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All conductors lose a certain amount of signal over distance. The "bigger" a conductor is, the less signal is lost over distance (you'll see why this is important later).

Also, dual/quad shield refers to how many layers of "shielding", or layers of "silver metal", cover the dielectric.

The dielectric is next, which is the opaque, white, waxy part of the cable. This is insulation from shielding.

The shielding is the layer of braided wire. The purpose of the shielding is just that. It shields the conductor from stray "outside" signals, also known as ingress (more on ingress later). It also keeps the signal being carried along the conductor INSIDE the cable (prevents egress, which is signal leaking OUT). Most RG6 has 2 layers of shielding (dual), but you can also find quad-shield (4 layers) cable out there. It is more expensive, and harder to work with.

The last layer, of course, is the rubber. This is just more insulation and there's no point in trying to describe what IT does.

Regular Coax Cable:


Dual-Shield Coax Cable:


Quad-Shield Coax Cable:


These pictures and more information on different types of coax can be found at:
http://www.smartwire.com/

Feedback received on this FAQ entry:
  • Regular cable has an aluminum foil tape applied over the dielectric then the braid, Tri-shield(not dual shield) has a foil tape over dielectric then a braided shield and then another foil wrap and the Quad-Shield looks good.

    2012-09-07 08:21:30

  • ""The caps are a good thing, but most of the cable used is 75 ohm cable so you would need a 75 ohm cap or it will cause an impedance mismatch which can cause you problems."" very important quote, open ports will cause pop outs, from the pole to behind the tv. EVERYTHING MUST BE TIGHT

    2012-01-19 13:17:19 (drcable See Profile)

  • The caps are a good thing, but most of the cable used is 75 ohm cable so you would need a 75 ohm cap or it will cause an impedance mismatch which can cause you problems.

    2011-09-11 20:15:42

  • 4 12 11 Couple things. Yhe coax cable is actually a wave guide. At high frequency, somethink called the skin effect takes over in the wave propagation and the electrons only travel on the surface of the conductor and not in it so a center conductor diameter becomes irrelavant and thinks like quad shielding' proper line tremination, and not exceeding maximun cablle bend raduis wil produce faster, cleaner, less distorted, wavefroms, ie your signal. Also if use have splitters with unused connections, buy 50 ohm terminator caps at an electronics store for them. The center conductor diameter and legnth should insure a good electro/mechanicl joint at the connector mating. Also the materal with the highest electryon mobility, ie GOLD is the highest. So a gold plated copper center conductor would produce the best results. Or so they say. Neet trick. Apply (Fill ) the connector connections with de-electric grease. You get "0" corrsion, for many, years. Also works for aluminum flash lights(no more battery electrolisys, turn signal bulbs, etc. I've pulled apart these items 5, and 10 years later. Still like brand new. Bla, Bla, bla MichaelJoBillyJimBob.

    2011-04-12 15:03:53 (mvallino See Profile)



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by Raydr See Profile
last modified: 2002-03-01 09:21:39