This shield circuit is from an American documentation from 1969. The components can be modified according to the relay and power, and the coupler can be of a modern type.
This circuit was found in Radio Electronics from the 90s. The CMOS integrated circuit is a PLL not...
This circuit was found in a Japanese publication in 1975. It provides 30 W per channel using the...
Depending on the value of C1, this oscillator can produce signals of up to 1 MHz. For a capacitor of 10...