Two PNP transistors, 2N1265, to oscillate the 440 Hertz tuning fork. Coils to oscillate fork are from 2000 ohm earphones so I added 1 K ohms in circuit at sides of fork to give resistance that would be in coil. Aluminum box and brackets in box to not have magnetic interference. Above AC generator is to run simulator whereas tuning forks would vibrate in real circuit if earphone coils are close but not touching forks. Remember, if box is moved or vibrations of where box sets will affect slightly moving tuning fork. Right side 2K resistor is output voltage to adjust for 1 to 2 K headphones, oscilloscope, or amplifier.
