Roger, ZR3RC wrote:
"These dishes also have very narrow beamwidth making their aiming very
precise."

You are right. Even an 18-invh dish needs a pretty good elevation angle
in the UK to get best reception in the KU band from a satellite parked
over the equator. I checked the Direct TV website. A geostationary
synchronous bird flys at more than 22 000 miles above the earth`s
surface. The horizontal distance is always a fraction of the altitude of
the satellite, so the elevation angle for line of sight is substantial
no matter what the azimuth. I am still puzzled as to why so many dishes
I saw in Scotland were aimed so low.

Direct TV gives instructions on how to align a dish in their service.
They send an initial elevation angle "tick-mark" setting to the
customer. It is then up to him to acquire the bird and optimize setting
the dish for best signal.

Direct TV has 3 satellites available to the customer, and though they
are several degrees apart along the equator, one azimuth setting of the
dish is expected to give satisfactory signals from all three.

Best regards, Richard Harrison, KB5WZI