We found this circuit in American documentation from the 1980s. Transistors can be of general use. The frequency range of the generated signals ranges from 500 kHz to 10 MHz.
This receiver with two common JFETs was found in an old English documentation. The phone is...
This TTL circuit with the 7493 makes the binary count of the pulses sent by a flip-flop with the...
This circuit was found in a Popular Electronics from the 90s. The counter circuit is not common...