Portable jobbies don't have big aerials like it's possible to mount in/on cars. Also cars models could include signal amps that portable units couldn't power.
Bored? http://www.navcen.uscg.gov/pubs/gps/sigspec/gpssps1.pdf
@hippy started
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Portable jobbies don't have big aerials like it's possible to mount in/on cars.
Also cars models could include signal amps that portable units couldn't power.
Bored?
http://www.navcen.uscg.gov/pubs/gps/sigspec/gpssps1.pdf