!

A49-11X Hmm, I seem to remember one of the old valve suppliers,-- Langrex I think--Still has stock of 'em, so all isnt lost if the CRT is stuffed.....


I called Langrex when I thought my GEC tube was stuffed as they still have it listed. Sadly they are "unable to locate them" .....

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