Coaxial Cable Signal Loss: What Affects Signal Loss, How to Calculate and Minimize It

Are you having problems with a weak antenna signal? Until recently, if your TV image was perfect, it’s time to check antenna connections. Perhaps you are dealing with signal losses somewhere in your coaxial cable lines. If that sounds good, here is what to know about coax setups and problems with the signal! This guide helps to learn everything about the coaxial cables signal loss. First, you’ll know how cable lengths and frequency can affect it. Next, you’ll discover how to calculate the loss in different types of coaxial cable. Finally, you’ll reveal which setup will cause minor signal losses.

The Basics of Coaxial Signal Loss

Coaxial cables with connectors

Caption: Coaxial cables with connectors

First, it’s vital to see how we measure signal losses in coax cables. The typical unit is dB or power decibel. It is the ratio of power on a logarithmic scale. This unit is the baseline to check how the cables mentioned above perform. Therefore, you’ll find experts around the globe using dB to describe attenuation.

Attenuation is another name for the loss of signal quality in networks and other connections. Three different factors could affect the loss strength.

Does Cable Length Affect Signal Loss?

 Large rolls of cables

Caption: Large rolls of cables

The length of the cable runs can affect signal attenuation. Furthermore, it’s expected that the resistance, capacitance, and conductance per unit length vary. Therefore, radio signals can face losses. 

Using a 50-foot cable setup might lose up to 20% of the original signal. And those in the 100′-200′ range can have losses up to 50%. Therefore, you could compromise the movement from antennas to receivers. This problem could appear if you need to run a 100-foot cable throughout the house.

The experts suggest limiting antenna cables to 15 feet. Then, if there aren’t other causes of signal losses, the attenuation should remain low.

Does Frequency Affect Signal Loss?

The frequency can affect signal loss, especially when entering the UHF range. So, a high-frequency signal transmission has more chances of losing maximum signal strength. That’s because:

Resistive Loss

The center conductor in your coax cable has some resistance. That resistance leads to heat dissipation. Radiofrequency currents might appear close to the conductor’s surface, which is a “skin effect.”

The resistance reduces, and signal quality improves with a bigger outer diameter. Apart from this, the signal frequency also affects its strength. You’ll find high-frequency signal transmission boosts the skin effect. Regardless of the cable type, an increased frequency decreases the conductor’s area where the current flows.

Dielectric Loss

This cable loss is more complicated to explain than the resistive type. It is because your electrical cable has insulation around the electric field. The dielectric insulation ensures the central conductor remains away from the shield around the coaxial cable connectors. If you opt for additional insulation, you increase the dielectric loss.

An RF coaxial cable won’t significantly dielectric loss in the HF range. On the other hand, VHF and UHF ranges can lead to it. Also, depending on the sizes of coaxial cable, you might need extra insulation. That will also increase dielectric losses.

If you want the lowest signal loss, you’ll need minimal insulation. A more prominent conductor with an oversized outer diameter is best to combine with this insulation option.

Does Signal Loss Depend on the Cable Type?

Coaxial cables connected to LNB inputs

Caption: Coaxial cables connected to LNB inputs

Yes, the difference isn’t only in the feet of cable and frequency. The type of cable for video or other purposes also affects signal quality. Here is an overview of the typical applications of coaxial cable types!

RG-6 Cable

RG6 coaxial cable

Caption: RG6 coaxial cable

RG6 cables are your first option when choosing a cable for HDTV. First, you can pick from two to four shielding layers of foil. Additional outer layers boost durability and sturdiness. Therefore, this aerial/ sat antenna cable lasts longer and is more resistant to interference. If you put the wiring outside, use the “quad-shield” cable. 

Coaxial Cable Signal Loss– RG-11 Cable

Coaxial Cable Signal Loss--An electrical cable

Caption: An electrical cable

This is a smart pick if you need a more extended and more extensive cable. You can pick up to four shields while ensuring a low loss. An RG-11 line can even handle strong radio frequency signals. On the other hand, itit’sricier than some alternatives. Therefore, this is a commercial cable for demanding transmissions. If you need an RG11 line, you can find custom solutions at Clooms.

Coaxial Cable Signal Loss– RG-59 Cable

This option was the primary for OTA TV before the switch to RG6. Today, not a lot of people use an RG-59 cable. ThThat’secause it only has a single layer of foil as a shield. Despite that con, an RG59 line can be suitable for games, recordings, or a similar video signal.

Coaxial Cable Signal Loss– Twin-Lead Cable

Replace it as soon as possible, whether you call it ribbon, flat, or twin-axial cable. You can get the expected results in the VHF signal frequency. However, the loss shows as soon as you pass the RF2-6 range. Furthermore, twin-lead units come without any shielding. So, they wowon’terform in UHF ranges and araren’turable.

How to Calculate Signal Loss

Coaxial Cable Signal Loss--A TV with a bad signal reception

Caption: A TV with a wrong signal reception

If yoyou’dike to calculate the loss of your aerial signal, there’s a simple formula:

K1 x F + K2 x F + CLF x F = CL

K1 marks the resistive loss, and K2 the dielectric constant. F stands for frequency in Hz, and the CLF is the connector loss factor. You use 0.12 (a straight direct connection), 0.21 (straight to right-angle or vice versa), or 0.30 (right-angle to right-angle).

The result is the cable loss in DB per 100 feet. You can learn more about RF calculators in our detailed guide.

Coaxial Cable Attenuation in dB per 100 feet

Cable1 MHz10 MHz50 MHz100 MHz200 MHz400 MHz700 MHz900 MHz1 GHz
RG-60.160.571.42.02.84.35.66.06.1
RG-110.140.421.01.52.23.54.15.26.6
RG-8X0.20.782.03.04.56.07.98.8/
RG-580.441.44.14.87.511.8///
RG-590.61.12.43.44.97.09.711.112.0
RG-2130.170.551.31.92.54.17.58.08.2
RG-2140.170.551.31.92.74.16.57.69.0
RF9913**0.150.40.91.41.82.63.64.24.5

Coaxial Cable Signal Loss–Which Cable Has the Least Signal Loss in dB?

Coaxial Cable Signal Loss--A human hand holding a coaxial cable

Caption: A human hand holding a coaxial cable

If you want optimal electrical signals, avoid long cables. However, it’s not always possible to prevent signal leakage that way. Therefore, the first step is to minimize the length of your line for HDTV or video if possible.

Next, what is your preferred RF signal frequency? If you can lower it, that can lead to signal gain. For example, those who use 2.1 GHz level signals can expect a loss of 7 DB per meter. But if you lower the frequency to 700 MHz, the loss of your internet signals would be more than two times lower.

Conclusion

Signal losses are vital to consider in any range. They can compromise the performance of your aerial signal, which indicates you need to find the best solution. At Clooms, we have years of experience in producing coaxial cables. Our experts can help identify the best solution and deliver high-quality lines quickly!

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