Frequency Meter

Components :

Resistor                    : R1 47k                                 : R8 1M

                                : R2 12k                                 : R9 100K

                                : R3 330k                               : R10 10K

                                : R4 5k6                                 : R11 1K

                                            : R5 12k                                 : R12 100ohm

                                            : R6 21k                                 : R13 470ohm

                                            : R7 10M                               : R14 100k

                Capacitor             : C1 25 µF                             : C4 10 nF

                                            : C2 470 pF                           : C5 12 µF

                                            : C3 25 nF

                Diode                   : D1, D2 IN 4148

                Zener Z                : BZ 88

                Transistor             : TR1 BC149

                                            : TR2 BC147

                IC                        : NE 555 (2)

                Milli Ampere Meter 15 mA

Frequency meter can be used to measure frequency from audio receiver or transmitter signal will be reinforcement from TR1, transistor pass through CS and then enter in IC555 and out put is will enter again in IC2 so we can see frequency enter.