Quote:
Originally Posted by Travellingwave
Hi Mark.
I am planning to dissolve the pitch on the LOPTX as suggested elsewhere.
Cheers.
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Hi
Yes, I totally recommend this method. As detailed by Argus25 and used by several forum members, this should be followed by varnishing (e.g., by dipping in marine spar or transformer varnish) or by spraying/coating with an anti-corona lacquer. I recently got a scrap chassis for parts where the LOPT was is a poor condition (paxolin former broken at the base, teared EHT contact, broken EY51 heater winding contact and clear signs of damp storage) but with all major windings surprisingly fine. By dissolving the pitch in white spirits - just be *very* careful with the ultra-thin (110 micron) wire connections in the overwind! - I was able to go from the condition shown in the first image to the clean and repaired state shown in the second image and the final varnished result. Judging by your description, your LOPT could be in a much better initial condition and the process should be straightforward, even though it can take up to two weeks in total.
In my first and only TV restoration so far (also a TV22 Mk2), the only element that failed after a few hours of operation was the LOPT, which had been left untreated and quickly developed a shorted primary (later rewound). I have a second set in even better original and untouched condition (it's an original "hybrid", with a Mk1 RF deck populated with EF91s and a Mk2 main chassis) and will give its LOPT the same treatment prior to using it on the set.
Good luck with your new project!
Helder