The basis of this circuit is the HA2400 released at the time. The circuit is from a Radio Electronics magazine from March 1980. The power supply must be symmetrical at 15 V.
This circuit, found in a 1980 publication, limits the amplitude of the output signal to a value...
This VFO was found in a 1980s documentation. The central frequency is given by the crystal and the...
This traditional complementary configuration is from 1990 documentation. The transistors must have...