The operational amplifier used in this circuit is uncommon today, but the configuration can be made with more modern operators. The power supply is symmetrical.
Found in an English documentation, this circuit provides a 50 Hz signal according to the local...
This circuit provides 15W per channel and can operate with a single power supply. The circuit is...
This preamplifier for the 6 or 2-meter range was obtained from an American documentation from the...