I am preparing to bring back to life a 1936 Crosley Model 715 Table Top that belonged to my grandparents - and on which my dad and uncle once listened to programs like "The Lone Ranger." It has paper capacitors and if I just plug it in after sitting in an attic for 40 years, it will be very unhappy. It could also have all manner of other shorts and problems that could cause it to catch on fire. Better to warm it up carefully using a VARIAC. I don't have one, so I built one using an incandescent light bulb. The idea is that as the watts go up, the light bulb bears the brunt and lights up and turns energy into power or Watts into heat and light, or whatever semantics you prefer :-) The bulb is in SERIES along the hot wire and one mixes and matches wattage to achieve the desired volts.
I tested it on my Technics receiver - which draws 53Watts at "Idle." First, I tried a 60Watt bulb, and it pulled down the voltage too far - the receiver cycled on and off as the bulb lit brightly, then went out. A 100 Watt bulb yielded a drop in voltage down to 104.5 Volts. I believe that the Crosley draws 35 or so watts, so the 60 watt bulb may be appropriate to start out with - may yield 50 or 60 volts or so. I'll let it simmer for a couple hours. Then, I'll screw in the 100 Watt bulb and let it think about that for a few hours, then bareback into the outlet if all is well.
