Results 1 to 7 of 7

Thread: Split XM and GPS Signal (Use only one antenna?)

  1. #1
    Constant Bitrate
    Join Date
    Apr 2004

    Split XM and GPS Signal (Use only one antenna?)

    Has anyone tried splitting the signal from one antenna to go to both XM and GPS? I'd rather not mount two antennas.

  2. #2
    MySQL Error jcdillin's Avatar
    Join Date
    May 2003
    Miami, FL
    you might be able to find a combo antenna, but your not going to be able to split the signal from the same antenna
    S60 Install

  3. #3
    Low Bitrate Erorus's Avatar
    Join Date
    Feb 2005
    XM and GPS probably use very different frequencies, which means different antenna configurations are required.

  4. #4
    Low Bitrate jimothy's Avatar
    Join Date
    Oct 2004
    Northern VA
    I was under the impression that XM also transmitted GPS as a part of their feed. Of course I might be completely off-base here. But I thought frodo's new app used GPS extracted from XM (i only skimmed the site so i may have mis-interpreted).

    edit: here's the page

    . This page uses a custom XM Radio client that uploads GPS coordinates, Song Info (and soon OBDII data) to a webservice.(Via cell phone) This allows the vehicle to be tracked
    I guess it's a bit ambiguos, so I'm not sure if that means you need a seperate GPS source or not.

  5. #5
    Jesus Freak antimatter's Avatar
    Join Date
    Jan 2004
    it is seperate
    -Jesus- King of Kings Lord of Lords

  6. #6
    Low Bitrate Erorus's Avatar
    Join Date
    Feb 2005
    XM radio only has two geosynchronous satellites. To get any sort of GPS reading, you typically need at least 3 satellites (4 to get altitude).. and even then your accuracy may not get over 200ft. To get the 30ft or better accuracy you need to pull in 6 or more satellites, which most GPS receivers can (I think most can do up to 12 satellites).

  7. #7
    Join Date
    Oct 2003
    XM and GPS run on different frequency ranges as well as different polarization.

    Most XM antennas use a active design. The receiver actually powers a small amplifier and filter in the antenna.. external GPS antennas are usually not active.

    All of these differences make it practically impossible for both services to share the same antenna.

Similar Threads

  1. Earthmate GPS hates XM
    By R32 JUhl in forum GPS
    Replies: 2
    Last Post: 02-13-2005, 10:59 AM
  2. 2.4 GHz Mobile Antenex Antenna
    By Mrbmw99 in forum Wireless Communications
    Replies: 16
    Last Post: 01-18-2005, 01:49 AM
  3. XM And GPS Problem?
    By legend5761 in forum Car Audio
    Replies: 5
    Last Post: 12-17-2004, 12:12 AM
  4. Programming for XM and GPS without hardware?
    By The Durango Kid in forum Software & Software Development
    Replies: 3
    Last Post: 07-29-2004, 10:19 AM
  5. The plan, diagram of planned setup. VGA, GPS, XM Radio, Laptop.
    By rally1 in forum General Hardware Discussion
    Replies: 0
    Last Post: 11-25-2003, 07:13 PM


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts