diff --git a/src/ATC/approach.cxx b/src/ATC/approach.cxx
index 44784ab..98307cb 100644
--- a/src/ATC/approach.cxx
+++ b/src/ATC/approach.cxx
@@ -122,7 +122,7 @@ void FGApproach::Update(double dt) {
 			
 			int num_trans = 0;
 			// is the frequency of the station tuned in?
-			if ( freq == (int)(comm1_freq*100.0 + 0.5) ) {
+			if ( freq == kHz10(comm1_freq) ) {
 				current_transmissionlist->query_station( station, tmissions, max_trans, num_trans );
 				// loop over all transmissions for station
 				for ( j=0; j<=num_trans-1; j++ ) {
diff --git a/src/Navaids/navlist.cxx b/src/Navaids/navlist.cxx
index a7eca98..5deb425 100644
--- a/src/Navaids/navlist.cxx
+++ b/src/Navaids/navlist.cxx
@@ -30,6 +30,7 @@
 #include <simgear/math/sg_geodesy.hxx>
 
 #include "navlist.hxx"
+#include "../ATC/ATC.hxx"
 
 #include "strx.hxx"
 
@@ -149,7 +150,7 @@ bool FGNavList::add( FGNavRecord *n )
 FGNavRecord *FGNavList::findByFreq( const double freq, 
 		const double lon, const double lat, const double elev )
 {
-    const nav_list_type& stations = navaids[(int)(freq*100.0 + 0.5)];
+    const nav_list_type& stations = navaids[kHz10(freq)];
 
     SGGeod geod = SGGeod::fromRadM(lon, lat, elev);
     SGVec3d aircraft = SGVec3d::fromGeod(geod);
@@ -292,7 +293,7 @@ FGNavRecord *FGNavList::findByIdentAndFreq( const char* ident, const double freq
     if ( freq > 0.0 ) {
         // sometimes there can be duplicated idents.  If a freq is
         // specified, use it to refine the search.
-        int f = (int)(freq*100.0 + 0.5);
+        int f = kHz10(freq);
         for ( unsigned int i = 0; i < stations.size(); ++i ) {
             if ( f == stations[i]->get_freq() ) {
                 return stations[i];
@@ -444,7 +445,7 @@ FGNavRecord *FGNavList::findClosest( double lon_rad, double lat_rad,
 // Given a frequency, return the first matching station.
 FGNavRecord *FGNavList::findStationByFreq( double freq )
 {
-    const nav_list_type& stations = navaids[(int)(freq*100.0 + 0.5)];
+    const nav_list_type& stations = navaids[kHz10(freq)];
 
     SG_LOG( SG_INSTR, SG_DEBUG, "findStationByFreq " << freq << " size " << stations.size()  );
 
--- /tmp/ATC.hxx	2007-07-07 01:22:14.000000000 -0400
+++ b/src/ATC/ATC.hxx	2007-07-07 01:23:20.000000000 -0400
@@ -37,6 +37,22 @@
 SG_USING_STD(string);
 SG_USING_STD(ios);
 
+
+
+// Convert a frequency in MHz to tens of kHz
+// so we can use it e.g. as an index into commlist_freq
+//
+// If freq > 1000 assume it's already in tens of KHz;
+// otherwise assume MHz.
+//
+// Note:  122.375 must be rounded DOWN to 12237 
+// in order to be consistent with apt.dat et cetera.
+inline int kHz10(double freq){
+  if (freq > 1000.) return int(freq);
+  return int(freq*100.0 + 0.25);
+}
+
+
 enum plane_type {
 	UNKNOWN,
 	GA_SINGLE,
@@ -297,7 +313,7 @@
 	fin.setf(ios::skipws);
 	//cout << "Comm name = " << a.name << '\n';
 	
-	a.freq = (int)(f*100.0 + 0.5);
+    a.freq = kHz10(f);
 	
 	// cout << a.ident << endl;
 	
--- commlist.cxx	2007/07/07 05:35:22	1.1
+++ b/src/ATC/commlist.cxx	2007/07/07 05:35:45
@@ -124,14 +124,8 @@
 	lon *= SGD_DEGREES_TO_RADIANS;
 	lat *= SGD_DEGREES_TO_RADIANS;
 	
-	// HACK - if freq > 1000 assume it's in KHz, otherwise assume MHz.
-	// A bit ugly but it works for now!!!!
 	comm_list_type stations;
-	if(freq > 1000.0) {
-		stations = commlist_freq[(int)freq];
-	} else {
-		stations = commlist_freq[(int)(freq*100.0 + 0.5)];
-	}
+	stations = commlist_freq[kHz10(freq)];
 	comm_list_iterator current = stations.begin();
 	comm_list_iterator last = stations.end();