Found in an American circuit manual from the 1970s, this circuit can use any general-purpose transistor. The operating frequency range is from 600 to 4000 Hz.
This circuit was found in a Mullard transistor manual from 1960. Note the symmetrical power...
This amplifier step with a transistor has an input impedance of 100k to 10 M. The transistor can be any...
I found this little signaling transmitter in old American documentation. The circuit has a good...