This commercial circuit is from a Japanese magazine from 1967. It uses germanium transistors, and the coil can be made with 80 to 100 turns of fine enameled wire on a ferrite rod.
This decoder TTL circuit for 15-channel remote control was found in Selezione Radio, Italian...
The voltage gain of this DC amplifier is 100 times, given by the relationship between R2 and R1....
This circuit can be used both as a beat oscillator and for testing and adjusting AM receivers for...