Any ideas about how to solve this problem?

[cbenham]

Originally Posted by Giulio Maiocco

I may also try to reconstruct from scratch the missing transformer, but honestly I don't have the faintest idea of the needed turns ratio and number of turns of each winding

Please, can also anyone guess at the phasing of the winding on the HOT's cathode? Would it be connected "aiding" the primary winding or is it connected 180 degrees out of phase? What would be the effect of this winding? It's only 16 turns with about 100Vpp.

Some US sets used a transformer like the one you circled to feed push pull H pulses back to the 6AL5 AFC phase detector. Probably 50 to 100 volts peak to peak on the centertapped side. This is a guess.

I'll also GUESS the voltage going to the HOT cathode is + going. This is based on your drawing showing the winding feeding the EY51 Plate which is 'drawn' as being in the same phase, if the drawing is correct.

Best Luck,
Cliff