This is the circuit for the HM-10ª, an instrument sold by Heathkit. The circuit is from a Radio Electronics from May 1963. The indication is by an analog instrument.
This circuit was used to reinforce radio signals for listening on the phone, making it possible to listen...
This synthesizer circuit was found in a Radio Electronics magazine from May 1983. The circuit uses...
The circuit that gave rise to this configuration was found in a magazine of the 1980s with the...