This squelch circuit used in transmitters was found in a magazine for radio amateurs 73 in the 1980s. The circuit admits equivalent components.
This sensitive 5-band circuit was found in a September 1995 issue of Electronics Now magazine. The...
Found in 1967 General Electric documentation this circuit appears elsewhere in this section. SCRs are...
This circuit was found in documentation from the 1980s. It is powered by the audio signal that must...