The circuit is from 1968, but we can use a modern one like the 741. The symmetrical power supply voltage (two batteries or source) can be from 9 to 12 V.
This is the traditional configuration of an AC amplifier using the 741 integrated circuit. I found...
The oscillator shown in the figure generates a 1 kHz tone that is reproduced on the speaker with...
We found this wattmeter that operates between 100 kHz and 70 MHz in a 1974 amateur radio...