|
I looked at the Westinghouse schematic. The convergence transformer is similar in concept and the solid state solution would replace T702 and T701.
The Westinghouse uses a 5U4 Full wave rectifier. In order to get the higher voltage to provide the amplitude of the parabola, the extra wire would connect to one of the 5U4 plates. The circuit I have devised will double the voltage to obtain the 800v to 900v to run the circuit. So it could be made to work and would likely just drop in.
Below are some snapshots off the scope of the parabola. The scope minimum sensitivity is 50 volts per division or 400v vertical full scale. The amplitude is adjustable with the CT100 vertical amplitude and shape controls. I have adjusted for towards a perfect parabola. I found optimum convergence is with the parabola adjusted to be a little distorted. The peak amplitude is adjustable linearly without distortion up to about 700vp-p. In the Parabola 3 snapshot, I reduced the amplitude amplitude via the control briefly to show the parabola fitting the scope display.
Note the wide trace is due to the added horizontal modulation so this signal riding on DC roulghly 4.5kV is going to the convergence deplection plates.
|