Better picture of the back here
http://www.scientificatlanta.com/cus...ce/7004921.pdf
It does have an aerial combiner, but no RF bypass is available for it. The installer should set the RF channel appropriately for your area.
There's a few bits of that spec that aren't relevant to UK cable. e.g. you can't use the tuners in analogue mode and the Ethernet, USB, eSATA and IR remote out ports are not enabled.