I am using an RM502Q-AE and am using a 5 in 1 external antenna that has 2 LTE, 2 WIFI and 1 GPS SMA connectors. Most of the multi freq antennas have some kind of out of band rejection filters on the GPS/GNSS line. In this case pretty much everything is filtered except a couple of MHz around 1561 (BeiDou), 1575 (GPS) and 1602 (GLONASS.)
When I use a general antenna then GPS works fine, but when I use one that filters out all but these ranges then it does not work. Is there a setting that I need to set to tell the card to only use these frequencies?
