What is sweep testing and why is it important?

If you look at the specs on a lot of Solid Signal’s RG6 cable, you’ll find that it’s “sweep tested to 3GHz.” That seems to be a common trope with cables. Is it something really important, or is it the cable world’s equivalent of “rustproofing…” a feature that doesn’t do a whole lot but adds value in the consumer’s eyes?

Sweep testing is…

Sweep testing is the simple process of putting a whole bunch of signals through a cable and making sure that what you get out on the back end is within tolerances when compared with what you put in on the front end.

In the case of RG6 cables, the point is to make sure that you’re getting only the amount of loss you expect. As signals get higher in frequency, they have more loss over distance. Typically, a TV signal will lose about 4dB for every 100 feet, while a satellite signal could lose as much as 12dB for every 100 feet. That’s expected, and it has to do with the amount of energy it takes to have that high frequency signal in the first place.

The goal of sweep testing is to make sure your satellite signals aren’t losing, for example, 50dB over 100 feet. That would make it pretty much impossible for you to use that length of cable.

When all your cable for satellite TV and cable TV use is sweep tested to 3GHz, you knowthat the cable you put in will work the way it should.

How do you sweep test?

Advanced signal meters like the one at the top of this article perform sweep testing in labs and on site. Most people aren’t going to want a meter that costs well north of $5K, but if you need one, you’ll find it at Solid Signal. Commercial laboratories do most sweep testing of products. The people who buy this sort of meter do sweep testing on site to make sure that all the parts they’ve put in actually perform properly. This is common in advanced laboratories and broadcast facilities. It’s not the sort of thing you’d find your average satellite TV installer doing.

Here’s how you use a meter like this. You attach a signal generator on one side and test the signal on the other side. You compare what you get with posted specifications. Generally the manufacturer publishes spec sheets for their products. Then you can test the entire system, as built, to make sure it’s performing correctly.

Should you buy an untested cable ?

Generally speaking a manufacturer will sweep test cables if they want those cables to sell to installers. Cables that aren’t tested still might work. You simply don’t know. It means the manufacturer literally doesn’t care if you use it for cable or satellite. This used to be very common with television cable. Today’s cables will all be sweep tested. If it doesn’t say so on the cable, it probably says so on the manufacturer’s web site. You can find a lot of information about a cable by looking at the numbers printed on the side. Read them, then just google them.

Personally I stay with high-quality cables like our Solid Signal cut-to-order RG6 cables because you know they’re really good. For any other cable, do your homework before installing.

About the Author

Stuart Sweet
Stuart Sweet is the editor-in-chief of The Solid Signal Blog and a "master plumber" at Signal Group, LLC. He is the author of over 6,000 articles and longform tutorials including many posted here. Reach him by clicking on "Contact the Editor" at the bottom of this page.