This circuit was found in a 1966’s American publication. What it does is to receive a pulse and keep it for intervals of up to 1 minute at the output.
This circuit is from old documentation but can be applied to modern equivalent components. The...
In the figure we have a simple signal tracer circuit to be coupled to the volume control of an AM...
This signal amplifier for ATV in the 427 to 439 MHz band was found in a magazine 73 for radio...