In article ,
Michael wrote:

How exactly does satellite service for portable radio work ??? Is there a
release code that you punch up into the radio once you've paid for the
service or a card with an electronic code on it that you stick into the
radio someplace ???

The radio has a unique serial number so it can be programmed over the air.
When purchased new, an XM receiver can only get a "preview" channel and
one sample channel from each category (e.g. country, rock, talk radio,
etc). When you subscribe, you furnish your radio's serial number and leave
it running for a while. The remaining channels are enabled and then you
have full service for as long as you subscribe.