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-   -   Baird T5 restoration project. (https://www.vintage-radio.net/forum/showthread.php?t=152005)

Nuvistor 2nd Apr 2019 3:26 pm

Re: Baird T5 restoration project.
 
Play safe David, be a disaster if any worms remain and start on all that great woodwork you have done.

FERNSEH 2nd Apr 2019 4:18 pm

Re: Baird T5 restoration project.
 
Hi Frank,
That's right we know from past experience that those worms can re-emerge long after a state of dormancy.

Fit the new panel. It's identical to the original.

https://www.wisepropertycare.com/ser...tle/lifecycle/

DFWB.

peter_scott 2nd Apr 2019 4:50 pm

Re: Baird T5 restoration project.
 
Play safe but retain the reconstruction with the set.

Peter

FERNSEH 2nd Apr 2019 7:28 pm

Re: Baird T5 restoration project.
 
"Play safe but retain the reconstruction with the set."

Hi Peter, All the new parts made for the T5 are directly interchangeable with original pre-war parts.

DFWB.

line sync 2nd Apr 2019 7:55 pm

Re: Baird T5 restoration project.
 
Play safe david and fit your newly made one.
You never know there could be some hibernating in the original board.

Robin

beery 3rd Apr 2019 7:54 am

Re: Baird T5 restoration project.
 
Hi David,
I agree with others, do fit the replacement part.

Quote:

Originally Posted by FERNSEH (Post 1133754)
Hi Frank,
That's right we know from past experience that those worms can re-emerge long after a state of dormancy.
DFWB.

I seem to be reminded of an Ekco from the past...


Cheers
Andy

Freya 3rd Apr 2019 8:11 am

Re: Baird T5 restoration project.
 
With all the work so far, it would be a shame to see it attacked again. Will you spray with preventative treatment prior to the veneering ?

FERNSEH 3rd Apr 2019 9:27 am

Re: Baird T5 restoration project.
 
Quote:

Originally Posted by Freya (Post 1133911)
With all the work so far, it would be a shame to see it attacked again. Will you spray with preventative treatment prior to the veneering ?

Hi Steven,
I believe modern plywood uses non animal sourced glues to bond the laminar sheets together and is less liable to woodworm invasion, but nevertheless it will be a good idea to protect the newly constructed cabinet from any future woodworm problems.

Rest assured the new CRT support panel will be fitted in lieu of the original part.

DFWB.

mark pirate 3rd Apr 2019 10:46 am

Re: Baird T5 restoration project.
 
Quote:

Rest assured the new CRT support panel will be fitted in lieu of the original part.
Very glad to hear that David, I have had a set ruined by woodworm while in storage, it appears to have spread from the shelf unit it was stored on.
Both the cabinet base & shelf had to be burnt.

Thankfully it was in my (concrete) garage, rather than my house!
Looking forward to seeing the results of the veneering, keep up the good work.
:beer:
Mark

Argus25 3rd Apr 2019 11:41 am

Re: Baird T5 restoration project.
 
Quote:

Originally Posted by FERNSEH (Post 1125011)
The vision IF is 13mc/s, much higher than I thought it would have been.
Much more work needs to be done on the vision receiver but the results so far are very encouraging.

Looking at the signal on the video output valve it shows a limited HF response, as seen by the rounded corners on the sync pulses. It could be the capacitance of the scope probe on a high Z part of the circuit, making that look worse than it really is.

Regarding the "worm" do you know what sort of species it is ?

Many Bora beetles are insects, if they are, their chitinous exoskeletons dissolve in hydrocarbon solvents.

So, you can dissolve their bodies (melt them like the wicked Witch in the Wizard of Oz) simply by soaking/painting the timber with Terpentine. Also, there is the opportunity to paint and soak the timber panels with insecticide (not the inept green environmentally friendly type that is hopeless and doesn't work, but the real toxic deal).

If there are any residual wood destroying life forms there which could include insects or fungi, you should be able to exterminate them completely. Also , another option is to slowly raise the temperature of the wood to a value that is incompatible with life, around 125-135 deg C over 1/2 hr would do it without too much damage to the timber.

beltinge bore 3rd Apr 2019 2:36 pm

Re: Baird T5 restoration project.
 
Hello David

I think I might know which EKCO young Beery is referring to! It sits in my garage having had much new wood and plenty of woodworm treatment.

For some reason SHMBO won't let it in the house.

Regards Steve.

FERNSEH 15th Apr 2019 2:59 pm

Re: Baird T5 restoration project.
 
1 Attachment(s)
Time to apply wood dye on the side panels, but before any attempt to do this I'll test the various dyes and polishes on wood off-cuts. The attached picture shows that the finish needs to darkened in order to resemble the wood surfaces of the original panels.

DFWB.

FERNSEH 15th Apr 2019 3:07 pm

Re: Baird T5 restoration project.
 
1 Attachment(s)
After several applications of wood dye on the test piece I'm sure the side panels can be stained and polished.
But the wood dye should be applied outdoors and not in the workshop, nasty fumes given off during the application process.
As the attached picture shows the panel surface colour is still too light and needs more wood dye in order that it resembles the original dark finish.

DFWB.

FERNSEH 3rd May 2019 8:59 pm

Re: Baird T5 restoration project.
 
3 Attachment(s)
It has been established that the two power supply units and the sound and vision receivers are serviceable. The loudspeaker is OK, it just needs the frame repainting. Now the timebase unit must receive attention. In order that it can be tested my Baird T23 will need to be repaired. Another scary job because the CRT must be removed to fix that intermittent connection on the tube base.

Pictures of the T5 timebase unit. This is the early version without the interlace diode.

DFWB.

peter_scott 4th May 2019 7:43 am

Re: Baird T5 restoration project.
 
2 Attachment(s)
In the third photo there are three pots sitting on angled metalwork. What do they control and how do you access them for adjustment. They don't appear to be shown on the drawing below and there appears to be just a couple of blanking plugs corresponding with that location on the front panel.

Peter

FERNSEH 4th May 2019 10:31 am

Re: Baird T5 restoration project.
 
2 Attachment(s)
Hi Peter,
Those controls are presets for the line and frame timebase frequencies and picture height adjustment.
It's possible that very early production timebase units would have a 240/405 switch and that's the reason for those blanking plugs on the control panel.
The first attachment shows the control panel of the Baird T5. The circuit diagram is of the frame timebase in the T23. A Mazda AC/HL is used as the interlace diode.

DFWB.

peter_scott 4th May 2019 11:36 am

Re: Baird T5 restoration project.
 
Thanks David. Do you just push finger and thumb up inside the access to adjust them? Do you think this set has had the 240 line circuitry?

Peter.

FERNSEH 4th May 2019 12:00 pm

Re: Baird T5 restoration project.
 
Hi Peter,
In my Baird T23 timebase chassis there is evidence of wiring that might well have been used for the 240/25 and 405/50 systems switching, although the wires definitely haven't been connected to anything. Something similar can be seen in the timebases of first generation EMI sets where the dual standard cableforms were still fitted in later 405 only receivers. In very early T5 models the preset controls would have been used to permit easy switching between the two transmission standards.
The preset controls are only accessible when the back cover is removed.

DFWB.

FERNSEH 13th May 2019 9:44 pm

Re: Baird T5 restoration project.
 
1 Attachment(s)
The mirror lid escaped the attention of the woodworms and can be refurbished. It doesn't look all that pretty for sure but there is no doubt it can be saved.
A few pieces of veneer will have to be inserted to correct slight damage. The surface silvered mirror is in excellent condition.
A new laminated safety glass has been made. The original had become delaminated and was discoloured anyway.

The line output transformer has open circuit windings and that's holding up the timebase restoration.

DFWB.

beery 14th May 2019 6:26 am

Re: Baird T5 restoration project.
 
Hi Fernseh,
the one I restored which had electrolytics dated September 36 had tell tale shaddows of where the extra parts had been. Unfortunately the circuit diagrams I have, have had the dual standard parts deleted. Note that there was no extra valve like in the EMI sets.

I would be interested in the winding details of the lopt as it might give me some clues for the one I need to make for the Garrick which uses very similar timebases.

Cheers
Andy


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