This circuit is from the time when cars used contact breakers. This 80's version measures the dwell angle of the contact breaker for dwell adjustment using an era integrated circuit, the LM3917.
If you have a common analog multimeter, you can increase its input resistance in the measurement of...
Found in a 1968 documentation, this small amplifier was very popular at the time being used in...
Found in a magazine 73 for radio amateurs, this circuit operates in the 144 MHz band, at a...