I have a Raven 410 and a raven 310 antenna.  The 410 gives me a snr of around 38-42 on both 135 and 138 on WAAS.

The 310 gives me around 19-21 snr on the same satellites.

Is this normal? Does the 410 have that much better antenna

BTW I also have a Trimble EZGuide 250 with the AG15 antenna and it also gives me around 40 snr on the 2 WAAS satellites.

Maybe there is something wrong with the 310?