HDTV HDMI/DVI CAT-5 Extender System
One of the biggest complaints from consumers installing front projectors is the cable length limitation encountered with HDMI and DVI interfaces. As HDMI begins to make its way into the consumer electronics market complimenting the already established DVI interface, the need for longer cables become necessary, especially with the increasing popularity of front projection systems. It is not uncommon to find users asking for a long DVI or HDMI cable to solve this distance problem only to find that the video interface becomes unreliable. Unfortunately, long DVI/HDMI cables compromise signal integrity and eventually fall out of the DVI specification resulting in sparkles on the screen or a complete loss of picture. To solve this problem, Gefen Incorporated has introduced several new products that extend the length of DVI/HDMI signals. Gefen offers a variety of DVI/HDMI solutions including switchers, extenders, splitters and distribution amplifiers. The new HDTV Extender is designed to extend the HDMI interface, but is completely capable of supporting DVI signals as well when used with an adapter. Futhermore, the interface is also compatible with HDCP copy protection. Our focus will be on DVI since our products currently use this interface format. However, since more products are now showing up with the HDMI interface, we decided to review the HDMI version to show that it is fully backwards compatible with current DVI products.
If you are only intersted in DVI, Gefen also sells the DVI CAT-5 Extender that has DVI connectors instead of the HDMI connectors. Our tests utilized Accell Corporation's DVI-to-HDMI adapter along with their DVI-to-HDMI cable. The HDTV Extender supports 480P, 720p, 1080i, 1080p and other resolutions up to 1920 x 1200. The single link design supports pixel rates as high as 165 megapixels per second. In addition to 720p and 1080i signals, we ran a variety of VESA compliant timing signals to our projector with no problems.
The HDTV Extender package consists of a transmitter, a receiver, an AC power supply and an HDMI cable. The two interface boxes each have an HDMI connector and a pair of RJ-45 jacks. A standard pair of CAT-5 cables are used to transfer a single link DVI signal up to 150 feet from the source. Although Gefen does recommend using shielded cable for better noise immunity when running longer distances, non-shielded cable may work just fine in many cases. The AC power adapter plugs into the transmitter and the receiver gets its power from the transmitter through one of the CAT-5 cables. The transmitter and receiver are small and identical in size, each measuring only 3.4" W x 3.25" D x 1.25" H. The package we received also included a six-foot HDMI-to-HDMI cable.
Problem and the Solution
The HDTV Extender design leverages from proprietary high-speed communications technology that allows high-speed data to be reliably transmitted over standard CAT-5 cables. The HDTV CAT-5 Extender is a system that can transmit a DVI/HDMI signal up to a distance of 150 feet using two CAT-5 cables. We used unshielded CAT-5 to run approximately 50 feet and didn't encounter any problems with our setup.
- Kevin Nakano
H77 High-Definition HD2+ DLP Home Theater Projector
|Review - At a Glance|
Gefen - HDTV HDMI/DVI CAT-5 Extender System
Warranty: 1 year parts and labor
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