Interesting item for those of you who would like a vintage item. Probably needs rebuilding. http://cgi.ebay.com/Silvertone-power-shifter-Tube-Radio-Battery-Antique_W0QQitemZ5838418711QQcategoryZ294QQrdZ1QQcmdZViewItem

:Interesting item for those of you who would like a vintage item. Probably needs rebuilding. http://cgi.ebay.com/Silvertone-power-shifter-Tube-Radio-Battery-Antique_W0QQitemZ5838418711QQcategoryZ294QQrdZ1QQcmdZViewItem

Thomas,

I have one just like it. It is a pretty simple device and works surprizingly well. It has a power transformer with two secondaries. One is the high voltage winding feeding a selenium diode and a 1500 ohm resistor with electrolytic on both sides of the resistor. The low voltage winding feeds a full-wave selenium rectifier to a choke with large electrolytics on input and output of the choke. There are taps on the low voltage secondary and a socket and plug to adjust for the number of tubes in the radio. It works quite well, however, it injects some hum into the radio.

Radiodoc

There's an article in the November '05 Antique Radio Classified magazine about this Sears "Powr Shiftr." It first appeared in Sears' 1942 catalog.