Re: Baird T5 retoration project.
 

Hi Phillip,
it is indeed magnetically deflected and focused triode, yet has a 2" diameter neck!
The base is similar in size to the 12 pin Electrostatic base that was common at the time (as used on the VCR97 etc.) but with less pins. The base socket itself is shaped like a cup.

Cheers
Andy

Re: Baird T5 retoration project.
 

If you bust that tube you'll be sick as a parrot...

Re: Baird T5 retoration project.
 

I think you will find that this is the internal part of David's new cabinet for the T5. The original mirror lid will be salvaged and painted a lovely shade of pink. Then new sides will be made from trendy clear varnished OSB ;D

Cheers
Andy

Re: Baird T5 restoration project.
 

Hi Andy,
I'm sure the owner of the T5 wouldn't be all that happy if his set finished up like that Decca 121 I bought from a charity shop in Newcastle last year.
I can report that all the green paint has been stripped off the cabinet surfaces.

The 15mm plywood for the cabinet floor and shelf can be bought from B & Q. It's the furniture grade walnut veneered 9mm plywood I'm still on the lookout for.

DFWB.

Re: Baird T5 restoration project.
 

I've found some pictures of the Bakelite cup tube socket. I looks a bit like a distributor cap...

Hi David,
A quick internet search on my phone shows quite a few suppliers offereing single side walnut veneered birch plywood. However on closer inspection, none of the first few that I clicked on actually had Walnut available from stock.
No doubt it will be a case of it being made to order and hence expensive. Still probably the best option though.
Is a standard 1.2 x 2.4m sheet large enough to make the two sides when cut in half?

Of course there is still my OSB suggestion, very "on trend".

Btw. A cabimet maker once informed me that double veneered playwood was the way to go to prevent warping. Is this still the required thing to do with modern plywood with its more stable bonding resins?

Now, going back to the top of my post here and on the subject of Phillip's (Catkins) earlier question... Was such a wide neck a major problem for the magetic field of the scanning? EMI seemed to think so with their narrowed (at the scan coils) necks on their early tubes. Were they wrong? Think how many OBEs* could have been saved if they had not started off down the narrow neck route...

*Order of the Broken Emitron

Cheers
Andy

Re: Baird T5 restoration project.
 

Three 2400mm X 1200mm sheets (8 x 4) sheets of plywood have been ordered, delivery tomorrow.

The 9mm sheet is top quality grade A and is to be used in the construction of the front and side panels. The 12mm and 15mm sheets are BB grade for the construction of the cabinet floor and chassis shelf.

DFWB.

Re: Baird T5 restoration project.
 

This thread has gone deathly quiet just when we got to the climax of lifting the tube out and testing it!

Re: Baird T5 restoration project.
 

The tube remains in the cabinet until after the Christmas holiday.
In the meantime the plywood sheets have been cut up into more convenient to handle 1200 X 1200mm pieces. The vision and sound receivers will be connected to a power supply. There's a good chance that these units will be serviceable.

DFWB.

Re: Baird T5 restoration project.
 

Very wise David, a job best done when sober!
It does look quite a scary beast to handle, removing the 15" Mazda in my Ultra was nerve wracking enough, no doubt the tube in the Baird is a fair bit longer.
:beer:
Mark

Re: Baird T5 restoration project.
 

Hi Mark,
It sure is a long tube being something like 34inches! In comparison the 15" Cossor CRT in my Baird T23 is "only" 27 inches long.

The Emiscope 6/6 is 28 inches long.

DFWB.

Re: Baird T5 restoration project.
 

Restoration work has restarted. The new shelf for the receiver and timebase chassis assemblies is presently being made. 15mm plywood is the material used to make this part. The panel is marked out for various holes and the centre section which will be cut out for the CRT neck components.

Meanwhile the CRT remains in the cabinet.

DFWB.

Re: Baird T5 restoration project.
 

The new cabinet shelf and the old one for comparison.

DFWB

Re: Baird T5 restoration project.
 

Do you want to borrow my leather bomb disposal outfit before you remove that tube David? It takes 3 hours to get into it..

Nice start on that rotten cabinet. Once the tube is reinstalled it will be great fun to get the 'works' working. John.

Re: Baird T5 restoration project.
 

NEWS FLASH!
This evening the CRT was removed from the cabinet. A real scary job.

The tube now rests on the special receptacle that was made for this restoration project.
The CRT has a thick neck, 45.5mm, much thicker than the Cossor tube installed in my Baird T23.

Now the dismantling of the cabinet can begin.

DFWB.

Re: Baird T5 restoration project.
 

Relief! Well done David. I speak as someone who has been through the same experience.

How did you do it in a little more detail?

Steve

Re: Baird T5 restoration project.
 

Hi Steve,
Well, it was a sort of an anti-climax. Apart from dressing up like the Michelin Man wearing googles and a face visor the tube was simply lifted out and placed on the special stand. That was a good idea of Andy's to suggest I should make it to facilitate easy removal of the tube. It is a big tube but it doesn't weight very much being made with very thin glass.

The EHT transformer in my HMV 901 has failed so that's another tube out job before access to the power supply unit is possible.
And to think we thought the Emiscope 6/6 tube was a scary thing.

From the ETF: http://www.earlytelevision.org/german_crt.html

DFWB.

Re: Baird T5 restoration project.
 

Is the Cathovisor made of Pyrex?

I think the 6/6 being Pyrex is probably a bit safer.

Peter

Re: Baird T5 restoration project.
 

Hi Peter,
At this stage of the restoration I haven't examined the tube to determine if it was made with soft glass or Pyrex.
Agreed, I always believed that the Pyrex tubes were safer, but who knows?

The cabinet is coming apart nicely. Today I will make a new cabinet floor, very easy part to replicate.

DFWB.

Re: Baird T5 restoration project.
 

I've just done a Google search and found a Bonhams sale description for a 15 MW2. Scary yes, but could be worse.

Peter

"CATHOVISOR CATHODE RAY TUBE, BAIRD TELEVISION LTD.\nC.1936, Hysil (Pyrex glass), type 15 MW2, serial No. A2666, pre-mask screen diameter 14½". With the early roundel strip contact boss in black Bakelite, with gilt capital company transfer BAIRD reading across, exposed glass area at neck for heater element view, neck funnel with internal anodised beam coating, etched to cone section with serial and type details with BRITISH MADE below, good phosphorous coated screen field with no ion burn trace in disconnected status."

Re: Baird T5 restoration project.
 

Hi David,
I'm glad it came out without any trouble. I must admit, I was a bit worried about what would happen...


Cheers
Andy

Re: Baird T5 restoration project.
 

Latest pictures of the cabinet restoration.
This after noon I'll make the new cabinet floor.

DFWB.

Re: Baird T5 restoration project.
 

Todays job. Test fit the new cabinet floor.

DFWB.

Re: Baird T5 restoration project.
 

The replacement focus coil support. Two attempts to get this one right. Problems cutting out the 4" diameter hole.

DFWB.

Re: Baird T5 restoration project.
 

Today the construction of the new CRT support board was completed.
The frame oscillator transformer test fitted. As the panel appeared to be in better condition when compared with most of the other wooden parts in this set I did consider restoring it, but abandoned that idea when it started to disintegrate.

The third picture shows all the new parts made so far and the serviceable items including the CRT.

Coming up next: the loudspeaker baffle.

DFWB.

Re: Baird T5 restoration project.
 

Brilliant work, David. It must be satisfying for you to see how it is coming together.

Steve

Re: Baird T5 restoration project.
 

Hi Steve,
I'm really enjoying this restoration project and it's progressing very well. Today the loudspeaker baffle was removed. As the attached picture shows it's in a terrible state. A replacement baffle is being made. It should be finished tomorrow.

DFWB.

Re: Baird T5 restoration project.
 

The new loudspeaker baffle.

DFWB.

Re: Baird T5 restoration project.
 

Making good progress David.

It will be really interesting when you get to the parts on the outside of the cabinet!
I'm looking forward to seeing your solutions for those very difficult parts.
I'll certainly learn a lot!

Jac

Re: Baird T5 restoration project.
 

Good evening Jac,
The cabinet side panels should be easy to replicate. The front of the cabinet consists of three parts. The upper panel has the user controls, the middle section has the loudspeaker aperture and the much larger lower section has the door which conceals the pre-set controls.
The middle section has already been removed for inspection and like all the other plywood panels it is useless, completely rotten. So this is the next part to be replicated. 12mm plywood will be used to replace the original 1/2" thick plywood panel.

DFWB.

Re: Baird T5 restoration project.
 

Testing the sound receiver. Using a borrowed power supplier set to provide 250 volts HT and 4 volts for the valve heaters. The audio amplifier consists of a Mullard 354V triode and a Mullard PENA4 output valve. That part of the circuit is working OK and there is some activity when the top caps of the FC4 detector and TSP4 IF amplifier are touched. All the B & I make capacitors are leaky and will have to be restuffed.

The loudspeaker is of the energised type.

DFWB.

Re: Baird T5 restoration project.
 

A new loudspeaker panel has been made. After several attempts at making the new panel a perfect fit I can sign off this stage of the cabinet restoration.
Now a decision on what to do with that front panel. Should I restore it or make a replacement? There's still a possibility that some nasties exist in the eighty year old plywood. You have to be ruthless when it comes to dealing with woodworm infestation. Any doubt cut it out!

DFWB.

Re: Baird T5 restoration project.
 

I wouldn't take the risk david, there might be dozens of sleeping woodworms in there waiting to come out in spring time so the sooner you get all that infested wood out of your shop the better.
This is a very interesting restoration you`ve taken on and I look forward to reading all the new posts.

Robin

Re: Baird T5 restoration project.
 

More fodder for your next conflagration David!

Ed

Re: Baird T5 restoration project.
 

Hi Robin, Hi Ed,
I've decided that the front panel must be replaced. There could well be some horrors in the plywood waiting to destroy the cabinet again. And burn those old rotten parts as soon as possible!

Correction to my last post. The loudspeaker should be sited on the left side of the front panel.

DFWB.

Re: Baird T5 restoration project.
 

Anobium Punctatum just luuuuurves plywood - in fact, it was 'introduced' into this country via Indian [plywood] tea chests! The early [cabinet] shots posted by David seem to show lots of fresh frass on the bottom of the unit - indicating live activity. So - I'd go along with everyone's counsel regarding incineration of the various remnants.

Generally, woodworm is relatively easily eradicated using 'toxic box' techniques i.e. treating all surfaces with something like Five Star Cuprinol [prior to introducing the item into your home!]. The hibernating beetles need to eat their way out of the host wood - and fly once per year in order to mate!

Treatment does not however rectify the unsightly 'flight holes' produced by these insects - albeit that a moderate attack can sometimes be carefully disguised. Fortunately, woodworm is rarely 'structural' in its effect [unlike say Deathwatch] - but it does weaken wood and expose it to other potential maladies e.g. rot/fungal attack.

And in this instance ....... David seems to have happened upon a 'rare example' !!!

Re: Baird T5 restoration project.
 

Tractionist wrote: "Treatment does not however rectify the unsightly 'flight holes' produced by these insects - albeit that a moderate attack can sometimes be carefully disguised. Fortunately, woodworm is rarely 'structural' in its effect [unlike say Deathwatch] - but it does weaken wood and expose it to other potential maladies e.g. rot/fungal attack."

Hi Tractionist Good advice. Next week I will make a new front panel. It doesn't make sense fiddling about with the damaged front panel because even it can be saved by using chemicals it will need re-veneering. So why not apply the new veneers to a new solid panel instead.

DFWB.

Re: Baird T5 restoration project.
 

I was hoping that you'd say that David - but I didn't want to double-think the maestro! That front panel is riddled - in fact it looks as tho' it's taken a few hits with 'grape shot'!

Stay with it - it's coming together ........ :thumbsup::thumbsup:

Re: Baird T5 restoration project.
 

In fact the panel is so rotten it is possible to push a screwdriver blade through it.

However, the hardwood framework is in excellent condition so at least some parts of the original cabinet can be reused.

DFWB.

Re: Baird T5 restoration project.
 

The construction of a new front panel has started. 12mm plywood will be used and the outer surface will be book matched veneered to resemble the original panel.

DFWB.

Re: Baird T5 restoration project.
 

The rotten front panel was removed today. Superficially, woodworm holes apart, it looked like a solid panel but was in fact just like the other plywood panels - it resembled a Weetabix biscuit. Crumbled into dust.

DFWB.

Re: Baird T5 restoration project.
 

Have you scanned the logo/script?

Re: Baird T5 restoration project.
 

Hi Tractionist
We've taken photographic pictures of the TELEVISOR logo. That's one feature of the set that must be preserved. It might be possible to save the control panel. It seems to be solid, but I said that about the front panel. The T23 has the Baird name on the control panel.

DFWB.

Re: Baird T5 restoration project.
 

Hi David - if you can lift that part of the veneer [with a Kraft knife?] without damaging it .... it may be a good idea to both scan it, and see if you can incorporate it into the new veneered panel [marquetry style] ..... after having treated the rear of it with Cuprinol etc.

This always assuming that it too isn't perforated with worm flight holes ...... :wave:

Re: Baird T5 restoration project.
 

Tractionist wrote: "Hi David - if you can lift that part of the veneer [with a Kraft knife?] without damaging it .... it may be a good idea to both scan it, and see if you can incorporate it into the new veneered panel [marquetry style] ..... after having treated the rear of it with Cuprinol etc."

I was thinking about something on those lines. The critical part of the restoration will be the removal of the control panel. This will have to be done in order the new front panel can be fitted. Let's hope it doesn't disintegrate when comes to releasing the joints between the control panel and the upright corner pieces.

DFWB.

Re: Baird T5 restoration project.
 

After quite a few adjustments the new front panel was test fitted yesterday. The next stage of the front panel reconstruction will be to cut out the aperture for the timebase controls.

DFWB.

Re: Baird T5 restoration project.
 

This week I'll have to make a decision what to do with those cabinet sides. They are solid enough but as the pictures show are full of woodworm holes. No doubt with the use of wood filler the holes can be made to disappear but there's always the possibility there could still be nasties in the plywood.

Worth taking a chance or make new panels? Bear in mind the set does not belong to me and I don't wish to disappoint it's owner when those tell tale holes appear again on the cabinet.

The side panels are easy enough to replicate. Use 9mm grade AB plywood.

DFWB.

Re: Baird T5 restoration project.
 

Hi David,

I reckon you've answered your own question there ;)
Better safe for the customer !

Marc.

Re: Baird T5 restoration project.
 

Hi Marc,
There's nothing special about the side panels, no book matching of the veneers so as long as the best wood grain pattern on the new plywood is chosen there will be no problems with the final finish of the replacement panels.
But before a final decision about the fate of the cabinet sides is taken, let's find out what the views of other forum contributors are about the matter.

DFWB.

Re: Baird T5 restoration project.
 

No point spoiling the telly for ha'p'orth of ply.

Re: Baird T5 restoration project.
 

Hi Pillenwerfer,
I reckon those panels are for the chop! That'll keep me busy this week. No LCD TVs to be fixed when we're dealing with television history.

DFWB.