This QST circuit generates 4 frequency signals according to the crystals used. Transistors admit equivalents although the indicated types can still be found with some ease.
Suggested by Mullard in a1969 documentation, this circuit generates the erasure signal for tape...
A pulse applied to the input of this circuits results in a damped signal in the output. Frequency...
This circuit can activate a powerful lamp or call system when a telephone call occurs. Suitable for...