mrgl02 is correct, heavy foliage will reduce the signal strength. So will deep canyons or an obstructed view of the southern sky. By giving your antenna an unobstructed view of the sky, you can prolong reception a bit but it will cut out.
I've tried the mobile, home and GXM antennas and had the best success with the GXM but the signal still cut out. I don't know about Sirius but with XM they have terrestrial towers that compensate for the signal blockage by buildings, especially in heavy populated areas. Out in the boonies, you're on your owm.
Also be aware that in very heavy rain, the signal strength can be reduced.
I've tried the mobile, home and GXM antennas and had the best success with the GXM but the signal still cut out. I don't know about Sirius but with XM they have terrestrial towers that compensate for the signal blockage by buildings, especially in heavy populated areas. Out in the boonies, you're on your owm.
Also be aware that in very heavy rain, the signal strength can be reduced.
