what ever it is I would think it is interfering with the radio as an electrical device rather than the satellite signal. Probably they are using some old radio frequency equipment and your radio is picking up the interference.

How are you hooked up? Is is through the cassette, auxiliary connection, or is it via a radio frequency?

Um, now that you mention it, I think I’ve only noticed it since I switched from the cassette to the radio frequency.

It’s Tom Cruise communicating with his home planet.

Satellite radio transmits approx. 4 GHz and your FM transmitter transmits 87–108 MHz. If the gas station is transmitting in either of those ranges, you will get interference.

There are homes in my area that have Christmas lights synchronized to music, and they transmit the music in FM for passersby to hear. There is a limit on transmitter power if you don’t have a license. If FM is the cause, you ought to be able to change your transmitting frequency to avoid the interference. The new cordless phones operate at 2.4 GHz, and even 5.8 GHz. You can’t do much about that if the gas station has some newfangled phone.

But why would a gas station need to transmit anything? Especially what seems to be (from the sound, at least) a really powerful signal?

Do they have a big dish on the roof? Most gas stations in my neighborhood do. I don’t know why – Sat link to the DMV for smog check info? Sat link to the refinery for pricing info? Have you ever noticed that gas prices jump up the same amount at all stations almost at the same time? A sat link would be an easy way to put out pricing info to all gas stations simultaneously.