If you have a TTR1 tabletop radio: for specific help with this hardware the phone number is 1-800-635-7761.

Took four hours on the phone being switched between people named Jeremy, Ron and Jay to finally reach Garrett, who gave me the number listed above.

I signed up with Sirius, the TTR1 has the Sirius logo on it, but it is an XM radio.

To avoid frustration when calling Sirius, be sure to say "tabletop radio" at the outset, or the help folk think you are calling about a CAR radio.