2, technical parameters: a drag two wireless microphone. Main features: broadband transmission (50MHz), segmented receiving technology (two independent 25MHz sub-bands) : the two pass props of the receiver have independent 16 channels adjustable. Dual channel receiving circuit built into standard 1U metal case has professional quality of robustness, heat resistance and isolation of harmonic radiation interference. With "sound code and RF intensity" mute control, prevent other audio and video equipment and other radiation noise interference. With the "SET" automatic channel tracking button, as long as a SET key, can immediately make the transmitter automatically and accurately lock the receiver's working channel, no error and failure. Panel display: LCD false liquid crystal display, can display RF signal, channel, RF stability: ±0.005%(-10~50℃); Carrier frequency band: UHF 500~950MHz (standard: 640~690MHz); Frequency band width: 50MHz; Frequency adjustment: ∧ / ∨ selected desired frequency, and then press "SET" function key, the transmitter can automatically lock receiver with same working channel immediately. Receiving mode: secondary frequency conversion receiving; Sensitivity: S/N&gt when the offset is equal to 40KHz and the input is 6dBV; 80dB; Maximum offset: ±68KHz with volume expansion; Comprehensive S/N ratio: &gt; 105dB(A); Comprehensive T.H.D. : &lt; 0.5%@1KHz; Comprehensive frequency response: 50Hz~18KHz±3dB; Maximum output voltage: independent balance type: +10dB(2.5V)/600Ω, mixed unbalanced type: +4dB(1.25V)/5KΩ. Mute control mode: "sound code and RF intensity" dual mute control; DC power supply: 12V/1A; Technical parameters of wireless microphone transmitter: anti-interference design of mobile phone signal; Metal pipe material; Oscillation mode: PLL phase locking frequency synthesis; Carrier frequency band: UHF 640-690MHz; Frequency width: 50MHz; Frequency adjustment: automatic tracking receiver working channel; 10mW; Harmonic radiation: < -55dBC; Maximum deviation: ±45KHz; Preset channel: 200; Frequency response: 50~18,000Hz; Directivity: high heart directivity; Sensitivity: -80±3dB; Output impedance: 750Ω; Use batteries: two AA batteries; Operation display: digital screen simultaneously displays battery capacity, channel, low voltage warning; Maximum launch distance: 70 meters