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Old 13th Oct 2021, 5:04 pm   #14
G6Tanuki's Avatar
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 11,380
Default Re: 5FP7 project starting with the focusing coil.

The RSGB-manual SSTV monitor using a 5FP7 has this circuit to generatre HT for the tube, using a LOPT with the feed to the scan-coils removed.

The potentiometer varies the mark:space ratio of the oscillator and hence the HT.

These days I'd look to doing it using a 555 and a switching transistor scarfed from a SMPS.
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