This tube circuit was found in the magazine 73 for radio amateurs in an issue from the 1980s. Note the transformer used to power the circuit.
The S-meter is signal strength meter, coupled to telecommunications receivers to indicate the...
This circuit is suggested by Motorola, making it possible to use an optical coupler of type 4N26...
Dynamic analyzer is another name given to a signal follower or signal chaser. This circuit is from...