29-06-2018, 08:18 AM
I would suspect that the old timers did not worry too much about getting the center tap bang on. I recently tested a few fairly new tapped mains transformers and they had center taps near but not exactly middle.
The same applied to the HT windings. One side will always be different under load as the length and hence the resistance of half the winding will be different due to the bobbin diameter increasing as the winding proceeds.
The same applied to the HT windings. One side will always be different under load as the length and hence the resistance of half the winding will be different due to the bobbin diameter increasing as the winding proceeds.
Boater Sam.
