Restoring a Baird Everyman T29A.

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The Baird Everyman was released for sale in the later half of 1949 and was one of 4 models available at the time , these being The Portable, Everyman, Countryman and Townsman.
The Everyman was aimed at the man who could not quite afford a television and was priced at just 39 guineas including purchase tax. This works out at £40.90p in today's money.
Baird said of their Everyman model in an advert appearing in theAapril 1950 edition of Electrical & Radio Trading, this is the worlds lowest priced television. The Everyman is a 9" table model housed in an attractive sloping back cabinet and using only 11 valves.

It is quite apparent looking at the circuit diagram that this set was the cheap and cheerful of its time and that Baird used the least amount of components that they could get away with.

I purchased one of these sets over 2 years ago and because it was so far away from me I accepted the seller's offer to send it to me by courier. The seller assured me it would be well packed but when it arrived it was very apparent the little set had had a very rough journey. You can imagine how I was feeling whilst unwrapping the set as glass, screws, wood and other bits fell out. The set had obviously been dropped breaking most of the glue joints of the cabinet and worst of all the CRT was broken.

On removing the rear of the cabinet I could see the scan coils had been damaged by the broken glass on the flare of the CRT where the neck had broken off. I could also see all the valves were missing, the dropper had unravelled itself, the loudspeaker and baffle board had become detached, a couple of the rear mounted pots were broken, a few capacitors were missing including the mains smoother. The mains lead, valve screening cans, selenium rectifiers, a few resistors and worst of all the LOPT were missing. Also add to this lots of cut wires and a few alterations which didn't appear in the service sheets. Obviously this set had been used for parts along time ago but I wasn't expecting it. Needless to say I will never use a courier service again.

The chassis was in such a mess that I had to ask myself was it worth restoring it, but I liked the little set and they don't come up for sale very often so I decided to go for it. I had tried on a few occasions placing wanted adds for parts on the forums with no success so started thinking about fitting a LOPT from another chassis. I happened to have a Murphy V230 handy with a very tatty cabinet but it produced a raster so I knew the LOPT was good. I had never done this before so met up with John (HKS) at an event last year and showed him circuit diagrams and explained what I wanted to do. John gave me good advice and made me think it was no big deal and said go for it, you`ve got nothing to loose.

Before fully committing I had to do something with the scan coils because I hadn't got anything suitable to replace them with. The damage was such that I had to dismantle the coils to have a go at repairing them, so seeing the coils were coated in wax a hot air gun was used to melt this. After removing the two frame coils which were the damaged ones, the hot air gun was used again to melt the wax impregnated bandage that wraps around the coils. Finding and repairing the 4 damaged loops was done using a strong magnifying glass. The wire was as thin as hair so I kept my fingers crossed that I had joined the right ones together. The coils should read 700R each and I had a difference of 30R. The smallest size heatshrink sleeving was used and I painted the damaged area with varnish before wrapping the bandage back on. The fun part was fitting these two coils back where they had come from and I found that a piece of 36mm plastic waste pipe as used on your bathroom sink is slightly larger than a CRT neck so this was used, enabling me to heat the coils up and squeeze them back into the scan coil assembly until the plastic pipe would pass through. This was a time consuming and very messy job that I never want to do again.

I next removed the LOPT from the Murphy and made a mounting plate to fix it to the Baird chassis. I found a dropper that was too long so used a stone cutting disc on an angle grinder to cut it down to size. The main smoothing electrolytic can took a while to find because this is an American style having 4 twist lugs which secure it to the chassis. The usual chassis restoration followed after this including restuffing 4 electrolytics and putting right several changes that had been made. A new mains lead was fitted, a silicon rectifier and resistor to replace the missing selenium rectifiers and a set of valves was found.

Because there was a high probability that things would go wrong I decided to power the chassis up with no CRT fitted. On powering up the chassis I was very pleased to measure 6kV off the newly transplanted LOPT and the HT was good at 180V, however after the chassis had been on for about 5 mins I noticed the anode of the frame osc valve was glowing red.
After switching off and making tests I found the frame blocking osc transformer was faulty, so that's why the mounting screws were missing. This transformer was sent to our Ed Dinning to be rewound and he made a marvellous job and after refitting it the osc valve no longer over heated.

It was now time to fit a CRT so a CRM92 was found but because this has a longer neck than the CRM91 the focus magnet assembly had to be moved back and also the bulb is a bit larger so I had to modify the fabric strap which holds the CRT to the front of the cabinet. On powering up again the CRT produced a raster but no signals from the Aurora were shown on the screen. It turned out the RF stages had been retuned to receive another channel but after a bit of adjustment a test card was being displayed on channel 4 Birmingham. Time was spent playing with the LOPT trying to get the best out of it and as you will see from the pictures the end result is pretty good. I was lucky the line hold locked in the mid range of the line hold pot. I feel a lot more confident about fitting a LOPT from another chassis in the future if the need arises. I next completely realigned the chassis and this made huge improvements to the sound. A new 10P14 frame output valve cured the lack of height.

At various stages whilst waiting for parts I carried on with the cabinet, gluing it back together and making wooden supports to keep the dimensions of the cabinet correct. Clamps were used in other areas and glue blocks had to be made as some were missing. I had to make 2 wooden pieces that fit on the top inside edge of the cabinet front which hold the rear cabinet section in place. About 10-15 woodworm holes were filled using beeswax wax rubbing blocks and then the cabinet had a linseed oil mix applied. The expanded metal ventilation side grills would not clean up so were treated to a few coats of gold spray paint. Although far from perfect the cabinet has turned out quite nice and I'm pleased how it glued back together.

On the whole I'm pleased how the set has turned out, the CRT is not the brightest but you could sit and watch a film on it.

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More pics:-

Pictures 1 & 2 are cabinet damage.
Picture 3 is the Baird circuit diagram.
Picture 4 is the Murphy circuit showing the LOP stage.

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And more pics:-

Picture 1 restored chassis and CRT.
Picture 2 Murphy LOPT and mounting bracket.
Picture 3 Murphy LOPT fitted on baird chassis.
Picture 4 replacement CRT fitted.
Picture 5 showing test card with poor horz linearity.

[FERNSEH]

Hi Robin,
A good job done, well worth all the effort. It's amazing how the designer got away with such simple signal circuits, just one common vision and sound RF amplifier followed by single stage sound and vision RF amplifiers.
Good idea employing a Murphy V230 line output transformer. Obviously you have omitted the efficiency diode, perhaps the line linearity might improve by incorporating such a device.
I suppose in modern sales parlance the Baird T29 would be called an entry model.
DFWB.

[MonochromeMarc]

Hi Robin,

A very impressive recovery from a near disaster, very well done !

Marc.

[DangerMan]

You are right to feel pleased too!
Nice set and a cracking job all round.

Pete

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Thank you for the praise guys.
I've got more pictures to add tomorrow.

Robin

[Brigham]

'Just' 39 gns. is over two grand in today's money!

[Heatercathodeshort]

What a simply cracking job Robin. This was not an easy task and there are very few around that would be capable of carrying it out.
The line linearity is always a problem with LOPT substitution but at least it gets the chassis working and is well worth the trouble taken.
A damper diode would no doubt clear up the linearity problem but it would spoil the incredibly low number of valves employed. Regards, John.

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I meant converting it to pounds and pence.
Just wanted to say david the choice of LOPT was purely based on the fact that the murphy was of a similar age , was a scrap set and the LOPT worked.
One thing I wanted to ask is can anything be done to improve the horizontal linearity ?
I`ve read that this was sacrificed on cheaper made sets and that this is how this set is meant to be , in fact forum member stevehertz told me last year that he restored one of these sets along time ago and I believe he said his set also displayed poor linearity.
Thank you for the capacitors steve , I used a couple of them.
I still need to make a bottom inspection cover for this set as this was also missing.
Whilst restoring this set I noticed that one of the chassis grounding tags moved as I was unsoldering a component from it so I went round all of them and found most of them were loosely fitting.
This could have caused a load of faults if not noticed.
The tags are riveted to the chassis and my way of dealing with them was to support the chassis one side and use a hammer and a long bolt to hit the top of the rivet on the other side.
This didn`t work for two of them so they were drilled out and 6BA screws and nuts fitted.

Robin

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Here are some more pics.

Picture 1 showing the wooden blocks I had to make to support the rear cabinet.
Picture 2 showing the underside of chassis after restoration.
Pictures 3 & 4 the finished set.

[FERNSEH]

The Baird T29 has eleven valves, can this number be reduced? Well, V2 the vision and sound demodulator diodes can be replaced by germanium diodes, but such devices were not readily available to TV manufactures in 1949. Frame timebase valves V7 and V8 could be replaced by a single valve, the 6SN7GT has been used successfully as a frame oscillator and output valve.
The 12SN7GT has a 0.3amp heater for series chains. The Viewmaster TV employs a selenium EHT rectifier, that gets rid of the EY51.
So there we have it, valve count reduced to eight!

DFWB.

[Lloyd 1985]

Shame about all that damage, but you have done a brilliant job on restoring it! The styling of the cabinet is very similar to the Philips 385U TV. Actually, it looks slightly better than the Philips!

I would never trust a TV like this to a courier, they just aren't careful with stuff any more, I remember at work me and my boss stood and watched in horror as the courier picked up a flight case containing brand new computer equipment (that I'd just finished building and testing!) and launched it with force into the back of the van. My boss made him take it out of the van and wait whilst we tested it again! These old TV's were made when the delivery drivers were more careful with stuff, especially if labelled as fragile. You also have to factor in that time has taken its toll on old glue joints in wooden cabinets, and they have already weakened before being bashed about.

Regards,
Lloyd.

[Heatercathodeshort]

If you can't pick it up personally, don't risk it. John.

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I fully agree john although it was rotten luck for that damage to happen on the very first time I had a television sent by courier.
There is something not quite right almost at the top of the test card which makes me think the repair to the frame scan coils was not as good as it could have been but I did my best.
There is unequal line spacing and bending of the vertical lines near the top.
Please see picture.

[1100 man]

Hi Robin,
I would just like to add my congratulations on a very professional restoration. It's always nice to see a basket case being brought back from the dead! (I'm a sucker for them myself ) Interesting to read about the LOPT transplant- I have a similar need to do so with a set I have.
I imagine any set where the tube neck is clamped to the chassis is almost bound to snap the end off if dropped, so probably there was nothing the sender could have done to prevent this, packaging wise.
We used to service timelapse VCR's which arrived by courier- I seem to remember the Mitsubishi HS5600 was a very poor traveller, often being reduced to a pile of smashed plastic
Well done,
Cheers
Nick

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Thank you for your comments nick.
Here is a picture of a fault condition that happened during restoration that had me confused for a while.
During my tests I could feel AC on the chassis so switched off and reversed the mains polarity and on switching back on the fault had garn.
You can imagine I was surprised by this so I swapped the mains back again and the fault reappeared.
Can any body offer an explanation for this ?
Also has any one got thoughts about my possible scan coil problem on post 15 ?

[Freya]

How are you powering your aurora, transformer or switch mode ?

on the Baird it may be worth check or change C11.

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Switch mode Stephen .

[Freya]

I have had some surprising differences using transformer vs switch mode with the aurora on many of my sets, so much so that I stick to transformer now.
Some of these were patterning, cogging to varying degrees. The power supply could be switched over from one type to the other whist the tv set was on and the previous issue disappeared.
I must admit to not trying the polarity of the sets mains connector at the time.


Might not be relevant to you but it was something I have encountered.