It's a Technomate digital modulator, it works like the old analogue modulators in VCRs except this is digital and a standalone unit. Basically, you feed it via its HDMI socket, you then select an LCN, in my case 198 and 199 as I have two modulators, then select a spare UHF channel via its menu, then a coax feeds into my distribtion amp in the loft that feeds the TVs in the house. You just then rescan your digital channels and watch it like you would a freeview channel.
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