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Marconi 4701. 2000 series colour. My greatest restoration p

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

Post by Till Eulenspiegel » Tue Dec 22, 2015 1:05 pm

At last those colour bars.

Till Eulenspiegel.
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4701_0205.jpg

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

Post by sideband » Tue Dec 22, 2015 1:56 pm

...bit of hum to cure but it's nearly there! At least the tube is good and the colours are all there and in the right place. :thumb

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

Post by Till Eulenspiegel » Tue Dec 22, 2015 2:04 pm

The CRT is excellent, in fact it's as good as new. But that's right there is still a few jobs to do including that hum bar in order to have the set ready for the deadline of Christmas Day.

Till Eulenspiegel.

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

Post by Till Eulenspiegel » Wed Dec 23, 2015 8:53 pm

I'm not so certain if the Marconi will be ready on Christmas Day.
Last night the regulator board blew up, many components will have to be replaced.
The picture was taken before the disastrous event.
Anyway, it's almost 8pm and I'm going into the workshop to attempt a repair.

Till Eulenspiegel.
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4701_0206.jpg

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

Post by Katie Bush » Wed Dec 23, 2015 9:10 pm

Well now,

That's an impressive enough feat in itself! But, if I remember those early Thorn models, they gave the engineers quite a healthy run around in their day!

If you can keep that set working, even as it is, then the Queen's speech should be quite watchable, as long as the set lasts that long! Though I wouldn't reckon on watching the "Bond" movie, or whatever they're showing afterwards.

Keep up the good work.

With a Yuletide best regards,

Marion

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

Post by Till Eulenspiegel » Wed Dec 23, 2015 10:18 pm

Hi Marion,
21:18hrs: well it's good news, in fact I'll call it a News Flash! The set is working again, just one fault to sort out, the "55volt" supply is down to 42 volts. The result of this fault is that there is insufficient height. I'll now return to the workshop and find out if anything can be done this evening with the 55V regulator.
One thing is certain, the CRT is excellent. Absolutely brilliant.

Till Eulenspiegel.

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

Post by Till Eulenspiegel » Wed Dec 23, 2015 11:11 pm

The 55 volt regulator employs three transistors, VT1 the error amplifier and driver, a 2N698. The two parallel connected series regulators VT2 and 3 are a Texas type 2SO34. There doesn't appear to much information on this type, a type NT130 is said to be a near equivalent. I suspect the popular 2N3055 would serve as a replacement. The 2N3055 is one of those components that seems to be have been around for ever, the Radiomuseum suggests since 1960. I didn't think it was that early, I would have thought it was about 1964.
http://www.radiomuseum.org/tubes/tube_2n3055.html

Anyway, the 55volt regulator fault turned out to be an easy fix. The wire going to the collector of one of the 2SO34 transistors had become disconnected. The picture is now at full height again.

Till Eulenspiegel.

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

Post by Till Eulenspiegel » Thu Dec 24, 2015 12:51 pm

Steven Fry offers up a prayer in order that the set will work tomorrow at 3pm.

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

Post by Cathovisor » Thu Dec 24, 2015 12:59 pm

I shall make a point of having my 'phone connected to my sister's Wifi and will be checking here after 3pm tomorrow, Till... :bba

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

Post by freya » Thu Dec 24, 2015 1:20 pm

Great colour, looks amazing considering its been asleep so long.

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

Post by Focus 2 » Thu Dec 24, 2015 1:21 pm

Wow! This is real colour television! A fantastic achievement.

Cheers
Brian

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

Post by marc » Thu Dec 24, 2015 1:46 pm

Hi Till,

What can I say other than well done... :aad
The CRT looks to be a belter.
ttt:
Marc.

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

Post by Till Eulenspiegel » Thu Dec 24, 2015 2:07 pm

Hi everyone,
Well, let's hope the set behaves itself tomorrow for the Queen's Speech at 3pm.

So will I have to find another wreck to restore for next year's Queen's Speech?

Till Eulenspiegel.

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

Post by malcscott » Thu Dec 24, 2015 2:33 pm

Hi David, the Ekco CT102 which has kept your 2000 company for the past 36 years sits patiently awaiting your attention, Malc :qq1

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

Post by Till Eulenspiegel » Thu Dec 24, 2015 4:29 pm

Hi Malc,
I hope it's in a bad state, bear in mind I don't do easy.

Till Eulenspiegel.

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

Post by rob t » Thu Dec 24, 2015 8:05 pm

I must say its reading epic restore projects like this that make it worth being a member of this forum.
well done i look forward to the next battle .
Rob t

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

Post by TVJON74 » Thu Dec 24, 2015 9:18 pm

Well done Till,

You have yet again done a sterling job.
The picture looks amazing.
Hope you enjoy the Queen.
ttt: :aad

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

Post by Till Eulenspiegel » Thu Dec 24, 2015 9:42 pm

Hi Jon,
Let's hope the set does it's patriotic duty and work properly at 3pm tomorrow.

Coming up, the construction of a cabinet stand for the set. I reckon it deserves one. Only one problem though, the front legs have a concave shape to match the corners of the cabinet. Shouldn't be an impossible task to make one. Same style of stand was used on other 19" 2000 series sets.

Till Eulenspiegel.

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

Post by TVJON74 » Fri Dec 25, 2015 3:49 pm

Hope you got the Marconi warming up Till?

Not long to go now! ttt:

I'm sure creating a set legs will be a breeze for you and your talents.

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

Post by marc » Fri Dec 25, 2015 4:09 pm

Hi Till,
So, how was the Queen in Marconi vision ? ttt:

Marc.

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

Post by Till Eulenspiegel » Fri Dec 25, 2015 4:23 pm

Hi Everyone,
I'm sorry to only offer up bad news, the set has let the side down. Everything was prepared, set top box working and tuned to BBC1. Switched on the Marconi, the picture appeared and within a few minutes then faded out. Now there is just a blank raster. Panic stations!
Flicked over the "set white" switch to reveal a thin white line, so that proves the first anode voltage is there. The voltages on the RGB transistors are high so it looks like a fault on the video board.
The set working beautifully last night.

I'd decided to try the next best thing, the GEC 2028, and guess what? it doesn't work either.

So there we have it, it's going to be a recording of the Queen's Speech. it's all very disappointing.

Till Eulenspiegel.
Last edited by Till Eulenspiegel on Fri Dec 25, 2015 4:47 pm, edited 1 time in total.

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

Post by ntscuser » Fri Dec 25, 2015 4:41 pm

Sorry to hear that Till after all the hard work you put into it. Image

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

Post by Till Eulenspiegel » Fri Dec 25, 2015 4:45 pm

You know, I had a feeling this would happen. Glasnost rules of course, no photo shop pictures allowed. It has to be the real thing or nothing.

Till Eulenspiegel.

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

Post by Focus 2 » Fri Dec 25, 2015 4:53 pm

Really sorry to hear that after all the effort you put in to the project, a superb effort nevertheless.
I think Buckingham Palace should be made aware of this thread and an award given.
Would be a knighthood if it was down to me.

Cheers and Merry Christmas
Brian
Last edited by Focus 2 on Fri Dec 25, 2015 5:21 pm, edited 1 time in total.

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

Post by Electrical » Fri Dec 25, 2015 5:04 pm

The Queens speech is repeated on BBC2 at 18:20, so you may have time to sort it out.
Regards Stan.

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