problems with sirruis satelitte radio

My sirruis satelitte radio has been receiving only spotty reception for the last 6 months, both in the house and car. I've moved the antenna every which way and sometimes it works, but mostly not.  I've had the radio for years and it always worked fine.  What confuses me is that it barely works at home or in the car and they use different antennas. I did call tech support at Sirruis but didn't get much help. Any ideas