The circuit presented is from the Motorola Linear Databook of 1990. The integrated circuit is a transconductance operating and the power supply need not be symmetrical.
This circuit is a from publication 1980, but still can be mounted with BC548 transistors for Q1...
The integrated circuits used in this 1989 project are uncommon today, including the IF coil that...
This circuit uses a GE optical coupler. Equivalents can be tried. The circuit is from the GE...