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[Andrew Welker]

Ole Anderson

I am considering a CAT 5 solution to getting signal to 2 projectors, over 100 feet thru exist conduit. Can someone give a definitive answer regarding signal quality loss? Will it be noticeable to the average person? XVGA. DVD and Easy Worship plus possible Power Point.

You will see very little signal degradation using one of the mentioned solutions (Magenta research, Extron, etc.).  We recently used a Magenta piece to run about 700 feet between 2 buildings, sending VGA over the CAT5 with no noticable signal loss.

The biggest issue you will run into is skew between the different colors because of different lengths of individual wires in the CAT5.  The Magenta piece (specifically the AK500 reciever) has EQ for the separate colors built in to help with the skew problem.

One other thing to keep in mind is that while the signal is running over CAT5, it is not ethernet and cannot go through network devices.  Also, the transmitters and receivers are not compatible across manufacturers, so you can't use an Extron transmitter and a Magenta receiver or vice versa.

Hope that helps.

Andrew  

[Ole Anderson]

Andrew,

Thanks for the reply.  My supplier/contractor said he hasn't had a lot of success with CAT 5 and recommends a small diameter bundled RGBHV mini coax cable (like Belden 1522A) as being good to at least 150 feet.  I hear others saying that for that distance go with five separate quad shield coax cables like Belden 1694A, which of course may be the best solution, but is quite expensive and very bulky.

[Andrew Welker]

For runs that short, I would also suggest going with the bundled 5-wire unless there is an issue such as conduit that is too small or other issues that make pulling a bundled cable difficult in comparison to a CAT5.  We typically use Covid 0500, which is similar to the Belden 1522A.  Make sure you get the correct BNC connectors for whichever wire you use.  One thing to keep in mind as well is that you might need some converters to go from and HD15 output to the 5-wire cable, usually male HD15 to 5 male BNC's.  Covid also makes these in standard lengths as well as custom lengths.

Andrew

[Tom Matthews]

I just read the posts in this forum.

I also visited the Magenta Research web page.

It seems that the Magenta Research product does not send the video as digital data, but as an analog signal over the CAT5 cable.  I couldn't find a clear statement to that effect, but I infer it from the information.  For example, one of the receivers has a "switchable equalizer".  For digital data, the equalizer is adaptive (i.e., automatically adjusts itself) and embedded in the first layer of electronics to interface with the cable.  

I wonder if the Magenta Research products are simply good cable drivers and receivers that make use of the high bandwidth and controlled impedance of CAT5 cable?  I could not find an explanation of how the Magenta Research product gets the digital video information directly out of the computer, so maybe that is not what it does.  Yet they also mention serial data transmission, so I'm still confused.  

Does anybody know what these products do?

Tom

[Brad Weber]

Tom,

I'm sure you'll get reminded soon, but you need to use your real name.

Quote:

I could not find an explanation of how the Magenta Research product gets the digital video information directly out of the computer, so maybe that is not what it does. Yet they also mention serial data transmission, so I'm still confused.

There are many common misunderstandings regarding CAT products.  Specific to your comments, CAT5 interfaces do not convert the signal format, they just transmit it over UTP cable.  They won't get digital video information if you have an analog output.  If the computer has a digital video output (DVI, HDMI, SDI, etc.) and you use a matching CAT5 interface, then you will be transmitting the digital signal.  If your computer has an analog output (VGA, RGBHV, YPbPr, Y/C or composite video), then you will need a matching interface and will transmit an analog signal.  It should be noted that just as DVI and HDMI type digital signals are limited in how far they can be transmitted over standard cabling, they are also typically much more limited in how far they can be run over CAT5.

The serial data transmission referenced is RS-232/422/485 data typically used to communicate with or control a display or device at the receiving end.

In general, UTP solutions (CAT5/5e/6) are simply a transmission interface that allows extended transmission distances over UTP cable.  They do not change the basic signal information.  If it is an analog RGBHV or VGA signal in, it is sent as analog RGBHV and it is an analog RGBHV or VGA signal out.  If it is DVI in then it is the digital signal sent and DVI output.  Much like standard cabling, audio/video over UTP transmission is also essentially a "point-to-point" transmission and while it is possible with the right products to route, DA and loop just like standard cabling, it is not a data network approach.  It is also important to note that you cannot mix devices from different manufacturers, they need to match.  These interfaces are not data network interfaces, they are a way to use CAT5 type cable for signal transmission but are not intended to put the audio and and video onto a data network.

This is very different than the streaming type encoder/decoder devices that convert the signal, typically to something like and MPEG-2 or MPEG-4 stream.  These devices do convert the audio and video to a data stream that can be transmitted over a data network.  Although you may lose some specific functionality and compatibility, the stream data is standardized and so, in theory, you could use any MPEG encoder and decoder and they would not have to be from the same manufacturer.

[Tom Matthews]

Brad,

I hope I fixed my profile to show my full name.  

So if I understand correctly, that the CAT5 products provide an analog signal path over CAT5 cable.  The _path_ is analog, but that path may convey a digital signal provided that the bandwidth requirements of the digital signal are met by the analog system.

I am presently trying to come up to speed on digital displays.  Our church is expanding into a new facility and we would like to equip a couple of rooms with displays.  That question is beyond the scope of this thread, and it may well show up as a new thread.

In the meantime, can you (or anyone) recommend a primmer I can read on digital signal formats?  I cannot recognize most of the acronyms you have listed in your post.  

Tom Matthews

[Brad Weber]

I strongly recommend looking at the technical information on Extron's web site at http://www.extron.com/technology/index.aspx.  There is a great deal of good information on digital displays, CAT5 systems, HDTV, etc. avaliable and every time I go to one of Extron workshops or classes (like just last week at NSCA) I learn something new.  Especially for coming from a manufacturer, much of the information is amazingly general in nature and not a product sales pitch.

FWIW, this kind of support and education is a major reason why many industry professionals think so highly of companies like Extron versus those that seem to simply sell boxes for the lowest price and in whatever manner possible.

[ProSoundWeb Community]