Select the microphone cable systems should be the issue

In recent years, both for comfort and energy efficiency reasons, air conditioning and lighting systems are increasingly using electronic digital control technology. The numerical control system wiring in the weak will microphone signal line generated electromagnetic pulse noise.

Microphone cable carrying the signal amplitude range of 1 / 100 V (10mV) ~ 1 / 1, 000,000 volt (1μV) between the wiring cable selection process or a small error in the microphone system may be collected into a big noise antenna.

The following sections summarize by way of Q & A microphone system configuration problems.

Q1. What should be used under the conditions of the two core Mac cable?

Two core cable Mike does not apply to noise as a major consideration and a high level audio signals, can reach-20dB ~ 0dB environment. At this point, the two core cable show their small diameter, low-cost advantage. Of course, if not the line level but the microphone level, it should use the four quad-core cable line.

Q2. What conditions should be used four quad-core Mac cable?

More important factor in the noise, or signal level only-50dB or less environment should use four quad-core Mac cable. And compared the two core shielded cable, this cable can block out 90% of the noise

However, if such a cable with large-capacity power cables along the alignment, in order to secure that it should be penetrated into metal tubes.

Q3. Quad quad cable is not expensive?

The cost of this cable has greatly declined in recent years. Decades ago, only large concert halls and professional radio stations can afford them can be used. In 1981, Canare has developed the cost of using the aluminum foil shield four quad-core cable. In addition to traditional professional equipment other than that this cable in many non-traditional areas such as wedding halls, classrooms and other schools have also been widely used up.

Q4. If you do not use metal conduit, Mike cable should be far away from power cables?

If using metal conduit, can be found from Figure 3 should be left between the cable spacing. Note that if the fabric without regard to discharge the cable spacing problem, are prone to noise problems in the future is very delicate. Since Mike's signal cable is very weak, so it should be possible to use metal conduit.

 

Q5. In the use of current when a very large cabinet, which issues should be considered?

And question 4 (do not use metal duct should be considered in the problem) the same answer.

Q6. Use soft cloth metal conduit cable discharge What are the disadvantages?

Metal hose can reduce the noise, but not as effective metal hard pipe, it is recommended to use metal hose threading the cable line spacing should be left.

 Q7. What is the "wave masking"?

With corrugated metal shield is made of spiral wound around the cable shielding layer formed mainly used for underground cables. The shielding effect between the bare fabric cable and metal pipe threading between the disadvantage of poor flexibility, be particularly careful when bending.

Q8. Mike Cable There are many types, selection criteria, how?

The same types of shielding, they are only on some specific aspects of different uses according to the specific requirements to select the cable type.

Braided copper shield

No matter how many times through the bending, winding, twist, or retractable, shielded copper network can maintain a good shielding ability. As a hand-held cable or extension cable is ideal when using this type. In order to ensure a high shielding ability, which was especially fine cable knit, so than other types of cable costs are expensive, better results. It does not end processing needs of professional experience.

Spiral shield

Spiral copper shield around the cable is tightly wound as spiral. Wound twice around the opposite is also known as "double-helix shield" better shielding. Prices are between spiral shield and foil shield bronze mesh screen between the price. Although no side deal with relatively simple, but very active shielding performance will not spiral down, spiral shield is designed for fixed installation.

Aluminum foil shield

Molten aluminum foil shield is made of polyester film with aluminum foil, aluminum foil with a wound cable. The cable line is not end of treatment simply, the price is also cheaper for fixed installation. The need to pass through metal pipe laying aluminum foil shielded cables, be sure to use the rope filled with variety. When the threading operation, filling ropes to protect cables not due to excessive force and kink or retraction. Aluminum cable is now widely used in multi-function hall, stadium and other environment.