What is using the HDMI socket, another TV? So the TV you want to use it with is actually a second TV?
Do you want high-definition on the second TV?
If so, you must use the HDMI socket to connect to the second TV. You will therefore have two TVs connected to it and you need a HDMI splitter. Or unplug one TV from the socket manully when you want to use the other TV. Having solved the problem of only one socket but two TVs, you then need cable to go to the second TV. Use HD Baluns and CAT5 as suggested above, or use a decent-quality long HDMI cable, depending on how far it will be. HDMI can survive around 15m with a decent cable. Or you can use a wireless HDMI transmitter, bu tthese are expensive.
If you don't need HD on the second TV, then you can connect via SCART/composite instead. The Humax has two SCART sockets so you should be OK, or are both in use? If they are both in use then you will need a SCART splitter. Having solved the problem of finding a free SCART socket, you can either use a long SCART or composite cable, provided your TV has a SCART or composite input. Or you can use a video sender as linked to above.
If your second TV has DLNA then you can install the custom software for the Humax (search the forum for details) that will allow you to stream recordings over the network. You can also stream the live buffer file but it will be some seconds behind.