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.
We found this configuration in an early 1977 publication. The PNP transistor may be the BC558 and...
This circuit is indicated to operation with piezoeletric transdicers or other with high impedance...
This circuit was found in a 90s Radio Electronics. The load is an LED, but the circuit can be...