For a long time now we have had two HD TVs. A 40" Sony Bravia in the living room and a 32" LG in the Conservatory.

We also have two Sky boxes. Our tweaked SkyHD box is connected to the Sony giving us glorious HD quality pictures to drool over. The LG is connected to a Sky+ box, but as that's not HD, it only gives a SD picture.

The SkyHD box is also connected to the LG in the conservatory so we can watch it in there if we fancy it. That signal is sent via coax and therefore isn't HD even if the program we are watching is.

Split the Signal

We had looked at the possibility of transferring the HD signal onto two HD TVs at the same time in the past.  Turns out to be a simple case of splitting the HD signal at the source, SkyHD in our case, and transferring the signals to the two TVs.

HDMI Cables

The most difficult thing would be cable length. HDMI cables, used to carry HD signals, are only certified to transmit HD up approx 15mts. After that the quality could start to degrade. You could however boost the signal using a HDMI repeater.

In our house even the shortest route from one tv to the other (Under the carpet) would mean a cable run over 15mtrs.

Using our LAN

Whilst researching our LAN we found that people had successfully used Ethernet cables to send a HD signal well over 30mtrs without the quality suffering. This was a fact we kept in mind when we created our network.

You still need to split the signal but rather than connecting the HDMI cable to your TV you plug it in to a little box called a Balun.

Baluns convert the HD signal so it can be carried over Ethernet. At the other end of the Ethernet cable is a second Balun converting it back.

They actually split the HD feed in two separate signals, audio and video. Each signal needs to be transferred on its own Ethernet cable.

Set Up

In the loft network ports LIV-3 and LIV-4 were patched to CON5 and CON-6. This effectively gave us two long Ethernet cable runs starting in the living room, going up into and across the loft before coming back down and ending in the conservatory.

In the living room the signal from the SkyHD box was split, with one HDMI reconnecting the Sony TV and another going to the Balun. Two short Ethernet cables connected the Balun to ports LIV-3 and LIV-4.

Two more Ethernet cables connected CON-5 and CON-6, in the Conservatory, to the second Balun with another HDMI cable going from it to the LG TV.

Remote Control

As mentioned we already have a coax connection from the SkyHD box to the conservatory TV. That has a TV-Link Magic eye allowing us to operate the SkyHD box remotely.

This was left in place as the Magic Eye cannot be used across Ethernet.

Did it work?

In a word, yes!