diff --git a/gnss-converters.cabal b/gnss-converters.cabal
--- a/gnss-converters.cabal
+++ b/gnss-converters.cabal
@@ -1,6 +1,6 @@
 cabal-version: >=1.22
 name: gnss-converters
-version: 0.3.37
+version: 0.3.38
 license: BSD3
 copyright: Copyright (C) 2016, 2017 Swift Navigation, Inc.
 maintainer: Swift Navigation <dev@swiftnav.com>
diff --git a/src/Data/RTCM3/SBP/MSM.hs b/src/Data/RTCM3/SBP/MSM.hs
--- a/src/Data/RTCM3/SBP/MSM.hs
+++ b/src/Data/RTCM3/SBP/MSM.hs
@@ -30,7 +30,7 @@
 -- | Derive sender from station.
 --
 toSender :: Word16 -> Word16
-toSender station = station .|. 61440
+toSender station = station .|. 61568
 
 masks :: Bits a => Int -> a -> [b] -> [b]
 masks n a bs = fst <$> filter snd (zip bs $ testBit a <$> [n-1,n-2..0])
@@ -59,9 +59,9 @@
   | sig == 15 = Just 1
   | sig == 16 = Just 7
   | sig == 17 = Just 8
-  | sig == 22 = Just 9
-  | sig == 23 = Just 10
-  | sig == 24 = Just 11
+  -- | sig == 22 = Just 9
+  -- | sig == 23 = Just 10
+  -- | sig == 24 = Just 11
   | otherwise = Nothing
 
 toGpsSignal :: Word8 -> Word8 -> Maybe GnssSignal