This circuit of a 1969 Electronic Design uses RTL logic. The setting can be adapted to TTL. The frequency is given by the crystal.
In the figure we have a wireless wiretapping circuit for the frequency range determined by L1. For FM...
This voltage follower or amplifier with unit gain uses an unusual operational amplifier nowadays. The...
Found in a 90’s Electronics Now, this circuit has its output connected to an audio amplifier. The...