A splice to the cable has two issues:
--without proper connectors installed, signal is
lost from the disruption of the cable/wire/cable
--losses build up with distance: the current cable
is whittled down for just the length you have
An longer run needs thicker or pricier lower-loss cable,
nice connectors, and ocaisionally, an amplifier
at the antenna end.
Some stuff made for the job:http://www.sirius.com/servlet/ContentSer...d=1128803463598
Leaving out extra connectors saves expense. At that
length, most of the money is in the cable itself.
On the West US coast, you will have a bit more signal
to work with than the East coast.