Vidor 9" table model model CN369A. 1948.

[mark pirate]

A great result John, I wish I was in my nice warm workshop instead of welding my van for its MOT!

The picture looks superb, I look forward to seeing the finished set, I hope you have another lined up, as the weather is even colder next week....

Mark

[Heatercathodeshort]

1946 HMV1803. 1948 Peto-Scott 12". 1947 Ultra W470. These are just the mains EHT ones. Then there is the Ekco T196 15" and the Philips 1700A projection and.....
Don't hold your breath. These are long term projects. When I start something I like to finish it. The Ultra is a classic example. 90% finished then put aside for something else. It needs a kick start as it's a cracking tube and picture. Final pics of Vidor next week. John.

[mark pirate]

The Ultra is a classic example. 90% finished then put aside for something else.

My Bush TV22 is also about 90% done, I will be sending off the blocking transformer for a rewind in a couple of weeks, the set has been waiting for completion for over a year now

I also have two Peto scott 405 line tellys to start, and an ever increasing pile of radio's patiently waiting their turn, who said retirement was a time to relax?

Mark

[IJK2008]

John

Like all your threads I have really enjoyed following this one.

As usual a great result.

I like pre 1950s sets but mains EHT is a step too far for me!

Ian

[Heatercathodeshort]

Thanks Ian. I have really enjoyed this one myself. I have often looked at the layout of the Vidor CN377 series in the 48-53 Newnes books and thought 'I would like to have a go at one of those'. I never thought I would and I am very grateful to another vintage television enthusiast [Thanks very much John] for entrusting the little Vidor to me. It will be in good hands I assure you.
Mains EHT demands respect but so does a AC/DC live chassis receiver. If you think 50c/s EHT is dangerous you want to see the things neon sign installers/repairers get up to. Not to be recommended or seen by the faint hearted. Take great care as always and thanks again, John.

[Stubble]

John

I have been riveted to this thread, very enjoyable seeing this fine set coming back to life, a proper television it is too.

Excellent and thank you for sharing.

Lee

[Heatercathodeshort]

Thanks Lee. I have enjoyed it as much as you and that is what it's all about. It's only old tellies and a bit of a challenge. Great fun. John

[Heatercathodeshort]

I carried out the final electrical bits this afternoon. Taking great care, cleaning, adjusting and sorting out a minor wiring problem, I have managed to retain the original sliders. The line hold was O/C at one end so I simply reversed the connections. They are of very good quality.
There were three assembly faults on the Vidor that were discovered during the overhaul. The H.T. supply passes through several tag strips on its journey around the chassis. At a couple of tags the wire had been slipped through the tag eyelet, sleeved and run along to the next tag, repeating the mistake a second time. As assembly continued extra wires were mechanically secured to the tags then finally soldered. Insufficient heat and solder was applied at this point leaving the bottom looped through H.T. wire completely dry joint at two points. It was only when I heard slight arcing taking place that I discovered the fault and that was after much probing.
I bet this was the only stock fault in these little receivers and Vidor may have sent a technical sheet to their agents advising them of a possible problem.
The second one caused some very odd behaviour of the rear sliders and this was first picked up earlier on when fault tracing the timebase generators.
It was noticed that removing the cathode connection from the line output valve to the 200 ohm width slider not only collapsed the line but the frame also It was also noted when rigging up a temporary line hold control, that a connection had to be maintained to the faulty width control slider to maintain frame scan...All very odd.
This afternoon the mystery was solved. All four slider controls have one end connected to the chassis. They are linked with a short length of black wire looped through the connecting tags. All very satisfactory but the assembly lassie had forgotton to link this to earth and the sliders were being returned to chassis via the width slider and the cathode of the line output valve! The connections were blackened and an earth wire had never been fitted from new.
Surprisingly probably due to the very low resistance involved it had no effect on the picture but it did make the controls rather interactive. With an earth link in place and the contols repaired the electrical work is now finished.
Just a few minor mechanical items to complete.
The remains of the TV22 mask must be removed from the replacement CRT. It is stuck around the rim of the CRT bowl and it looks like I will have to soak it in diesel to soften the goo so that it can be rolled off.
The second item is to extend the brilliance control spindle. I discovered a suitable EX WD one for the focus pot and I know I have some more somewhere but you don't use them a lot these days and I've probably pugged them into a 'safe place' somewhere.
Just a cabinet clean up and all should be well.
The test card is incredibly stable. Not a trace of drift and even the electromagnetic focus keeps sharp over an extended period. The metered EHT is up with the PYE D16T at around 6.5kv giving splendid pictures. The EHT with a mains derived system is usually no higher than 5kv maximum but there are a couple of Ekco's at 12kv....
Not a lot to do now, just the frustrating bits.

Mention is made in another thread about the blue glow in PL/EL38 line output valves. As David has mentioned, this is quite normal and can often be observed in EL84 audio output valves. This does not show a fault or in any way soft unlike the purple haze you get with a poor vacuum valve. The blue glow in the 38 series line output valves is in sharp focus and very clearly defined. One picture shows the EL38 in the Vidor. The valve heaters appear to be over run due to the time exposure.
John.
P.S. The odd sword shaped test card is viewed through the back of the MW22-14C tube.

[line sync]

Hi john
When you used the 50uf cap to discharge threw the line scan coils , how many volts was it charged up to ?
I have a set which has the picture shifted to one side and eventully gave up on it thinking i may have had a tube fault , so this little cap discharge trick may solve my problem.
Have you managed to get the decomposed rubber of your vidor c.r.t yet ?
I,ll be interested to here how you tackle this problem .
I used a stanley knife blade to cut the remains of a mask off once but the rubber was soft.
I,m looking forward to seing the vidor in its cabinet.

Robin

[Mikey405]

That's an amazingly good picture John. Well done on an excellent job sorting that out.

Kind regards.

From Mike.

[Heatercathodeshort]

Originally Posted by line sync

When you used the 50uf cap to discharge threw the line scan coils , how many volts was it charged up to ?Robin

Hello Robin,
Nothing special here. I just grabbed the nearest electrolytic to hand and stuck it across the H.T. line. After disconnecting one side of the line coils [the other side goes to chassis] I discharged it across the vacant pin. I got the polarity right first time so it is fine. The cap was 32uf but anything from 8-100uf should be OK as the scan coil wire is very thick.
Once I remove the remains of the old rubber mask from the tube I will be able to reassemble the Vidor. It will not take long but the rubber is like concrete and will require softening. Regards, John.

PS Thanks Mikey!

[Hunts smoothing bomb]

That picture looks truly superb John.
Even though this set was made some 30 years prior to my existence, I find the valve line up, minimal component count, use of helium thyratrons and general layout most interesting. Exciting even.

Great write up again John

Cheers and all the best.

[Heatercathodeshort]

I promised to post the pictures of the Vidor when boxed up. I did notice when working on the chassis that the line output transformer was not the original. The stain on the chassis was larger than the type fitted. It looked like a Vidor part but was obviously taller and narrower than the original causing the top of the circular can to foul on the scan coils, not nice. It was not possible to move this to a new position on the chassis due to other components getting in the way. I decided to remove it and have a look at the contents of the can.
Only three wires emerge from the bottom. H.T. to the primary and two secondary for the line scan coils. The other primary wire is passed through the top of the can to the anode of the line output valve EL38. No flyback EHT remember.
The small transformer is encased in a rubber 'sock' to reduce the 10kc/s whistle and 'stuffed' into the can. There was plenty of space at the top and bottom with the assembly able to slide vertically by a fair amount.
It was decided to cut approximately one inch from the bottom of the can and re drill holes for the fixing lugs and the lead out wires. The whole assembly was fitted back in the can and a new fixing hole was drilled in the chassis.
The LOPT is now in a much better position under the tube neck assembly and it works a treat barely getting warm after a few hours of use.
Considering the very poor storage [garden shed] that must have continued for half a century, I was very lucky to save this little Vidor. It could easily have got soaked due to a failing roof or eaten away by woodworm. As it turns out the only slight damage is a small piece of flat veneer that is missing from the right hand side of the upper rail. It was well worth all the many minor problems encountered and as we all know, problems can be solved, issues can only be talked about!
Final shots showing cabinet and general appearance with live pictures. [Hand held 1/25th second! Hence dodgy focus]
Regards, John.

[ianm]

Hi John,

That's a really excellent final result, well done! You'll no doubt remember that I've got one of these too and I'm certain there aren't many about. I wonder how many actually exist now.

[Heatercathodeshort]

Hello Ian,
I must admit I did wonder that myself. It would be intersting to know if any Forum member has a working example of Vidor with mains EHT.
The switched channel 1/4 model must have been very popular with agents in the Bedford/Northampton area.

Old television receivers are like scabs. You can't leave them alone and you just have to keep picking at them..
I spent a few moments this morning remounting the little tube. The neck is held by an elaborate clamp and with a bit of fiddling I managed to centre the tube in the focus assembly with the wing nut adjusters for picture positioning mid way.

It is now centred correctly! Before passing a current through the line coils it was miles off but after I gave them a jolt, it was just about brought into line with over adjustment of the wing nuts. The extra fiddling has paid off and I don't think I can improve the result. The FINAL picture taken a few moments ago. John.

[Nicklyons2]

I don't know who to give the biggest credit to; HeaterCathode or the original designer - the picture and the set are a credit to both. I'm minded to wonder if anyone will be restoring a current flatscreen set in half-a-century plus; sadly, I fear many of us won't be around to find out - but I think we might hazard a guess.

The Car guys have a site 'how many left' where you can find out how many vans/cars of any given model are still running in the UK but, as the TV licence isn't 'tagged' to a particular set we'll never know how many of our 'vintage' specimens are still running.

[Heatercathodeshort]

Definitely the team that designed this little Vidor Nick. 1948 exactly the same age as me! Well enjoyed and a pleasure to work on such a well thought out receiver. Vidor had one of the best pedigrees and like so many great makes, sadly not recognized for their efforts.
Cheers, John.

[audiomagpie]

Enjoyed this whole episode, as ever John.

Fantastic result!

Greg

[line sync]

Hi john ,
Another really great read and first class restoration.
That vidor shows a really good picture and does,nt it look nice in its cabinet.
I wonder how david,s getting on with his masteradio ?

Robin

[FERNSEH]

It's shame that Vidor pulled out TV manufacturing in 1955. Perhaps they had the wrong image, perceived as just the products of a battery maker. The fact is as I wrote earlier, Vidor radios and TVs had real heritage being essentially rebranded Burndept products. A well respected pre-war manufacturer.
I'm sure that Burndept made a pre-war TV set, or intended to do so.

DFWB.