Found in a 1924 publication, this 2-valve receiver has a speaker output. Power comes from several batteries. Information about the coils is given.
This electronic flash circuit was found in the March 1961 Radio Electronics magazine. The circuit...
Like the previous circuit, this is used in the analog part of the telephone lines. The same...
This circuit was found in documentation from the 90s, being indicated for use with tape recorders given...