Sorry but I am not technical about this but I will try to explain my set up as best I can. On Monday I some lost channels on my Panasonic HDD recorder and assuming it was due to recent changes I retuned. The channels did not return. I retuned my Panasonic TV and that has all the channels. The aerial first goes to the recorder and then to TV. They are also connected via an hdmi lead. Why does one work and not the other. I have two wideband aerials were installed about 2005, one pointing to london and one to anglia as at that time I couldn't get all the channels on one aerial. From what I can recall I have a mast head applifier which I assumed is powered as I have a box in the room which has to be powered for the aerial to work. I have another TV in the kitchen and that also gets the missing channels. All the missing channels seem to be on two mux's SDN and ARQB. Don't know what mux means but I found a list and this was a common factor. Any suggestions please.