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.
We found this circuit in an Electronic Design from the 80's. The generated tone can be changed as well...
In the figure we have an oscillator circuit by Wien Bridge (Wien Bridge Oscillator). The frequency of...
We found this circuit in Intersil documentation from the 1980s. The circuit applies to other...