Cables for WiFi antennas

The 2.4 GHz frequency standard for WiFi networks is considered an RK-50 cable. It is quite rude. Let us express it more subtly: cables for WiFi antennas have a characteristic impedance of 50 Ohms, with a minimum loss per linear meter( dB / m).The first is indispensable for perfect matching devices in the network, the second - for minimal power loss. The mentioned RC-50 will not always be the best option. Today let's see which cable to choose for the organization of a local wireless network.

The impedance of the WiFi antenna cable

Inside the cable of the WiFi antenna, a central core is stretched, it will be mistaken to assume that current is flowing. An electromagnetic wave occurs inside at such a frequency. A grounded shield will be useful, otherwise the wire will begin to radiate energy, and the attenuation will become prohibitively large. A cable operating on the principle is called coaxial. Equipped with a dwelling of one or more wires, a screen( usually wicker).

Plays the role of the ohmic resistance of the cable, expressed by ohms, the characteristic impedance of the radio equipment becomes more important. It can be strikingly different, the main thing is that it does not accumulate in running meters, like ohmic. In the WiFi environment, the accepted standard of equipment is the characteristic impedance of 50 ohms.

Important. Radio channel operates with variable frequency. The values ​​of capacitance and inductance of the channel should be taken into account. Forming the characteristic impedance( square root of the ratio of values).

Antennas, cables, receiving, transmitting devices. Something else is being used, special matching devices will be required. Sometimes done intentionally for cost savings. A 75-ohm high-quality cable is cheaper than a 50-ohm cable; if you have a long line, it’s profitable to think about changing. The minimum CWS will be 1.5, corresponding to a loss of 10%.It can repeatedly pay off in a long line, laid with a cable for digital television, wave impedance 75 Ohm.

Idealizing the situation, let's call the CWS equal to one. The traveling wave mode has been established, no backward reflection occurs. Cable properties are aimed at minimizing losses. The standing wave ratio is determined by the ratio of the maximum and minimum amplitudes of the line field.

Phase speed of the line is less than vacuum. The wave propagates through the cable, it becomes shorter( not 12.5 cm at 2.4 GHz, less).Transmission slows down, in practice for household appliances does not play a big deal. If the line is not long.

RC-50: made by USSR
  • Black polyethylene insulation of low density( high pressure).
  • Outer diameter - 8 mm.
  • Operating temperature: minus 50 - plus 60 ºС.
  • The coefficient for wave shortening is 1.5.
  • The price of some intricate dealers hide, according to some information, 75 rubles per meter of cable RK 50-7-11.Apparently, businessmen are waiting for a call!
  • The first number in the designation will be the characteristic impedance, the second - the outer diameter of the inner insulation with cut-off tenths, the last is composed of two numbers:

    1. Insulation type( 1 - solid insulation with high heat resistance)
    2. Development number.

    For comparison, the WiFi antenna cable RK 50-7-11 is used at temperatures of minus 60 - plus 85 ºС.Mark is thicker, heavier, it is worth thinking twice before getting involved. The bending radius during transportation is not less than 100 mm. Defined by the core class. If there is one wire, there is not much to expect, in some brands there are multi-wire cores( of particular flexibility).If you try to tie up the bundle in the middle after buying to save space, there may be an incident in the form of mechanical damage to the WiFi antenna cable. The minimum radius decreases with increasing operating temperature.

    The attenuation of the product at a frequency of 2.4 Hz is omitted, there are figures for other wavelengths:

    • 0.2 GHz - 0.14 dB / m;
    • 3 GHz - 0.8 dB / m.

    We conclude that at the WiFi broadcast frequency we expect damping of 0.7 dB / m. Serious value. For a height of nine, the loss can negate the result of using a good directional antenna( if there is no signal amplifier that has chosen the roof).

    Coaxial cable Belden H1000

    According to eyewitnesses, you will find the Belden H1000 at a price of $ 1.8 per meter( source quoted).They found a bay in rubles with the running price of 90( to the Crimea).

    More expensive RK - 50, let's see what they are going to slip, taking the money:

    1. Wave resistance 50 Ohm with an accuracy of 4%.
    2. Attenuation 0.25 dB / m. Sources given for cable length 100 meters.
    3. Outer diameter 10.3 mm.
    4. Wave shortening coefficient - 1.2.
    5. Operating temperature minus 40 - plus 80 ºС.
    6. The minimum single bend radius is 50 mm. It is necessary to enclose a special element under the roof edge that excludes fragility.

    The cable will provide a much lower attenuation of the signal at a higher or similar( what is $ 1.8?) Price.

    RG-6 U cable of digital television in relation to WiFi

    The product is shock cheap. At a price of 10 rubles per meter, it looks more interesting than a native WiFi-antenna cable. Let's see the skills of a new friend:

    1. Wave resistance 75 Ohm.
    2. The meter attenuation for the 2.4 GHz frequency is 0.355 dB / m.
    3. Operating temperature minus 50 - plus 75 ºС.
    4. Outer diameter - 7 mm.
    5. The minimum bending radius is 35 mm.

    The cable for the WiFi antenna looks attractive if you intend to solder the amplifier with your own hands, hoisting it on the roof. The problem of matching the resistances is solved simply on this side, in the field of reflection equipment they will, if not use special devices like a quarter-wave transformer.

    Consider the option of a budget solution to the problem of receiving a WiFi antenna, if most of the simplest equipment is supposed to be made by hand. The cable is supposed to be used for signal transmission of television systems, the product will serve as a home network. Inexpensive, with attenuation below RK-50, suitable material line. You can tell your friends how to make a cable for a WiFi antenna with your own hands.

    It looks interesting cable RG-11 U street with a cable, 19 rubles a meter. It is useful to throw between the houses, will not be torn by the wind.

    1. Wave resistance 75 Ohm.
    2. Operating temperature minus 60 - plus 60 ºС.
    3. Cable diameter 11.2 mm.
    4. The wave shortening coefficient is close to 1.3.
    5. Attenuation at 2.4 GHz is silenced, we conclude: large( dealer breaks).

    A cable for a WiFi antenna is used in limited quantities, provided that the parameters of the lines are harmonized, where enhanced durability is required. Rather, the low electrical characteristics of the product are associated with the requirements of the breakage force.

    Smart cable WiFi antenna LDF5-50A at 7 / 8ʺ

    WiFi cable antenna get the price of 80 rubles a meter, the product will provide shock low losses - 0.0663 dB / m. This is much lower than the products discussed above.

    1. 50 Ohm resistance with 2% accuracy.
    2. The coefficient of wave elongation is 1.16.
    3. The values ​​of operating temperature are ignored, according to some information, the product is suitable for outdoor installation. Specify the question from the dealer.
    4. Outer diameter 28 mm.

    The closest twin of a miracle of technology is considered to be a cable RC-50-22-37 with similar characteristics.

    1. Attenuation is 0.07 dB / m at 2.4 GHz.
    2. The coefficient for wave shortening is 1.13.
    3. Operating temperature minus 60 - plus 80 ºС.
    4. The minimum bending radius is 120 mm once.
    5. Outer diameter 27.7 mm.
    6. Price remains unknown.

    Conclusion

    In the light of what has been said, the cable RK-50-22-37 looks very profitable to Russia. It’s hard to get, we would recommend asking the dealer or manufacturer for details on the operating conditions of the LDF5-50A at 7 / 8ʺ.It is not an isolated case when Russian enterprises show a cold attitude towards the consumer. In their eyes, the buyer should spend time, money on calls, searches instead of conveniently purchasing the right amount of the product, having received preliminary information in advance. Disgusting support for the production of the scourge of Russian factories, factories, products not only impossible to buy, difficult to learn. Apparently, the homegrown method of dealing with espionage, which is so often loved to apply to ordinary citizens.

    Because of this, we advise you to wait with a search for domestic products. Looking for what you need cable. For the construction of a home network, foreign equivalents are more accessible. If the WiFi-antenna belongs to a well-known company, let the supply department alert in time. Perhaps, the thrust is adjusted!

    For an ordinary citizen it is easier to find what you need on the network, visit the nearest store, order. Alternatively, run to a network installation company. Unless, of course, there is no desire to put up with low speed. Tricolor free set( stock).Let the cable be thrown onto the roof, the frequency is 2.4 GHz, or 5 GHz. Line use 😉

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