I used to have a 1948 Hallicrafters TV and it had yet another type of high voltage supply. There was a 100 kHz oscillator driving an air-core transformer in nor

I used to have a 1948 Hallicrafters TV and it had yet another type of high voltage supply. There was a 100 kHz oscillator driving an air-core transformer in normal (not flyback) mode. The potting had gone bad on the transformer, and I couldn't find a suitable replacement, but I did find one that had the right secondary winding. Since it was air-core I just cut the secondary off that and the primary off the original and glued them together. Worked great.