Airline Model 24BR-521B Midget Table Radio (circa 1941)
Montgomery Ward (who sold radios
under the "Airline" trade-name) made a
series of these midget ac/dc-powered
radios available through catalogue sales
over a period of several years.
Remarkably, this small cabinet houses a
full 5-tube "all American five"
superheterodyne chassis with tubes:-
12SA7 (mixer/LO), 12SK7 (IF), 12SQ7
(2nd detector/AVC/1st AF), 50L6GT
(audio output), 35Z5GT (rectifier). The
radio covers the standard broadcast
The radio's distinguishing feature, aside
from its very small size, is that it utilizes
permeability tuning, whereby the
inductance of two coils is varied to
change stations rather than the more
standard capacitative tuning approach.