Quote:
Originally Posted by old_coot88
I can't pull up the schematic on my (Linux) rig, but am curious as heck about that series/parallel filament wiring. Presumably it's running from B+ thru a dropper. If so, then if one string goes open, then the other string will have twice the voltage on it. A zener would be great for protection, but there were no zeners when the radio was made. Just bein' curious.  |
That radio has a small power transformer with a winding for the B+ and a winding for filaments. The B+ uses a tiny selenium and the filament supply uses a selenium bridge for that purpose.