【 Weak current College 】 quality wireless microphone system must have the technical characteristics---Power By 【 China power house network 】

Wireless microphone system for quality and function of the distance and wireless microphone system stability, anti-interference ability, the transmitter power and receiver sensitivity, transceiver antenna, efficiency wireless microphone technical characteristics and the closely related field propagation conditions.

(1) high stability quartz Crystal oscillation of PLL PLL frequency synthesizer technology

Wireless microphone in a variety of environmental conditions (temperature, humidity, voltage, vibration and shock, and other changes in environmental factors) to stable work and get a good sound quality, accepted and transmitter carrier frequency stability is the most important basic conditions. Because if the carrier frequency drift, not only makes wireless transceiver system difficult to normal stable work, influence the quality of audio output, but also happens harmonic interference between channels. To this end, the modern high-quality wireless microphones are highly stable quartz crystal oscillator. However accurate quartz crystal oscillator can't change the oscillation frequency, the only solution to the problem of fixed frequency stability, cannot implement multiple channel frequency selection problems. To the quartz Crystal oscillation frequency phase-locked loop PLL frequency synthesizer technology enables the carrier frequency is adjustable, its frequency stability is completely the same as with quartz crystal oscillator.

(2) the diversity reception technique and AGC automatic gain control

Because indoor objects reflection and absorption, transmission of multiple means of electromagnetic waves, make the space distribution of electromagnetic field strength is complex, in addition the frequent mobile wireless microphone, enabling the receiving antenna of the electromagnetic field intensity occurring great fluctuation in signal drops when voice "dumb" or poor sound quality. To do this, the wireless microphone receiver with dual antenna diversity reception technique (Diversity) and AGC AGC technology to give up. Diversity reception technique is located at some distance apart (wavelength) of two sets of identical reception antennas and two sets of identical reception circuit, and through the build-in a computer chip circuit automatically detects and automatically select a strong way to receive the signal as the then receives the output signals, in cooperation with the AGC circuit, can effectively resolve the signal "dead point". This diversity reception technique is also commonly known as solitary double your signal.

Leaves-tunnel is the market a lot of cheap fake double antenna wireless microphone receiver, these counterfeit products in addition to have two receive antenna, there are no diversity reception device, so you cannot resolve the signal the "dead point" issue.

In addition there is also a cheap called "double-a dual-income" of a wireless microphone, this is the "single single receiving" two sets of wireless microphone device installed in a case of simple systems, there is no diversity reception function.

(3) noise suppression technology

Interference signal increases wireless microphone noise output, reducing the sound output quality, serious will enable wireless microphone does not work. Interference signals from a variety of industrial interference, TV and radio signal interference, mobile phone and radio interference, military communications systems of interference and wireless microphone all adjacent channel interference between ... And so on. Especially wireless microphone in the audio signal of a clearance period. Harsh noise is disturbing. To do this. High-quality wireless microphone offers a variety of effective noise reduction technology, the most common are:

● Squelch circuit: the gap in the audio signal, noise, during this time wireless microphone can automatically stop noise output, become mute output can be effectively improve output audio signal/noise ratio (S/N).

• Pilot signal technology: Wireless words simply transmitting audio signals at the same time, join an inaudible ultrasonic pilot signal 32KHz. Receiver squelch circuit to identify this pilot signal, the receiver only detects when the pilot signal to output sound signal, thus effectively prevent from another transmitter unwanted signals or noise as well as from wireless microphone power is switched on and off when the RF noise and burst noise.

● Frequency agile technology: different places of wireless microphone, experiencing interference frequencies vary, sometimes the same places for different times of the frequency of interference. To effectively avoid the disturbance frequency, wireless microphone should have quickly change the capacity of the choice of channels, this is the "frequency-agile technology." Anyone who can select channels of wireless microphone system (including the transmitter and receiver) is used for frequency agile practices.

(4) wireless microphone transmitting power and range

Wireless microphone effective distance General provisions, in the open plains of 100 meters ~ 180 meters. The need for more far distance. You can launch the effective role of distances to erect high receiving antenna with low loss cable to receive signals to a receiver in the distance. If necessary, the antenna can be inserted into the antenna amplifiers.

Wireless microphone transmitting power and range. Although raising the transmitter output power may increase the effects of distance, but affect the battery time of continuous power, but also on personal health damage, therefore different transmitter output power of the General provisions in the 2mw ~ 50mw between (and selection of the band).

(5) wireless microphone transmitter power supply

Whether it is handheld wireless microphone or pockets-wireless words Jane, their transmitter using the small battery-powered. Should be able to guarantee that the new battery to a normal continuous power supply 6 hours. Wireless microphone for the power supply is involved the use of cost and use features of important conditions. General wireless microphone common battery model for small laminated battery 9V. Because the battery's quality is not homogeneous and cannot indicate a cumulative use of time. Therefore often use intermediate appears sound variation, sound choppy and distance reduced, troubles. To eliminate these troubles, the number of new listings of high-performance wireless microphone has a rechargeable lithium battery of high energy or purchase easy General 2 sections (3V) 5, alkali-resistance of battery power. To ensure continuous power for 6 hours, also has a cumulative use of time and lastThe remaining 1 hour alarm, very reliable. Very convenient.