UHF 621.5~643.7Mhz Fixed Frequency Point 1 to 4 Wireless Lapel Microphone Description: This product adds several new domestic unique technologies based on the original microphone technology, which makes the system have ultra-high sensitivity, strong anti-interference ability and excellent stability. The original technology includes high-efficiency low-cost RF emission technology and SMT production process in the United States, and uses a locking frequency of better than 10ppm quartz crystal, dynamic audio compression, expansion circuit, image frequency suppression circuit, switch-time shock elimination circuit, anti-return circuit variable output control technology, computer EDA, analog online auxiliary design, etc.   Features: Adopt domestic unique technologies to achieve ultra-high sensitivity, strong anti-interference ability and excellent stability. With fixed frequency point, it can be used as soon as it is booted, very convenient. Independently adjustable four-channel volume, provides 1+4 audio output, and the four-channel audio output is independently controllable. The conference/handheld/collar clips in the transmitter can be mixed and matched e. Stackable machine, 5 sets of different frequency points can be used at the same time. Specification: Name: UHF one for four professional wireless Lapel microphone Model: UF-4000 Battery: AA x 2 (not included) Frequency Range: UHF 621.5~643.7Mhz Transmit Power: <30mW (according to the applicable country specification) Harmonic Power: <35dB (main wave) Battery Life: >10 hours Oscillation Mode: Quartz crystal oscillation Stability: 10PPM Wireless Interface: BNC/50Ω Maximum Frequency Offset: 50KHz Signal to Noise Ratio: >103dB Distortion: <0.5%@1KHz Image Interference: >85dB Adjacent Rrequency Interference: >75dB Frequency Response Range: 50Hz~16KHz Squelch Control Mode: Multiple squelch circuit Maximum Output Level: +10dBV Sensitivity adjustment range: 12-32 dBμV Power Supply: External DC power supply, 0.8A, 12~15V DC Use Distance: Open environment: 50-80m / 164-262ft, complex environment: 30-40m / 98-131ft Host Size: Approx. 48x19x4cm / 18.9x7.5x1.6in   Package List: Transmitter x 1 Receiver x 4 Antenna x 2 Manual x 1 Audio Cable x 1 Power Adapter x 1 Lapel Microphone x 4