Good morning,
This TV has had a rough time of it over the past 20 years mainly due to being owned by me!
It's been dragged from pillar to post, moved in various vehicles, had stuff piled on top of it, stored in a woodworm infested barn and finally a very damp loft. However, it's never been mortally wounded but has collected a few more battle scars!
It belonged to a friends' Grandmother and spent it's life in Felixstowe, so technically I am only the second owner!
20 years ago, 'getting it working' was more my thing rather than overhauling it with any thought of long term reliability. All sorts of odd ball components have been tacked in, most of the originals are still there with one wire cut. It did get to the point of producing very good pictures and was used a fair bit.
Back then, a standards converter was a distant dream: they were available but expensive. A friend, who was an electronics designer, had converted a 525 line B/W camera (1 inch tube) and a Sharp monitor to work on 405. The camera, pointed at a 625 line picture, produced remarkably good 405 pictures. A channel 1 modulator was built 'rats nest' style and a usable system created.
A few years ago, I decided that an Aurora was too good an opportunity to miss at £200, so I bought one. Without thinking, I dragged the Marconiphone out of the loft and fired it up. The poor thing had been up in the damp for 5 years and being powered up was too much for it: it worked for a few minutes and then died. I should have remembered from my years delivering TV's & VCR's in the winter that powering them up was a disaster unless they had warmed up first.
There was not much activity from the line stage, so I disconnected the EHT overwind and could then get a healthy spark from the PL81 top cap. I concluded, wrongly, that the overwind had developed shorted turns. I couldn't justify spending the money on getting it re wound, so it was put to one side with thoughts of a LOPT transplant if something suitable should come up.
Last year, I was experimenting with 'ringing' LOPT's and looking at the results on a 'scope. Confidently expecting the one from this set to be dead, I was amazed to see a perfect ring trace! Putting one turn of shorted wire round the transformer, killed the ring completely, so the transformer must be OK electrically.
So last month, I put the transformer back in the chassis and powered it up. The transformers in these sets seem to go through a whole series of wheezing, gasping and generally strange noises before settling down to a steady whistle. Just as it was getting into it's stride, a small plume of smoke and an arcing sound occurred. This seemed to be coming from the inboard end of the overwind near the core.
As detailed here
https://www.vintage-radio.net/forum/...=142919&page=2 post 33, the wax was removed from the overwind and the former removed. A charred area was found which was conductive so the winding had been arcing through the former to the ferrite core.
This was cleaned up and temporarily re assembled to prove the point. Amazingly, it all worked perfectly and a really good picture resulted. I had forgotten how good the picture was on this set- the Mullard tube is in great shape with pin sharp focus.
I think the set now needs the TLC it deserves. Not a total rebuild, but a sympathetic change of necessary components and all the odd capacitors that have found their way in there. I can also do a proper repair & re insulate on the LOPT.
All the best, Nick.