Found in a 1924 Gernsback publication this circuit uses 4 batteries for power and loop antenna. Listening is over a high-impedance type earphone or loudspeaker common at the time.
Found in a publication for radio amateurs from the 1990s, this circuit makes it possible to...
I found this circuit in a Popular Electronics from November 1999. The magazine is no longer...
This simple transistorized receiver with earphone was found in a Japanese publication from the...