This stereo FM transmitter module has good sound transmission quality, with built-in microphone. module board version: LCD_FM_TX_V2.1.9
I buy this module on Aliexpress, total cost is $7.22 (including shipping). when the module connected to PC/laptop over USB, Windows detects it as sound device and sound from the PC will transmitted. AUX in 3.5mm port is used for stereo analog audio input. microphone turns on when no external connections. Mic on the module is sensitive, it can pick up sounds on the entire room, make it ideal for audio baby monitors or suitable for audio room monitors. Mic is single channel or mono input, but the signal is still appear stereo. when AUX input is used, then the Mic is closed.
using 80cm telescopic whip antenna, and a Li-ion 18650 battery, transmit range can reach +/- 70 meter. its enough when used on home, or in outdoor activities.
Warning, take care with using any transmitter module. It's illegal in most countries to operate a radio transmitter without a license.
for this reason only low power and minimum range is used.
pros:
multi input option: USB audio, AUX in, built-in mic
PLL & DSP on-chip system (using Quintic QN8027 chip)
Digital frequency readout
stable & high performance FM stereo transmitter module
mini compact size
can run with one Li-Ion 18650 battery, or Li-Poly battery
cons:
power is limit arround 100mW
coverage range arround +/- 70 meter
need power amp and good antenna system to reach more range
application:
portable Stereo FM Transmitter
USB PC/Laptop Audio Broadcast
wireless microphone
maternal & infants custody
phone audio broadcast
room monitor
baby monitor
