[John Candle]

Directional Tv antennas have a what known as forward beam width , the bigger and longer the directional is , the higher the gain (signal gethering ability) of the antenna and narrower the forward beam width of the antenna. The compass width of the Tv stations of north , north west is 56 degrees. Large Tv antennas have what is measured as -- half power beam width. Typical half power for Large antennas is 20 , 35 degrees. So what happens is the loss of stations that are out side of the beam width. It's a balancing act , the wider beam width of a smaller antenna with beam widths of 60 , 70 , 80 beam widths and lower gain ----or---- a bigger longer Tv antenna with a beam width of 20 , 35 and higher gain. If compromise can not be found with stations you will like to keep and stations you will give up. Then to receive All the stations that are receivable from Tv stations that have widely spaced directions , you will have to go to a rotor or more the one antenna pointed in different directions , and in this situtaion because of the mix of UHF and VHF Tv in the directions that you will like to receive , more then one antenna can not be combined on to one coax. I am very tired now , I will be back with more info.