diff --git a/MAC/APL/PAC/BeamServer/src/beamctl.cc b/MAC/APL/PAC/BeamServer/src/beamctl.cc
index 21899a8770e6eb43984f6090e5399d963f5ccb2d..fa202bc2d8fe3f9163e5ebd23cf7c432d3026a6a 100644
--- a/MAC/APL/PAC/BeamServer/src/beamctl.cc
+++ b/MAC/APL/PAC/BeamServer/src/beamctl.cc
@@ -158,7 +158,6 @@ GCFEvent::TResult beamctl::create_subarray(GCFEvent& e, GCFPortInterface& port)
 	start.name   = BEAMCTL_ARRAY + formatString("_%d", getpid());
 	start.parent = m_parent;
 	start.subset = getRCUMask();
-	start.nyquist_zone = m_rcumode()(0).getNyquistZone();
 	start.rcumode().resize(1);
 	start.rcumode()(0) = m_rcumode()(0);
 	
diff --git a/MAC/APL/PAC/CAL_Protocol/src/CAL_Protocol.prot b/MAC/APL/PAC/CAL_Protocol/src/CAL_Protocol.prot
index cca5920a92cb03fdd92a903186a32defe9e16936..365302c90409b0d8d8fda257185b8a7f8dcd3450 100644
--- a/MAC/APL/PAC/CAL_Protocol/src/CAL_Protocol.prot
+++ b/MAC/APL/PAC/CAL_Protocol/src/CAL_Protocol.prot
@@ -74,12 +74,6 @@ event = {
 	    name = "subset";
 	    type = "std::bitset<MEPHeader::MAX_N_RCUS>";
       };
-      param = { // nyquist_zone
-	    name = "nyquist_zone";
-	    type = "int";
-      };
-      // sampling_frequency and nyquist_zone determine the spectral window
-
       param = {
 	    // RCU control byte controls the setting of all
 	    // RCU's for this subarray
@@ -87,6 +81,8 @@ event = {
 	    type = "RSP_Protocol::RCUSettings";
 	    userdefined;
       };
+      // nyquist_zone is deducted from RCUSettings
+      // sampling_frequency and nyquist_zone determine the spectral window
 };
 
 event = {
diff --git a/MAC/APL/PAC/CAL_Protocol/src/SpectralWindow.cc b/MAC/APL/PAC/CAL_Protocol/src/SpectralWindow.cc
index 94dbcc6c20b0654d1feec6239386101c46d4dbd5..5ca62a4241f226d5965e0ad66161554002adb242 100644
--- a/MAC/APL/PAC/CAL_Protocol/src/SpectralWindow.cc
+++ b/MAC/APL/PAC/CAL_Protocol/src/SpectralWindow.cc
@@ -38,9 +38,6 @@ using namespace blitz;
 using namespace LOFAR;
 using namespace CAL;
 
-#define SPW_DIMS    2
-#define SPW_NPARAMS 3 /* sampling_freq, nyquist_zone, numsubbands */
-
 SpectralWindow::SpectralWindow() :
   m_name("undefined"), m_sampling_freq(0), m_nyquist_zone(0), m_numsubbands(0), m_rcucontrol(0)
 {
diff --git a/MAC/APL/PAC/CalServer/src/CalServer.cc b/MAC/APL/PAC/CalServer/src/CalServer.cc
index 96390e1e725fdb77cb5b19856cf6ca413f50de09..e2bee7aaefb1e290459e2ee232dd7552504e276d 100644
--- a/MAC/APL/PAC/CalServer/src/CalServer.cc
+++ b/MAC/APL/PAC/CalServer/src/CalServer.cc
@@ -572,13 +572,13 @@ GCFEvent::TResult CalServer::handle_cal_start(GCFEvent& e, GCFPortInterface &por
 		else {
 			// create subarray to calibrate
 			SubArray* subarray = new SubArray(start.name,
-												parent->getGeoLoc(),
-												positions.copy(),
-												select,
-												m_sampling_frequency,
-												start.nyquist_zone,
-												GET_CONFIG("CalServer.N_SUBBANDS", i),
-												start.rcumode()(0).getRaw());
+							  parent->getGeoLoc(),
+							  positions.copy(),
+							  select,
+							  m_sampling_frequency,
+							  start.rcumode()(0).getNyquistZone(),
+							  GET_CONFIG("CalServer.N_SUBBANDS", i),
+							  start.rcumode()(0).getRaw());
 
 			m_subarrays.schedule_add(subarray);
 
diff --git a/MAC/APL/PAC/CalServer/test/CalTest.cc b/MAC/APL/PAC/CalServer/test/CalTest.cc
index bb9517e04a464d2f010b6bbccee5660eaf4cefb5..5e8fc7206e030a26a6519b7603d559cf3d78cace 100644
--- a/MAC/APL/PAC/CalServer/test/CalTest.cc
+++ b/MAC/APL/PAC/CalServer/test/CalTest.cc
@@ -159,7 +159,6 @@ GCFEvent::TResult CalTest::test001(GCFEvent& e, GCFPortInterface& port)
 	    break;
 	  }
 	}
-	start.nyquist_zone = m_nyquistzone;
 	start.rcumode().resize(1);
 	start.rcumode()(0).setRaw(m_rcucontrol);