Quote:
Originally Posted by old_tv_nut
A voltage or current ratio of 23:1 sounds way too big. Horizontal output tube pulse voltage is not 23 times horizontal transistor pulse voltage. Maybe more like 5:1 ?
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My numbers are off. I have a Panasonic BT-H1390Y professional video monitor that uses the M34AFA13X02 CRT and yoke that I have several NOS units of and plan to use in my DIY TV.
I just checked the Panasonic BT-H1390Y with my 3kV oscope probe to check the voltage waveform at the collector of the horizontal output transistor and it is about 860 volts peak to peak. The math I am using is the max pulse plate voltage on the beam power pentodes that were commonly used for vacuum tube based color TVs, which is around 7500 volts divided by 860 = 8.7. So 8:1 is closer to what is needed. But a more accurate calculation would be to measure the vpp of the waveform inbetween the flyback pulses, right? Matching on the flyback pulse seems a bit of a backwards way of getting to the transformer step down ratio.