Found in a 1966 American publication, this circuit generates a 25 MHz rectangular signal for testing flip-flops. Transistors are from the era. No information is given about L1.
The sound produced by this circuit, from a 1978 publication, depends on the humidity between the...
In a September 1992 Radio Electronics article, we found this basic 555 circuit used to generate fixed...
This circuit is suggested by Motorola, using a 4N26 type coupler and an MC1733 type operational....