Lyndhurst Garden House

Lyndhurst Garden House
Lyndhurst Garden House

Friday, April 12, 2013

RG-6 coax

My current plan for whole house network includes 2 RG-6 coaxial cables to each room.  These could be used for analog standard definition video (NTSC), S-Video (using both cables), stereo audio, FM or VHF antenna, stereo audio, mono balanced audio, or broadband signals.  One RG-6 is capable of huge bandwidth, possibly more than twisted pair digital cables like Cat-6a.  Digital cables were invented not to have huger bandwidth than coax, but to be cheaper.  In almost every application where analog is needed, RG-6 will work, with very little loss.

Here's an interesting discussion of coaxial cables.

Quad shield was developed to prevent cable tv break-in, where a strong local channel leaks into the cable and causes beats with cable channels.

Elsewhere I've seen it said that Belden has triple shield equivalent to quad shield of other manufacturers.  But belden also has quad shield.

The UHF connector (UHF does NOT stand for Ultra High Frequency, in fact it's very frequency limited) is kept alive by Hams and CB's.

The BNC was a hit for lab applications in the 1950's but tends to cause grinding in aircraft so a special screw-on aircraft version exists.

The holy F connector which is required on US consumer products requiring VHF antenna was originally designed to be a connector cheaper than dirt because it can re-use the center conductor of the cable itself.

All of the coax types named "RG-xx/U" are mil specs, but the modern variants are generally entirely different than the originally specified cables (which were performance constrained by modern standards, copperweld instead of copper, and just a single braided shield instead of multiple shields, etc.  But now the name "RG-6" is vague because there are so many possible variations; in the old mil spec system each variant had a specific designation.



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