Each MaveriX goes out with an A631 antenna preset to "Auto". If you are using an A222 or an A631 that was previously used with a Rebel and the SBAS PRN says "138" instead of "Auto" in the MaveriX, you will need to hook the antenna up to a Rebel and change the SBAS PRN to "Auto". There is no way of changing that PRN in the MaveriX. For more information, please contact Customer Support at 1-800-247-3808.