Stroboscopic Tuner (May 1996):
The values for R1 and R2 were transposed in the component overlay diagram, on page 67 -- R1 should be 1.5M and R2 should be 820k.
If you are having problems with the sensitivity of the microphone input, try checking that these resistors are installed correctly.
The circuit diagram and parts list are correct. 
Also transposed were the 6V battery connections shown on the overlay diagram; the battery should be connected with positive going to the positive side of C9.