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beery · 19th Jun 2021, 2:17 pm

Here we go! First of all the story of the mask and another CRT

I recently found a 12" round CRT being advertised for sale online. What was unusual about it, was that it was mounted on a wooden frame, together with part of the front of an old TV and included the CRT mask as well.
I put in an offer and it was accepted. I offered more than an untested 12" CRT, because it was the mask I was really after and I didn't want to miss out on the sale.

A friend helped me collect it from a place near the Cambridge fens, between Cambridge and Peterborough. IT turned out to be amongst the last items being sold by a collector who had to give up his hobby for health reasons. He still kept his favourite sets and it was nice seeing the small collection he had left. Whilst there I was able to buy some vintag components as well.

When I got home I found that the CRT in question was a Mullard MW31-18. Being a straight gun tube, it is a much better replacement for the original MW31-7 in the Baird Garrick other than the MW31-74 that I had fitted. The ion trap magnet of the MW31-74 was really in the way of things. I tested the CRT and it was just into the good area, in fact I was sure it was better than this as the meter on my tester is a bit sticky.

The rubber mask is a much better replacement than the Bush TV24 style mask that I was planning to use. The extra picture width required to fill the 'double D' mask was going to be a problem, the cabinet had no way of mounting the mask and the outer edges of the mask were not wide enough to fill the safety glass.
The newly obtained mask was of the type that holds the safety glass as well. This arrangement ususally causes the mask to deform due to the weight of the glass and this mask was starting suffer in that way. As the Baird Garrick hs the safety glass fixed to the cabinet, I decided to cut off the part of the mask that retains the glass.

More to follow...

BTW, I never did find out what set the CRT came from. The scan coils look a bit PYE like, indeed the mask looks like a larger version of the LV30 mask, rather than a GEC one which has much thinner rubber. The scan coils had a four pin plug on a bit like a Vidor and the focus unit was an off the shelf item. The badge at the front was merely a transfer (now missing), I wondered it if was from a Sobel. Any ideas?

Cheers
Andy

19th Jun 2021, 2:17 pm	#96
beery Heptode Join Date: Jun 2006 Location: Ware, Hertfordshire, UK. Posts: 988	Re: Baird Garrick Here we go! First of all the story of the mask and another CRT I recently found a 12" round CRT being advertised for sale online. What was unusual about it, was that it was mounted on a wooden frame, together with part of the front of an old TV and included the CRT mask as well. I put in an offer and it was accepted. I offered more than an untested 12" CRT, because it was the mask I was really after and I didn't want to miss out on the sale. A friend helped me collect it from a place near the Cambridge fens, between Cambridge and Peterborough. IT turned out to be amongst the last items being sold by a collector who had to give up his hobby for health reasons. He still kept his favourite sets and it was nice seeing the small collection he had left. Whilst there I was able to buy some vintag components as well. When I got home I found that the CRT in question was a Mullard MW31-18. Being a straight gun tube, it is a much better replacement for the original MW31-7 in the Baird Garrick other than the MW31-74 that I had fitted. The ion trap magnet of the MW31-74 was really in the way of things. I tested the CRT and it was just into the good area, in fact I was sure it was better than this as the meter on my tester is a bit sticky. The rubber mask is a much better replacement than the Bush TV24 style mask that I was planning to use. The extra picture width required to fill the 'double D' mask was going to be a problem, the cabinet had no way of mounting the mask and the outer edges of the mask were not wide enough to fill the safety glass. The newly obtained mask was of the type that holds the safety glass as well. This arrangement ususally causes the mask to deform due to the weight of the glass and this mask was starting suffer in that way. As the Baird Garrick hs the safety glass fixed to the cabinet, I decided to cut off the part of the mask that retains the glass. More to follow... BTW, I never did find out what set the CRT came from. The scan coils look a bit PYE like, indeed the mask looks like a larger version of the LV30 mask, rather than a GEC one which has much thinner rubber. The scan coils had a four pin plug on a bit like a Vidor and the focus unit was an off the shelf item. The badge at the front was merely a transfer (now missing), I wondered it if was from a Sobel. Any ideas? Cheers Andy Attached Thumbnails __________________ www.youtube.com/user/andyvalve100