Signstek 7W 7C FM Transmitter Mini Radio Stereo Station PLL LCD with AntennaFashion Black Stereo clear sound: the control panel is consisted of AT89C2051 and AT24C02; after the stage by two 2SC3355 and one 2SC2053 total of three power amplifier to ensure that the three-dimensional sound quality output effect Good shielding: Structure design closely, not because of external signal induction frequency drift Excellent heat dissipation: The stability of the chassis using high quality aluminum alloy material, lightweight and excellent heat dissipation can work continuously to ensure that equipment High-fidelity high stability: Motherboard is adopted by next-generation integrated NC FM stereo radio transmitter chip the BH1415 from Japan ROHM Company, built-in PLL frequency PLL, audio pre-emphasis, limiter and low pass filter circuit to achieve high fidelity, high stability signal transmission Easy to use: Panel use LCD to display the transmission frequency, according to the identification of the interface to connect to other hardware, easy to adjust and it is intuitive <span class="a-text-bold">Please Note: </span>The transmission range depends on many factors. The true distance is based on the sensitivity of the receiver, antenna of the receiver, and the building and other obstructions, which are between the transmitter and receiver. And the distance will much more in countryside. FM Transmitter Frequencies: 87-108Mhz Tuning Step: 100Khz/0.1Mhz Power Supply:12V DC (The current load of power supply should over 2A) Stability of Frequency: 0ppm-10~+50 Frequency Response: 76 ~ 108Mhz Transmission distance: about 200m (A barrier-free environment) Signal to Noise Ratio: &gt;70dB Distortion: &lt; 0.5% Operation Time: True 24/7 Antenna Design: Metal Telescoping Antenna Antenna Connector: TNC type Output Impedance: 50 ohm RF output power: 1W/7W (Power can be switched) Audio Input Connector: 3.5mm Mic Input Connector: 3.5mm Antenna type: TNC telescoping antenna Tuning Design: Stable PLL Technology Transmission Signal: FM Stereo Size: 160mm*95mm*54mm 1. Hold on/off button in while plugging the power plug in. (Hold for 3 sec after power is applied) 2. Select H (High) or L (Low) using + and - buttons then push on/off momentarily. 3. Set to 108 MHz FIRST using +/- buttons. Then push on/off momentarily. (Must be first) 4. Now set to 87.5 MHz using +/- buttons. Then push on/off momentarily. 5. The unit will shut off in a few seconds. 6. Turn it back on and adjust to the desired frequency with +/- buttons. The transmitter is now ready to use. FM Transmitter *1 Professional antenna *1 Power supply *1 Power cord *1 Audio cable *1 English manual *1