Coax Cable Comparison

The following charts compare various type of coaxial cable used in VHF and UHF data radio systems.  All coax cable has a certain amount of signal loss.  When an antenna is connected to a radio modem using any type of coax cable, the transmit signal is attenuated as it passes through the cable, so the actual transmit radio power into the air is less than the amount of power the radio puts out.

Also, when a data radio modem is receiving a signal, the receive signal that reaches the radio’s receiver will be weaker than the signal that reached the antenna.  The received signal will be attenuated as it travels down the coax cable to the radio’s receiver. If you want your data radio system to have the widest possible coverage, you should minimize your coax cable losses.

The amount of coax cable attenuation primarily depends upon the diameter of the cable and the dielectric material used to insulate the center conductor.  Small diameter cables are easier to install and use, but small diameter cables loose a lot more signal than the larger-diameter versions.   For cable runs less than a few feet, any cable type will do.  For coax cable runs 10-20 feet, you may consider using lower-cost middle-sized cable such as RG-58. For cable runs of over 20 feet, consider using the best quality cable you can afford (if you are trying to build a system with wide coverage and high reliability).

Coax Cable Comparison (English)

Cable Group

Attenuation in dB per 100 feet

Outer Diameter (inches)

30 50 100 150 450 1000 2400
LMR-100A® 3.9 5.1 7.2 8.9 15.8 24.1 38.0
LMR-200® 1.8 2.3 3.2 4.0 7.0 10.4 16.5 0.195
LMR-240 Ultra® 1.3 1.7 2.9 3.6 5.3 9.5 12.7 0.240
LMR-240® 1.3 1.7 2.4 3.0 5.2 7.9 12.7 0.240
LMR-400 Ultra® 0.8 1.1 1.5 1.5 3.2 5.0 7.9 0.405
LMR-400® 0.7 0.9 1.3 1.5 2.7 4.1 6.6 0.405
RG-174 5.5 6.6 8.8 10.3 18.1 27.4 43.0 0.100
RG-213 1.0 1.5 2.1 2.8 4.4 7.1 12.0 0.405
RG-214 1.2 1.6 1.9 2.4 5.1 8.0 13.7 0.405
RG-316 4.3 5.6 7.9 4.4 17.2 26.1 45.0 0.110
RG-58A/U 2.5 4.1 5.3 6.1 10.6 24.0 38.9 0.195
RG-8/U FOAM 1.0 1.2 1.8 2.4 4.4 7.1 12.0 0.400
RG-8X 2.0 2.1 3.0 4.7 8.6 12.9 21.6 0.242
RG218/U 0.4 0.6 0.8 1.0 2.0 3.8 6.4 0.870

The chart above is in English units.  Below is the same data, in metric:

Coax Cable Comparison (metric)

Cable Group Attenuation in dB per 100 meters Outer Diameter (mm)
30 50 100 150 450 1000 2400
LMR-100A® 12.5 16.3 23.0 28.5 50.6 77.1 121.6
LMR-200® 5.8 7.4 10.2 12.8 22.4 33.3 52.8 4.95
LMR-240 Ultra® 4.2 5.4 9.3 11.5 17.0 30.4 40.6 6.10
LMR-240® 4.2 5.4 7.7 9.6 16.6 25.3 40.6 6.10
LMR-400 Ultra® 2.6 3.4 4.8 4.8 10.2 15.8 25.3 10.29
LMR-400® 2.2 2.9 4.0 4.8 8.6 13.2 21.1 10.29
RG-174 17.6 21.1 28.2 33.0 57.9 87.7 137.6 2.54
RG-213 3.3 4.8 6.7 9.0 14.1 22.6 38.4 10.29
RG-214 3.8 5.1 6.1 7.7 16.3 25.6 43.8 10.29
RG-316 13.8 17.9 25.3 14.1 55.0 83.5 144.0 2.79
RG-58A/U 8.0 13.1 17.0 19.5 33.9 76.8 124.5 4.95
RG-8/U FOAM 3.3 3.8 5.8 7.7 14.1 22.7 38.4 10.16
RG-8X 6.4 6.7 9.6 15.0 27.5 41.3 69.1 6.15
RG218/U 1.3 1.8 2.6 3.3 6.5 12.2 20.5 22.10

Filed under: Data Radio Technology, Installation Information | Posted on February 22nd, 2011 by John Sonnenberg

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