Mini FM Transmitter Microphone Module MIC Wireless Audio Transmitter 100MHz Mini Bug Wiretap Dictagraph Interceptor Mini FM Transmitter Microphone Module MIC Wireless Audio Transmitter 100MHz Mini Bug Wiretap Dictagraph Interceptor Operating voltage: wide 0.7V to 9V Frequency adjustment range: wider than 88-108MHz Transmission distance: the operating voltage of 9V, the use of 70 cm wire antenna, open place to launch a distance of 50-100 meters, the actual look at the environment The relationship between the operating voltage (volts) and the supply current (mA) and the transmit power (dBm) is as follows: 9V, 24mA, 10.2dBm (i.e., 11mW) 8V, 21 mA, 9.5 dBm 7V, 19mA, 8.5dBm 6V, 17mA, 7.1dBm 5V, 14mA, 6.1dBm (about 5mW) 4V, 12mA, 4.5dBm 3V, 9mA, 2.2dBm 2V, 6 mA, -1 dBm (about 1 mW) 1.5V, 4.2 mA, -4dBm (about 0.5mW, the general family environment emission enough to use, green, radiation is small!) 1V, 2.4mA, -9dBm 0.7 V, 0.9 mA, -20 dBm (i.e., 0.01 mW) Baby wiring method: The back of the core board marked with +, -, and ANT, respectively, on behalf of the power positive, negative and antenna side, the antenna is generally welded a 0.7 m long short wire OK, very easy! This product will be put the sound around the on-board microphone into FM radio radio signals emitted, To achieve pickup and wireless audio FM transmitter, Product launch frequency is adjustable, The green component on the core board is adjustable capacitance, Change the adjustable capacitor can change the transmission frequency, Adjustable range covers the 88-108MHZ GB FM section. You can use the radio and mobile phone as a receiver! (Mobile phone headset line to do relatively poor antenna sensitivity is not recommended as a receiver) This product is widely used in voice pickup transmission, audio MIC, the elderly and children's sleep monitoring, and other occasion need sound pick up! 1.This product has an unparalleled wide voltage operating range from 0.7V to 9V! . Electronic technology people can understand a PN junction conduction voltage is 0.7V! That any battery can make this product work well (A dry batteries, lithium batteries, button batteries, carbon batteries, solar cells, lead - acid batteries, all kinds of common batteries!) 2. transmit signal pure, stray signal suppression to-60dBc! 96.5MHz about 50MHz bandwidth is very clean, the actual signal as shown below (the most professional test with 3.6GHz RF spectrum analyzer) 3. has very low power consumption, the working current is only 0.9mA at 0.7V. Using a single AA battery 1.5V power supply, the current is only 4.2mA, If you use the capacity of 3000mAH AA Ni-MH rechargeable battery, you can work continuously 3000 / 4.2 = 29.76 days! . . Wow, a month! 4. frequency adjustable, adjustment range covers 88-108MHz, the actual much wider than this frequency, through the adjustable capacitor with a sense of screwdriver adjustment. 5. all components using SMD components, stable and reliable performance, product consistency, o vercomes the problem of pin assignment parameters of conventional plug-in devices. All using the machine chip welding, solid and reliable, not a general DIY manual weldingcan be comparable! 6 small size, only one dollar coin size, easy to carry and hidden and so on. 1.What does the receiver use? Receive the use of ordinary FM radio, hand-knob to find the channel better!The use of digital receivers must be able to manually carefully enter the receiving frequency,such as input 88.1 MHz, 88.2 MHz, 88.3 MHz ... 108.0 MHz,for mobile phone reception we do not recommend use,cell phone use the headset cable as the receiving antenna, low sensitivity, interference, the effect of an impact! 2. How far is the launch distance? Can wear a wall? a. When tested at 9V voltage power supply, open places, using 0.7 m wire antenna test firing distance of 50 meters!the actual communication distance due to the environment, antenna placement, receiver sensitivity, etc. are different, so for reference only! b. This product can wear walls, but it depends on the specific wall of reinforced concrete structure, thickness and density!Generally able to wear 2-3 ordinary wall, through the walls of the capacity of the relationship with the specific location of the launch antenna length, power supply battery voltage, receiver radio sensitivity many influencing factors.It's a complex issue, the actual situation or to test shall prevail. 3. What battery is used? All common batteries can be used,the difference is only different working hours and firing distance,the higher the working voltage, the greater the emission distance, the longer the battery capacity, the longer the working time,you can according to the battery capacity and we listed above the emission current to roughly calculate the working time,actual working hours to the actual battery capacity prevail! 4.What is the difference between this product and ordinary FM microphone? This product pickup sensitivity is very high,not suitabl