[Retired]

Hi,

Thank you Dom for taking the time to add such a comprehensive reply it is much appreciated and I’m glad I asked the question; all points duly noted and I’ll also use your method to check the CRT is fully discharged before handling.

As you requested I’ve taken a few pictures of the Metrosil connections and these are included below. The Metrosil is simply located at its loose end into a metal bracket not being nipped down tightly and I think it is also secured inside the cabinet by a clip. The two leads connect one to the side of the CRT and the other by a socket arrangement into the LOPT by the U25 rectifier sharing one of the connections. It’s interesting to learn that the Metrosil can be omitted; thanks for the information Jeffrey; I had already connected it so will leave it in place but I would be interested to learn of its intended function?

I’ve made good uninterrupted progress today. I did consider by-passing the switch as you kindly suggested Jeffrey but decided I would eventually have to sort the switch out at some point might as well do the job up front. I had an identical switch in stock it being coupled to a pot so it wasn’t a big job to transfer the switch to the pot on the chassis. Joe’s tip about not switching the neutral sounded excellent so I shorted one pole of the switch to chassis by simply soldering a wire to the two tags; this meant I could still connect the new mains lead to the switch; out of curiosity I checked for continuity and both poles gave good readings but once again thanks for the advice to both Jeffrey and Joe about testing these switches. I did take the opportunity to blast some switch cleaner in before fitting. The new mains cable was quickly fitted; I did have a look around the rear of the chassis for a grommet to mark the entry of the cable but couldn’t find one so for the time being I just soldered it in place.

As my isolation transformer and 100W lamp are hard wired into the workshop control panel I decided to use a spare lamp holder and the Variac to apply power and made up the circuit as can be seen in the picture.

At last I could switch on and set the Variac at 100V to start with leaving it powered for quarter of an hour but as there were no signs of stress I increased the voltage to 240V over the next quarter of an hour and the 100W lamp lit up like a laser the chassis wasn’t objecting; the only noise was the Variac buzz. As the valves were still dirty I could only see one of the small valves lit up and after leaving the chassis under power for a while I then switched off.

I felt at a number of the valves and a few were warm with the big valve which I think could be a PY32 being the warmest; it only has 32 remaining the rest of the details being lost. I did not touch the U25 but the other two valves within the LOPT housing felt cold. This brought me up to tea time so I knocked off for the day but had enjoyed myself tinkering around and I plan to spend more time on the chassis tomorrow; my friend Tony (Aerodyne) has already suggested I power up and take voltage readings on the electrolytics so I’ll tip the chassis up to gain access. I did check to see if the big electrolytic can had warmed up but it remained cold.

This being my first TV there is a lot to take in all at once so please bear with me whilst I learn to walk; I am making steady progress and with all your generous help I’m sure to win through in the end. I’m now locked into this project and totally committed to getting the set working however long it takes me. I’m pleased to have put 240V into it without suffering a big bang or blue flashes.

Thanks once again everyone for all your valued input. Out of interest I’ve just bought a new External hard drive at 1TB for storing all my radio/TV information as I’ve become fed up with going through stacks of CD’s whilst trying to find pictures or notes; its time I got organized better; the drive is due to arrive shortly and at around £58 delivered I was amazed at how little it cost as my normal hard drive I bought a few years ago whilst upgrading my computer cost £80 for 80 GB.

Kind regards, Col.