The resistors R1 and R2 consist of 8 220 ohms x 2 W resistors connected in parallel. The dissipation must be higher for high transmitter power. The indicator can be the multimeter.
This low Power output stage can source a fraction of watt to a small loudspeaker. The transformer...
This circuit uses a triac to detect the level of a reservoir, and a sensitive SCR connected to the...
EZP-Q metallized polypropylene capacitors from Panasonic's can be purchased from Mouser...