Copper-coated steel vs. solid copper… what’s the difference?

If you’re a commercial installer, you’ve been told that you must use solid copper for trunk runs. On the other hand, copper-coated steel is fine for home runs, especially shorter ones. Did you ever wonder why?

It’s the skin we’re in

The answer is “the skin effect.” You can learn a lot more about this term in this tutorial here, if you’re interested. But, here’s a basic explanation.

RF transmissions only travel along the outer edge of a cable, not all the way through. On the other hand, DC power travels all the way through the cable. Proper DC power levels are important everywhere, but especially so in commercial installs where you can be working with much longer runs. If you’re using commercial equipment, you’ve got to make sure you’re properly powering everything.

What happens when you use the wrong cable?

Let’s say that you are installing an amplified antenna and you use copper-coated steel cable. What would happen?

Given a typical run of 50 feet or more, there wouldn’t be enough voltage for the antenna’s amplifier to work at all. This could mean that the antenna doesn’t work at all. In that case the only reception you would get would be through the cable itself. You’d probably have a bad experience and not get many channels at all.

In the best case scenario, the antenna works without an amplifier. This means you’ll probably get a few channels at best. You certainly won’t be getting the performance you’re paying for.

Copper-coated steel is ok for short runs and home runs (runs inside the premises) because there is little concern about DC power loss. The signal doesn’t penetrate through all the way to the center of the cable anyway.

How can you know which kind of cable you have?

If you have steady hands, you can shave away the outer bit of the center conductor. You’ll see the gray steel at that point. But, of course, that ruins the cable. If you’re working with cable by the reel, then you can use a scrap, but if you’re working with premade cables, you’re going to ruin a cable just to test it. There’s a better way.

If you look on the side of most cables, you will find a code that is printed there. All you need to do is search for that code online and you’ll get all the information you need. Look for the words “solid copper” or the letters “CCS” to see what you’re looking for.

Another thing you can do is look for these molded plastic ends. If you have a cable with plastic ends, even if it looks otherwise like a high-end cable, it’s probably got steel in the center conductor. Professional-grade cables won’t have ends like these. In the case of the image above, the gold color on the connector is also a dead giveaway that this isn’t a quality cable.

Get the cable you need from Solid Signal

Of course, it may be more trouble than it’s worth to carry two different types of cable and remember which one to use. There’s no harm at all in using solid copper for home runs, either. When you’re ready to get the cable you need, check out the great selection at Solid Signal! You’ll find cables for every budget as well as all the free tech support you’ll need, in order to know you’re getting the right cable.

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 8,000 articles and longform tutorials including many posted here. Reach him by clicking on "Contact the Editor" at the bottom of this page.