This circuit is from a 1972 Motorola publication. The used transistor can still be found, but it can be used equivalent. The circuit is powered by the amplifier with which it must operate.
Found in 1968 Mullard documentation, this circuit uses period components. The transistors are...
In the figure we have a modified multiplier circuit that can operate with the sextuplicator with...
This circuit converts signals from the 350 to 500 kHz band to the 4.36 to 4.5 MHz band, enabling...