Will an XM antenna work in a Sirius radio?

April 6, 2006 3:14 PM

Will an XM antenna work on a Sirius radio?

I can into possession of a home kit for XM, but I have Sirius....will the XM antenna work in my radio?

posted by keep it tight to technology (8 comments total)

What is the form factor of the antenna? Is it a dish, or a whip, or something else?
posted by Steven C. Den Beste at 3:25 PM on April 6, 2006

This thread says it will most likely work.

From here:
I use the XM antenna for my Sirius radio and it works just fine. An antenna is an antenna...they're both doing the same thing. If you get the stuff and it works without too much modification let me know so I can try it too Very Happy
posted by daninnj at 3:49 PM on April 6, 2006

and I just realized I included the emoticon in my copy and paste job.
posted by daninnj at 3:50 PM on April 6, 2006

I know that the new VW Jetta comes with a satellite antenna preinstalled and either a XM or Siruis module that can be swapped after purchase. Perhaps there is two antennas in the housing on the roof but I doubt it.
posted by jeffmik at 3:54 PM on April 6, 2006

Even if they do work, any random antenna will not work for anything that requires one. Antennas are made for specific ranges of frequencies. This is why a CB antenna sucks for Wifi, etc.

As long XM and Sirius operate within the same range of frequencies they should work.
posted by cellphone at 4:21 PM on April 6, 2006

I did some research online. XM and Sirius both operate in the 2.3 GHz band, so that part's fine.

What's different is that XM uses geosynchronous satellites, whereas Sirius is using a constellation of LEO satellites. Geosynchronous satellites don't move in the apparent sky, but LEO satellites move constantly and will fall below the horizon even as others appear on the opposite horizon. What I read said that there are always three Sirius satellites in your sky at any given moment and the implication was that you were getting signal from all of them.

So that's why I asked about form factor. "Cellphone" above is right that the frequency matters, but the frequency is close enough to being the same for both that it's not an issue. But if the XM antenna is a dish, it won't work for Sirius.
posted by Steven C. Den Beste at 8:33 PM on April 6, 2006

They both operate in S-band at 2.3 GHz. Any antenna for one should work with the other just fine.

That said, as I recall, the two systems' satellites use very different orbits: XM uses standard circular geostationary orbits, whereas Sirius uses elliptical (but still geosynchronous) orbits. See Google or Wikipedia for more ...
posted by intermod at 8:34 PM on April 6, 2006

The orbits won't matter; the XM antenna has to be able to pick up the satellite regardless of what direction your vehicle is pointed and where you are in the country, so it has the same design criteria as the Sirius antenna -- pick up the satellite at any likely angle. Neither type of antenna is dish-like.
posted by kindall at 11:38 PM on April 6, 2006