This electronic Morse Key for telegraph message transmission was found in an American 1980s amateur radio documentation. The circuit uses TTL technology and must be powered by a 5V voltage.
This circuit can turn-on (only) a load (relay or lamp) when S1 is pressed. The circuit can be used as...
The circuit shown uses the LM324, but can be implemented with other operational ones. The source...
This circuit was obtained from a 1977 magazine, but can still be mounted using BC548 for TR1 and...