1st generation UK colour TV?

[Combwork]

Back in the 1970's my wife and I had a small workshop repairing antique musical boxes. The landlord was OK with this as long as I put up some kind of shop display to keep in line with other shops on the street. I've always had an interest in (but no technical knowledge of) old radios so I started to buy them, very cheap. I had an arrangement with traders at the local market that for a minimum payment of £2, I would buy absolutely any radio they brought to me. This guaranteed that I'd not only get the trash, but also anything decent that came their way. Then I got a 'phone call from a local TV shop that refurbished old TVs they'd taken in part exchange. They'd just taken in a huge colour set in a polished wood cabinet and decided they'd rather not get involved, so I got it. Turned out to be a DECCA CTV25; one of the first batch of production colour TV's in the U.K. In 1966 it cost about £600 ($1200); not much less than a small family car.

Question? It had transistor audio but valve (tube) video including a valve driven EHT supply. Took about 3 minutes to warm up before the picture appeared but provided the convergence and focus were set up properly, it had one of the best pictures I can remember seeing. The EHT supply was hidden inside a 12" high metal box with a radiation hazard symbol on the front along with the warning "Do not operate with this cover removed". Was this serious, or was it just to keep meddling fingers out of something that could kill?

The set had push-button tuning and a nasty habit of arcing when the channel was changed. I was told this was due to a momentery spike in the EHT supply as the brightness dipped. This only happened when my wife was watching it on her own; once when I was out she claims it arced, smoked and she saw flames so she unplugged it and threw a plantpot full if sand into the back. Although incredibly it still worked after this, she made it clear that that f****** fire hazard had to go. Fair enough, now it's in a museum.