Information about RG Coaxial Style

RG-style Coaxial Cable

(blogger@L-com.com)

Following our popular post about Antenna Coax Cable Types where we talked about the low-loss style coaxial cable used in antennas, we wanted to spend a moment talking about the RG-style coaxial cable.

RG is sometimes attributed to mean "Radio Guide". The different standard RG numbers were originally set by the US government long ago. In fact, the actual letters stood for:

• R = "Radio Frequency"
• G = "Government"
• U = "Universal Specification"
• A, B, C, etc., = Added after the standard number to indicate a modification from the original standard, such as to change the center conductor from solid to stranded to improve flexibility

So, a cable referred to as RG188A/U is really the universal standard 188, with modification "A", set up by the government for radio frequency use. Today, RG references are no longer precise and are more of a general reference. Individual vendors may have slightly varied specs for the same RG cable, so it is important to understand those specs for your application.

Coaxial cable

What is Coaxial Cable? (customerservice@L-com.com)

Coaxial or Coax cable is so named because the signal inside the cable runs on two (co-) axies: the center conductor and the shield. This is a relatively old cabling technology that was originally developed for military use. Coax cables were found to be so durable and efficient at carrying all sorts of signal types from data, video, audio, and more, that the standard soon became commercialized. Today, coax remains a very popular cable assembly type for cable TV, antennas, high-end audio/video equipment, and security equipment.

Though there are a few standards of coax cable available on the market, L-com only really carries the "RG" styles. RG stands for radio guide, and each cable type is generally called by RG followed by a number indicating the standard number of the cable. That is sometimes followed by a letter to indicate a sub-standard, and then the letter "U" to indicate that the standard is universal. But all this doesn't help you figure out what kind of cable you need!

With coax, the application generally dictates the kind of cable. Video cables nearly always use 75 Ohm styles of cable. Data and antennas usually use 50 Ohm styles. The different styles may have different flexibilities, diameters, attenuation, jacket types, and other factors that make one cable the ideal fit.

If you have an application but don't know what cable you need, try giving us a call or emailing directly to our tech support group at support@L-com.com. You may also find our Coaxial Cabling Tutorial helpful, available free on our web site.