Coaxial cable consists of a central conductor. a) Threaded connector

Choose the right coaxial cable worth under specific task And with the parameters you need. What criteria are the most important for you? That's what you should consider when choosing coaxial cable:

Type of cable

There are two main types of coaxial cables: with a resistance of 75 ohms used mainly for video, and with a resistance of 50 ohms used mainly for data transmission and wireless communication. Common, have different caliber and different copper content in the central conductor to ensure the flexibility of the cable. The total size can reach 30, 150 and 300 meters, usually delivered to them. A typical RG type for data transmission can be used outside the room. Available in 30, 150 and 300 meter coils, most have an outer shell of teflon, which helps protect the cable from temperature effects.

Frequency

Another important factor of the coaxial cable is the operating frequency. As the frequency increases, the signal energy goes from the central cable conductor to protect the cable from noise. An important cable parameter is the signal parameters and how much it can move via a cable of a certain length at a given frequency of the signal and the power level. The higher the signal frequency, the less distance.

Weakening

Cable attenuation is a signal loss parameter for a certain distance. The higher the frequency, the greater the attenuation value, and the greater the diameter of the central conductor, the smaller the attenuation. For example, a cable with 14 central conductor can carry the signal (at a certain frequency and power) by about two times the distance than the cable with 20 AWG. When choosing a coaxial cable, it is very important to know, damping parameters.

Impedance

The wave resistance of the coaxial cable is an important parameterwhich affects the conductivity of the signal. This parameter is called the impedance of the transmission, this is the relationship between the cable capacity per unit length and its inductance per unit length. For optimal signal transmission, the wave resistance of the cable must be coordinated with the impedance parameters and with load resistance.

Questions arising when choosing a coaxial cable. What:

• Weakening (Loss introduced): power loss. Weakening increases with increasing frequency. Changing the attenuation is determined at the output of the system before and after connecting the cable and / or device.
• Frequency: Once periodic action occurs within one second number. Measured in Hertz.
• Resistance: Simply put, impedance, in a coaxial product, is to measure the stream resistance. Unit of measurement is OM.
• Central conductor: Single-core or stranded wire in the middle of the coaxial cable. The diameter of the AWG conductor.
• Radius of bend: radius at which you can bend the cable without any side effects.
• Coaxial adapter: The device used to connect one type

Coaxial cable (from lat. Co - together and AXIS - axis, that is coaxial; Spoken coaxial from English. Coaxial) - electrical cable consisting of a central conductor and a screen located coaxial and separated by insulating material or air interval. Used to transfer radio frequency electrical signals. Differs from the shielded wire used to transmit permanent electric current and low-frequency signals, more homogeneous in the direction of the longitudinal axis section (the cross-sectional form, the size and values \u200b\u200bof the electromagnetic parameters of the materials are normalized) and the use of more qualitative materials For electrical conductors and isolation. Invented and patented in 1880 by the British physicist Oliver Hevisayd.

TV RG-59 coaxial cable used to connect antenna to television receiver

Device [ | ]

Coaxial cable (See Figure) consists of:

Due to the coincidence of the axes of both conductors, the ideal coaxial cable, both components of the electromagnetic field are fully focused on the space between the conductors (in dielectric insulation) and do not go beyond the cable, which eliminates the loss of electromagnetic energy to radiation and protects the cable from external electromagnetic tips. In real cables, the limited output of radiation outwards and sensitivity to the tips are due to the deviations of geometry from ideality. The entire useful signal is transmitted via an internal conductor.

History of creation[ | ]

• 1855 - William Thomson considers the coaxial cable and receives a formula for the routine capacity.
• 1880 - Oliver Hevisida receives British patent No. 1407 on a coaxial cable.
• 1884 - SIEMENS & HALSKE Patents Coaxial Cable in Germany (Patent No. 28978, March 27, 1884).
• 1894 - Nikola Tesla patented an electric conductor for variable currents (Patent No. 514167).
• 1929 - (English Lloyd Espensied) and Herman Effelt from AT & T Bell Telephone Laboratories Patched the first modern coaxial cable.
• 1936 - AT & T built an experimental television data line on a coaxial cable, between Philadelphia and New York.
• 1936 - the first television program on a coaxial cable from the Berlin Olympic Games in Leipzig.
• 1936 - between London and Birmingham Postal Service (now the company BT) has a cable for 40 telephone numbers.
• 1941 - the first commercial use of the L1 system in the US company AT & T. Between Minneapolis (Minnesota) and Stevens Point (Wisconsin) launched a TV channel and 480 telephone numbers.
• 1956 - the first transatlantic coaxial line is laid ,.

Application [ | ]

The main purpose of the coaxial cable is the transfer of a high-frequency signal in various fields of technology:

In addition to signaling, cable segments can be used for other purposes:

There are coaxial cables for transferring low-frequency signals (in this case, the pole serves as a screen) and for DC high voltage. For such cables, wave resistance is not normalized.

Classification [ | ]

By destination - For Systems cable television, for communication systems, aviation, space technology, computer networks, household appliances etc.

International Designations[ | ]

Systems of the designations in different countries are established by international, national standards, as well as their own standards of manufacturers (the most common series of brands RG, DG, SAT).

Categories [ | ]

Cables are divided by the Radio Guide scale. The most common cable categories:

• RG-58 / U - a solid central conductor,
• RG-58A / U is a stranded central conductor,
• RG-58C / U - Military cable;

"Thin" Ethernet[ | ]

It was the most common cable to build local networks. The diameter of about 6 mm and considerable flexibility allowed it to be laid almost in any places. The cables were connected to each other and with a network board in a computer using the BNC T-Connector. Between themselves cables could be connected using BNC (direct connection). At both ends of the segment, terminators must be installed. Supports data transmission up to 10 Mbps to a distance of up to 185 m.

"Fat" Ethernet[ | ]

Thirdly, compared to the previous, cable - about 12 mm in diameter, had a thicker central conductor. I was bad and had a significant cost. In addition, when joining a computer there were some difficulties - AUI transceivers (Attachment Unit Interface) were used attached to network card With the help of a branch, piercing the cable, so H. "Vampires". Due to the thicker conductor, the data transmission could be carried out at a distance of up to 500 m at a speed of 10 Mbps. However, the complexity and high cost of the installation did not give this cable of such widespread as RG-58. Historically, the RG-8 corporate cable had a yellow color, and therefore sometimes you can meet the name "Yellow Ethernet" (English Yellow Ethernet).

Auxiliary elements of the coaxial tract[ | ]

• Coaxial connectors - to connect cables to devices or their joints between themselves, sometimes cables are produced from production with installed connectors.
• Coaxial transitions - for the articulation of cables with unpaired connections with each other.
• Coaxial tees, directional branches and circulators - for branches and branches in cable networks.
• Coaxial transformers - to match the wave resistance when connecting a cable with a device or cables.
• Terminal and passing coaxial loads are usually consistent - to establish the right modes Waves in the cable.
• Coaxial attenuators - to attenuate the signal level in the cable to the required value.
• Ferrite valves - to absorb the reverse wave in the cable.
• Graphically distributors based on metal insulators or gas-discharge devices - to protect the cable and equipment from atmospheric discharges.
• Coaxial switches, relays and electronic commuting coaxial devices - for switching coaxial lines.
• Coaxial-waveguide and coaxial striped transitions, symmetrical devices - for dusting coaxial lines with waveguide, striped and symmetrical two-wires.
• Pass and end detector heads - to control the high-frequency signal in the cable by envelope.

Basic normalized characteristics[ | ]

Calculation of characteristics[ | ]

Determination of the rose container, the pattern inductance and the wave resistance of the coaxial cable according to known geometric sizes is carried out as follows.

First you need to measure the inner diameter D. The screen, removing the protective shell from the end of the cable and wrapped the braid (the outer diameter of the internal insulation). Then dimmeter is measured d. Central veins, removing pre-insulation. The third parameter of the cable that needs to be known to determine the wave resistance is the dielectric permeability ε of the material of the internal isolation.

Running capacity C H. (In the international system of units (C), the result is expressed in the Farades per meter) is calculated by the cylindrical capacitor capacity formula:

C H \u003d 2 π ε 0 ε ln \u2061 (d / d), (\\ displaystyle c_ (h) \u003d (\\ FRAC (2 \\ pi \\ varepsilon _ (0) \\ varepsilon) (\\ ln (d / d))) )

Running inductance L H. (in the SI system, the result is expressed in Henry per meter) is calculated by the formula

L h \u003d μ 0 μ 2 π ln \u2061 (d / d), (\\ displaystyle l_ (h) \u003d (\\ FRAC (\\ Mu _ (0) \\ Mu) (2 \\ pi)) \\ ln (d / d) )

Z \u003d l h c h \u003d 1 2 π μ μ 0 ε ε 0 ln \u2061 d d d ≈ lg \u2061 (d / d) ε ⋅ 138 Ω (\\ displaystyle z \u003d (\\ sqrt (\\ FRAC (L_ (H)) ( C_ (H)))) \u003d (\\ FRAC (1) (2 \\ PI)) (\\ SQRT (\\ FRAC (\\ Mu \\ Mu _ (0)) (\\ Varepsilon \\ Varepsilon _ (0)))) \\ ln (\\ FRAC (D) (D)) \\ APPROX (\\ FRAC (\\ lg (d / d)) (\\ sqrt (\\ varepsilon))) \\ CDOT 138 ~ \\ OMEGA)

(Approximate equality is valid in the assumption that μ \u003d 1).

The wave resistance of the coaxial cable can also be determined by the nomogram shown in the figure. To do this, you need to connect the straight line of the point on the scale D / D. (The ratio of the inner diameter of the screen and the diameter of the inner core) and on the scale ε (dielectric permeability of the internal insulation of the cable). Point of intersection spent straight with a scale R. The nomogram corresponds to the desired wave resistance.

The speed of propagation of the signal in the cable is calculated by the formula

V \u003d 1 ε ε 0 μ μ 0 \u003d C ε μ, (\\ displaystyle v \u003d (\\ FRAC (1) (\\ sqrt (\\ varepsilon \\ varepsilon _ (0) \\ mu \\ mu _ (0)))) \u003d ( \\ FRAC (C) (\\ SQRT (\\ Varepsilon \\ Mu))),)

where c. - The speed of light. When measuring delays in paths, designing cable lines of delays, etc. It can be useful to express the length of the cable in nanoseconds, for which the reverse signal of the signal is used, expressed in the nanoseconds per meter: 1 / v. = √ ε · 3.33 ns / m.

Limit electrical voltagetransmitted by the coaxial cable is determined by electrical strength S. The insulator (in volts per meter), the diameter of the internal conductor (since the maximum voltage of the electric field in the cylindrical capacitor is achieved near the internal plating) and to a lesser extent with a diameter of the external conductor:

V p \u003d S d 2 ln \u2061 (d / d). (\\ displaystyle v_ (p) \u003d (\\ FRAC (SD) (2)) \\ ln (d / d).)

see also [ | ]

Notes [ | ]

Literature [ | ]

• N. I. Belorussov, I. I. Grodne. Radiofrequency cables. 2nd ed., Pererab. - M.-L.: GosEnergoisdat, 1959.
• T. I. Izyumova, V. T. Sviridov. Waveguides, coaxial and strip lines. - M.: Eney, 1975.
• D. Ya. Galperovich, A. A. Pavlov, N. N. Khrenkov. Radiofrequency cables. - M.: Energoatomizdat, 1990.
• Electrical cables, wires and cords: Reference / N. I. Belorussov, A. E. Sahakyan, A. I. Yakovlev: Ed. N. I. Belorussov. - 5 ed., Pererab. and add. - M.: Energoatomizdat, 1987. - 536 p.; Il.
• Amateur radio at square. Ed. B. G. Stepanova. - M.: Radio and Communication, 1991.
• Reference book of a radio-designed designer. Ed. N. I. Chistyakova. - M.: Radio and Communication, 1990.
• J. Davis, J. J. Carr. Pocket reference book of the radio engineer. Per. from English - M.: Dodek-XXI, 2002.
• Kashkarov A. P. Popular directory of the radio amateur. - M.: IP "Radiosoft", 2008.- 416 C.: IL. See with. 250.

Regulatory Technical Documentation

• GOST 11326.0-78. Radio frequency cables. General specifications.
• IEC 60078 (1967). Radio frequency coaxial cables. Wave resistance and sizes.
• IEC 60096-1 (1986). Radio frequency cables. Part 1: General requirements and measurement methods.
• IEC 60096-2 (1961). Radio frequency cables. Part 2: Private technical conditions on cables.
. ABC security
• Electrical characteristics of coaxial cables. Cqham.ru.

Coaxial cable - This is an electric cable consisting of a central wire and a metal braid, with each other separated by a layer of dielectric (internal isolation), as well as placed in a common outer sheath.

To calculate the resistance of the conductor, you can use the calculator for calculating the resistance of the conductor.

It was even recently very common, this is due to the fact that due to the metal braid, it has a high noise immunity, also higher allowed data transmission speeds (up to 500 Mbps) than in the case of twisted pair and large allowed transmission distances (up to 1 km and above). With unauthorized listening of the network, it is mechanically more complicated to connect to it and it also gives a wave fewer electromagnetic emissions. However repair and repair and mounting coaxial cable much more complicated, and its cost is higher (in comparison with cable based on twisted par, it is more expensive about 1.5-3 times). Installing connectors at the ends of the cable is also harder, so it is now used less often than twisted steam.

With Top Topology in Computer local networks, finds the main thing Application Coaxial Cable. Be sure to install terminators at the ends of the cable to prevent the internal reflection of the signal, and only one of the terminators should be grounded. Metal braid without grounding does not protect the network from external electromagnetic interference and does not reduce the emission of information transmitted over the network to the external environment. If you ground the braid at two points or more, then it may be out of order not only network equipment, but also computers. It is necessary to coordinate the terminators with the cable, that is, their resistance and wave resistance of the cable should be equal. If for example, a 50-ohm cable will be used, then only 50-ohm terminators are suitable for it.

Coaxial cable Less frequently applies in networks with a star "Star" or "Passive Star" (in the ARCNET network, for example). The coordination problem in this case is greatly simplified, no external terminators are no longer required at the free ends.

The accompanying documentation indicates the wave resistance of the cable. Most often used in local networks 50-ohm (for example, RG-58 or RG-11) and 93-ohm cables (for example, RG-62), 75-ohm cables used in television technique are not used in local networks. There is significantly less coaxial cable brandsthan cables based on twisted pairs, it is no longer considered promising.

Types of coaxial cable.

• Thin cable, more flexible and has a diameter of about 0.5 cm.
• Thick cable, more hard, it has a diameter of about 1 cm and is classic option of coaxial cablewhich is almost completely displaced by a modern thin cable.

The thin cable is used for transmission to smaller distances than the thick, due to the fact that the signal in it is hurting is stronger. But it is much more convenient to work with a thin cable, to each of the computers it can be quickly paved, the thick cable will need hard fixation on the wall of the room. When connecting to a thin cable, additional equipment will not be required and it is much simpler (using BNC bnc connectors), and when connected to a thick cable, you need to use special enough expensive devices that pierce its shells, also install contact with the central residential and screen . Compared to a thin, thick cable is more expensive than about 2 times, so the thin cable is much more often used.

Important the coaxial cable parameter, as in the case of twisted pairs, is the type of its outer shell. In this case, both Non-Plenum (PVC) and PLENUM cables are used in the same way. The Teflon cable is, of course, more expensive than polyvinyl chloride, the cable shell type can usually be distinguished by its coloring (yellow color BELDEN uses for PVC cable, and orange - for Teflon).

In the coaxial cable, typical delay values \u200b\u200bare for a thin cable of about 5 ns / m and about 4.5 ns / m - for thick. Still exist coaxial cables S. double screen (One screen is located inside the other and is separated from it with an additional layer of insulation), such cables have better noise immunity, as well as protection against wiretapping, but they cost a little more expensive than ordinary.

It is considered that now Coaxial cable outdated And in most cases it can completely replace the twisted pair or fiber optic cable. In new standards for cable systems, it is no longer included in the cable list.

Coaxial cable. What is it?

Probably, you have repeatedly heard such phrases like twisted para, shielded wire and high-frequency signal? So here coaxial cable - This variety twisted coupleBut with a much greater noise immunity, the most suitable conductor for the RF signal.

It consists of central veins (conductor), shielded layer (screen) and two insulating layers.

Internal insulator isolation central residential coaxial cable From the screen, external - to protect the cable from mechanical damage and electrical insulation.

Protection against interference coaxial cable. The cause of the occurrence of noise

What prevents interference in non-coaxial cable

It is necessary to immediately deal with the question of protection against interference. We will understand general principles The nature of their occurrence and influence of interference to the transmission of information.

So, we all know that there are some interference in power lines. They represent bursts and, on the contrary, the disappearance of the nominal (of which should be) voltage in the cable (in the wire). On the graph (the dependences of the voltage in the cable from time) interference look like this:

The cause of interference is the electromagnetic fields from other signals and cables. As we know from the course of school physics, electricity has two components - electric and magnetic. The first is the current of the conductor current, and the second is an electromagnetic field that creates a current.

The electromagnetic field is distributed in an environment in the form of a sphere in infinity. Passing through unprotected (not coaxial) Cable, the electromagnetic signal affects the magnetic component of the electrical signal in the cable and causes interference in it, rejecting the signal voltage from the nominal.

Imagine that we process (read) 10 V voltage signal with a specific clock frequency, for example in 1Hz. This means that we instantly write off the stress testimony in line every second. What happens if it is at the time of reading the interference will strongly dismiss the voltage, for example from 10 volts to 7.4 volts? Right, error, we consider false information! We illustrate this moment:

But we must remember that the voltage is measured from the hull (or from the minus). And the chip is that in electronics (in electronics of high-frequency signals) a large negative role is played precisely high-frequency interferenceAnd here it, in fact, truth: at the moment when the interference acts on central residential coaxial cable, the same interference acts on screen coaxial cableand the voltage is measured from the housing (which is connected to the screen), so the potential difference between on-screen part of the coaxial cable And its central residential remains unchanged.

Therefore, the main task in protection against interference when transmitting the signal is to keep the screen layer or the wire as close as possible to the central and always at the same distance.

What better protects from electromagnetic interference - twisted pair or coaxial cable?

Immediately answer the question. Coaxial cable protects against interference better than twisted para.

IN twisted pare Two wires of suits among themselves and are isolated from each other. The positive wire with bends can be given to a hundred millimeter from a minus, which removes, actually, plus from the case. In addition, the residentials of the positive and minus wire themselves, at the expense of isolation, have a certain gap among themselves. An interference can slip, but the probability is quite small.

IN Coaxial Cable Open Layer In a circle, fully envelops the central core. No interference can not go through the central custody, bypassing the coaxial screen. In addition, the quality of the material from which the coaxial cable is manufactured, according to the requirements state Standard superior quality materials for twisted par. Point.

Wave resistance of coaxial cables.

Wave resistance

Basic characteristics of the coaxial cable - wave resistance. This is a magnitude, in general, characterizing attenuation signal amplitudes in coaxial cable 1 mongo meter.

It turns out from the expression of private from the voltage of the signal, transmitted by coaxial cabledivided by current wherein voltage in coaxial cable, Merils in Omah.

But most importantly, remember that it characterizes - the attenuation of the transmitted signal. This is the essence of the wave resistance of coaxial cables. Reducing the amplitude of voltage and current - there is a signal attenuation.

In order to plunge into wave resistance of coaxial cables Deeper, you need to know many different concepts about the theory of electromagnetic waves, such as amplitude excluding attenuation, active routine resistance, attenuation coefficient electromagnetic waves in a coaxial waveguide, several permanent electrical values, then build a pair of integral wave graphs and understand that after all, 77 ohms are ideal for Soviet television, 30 ohms is ideal for everything except Soviet television, but the 50 ohm is the Golden Middle between Soviet Television , coax cable and everything else!

But it is better - remember the essence, and the rest - Believe the word)

Standards of wave resistances of coaxial cables:

50 ohms. The most common coaxial Cable Standard. Optimal characteristics According to the transmitted signal power, electrical insulation (plus from minus), the minimum loss of the signal when the radio signal is transmitted.

75 ohms. It was widespread in the USSR in terms of television and video transmission and, it is noteworthy, it is optimally suitable for these purposes.

100 Ohm, 150 ohms, 200 ohms. Used extremely rare, in highly specialized tasks.

Also, important characteristics are:

• elasticity;
• rigidity;
• diameter of internal isolation;
• screen type;
• metal conductor;
• degree of shielding.

Have questions? Write in the comments) We will reply!

Coaxial cable - the result of the efforts and works of many scientists. Famous physicists and engineers from different states worked on its creation:

• british William Thomson and Oliver Heviside;
• serb Nikola Tesla;
• germans Herman Effel and Lloyd Espireshid.

Currently coaxial cable Widely applied:

Coaxial cable Widely used to transmit high frequency electrons, to protect cable networks From external radio interference, as an interference agent. There are many other spheres of radio electronics, where applied coaxial cable.
If you look at the incision of this cable, then it can be disclosed with a copper or aluminum wire lamp, an external conductor of aluminum foil and a central conductor coated with a layer of insulation from light-stabilized polyethylene. Central veins is made of copper, aluminum or steel coated with copper. The outer insulating layer is usually made of PVC. As a rule, all types of coaxial cable are packaged in standard 100 meter bays.
The most common cable group is considered category RG. As a rule, the parameters of the representatives of this group coincide with the indicators of the radio conductory.
Classification on the Radio Radio
In the environment of specialists and scientists coaxial cables It is customary to distinguish between the Radio Guide scale, which means "radio conductory". This article provides basic information about the most common categories of coaxial cable:

• RG-11;
• RG-8;
• SAT-703. ;
• SAT-50. ;
• RG-58;
• 3C-2V;
• RG-59;
• RG-6;

The most famous types of coaxial cables
The RG-58 / U cable with a wave resistance of 50 ohms has a solid central conductor from irradiated copper. It is used in various spheres of electronics and radio engineering. Packed in 100 meter bays.
Widely distributed in everyday life and known as television, cable RG-59. / U is used to transmit information in video surveillance systems, as well as for broadband data broadcast. His wave resistance is 75 ohms. It has a conductor of steel covered with copper, thanks to which sheshev is enough. In the Russian Federation, a similar cable is manufactured with the marking of RK-75-3. Thickness RG-59. / U less than RG-6, as a result, the first is more convenient to connect to video cameras. Packed in standard 100 meter bays.
For convenience when installing video surveillance systems, a hybrid cable is most often used. RG-59. + 2 * 0.75. This is due to the fact that it may at the same time carry out electricity to operate the system and broadcast video signals. Such a double cable function is due to the fact that inside the cable, together with a central conductor and a fever, there is a two-housing conductor with an enlarged cross section. The latter is necessary for safety when powering the video system from the power grid. The cable is packaged in standard 100 meter bays.
When equipping video systems cable RG-59. + 2 * 0.75 can be replaced with copper thin 3C2V, the veins of which have a half aulimeter diameter, and the central conductor is made of copper or copper and steel. Such a replacement will give its advantages. Thinner and flexible 3C2V, moving behind rotating camcorders, will be much less frequently damage than its analog. The length of 3C2V is made of copper, and the screen is made of aluminum foil. The cable is folded into the standard 100 meter bays.
W. television cable RG-6U with a wave resistance of 75 ohms There is a Russian analogue of RK-75-4-x. Both types are used on end sites (from 100 to 200 meters) television lines. The cables from the RG-6 group are divided into several species depending on the material from which they are made. Packed in 100 meter bays.
The central wire in the CCS RG-6U cable is made of steel, which is covered with copper from above. This significantly reduces its cost. External conductor - aluminum. A pitch consisting of 48 or 32 0.12-millimeter veins is made of steel or aluminum. RG-6 is a little thicker than RG-59.. The first is used for devices operating at a higher frequency than systems equipped with RG-59; Also, the RG-6 is used for broadband broadcast, and packaged in 100-meter bays.
Central conductor SAT-703. It has a relatively large diameter and made of copper, and the outer conductor (foil) is made of aluminum. The on-screen strip consisting of 48 lived makes it possible to broadcast high-quality signals to any systems. Therefore, used in cable or satellite TV systems. In Avs Electronics, you can at competitive prices.
When installing household video systems, satellite or cable TV, when equipping premises and offices, video surveillance systems, when creating computer classes or salons, a coaxial cable is very often used.
The internal conductor of the RG-6 / U cable is made of copper, and the external (foil) is made of aluminum. A novel consisting of 48 lived, - copper. Suitable for applications in household conditions and in large-scale projects. This type of cable is able to broadcast glorifying electrochails of ultra-high frequency at considerable distances.
Indispensable to transmit signals on ultra-high distances (up to 600 m or more), the RG-11 cable is called the main. The increased strength of its external isolation makes it possible to operate this type on the streets, attics and in wells. To transfer the cable between houses, a special type of RG-11 is available, equipped with a cable. All subspecies of this cable category are not packaged in a 100 meter, and in 305-meter bays.