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Old 24th Sep 2020, 4:45 pm   #24
Heatercathodeshort
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Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,145
Default Re: My first foray into Old model TV repairs.

just a warning about the tuning control. It consists of a common plate moved by the tuning control sliding three iron dust cores into the aerial input, bandpass and oscillator coils.
Now here is where the problem lies. The iron dust cores rust and get stuck in the Paxolin coil formers. If you move the tuner setting the cores being stuck break up from their brass threaded adjusters leaving the cores stuck in the formers.
It is a fiddle to repair and I have done quite a number the first being a Ferguson 998T in an article I uploaded to the Forum many years ago.
It is a lot easier if you can obtain some similar adjusters from a scrap push button radio.
It might be possible to glue the bits back together but it might be an effort too far!
Check which channel the tuner is set to. It is marked on a little vertical scale just under the tuning knob/wheel. It would be easier to set you signal source to that channel rather than risk the damage mentioned.
Get the power supply and line output stages working first. The line oscillator is complicated. There are two .01uf capacitors inside the discriminator transformer and the oscillator will not run if these are faulty and they usually are! They look like resistors with the same colour band markings and usually go O/C . This all sounds a bit of a journey but if you tackle it in the right order and find the strength to prevent yourself from carrying out a damaging chassis clean [half inch paint brush and vacuum cleaner only] you may be surprised at what you can achieve. Take plenty of notes and pictures. Good luck with it.
PS. You have the octal plug fitted for a Type A Band 3 tuner therefore it must be a final production run. John.
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