This transmitter for the 40 meter or 7 MHz band was found in a magazine 73 for radio amateurs of the 90s. The circuit has a power of ½ W.
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...