There are several geostationary orbital slots for UHF satcom viewable from the US. Some of the locations are 15W, 22.5W, 23W, 100W, 105W, 173W and 177W. The numbers correspond to Longitude lines on a globe with the satellite parked over the equator at the specified Longitude. For example, the 105W slot is in line with Longitude that runs north and south through roughly Denver, CO. If you were in Denver you would point an antenna due south at 180 deg (true north) and at an upward angle of about 44 degrees above the horizon.
From San Francisco you would point the antenna to about 153 deg (true north) at an elevation of 42 deg to view the same 105W location. The orbital slots of 23W, 22.5W and 15W would be below the horizon from the west coast as they are out over the Atlantic Ocean and the orbital slots of 173W and 177W would be below the horizon from the east coast as they are over the middle of the Pacific Ocean. The orbital slots of 100W and 105W would be viewable from anywhere in the Continental US or CONUS.
Omni antennas can pick up some UHF satcom stuff depending on the satellite and its output power and its orbital location and look angle to the receiving site. An omni can work ok from San Francisco picking up the satellites over the Pacific Ocean because the look angle is very low and within the main lobe of most omni antennas. If you were in the southern most part of the US like Brownsville, TX (closer to the equator) trying to receive the 100W or 105W slots, they would be at a very high look angle upward where most omni antennas don't have any reception.
Most directional UHF satcom antennas like military surplus versions you see on eBay have a fairly wide pattern and are not very critical in pointing. You can be off by 20 degrees on some with little degradation. But they have the ability to point upward and they are tuned for the frequencies of interest and they are Right Hand Circular Polarization which will give the most efficiency for their size. A linear pol Yagi or vertical omni would take a 3dB hit in gain just because they are linear polarity and not the correct circular polarity.
I hope these few tidbits will help some people understand some basics of satellite reception.
Do we have a list of the actual viable birds names and azimuths? N2yo has a list but does not do transponders or freqs for specific birds
Found some thanks hunch it would be the USA series...
