Rewiring the filaments in a Hallicrafters S-120

I decided on modifying my S-120 after blowing out the panel lamps one too many times. A bad 880/100 Ohm glowbar resistor had been replaced with a 125 Ohm wire wound job a while back leading to a blowout situation of one of the number 47 panel lamp bulbs when the set was turned on at full line voltage (115V-117V). I rewired the tube filaments for 12V operation, added a 12.6V 1 A filament transformer mounted on top of the chassis between the filter cap and the output transformer. I also replaced the 50C5 output stage with a 12AQ5. The results justified the changes. The set now has a much faster warm up time (10 to 12 seconds) and no more lamp blowouts!

73, Rod   WB6FBF