UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - 5FP7 project starting with the focusing coil.

G6Tanuki · 13th Oct 2021, 5:04 pm

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.

13th Oct 2021, 5:04 pm	#14
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 11,380	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. Attached Thumbnails __________________ "The future's so bright I gotta wear shades". --Timbuk3