I found the service manual for this ( Based on information in there, this dates from 1937-1940 or from 1946-48 (the frequency for channel 1, which this TV has, is 44-50 MHz, where it was during those two periods of time). My guess would be the latter. Based on the manual, you had to be an electrical engineer to figure it out, all the while listening to your kid say "Dad! I wanna watch Howdy Doody!"