Frequently Asked Questions from TANO CABLE

The center conductor, insulation and shield of a coaxial cable form a capacitor; and, as many a microphone manufacturer will tell you, when the plates of a capacitor are deflected, a voltage is generated. (This is the basis of the condenser microphone!) Similarly, when the plates (conductor and shield) of our “cable-capacitor” are deflected (for instance, by stepping on it or allowing it to strike a hard floor), a voltage is also generated. Unfortunately, this voltage generally pops out of the amplifier as a distinct “whap,” and can be very hard on ears and loudspeakers alike. Effects of this type are called triboelectric noise.

The electrostatic shield’s charge-draining properties help greatly to diminish triboelectric effects. Triboelectric impact noise is also reduced by decreasing the capacitance of the cable with thicker and softer insulation because the deflection of the conductor is proportionally reduced. This is the main reason that the single-conductor coaxial configuration remains superior to the“twisted pair” for high-impedance uses—it allows thicker insulation for a given overall diameter. Triboelectric effects are accentuated by high source impedances, and are at their worst when the source is an open circuit—for instance, a cable plugged into an amplifier with no instrument at the sending end. Testing for this type of noise requires termination of the cable with a shielded resistance to simulate the source impedance of a real instrument.

The copper shield of a coaxial cable acts as the return conductor for the signal current and as a barrier to prevent interference from reaching the “hot” center conductor. Unwanted types of interference encountered and blocked with varying degrees of success by cable shielding include radio frequency (RFI) (CB and AM radio), electromagnetic (EMI) (power transformers) and electrostatic (ESI) (SCR dimmers, relays, fluorescent lights).

To be most effective the cable shield is tied to a ground—usually a metal amplifier or mixer chassis that is in turn grounded to the AC power line. Cable shielding effectiveness against high-frequency interference fields is accomplished by minimizing the transfer impedance of the shield. At frequencies below 100 kHz, the transfer impedance is equal to the DC resistance—hence, more copper equals better shielding. Above 100 kHz the skin effect previously referred to comes into play and increases the transfer impedance, reducing the shielding effectiveness. Another important parameter to consider is the optical coverage of the shield, which is simply a percentage expressing how complete the coverage of the center conductor by the shield is.

Tray cable is made for use in petrochemical refineries, industrial control systems, intercom systems, traffic controls relay, power extensions, and for many other high power functions. The cable is recognized for use in Class 1 and 2, Division 2 hazardous locations and for installation in trays, wireways, troughs, ducts, conduit and channels. Power Limited Tray Cable may be used for burglar alarms, petrochemical refineries, business machines, power limited circuits, intercom systems, cash registers, and industrial control systems.

Industrial Cable Industrial Cable from TANO Cable is supplied to a variety of industries. Industrial Cable is used in tough, demanding applications. This type of cable works in high temperature environments as well as high-voltage uses. It can withstand harsh treatment such as abrasion and contact with flames. TANO Cable stocks many types of Industrial Cable, including Multi-Conductor Control and Power Cable, Armored Power and Control Cable, and more. These are all available on our website. Instrumentation Cable Instrumentation Cables possess excellent electrical, thermal, and physical properties. This type of cable is designed to be able to withstand harsh treatment such as surface abrasion and even contact with flames, although it can be used in normal conditions as well. The specific types of Instrumentation Cables listed above are made to be used in circuits up to 600 volts. TANO CABLE also carries another very popular option, 300 Volt Instrumentation Cables, which is suitable for use in lower-voltage applications. Control Cables TANO CABLE's selection of high quality Control Cables includes flexible control cables and flexible automation cables. These cables are supplied to a variety of industries and applications, including robotics, manufacturing, construction, power and distribution, and more. They are common in both commercial and industrial markets.