01-04-2021, 04:05 PM
Hi.
This is proving a little more challenging. The issue is the feedback winding for the line sync and APC. The voltage is over 300v P-P, too much for the existing circuitry of the VT4, resistive dropping is not a good idea and I thought of using a line blocking oscillator transformer as a drop down stage, I did have one with just about the correct ratios but the waveform is badly distorted and totally the wrong shape. Everything else is fine with perfect width and EHT now tamed with the addition of 120pf tuning from the boost Diode to ground.
Back to the drawing board.
This is proving a little more challenging. The issue is the feedback winding for the line sync and APC. The voltage is over 300v P-P, too much for the existing circuitry of the VT4, resistive dropping is not a good idea and I thought of using a line blocking oscillator transformer as a drop down stage, I did have one with just about the correct ratios but the waveform is badly distorted and totally the wrong shape. Everything else is fine with perfect width and EHT now tamed with the addition of 120pf tuning from the boost Diode to ground.
Back to the drawing board.
