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Heatercathodeshort · 2nd Dec 2021, 2:29 pm

I have used the LOPT additional winding trick many times in the past. It always worked very well and saved the customer the cost of a new colour CRT. I seem to remember it occurred mainly in receivers of the late 80s early 90s period.

Two 2V isolation transformers from an earlier period for the notorious Mazda triodes! Note the percentage data.

In the UK I never encountered the USA plug in type 'brightener' probably because most of our chassis were AC/DC. The isolation transformers were well made and cheap, probably another advantage. In 1966 a Radiospares isolation/boost transformer cost 15/- [75p] They were produced with many secondary voltages to cope with the crazy range of CRT heater voltages that were common back then. John

2nd Dec 2021, 2:29 pm	#4
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: CRT Heater to cathode leakage I have used the LOPT additional winding trick many times in the past. It always worked very well and saved the customer the cost of a new colour CRT. I seem to remember it occurred mainly in receivers of the late 80s early 90s period. Two 2V isolation transformers from an earlier period for the notorious Mazda triodes! Note the percentage data. In the UK I never encountered the USA plug in type 'brightener' probably because most of our chassis were AC/DC. The isolation transformers were well made and cheap, probably another advantage. In 1966 a Radiospares isolation/boost transformer cost 15/- [75p] They were produced with many secondary voltages to cope with the crazy range of CRT heater voltages that were common back then. John Attached Thumbnails