Tube Lineup: 39, 36, 38, 37
The Emerson 25A was one of Emerson's low-cost radios first introduced in late 1932 for $25. In order to achieve the low costs, Emerson used a simple T.R.F. circuit in this radio and among the circuit tricks they used an inexpensive 37 triode tube as the rectifier tube. The 20A and 25A share the same chassis and were designed with a multi-pin connector at the rear for various external power accessories to allow the radio to operate off batteries or alternative power sources.