A scary Baird T23. - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

FERNSEH · 14th Dec 2016, 11:38 pm

More Scaryness. The mirror lid has been removed along with the wooden screen aperture and mask. The tube looks even more intimidating! The next stage is to lift the horned bomb up and away from its mounts.
The plan is to tilt the set forwards at about 30 degrees for easier removal of the tube.

DFWB.

Heatercathodeshort · 15th Dec 2016, 11:44 am

We could make 'Carry on Cossor' with all this Wendy Woo business David. Get on with it!
The 65/2 has a cloth bag dagged to the bulb presumably to stop bits of glass flying around when it implodes... Your early 65K looks as if it has lost its frock or was never fitted for one. John.

bobhowe · 15th Dec 2016, 5:29 pm

Hi was in the shop yesterday looking at this wonderful set & tube a bit scary but us Northerners are made from the hard stuff ( for the cold weather we have here

) & David will have it up & running soon with adapter plates regards Bob

peter_scott · 15th Dec 2016, 6:38 pm

When they are less horny you can play at balancing them on their small ends!

http://members.iinet.net.au/~cool386...dumont_crt.jpg

Peter

FERNSEH · 15th Dec 2016, 11:48 pm

The tube is out at last! Easy job to lift it out after all. Instead of trying to manoeuvre those "horns" through the metal cradle plate the trick is to remove the tube up by using the plate to lift the tube up and away from the cabinet.

The next stage is to make the cutouts in the original CRT mounting board to give adequate clearance for the horns.

DFWB.

FERNSEH · 16th Dec 2016, 1:17 pm

Bad news. The Cossor 65K/2 has a different shape bulb and will not fit in the T23. In order that it could be made to fit in the Baird T23 extensive modifications are necessary and no doubt this can done. However, there is three Cossor 65K tubes upstairs, one I know to be useless because it was removed from the T23 many years ago. The other two, who knows? Might as well take a chance and fit one later today, but first there is all that tidying up to do to the CRT mounting arrangements.

DFWB.

bobhowe · 16th Dec 2016, 2:12 pm

Hi David what a shame it won't work can you test the other 2 tubes like you did a while back with a crt using a eht supply & lt for the heater regards Bob

FERNSEH · 16th Dec 2016, 2:23 pm

Hi Bob, the Cossor 65K has a 4volt heater and has the usual indirectly heated cathode whereas the original Baird Cathodevisor 15MW1 has a 2.5volt directly heated cathode. I've picked one of those 65K tubes from the collection upstairs and it might have some potential of showing a picture of sorts. The is still some silveryness about the getter so why not give it a try?

DFWB.

bobhowe · 16th Dec 2016, 2:33 pm

Yes i would give t a try would be nice to see this working again with a brighter picture regards Bob

FERNSEH · 16th Dec 2016, 4:22 pm

And here is the tube as it was delivered in 1993 in the Shore Porters box.
How's that for an old company, established 1498!

DFWB.

Tractionist · 16th Dec 2016, 5:25 pm

Mmmmmm .......

There are outfits in the States that will fully refurbish tubes of this vintage - new guns/phosphors/dag etc. (At what price who knows?)

(David is a Geordie .... so he does 'why aye' a lot - but he invariably gets the job done ... to a superb standard !!)

FERNSEH · 16th Dec 2016, 5:59 pm

Hi, Why aye indeed but what would be cost of sending a tube over to the States? I quite like this set even if was a badly made load of junk when I first acquired it way back in 1993. Over the years I've tidied it up to a standard it should have been in the first place.

Certainly would be great to see a clear bright picture on the screen. The TRF unit does a good job resolving the 2.5Mc/s definition bars. Not bad for 1938.

Anyway, let's find out if the spare 65K tube is any good.

DFWB.

FERNSEH · 16th Dec 2016, 10:59 pm

But before the replacement tube is installed the CRT mounting board needs some attention, notice those crude cutouts for the CR tube's horns. More clearance is required and a more professional looking job done as well.

Also noteworthy are the extended pole pieces from the frame timebase oscillator transformer. Baird Television Ltd. applied this method of vertical deflection on all the companies' pre-war sets.
Some speculation whether this type of timebase was developed by BTL or Fernseh A.G.

DFWB.

Oliver35 · 17th Dec 2016, 11:23 am

I was wondering why there only appeared to be one set of deflection coils- what a bizarre technique. Was there an advantage to be gained by doing it thus, or was it just Baird being wilfully idiosyncratic?

ianm · 17th Dec 2016, 11:26 am

Quote:

Originally Posted by Tractionist

There are outfits in the States that will fully refurbish tubes of this vintage - new guns/phosphors/dag etc.

Hi Tractionist,

May we have details of these outfits, please? Thanks.

FERNSEH · 18th Dec 2016, 12:41 pm

Cut outs made in the original CRT mounting board to clear the "horns" on the Cossor CRT. Don't really like doing this sort of thing to an almost eighty year old TV set but it's either that or a possibly damaged CRT. If in the very unlikely event a serviceable Cathodevisor 15MW1/2 tube ever turns up an almost exact replica of the CRT board could be made.

DFWB.

Nuvistor · 18th Dec 2016, 12:55 pm

You have to work with what's available, far better to lose a bit wood than the irreplaceable CRT.
It's coming along nicely.
Frank

Heatercathodeshort · 18th Dec 2016, 1:25 pm

I'll second that. It's only a bit of wood after all. J.

peter_scott · 18th Dec 2016, 1:40 pm

I don't like modifying original stuff either but I agree that this is the right path to follow.

Peter

FERNSEH · 19th Dec 2016, 11:44 am

Tube mounting assembly is ready to accept the replacement CRT.

DFWB.

14th Dec 2016, 11:38 pm	#21
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: A scary Baird T23. More Scaryness. The mirror lid has been removed along with the wooden screen aperture and mask. The tube looks even more intimidating! The next stage is to lift the horned bomb up and away from its mounts. The plan is to tilt the set forwards at about 30 degrees for easier removal of the tube. DFWB. Attached Thumbnails

15th Dec 2016, 11:44 am	#22
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: A scary Baird T23. We could make 'Carry on Cossor' with all this Wendy Woo business David. Get on with it! The 65/2 has a cloth bag dagged to the bulb presumably to stop bits of glass flying around when it implodes... Your early 65K looks as if it has lost its frock or was never fitted for one. John.

15th Dec 2016, 5:29 pm	#23
bobhowe Heptode Join Date: Jun 2005 Location: Sunderland, Tyne and Wear, UK. Posts: 661	Re: A scary Baird T23. Hi was in the shop yesterday looking at this wonderful set & tube a bit scary but us Northerners are made from the hard stuff ( for the cold weather we have here ) & David will have it up & running soon with adapter plates regards Bob

15th Dec 2016, 6:38 pm	#24
peter_scott Dekatron Join Date: May 2003 Location: Edinburgh, UK. Posts: 3,274	Re: A scary Baird T23. When they are less horny you can play at balancing them on their small ends! http://members.iinet.net.au/~cool386...dumont_crt.jpg Peter __________________ http://www.nostalgiatech.co.uk https://www.youtube.com/c/PeterScott/videos

15th Dec 2016, 11:48 pm	#25
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: A scary Baird T23. The tube is out at last! Easy job to lift it out after all. Instead of trying to manoeuvre those "horns" through the metal cradle plate the trick is to remove the tube up by using the plate to lift the tube up and away from the cabinet. The next stage is to make the cutouts in the original CRT mounting board to give adequate clearance for the horns. DFWB. Attached Thumbnails

16th Dec 2016, 1:17 pm	#26
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: A scary Baird T23. Bad news. The Cossor 65K/2 has a different shape bulb and will not fit in the T23. In order that it could be made to fit in the Baird T23 extensive modifications are necessary and no doubt this can done. However, there is three Cossor 65K tubes upstairs, one I know to be useless because it was removed from the T23 many years ago. The other two, who knows? Might as well take a chance and fit one later today, but first there is all that tidying up to do to the CRT mounting arrangements. DFWB.

16th Dec 2016, 2:12 pm	#27
bobhowe Heptode Join Date: Jun 2005 Location: Sunderland, Tyne and Wear, UK. Posts: 661	Re: A scary Baird T23. Hi David what a shame it won't work can you test the other 2 tubes like you did a while back with a crt using a eht supply & lt for the heater regards Bob

16th Dec 2016, 2:23 pm	#28
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: A scary Baird T23. Hi Bob, the Cossor 65K has a 4volt heater and has the usual indirectly heated cathode whereas the original Baird Cathodevisor 15MW1 has a 2.5volt directly heated cathode. I've picked one of those 65K tubes from the collection upstairs and it might have some potential of showing a picture of sorts. The is still some silveryness about the getter so why not give it a try? DFWB.

16th Dec 2016, 2:33 pm	#29
bobhowe Heptode Join Date: Jun 2005 Location: Sunderland, Tyne and Wear, UK. Posts: 661	Re: A scary Baird T23. Yes i would give t a try would be nice to see this working again with a brighter picture regards Bob

16th Dec 2016, 4:22 pm	#30
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: A scary Baird T23. And here is the tube as it was delivered in 1993 in the Shore Porters box. How's that for an old company, established 1498! DFWB. Attached Thumbnails

16th Dec 2016, 5:25 pm	#31
Tractionist Heptode Join Date: Apr 2016 Location: Cheltenham, Gloucestershire, UK. Posts: 875	Re: A scary Baird T23. Mmmmmm ....... There are outfits in the States that will fully refurbish tubes of this vintage - new guns/phosphors/dag etc. (At what price who knows?) (David is a Geordie .... so he does 'why aye' a lot - but he invariably gets the job done ... to a superb standard !!) __________________ Red to red, black to black. Throw the switch and stand well back!

16th Dec 2016, 5:59 pm	#32
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: A scary Baird T23. Hi, Why aye indeed but what would be cost of sending a tube over to the States? I quite like this set even if was a badly made load of junk when I first acquired it way back in 1993. Over the years I've tidied it up to a standard it should have been in the first place. Certainly would be great to see a clear bright picture on the screen. The TRF unit does a good job resolving the 2.5Mc/s definition bars. Not bad for 1938. Anyway, let's find out if the spare 65K tube is any good. DFWB.

16th Dec 2016, 10:59 pm	#33
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: A scary Baird T23. But before the replacement tube is installed the CRT mounting board needs some attention, notice those crude cutouts for the CR tube's horns. More clearance is required and a more professional looking job done as well. Also noteworthy are the extended pole pieces from the frame timebase oscillator transformer. Baird Television Ltd. applied this method of vertical deflection on all the companies' pre-war sets. Some speculation whether this type of timebase was developed by BTL or Fernseh A.G. DFWB. Attached Thumbnails

17th Dec 2016, 11:23 am	#34
Oliver35 Pentode Join Date: Apr 2016 Location: Halesworth, Suffolk, UK. Posts: 188	Re: A scary Baird T23. I was wondering why there only appeared to be one set of deflection coils- what a bizarre technique. Was there an advantage to be gained by doing it thus, or was it just Baird being wilfully idiosyncratic?

18th Dec 2016, 12:41 pm	#36
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: A scary Baird T23. Cut outs made in the original CRT mounting board to clear the "horns" on the Cossor CRT. Don't really like doing this sort of thing to an almost eighty year old TV set but it's either that or a possibly damaged CRT. If in the very unlikely event a serviceable Cathodevisor 15MW1/2 tube ever turns up an almost exact replica of the CRT board could be made. DFWB. Attached Thumbnails

18th Dec 2016, 12:55 pm	#37
Nuvistor Dekatron Join Date: Aug 2013 Location: Wigan, Greater Manchester, UK. Posts: 9,433	Re: A scary Baird T23. You have to work with what's available, far better to lose a bit wood than the irreplaceable CRT. It's coming along nicely. Frank

18th Dec 2016, 1:25 pm	#38
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: A scary Baird T23. I'll second that. It's only a bit of wood after all. J.

18th Dec 2016, 1:40 pm	#39
peter_scott Dekatron Join Date: May 2003 Location: Edinburgh, UK. Posts: 3,274	Re: A scary Baird T23. I don't like modifying original stuff either but I agree that this is the right path to follow. Peter __________________ http://www.nostalgiatech.co.uk https://www.youtube.com/c/PeterScott/videos

19th Dec 2016, 11:44 am	#40
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: A scary Baird T23. Tube mounting assembly is ready to accept the replacement CRT. DFWB. Attached Thumbnails