It generates frequency within the following ranges
1,6khz up to 19khz manually (fine tune) or auto tuning when R2 is maximum
16khz to 25khz when R2 set to min...
the bandwidth can be narrower for example going from 1,4khz up to 10khz than from 16-20kz .... raising R1
so scanning occurs within this bandwidths and intermediates config of R2 pot
also divided by 10, 100 and 1000
so the led bliks at 1hz up to 25 hz
the gate goes from 0,5 hz up to 6,5khz approximately
0,5- 6 hz
5,6-65 hz
56-650 hz
560-6500hz
the scan circuit auto mode runs at 0,7hz scanning the all bandwidth within each half period.