remote TV using UTP cable

[zelea2]

I wanted to see my satellite channels on my bedroom TV so I've started researching what options I have.

First try was using a 2.4GHz video sender with an infrared back channel. The disadvantage of this solution is that you are subject to any interference from the 2.4GHz band like the WiFi networks around your house or your microwave oven radiation. The video quality is poor with moving stripes appearing on your TV screen all the time. Also your neighbour may watch what you are watching if he has a similar 2.4GHz receiver.

Next try was to purchase a Milestone system from BlueDelta. This consists of a pair of scart adapters powered at the master end transmitting the signal on inexpensive UTP channel. They also provide an infrared back channel to control your satellite equipment. The theory sounded good but the quality suffered. They are using just one pair of the UTP cable for video transmission, 2 pairs for the stereo audio and the last pair for powering the slave and returning infrared. This system was quite expensive 80£ from Maplin for maybe 5£ worth of electronics.
You have to use a potentiometer to get your image sharp but at the same time your start having ghosting effects. The most annoying thing was that your image brightness was constantly jumping which was very tiresome for the eyes. The infrared was not demodulated and the 38KHz signal was sent back verbatim which had the effect of missing your remote keys. I've got rid of the whole system and I recommend against purchasing one.

The solution I'm using now and I'm quite happy with is a passive SCART to UTP converter from svideo.com. I've paid for the SCART Balun Pair 500060+500061 some 45£. Each end has 4 transformers (luminance, chrominance, stereo audio) for cable impedance matching. The image at the other end is undistorted and clear even with a 50m UTP cable!!!. One of the reasons you'll get such a good video signal is that you are transmitting SVIDEO (Y+UV signals) for the video. I've chopped the UTP cable to some 10m that I needed and plugged it into my Dreambox. Some satellite receivers (like the Dreambox) have the audio SCART output protected to shorts. Because the audio signals are fed directly into the matching transformers it detects a short and shuts down the audio. I've fixed this easily by soldering 2 SMD 1uF caps in series with the audio transformers at the transmitting end. For the IR backchannel I had to find another device because all the UTP wire pairs were used. I found a very elegant solution: ONE FOR ALL - Wireless Remote Control Converter SV1100. The transmitter and its battery fit inside one AA/AAA battery space of your remote control. The transmitter picks up EM of your remote (not the IR signal), converts it to radio and sends it to the receiver. This has the advantage that you don't need to point your remote at anything. The receiver converts the signal back to IR and shines it via some IR LEDs placed near my Dreambox.