Tubes for the 1920's are no longer commonly available. The 1A5 pentode from the 1930 is still available for about $5. I modified the radio to accept the 1A5's. The radiola III requires four battery voltages 5V, 1.5 V, 20V, and 40V. I am making and AC adapter for the radio. I did not want two boxes so I made a box that the III will set in. The lower portion of the new box will contain the power supply. If I get it working I will post a video the nascent technology at work.
http://www.angelfire.com/scifi2/zpt/temp/Radiola_III_in_box.jpg Frank Znidarsic
