How to solve the noise and off-frequency of wireless microphone? Five Practical Debugging Skills

There are five problems in wireless microphone, such as noise, broken voice and frequent frequency, which are mostly frequency interference, signal occlusion, equipment setting, power supply and antenna layout. The following five sets of practical programs can be directly debugged, covering performances, conference rooms and classroom scenes.

Skill 1: Automatic frequency selection by sweeping frequency, and radical elimination of co-frequency interference (core solution of frequency breaking)
Most of the off-frequency and intermittent noises come from the same frequency conflict of surrounding WiFi, Bluetooth, other wireless microphones, stage lighting control desk and walkie-talkie.
Turn on all wireless receivers and turn off all transmitters (handheld/collar microphone);
Enter the receiver's "automatic frequency scanning/ACT frequency matching" mode, and the machine will scan the frequency band with clean environment and no interference;
A single microphone is turned on one by one, and the receiver and microphone ACT are in infrared frequency opposition, and multiple sets of microphones are staggered in different frequency groups;
Meeting room/small performance: at least 8MHz apart; In large-scale performances, multiple receivers switch different frequency bands (A/B/C grouping) to avoid getting together in the same group.
Pit avoidance: Don't manually fix the old frequency points, the signals around the venue will change at any time, and the frequency must be swept before each use.

Tip 2: Standardize antenna layout to eliminate weak signal noise caused by signal occlusion.
Blocking of walls, metals, cabinets and human bodies will cause signal attenuation, intermittent frequency cut-off and noise at the bottom.
External antennas shall extend out of the cabinet uniformly, and shall not be stuffed into the metal cabinet or hidden behind the equipment;
The two receiving antennas are V-shaped and placed at 45 degrees, so do not cling to each other in parallel; Multiple receivers are matched with antenna distributors to prevent antennas from grabbing signals from each other;
When the microphone is used, the transmitter should not cling to the metal belt buckle, mobile phone and charging treasure, and the Bluetooth/WiFi of the mobile phone will continuously generate RF noise;
Long-distance use: install high-gain antenna to avoid metal keel and metal partition of ceiling.

Tip 3: Power supply and battery inspection to solve low-voltage intermittent noise.
Insufficient power is the most easily overlooked cause of noise and frequency cut-off:
The microphone transmitter gives priority to the brand-new alkaline battery, and the voltage of the rechargeable battery decays quickly. When the remaining power is low, sonic boom and frequency disconnection will occur;
The receiver adapter uses the original power supply, and the inferior adapter has large ripple, which will produce continuous current noise;
If there is noise, change the battery first. Test: When the microphone voltage is lower than 1.2V, the RF emission is unstable, so cut off the frequency directly if you go further.
The power supply is unstable when multiple devices in the cabinet share the power strip, and the receiver is plugged into an independent socket separately, away from high-power power amplifier and lighting power supply.

Tip 4: receiver noise reduction, RF threshold debugging, and suppression of ambient noise.
When the ambient radio frequency clutter is large, the rustling noise will continue if the noise reduction is not turned on, and the speech will be broken if the noise reduction parameters are incorrect.
Adjust the "SQ squelch threshold" of the receiver: if the threshold is too low, all environmental clutter will come in and produce noise; If the threshold is too high, speak in a low voice and mute the frequency directly;
Debugging method: turn off the microphone, slowly raise SQ until the rustling noise just disappears, and then fine-tune it back by 1 grid;
Turn on the built-in low-cut filter (80Hz/120Hz) of the receiver to eliminate the buzzing noise caused by low-frequency ground vibration, air conditioning and stage ground current;
When there is interference, turn on the receiver RF filter to filter the surrounding broadband RF clutter.

Tip 5: Isolate environmental interference sources and avoid invisible radio frequency pollution sources.
Many noises are not the microphone itself, but the RF leakage of peripheral equipment:
The wireless receiver is far away from the router, Bluetooth speaker, LED large-screen driving power supply, dimming silicon box and wireless ear return; The large-screen power supply is the hardest hit by high-frequency noise, and the cabinet is separated from the large screen by at least 2 meters;
Stage wiring: the signal line of microphone antenna should avoid the high-voltage power line, and the high-voltage and low-voltage pipelines should be routed separately to prevent power coupling noise;
Mobile phones and wireless headphones are far away from the antenna area of the receiver, and operators should not hold mobile phones near the receiving host;
If there are a large number of 2.4G wireless devices in the site, UHF ultra-high frequency wireless microphones are preferred to avoid interference in the 2.4G frequency band.