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Old 6th Aug 2022, 10:02 am   #11
Heatercathodeshort
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Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,147
Default Re: Thorn 3000 - flywheel test point

The flywheel sync tended to 'pull in' sync when the frequency was a little off. Changing channels or just breaking the signal would result in line hold loss. [The notorious PYE V14]
Removing the sync allows the oscillator to be set at the correct frequency without the influence of the flywheel action.
It was certainly not uncommon. The early PYE FV2C from 1951 had a toggle switch on the back to remove the sync when correctly setting the oscillator.

I had a customer with one of these receivers when I was first in the trade. It was a 16" metal tube model, Mullard MW41-1. To think it was 15 years old then, past it's sell by date in 1964. It had a PYE box converter on it for the ITA. It worked really well! John.
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