At the time young Robert Cary Beck wrote this note to his father, the Great Depression was not yet resolved and Bob’s father was working at a job that required him to live apart from the family:
Jan. 20, 1937
Dear Daddy,
My pocket radio is most complete, here is a diagram of it.
Mother got me an old dictaphone tube for the coil tube.
I am going to tune it to W.F.A.A. (65 turns).
Love,
Robert Cary
P.S. My birthday is today, I am 12.
(Editor's note: WFAA was a popular Dallas/Ft. Worth radio station broadcasting on 570 kHz and 820 kHz.)
Here's a close-up of the schematic: