This circuit was found in a Radio Electronics from 1970. The coupler with LDR is from that time, but the circuit can be adapted to use modern components and act as a shield.
This oscillator with emitter follower was found in an American documentation from the 80's. The...
We found this circuit in 2005 Linear Technology documentation. The integrated circuit is LT1787...
The circuit is suggested by National Semiconductor in its 1994 Linear Applications Handbook. The...