Home Technology eMagazine Article

June 2008

eMagazine Index

Volume 13, Issue 3
June/July 2008

Cover Page

Infocomm 2008
Special News Report

Articles

Whole House Distributed HDTV

Cable Labeling TIPS

Home/Office IPTV-VoD System

Making HDMI Work over Cat-6/5

How to Select a Projection Screen

Interoperability in Smart Homes

It’s NOT all about the chips!

What’s a Home Without Music!

Acoustically Transparent Screens

Classic Home Toys #16 - Electronic Book Reader

Content Insider #101 – Content Your Way!

Content Insider #102 – Looking to HDTV

Content Insider #103 – Game Power

McIntosh Teaches Kids to See Sound

Product Reviews

Z-Wave Lighting Control Systems

The WGL All Housecode Transceiver V572RF32

Interviews

All-in-One Home Theater
Mike Pyle - SE2 Labs

Home Theater Projectors
Derek Burns - Projector Point

Outdoor TV
Joe Pantel - Pantel Corp.

Outdoor Sound
Alan Rottner - StereoStone

Making HDMI Work over Cat-6/5

Author: Scott Horman, AudioControl

Sending HDMI, particularly with HDCP, involves a lot of different things happening at very high speed.  Transmission or wiring errors often will result in no picture at all.  In component video, you can have problems and still get a picture ranging from pretty good to bad.  With HDMI, problems often mean no picture.

How You Install the Wire Matters!

Sending HDMI, particularly with HDCP, involves a lot of different things happening at very high speed.  Transmission or wiring errors often will result in no picture at all.  In component video, you can have problems and still get a picture ranging from pretty good to bad.  With HDMI, problems often mean no picture.

Error or losses in the signal chain accumulate.  If that last statement is not scary enough, losses may be tolerated on some content material more than others.  Bottom line, don’t cut corners.  Some past wiring practices will get you into trouble.  Be leery of jobs where someone else ran the wiring, and pay close attention to the advice below:

Do’s

  1. Use Category-6 (or better) network cable (attainable distances are shorter with CAT-5)
  2. Use CAT-6 RJ-45 push through connectors and use the associated strain relief at the connector
  3. Make sure the two wires in each pair are terminated to exactly the same length
  4. Siamese CAT-6 is a good choice but not required
  5. Keep the HDMI interconnect cable to the Driver and from the Receiver as short as feasible
  6. Use high quality HDMI interconnect cables and, if possible, use 340 MHz (Category 2) HDMI interconnect cables
  7. Treat all cable in a kind and gentle fashion (see “Don’ts” below) using large bend radiuses (minimum 1.25 inches)
  8. Use shielded cable ONLY FOR SHORT RUNS as the shielding attenuates the signal

Don’ts

  1. Pull or stretch the cable.  Maximum pull tension is only 25 pounds
  2. Staple or dent the cable nor over-tighten with cable ties
  3. Run parallel to power cables.  Run at right angle if possible
  4. Untwist pairs into RJ-45 more than ¼”
  5. Knot or kink the cable
  6. Use couplers or splice the cable.  Either will dramatically shorten the maximum cable length.  The HDMI signal is extremely sensitive to very small variations in impedance.

Much of the advice above is the same for gigabit Ethernet network wiring.

 

It’s important to run CAT-6 properly when using it to extend HDMI with AudioControl’s new BVHD-10