The signals from this circuit obtained from the 1965 Radio Shack documentation are picked up from a medium wave receiver. L1 and L2 have 80 to 100 turns of yarn 28 on a ferrite rod.
Phase and amplitude can be controlled in this circuit found in the May 1988 Radio Electronics...
The purpose of the circuit of the figure is to control a servomotor remotely using a simple signal...
We found this circuit in a 90s Popular Electronics. The circuit can be implemented with modern...