What Must todo

Just as in the transmitter circuit, the series of FM Wireless Microphone Receiver Hi Fi also uses an FM audio receiver module. Module used in the circuit FM Wireless Microphone Receiver Hi Fi has a good feture, namely audio FM receiver module has a function that is able to muffle the noise squel. Audio FM receiver module that is used in FM Wireless Microphone Receiver Hi Fi also does not require a lot of supporting components in the RF signal reception.

Audio FM receiver module only requires a 5 volt DC voltage source and a potentiometer P2 to set the threshold level of noise that will be muffled. Voltage source to an audio FM receiver module is also to go through the regulator is good, because if the quality of resources kuran it will generate noise. At the output line installed capacitors C3 and C4 as a couple and compensator for output in accordance with the amplifier or mixer (100mV rms).

To provide an output signal according to the needs and stable output signal audio FM receiver module on FM Wireless Microphone Receiver Hi Fi is fed to an audio preamplifier which uses IC TLC272. Levelk audio signal set by potentiometer P1. As a voltage regulator for power source circuit FM Wireless Microphone Receiver Hi Fi LM7805 regulator IC is used.

This FM wireless microphone is easy to build and has a useful range of transmission (over 300 meters outdoors). Despite its small number of components and an operating voltage of 3V to easily penetrate over three floors of an apartment building. You can tune anywhere on the FM band (87-108MHz) and its transmissions can be picked up at any point of view of the FM receiver.

The coil (L1) should be approximately 3 mm in diameter, 5 turns 0.61 mm copper wire. You can vary the Tx frequency by simply adjusting the distance between the coils. The antenna should be a half wavelength or quarter-time (100 MHz, 150 cm or 75 cm).

Parts list:

• T1,T2,T3: 2N2222 transistor
• R1: 10k 5%
• R2: 33k lin.
• R3: 12k 5%
• R4: 5.6k 5%
• R5: 2.2k 5%
• R6,R8: 47k 5%
• R7: 470 ohms 5%
• R9: 180 ohms 5%
• C1,C2: 47nF
• C3: 1nF
• C4: 33pF
• C5: 5.6pF
• C6: 8.2pF
• C7: 10nf
• L1: 3mm in diameter with 5 turns 0.61 mm copper wire
• K1: SPDT toggle switch
• Other parts: 2 AA battery holder, Electret microphone, antenna wire