diff --git a/matlab/TCV/gdat_tcv.m b/matlab/TCV/gdat_tcv.m
index c41288d457f70d827cecdd1a6650d75ea813fbf4..4885f998e7e92569d0111ca435cb213e4b6f2b7a 100644
--- a/matlab/TCV/gdat_tcv.m
+++ b/matlab/TCV/gdat_tcv.m
@@ -2133,7 +2133,7 @@ elseif strcmp(mapping_for_tcv.method,'switchcase')
           t1=sprintf('bad source for mhd: ''%s'', should be either ',gdat_data.gdat_params.source);
           t2=sprintf('''%s'', ',mhd_source_list{1:end-1});
           t3=sprintf('or ''%s''',mhd_source_list{end});
-          disp(sprintf('%s %s %s',t1,t2,t3));
+          fprintf('%s %s %s\n',t1,t2,t3);
           return
         end
       else
@@ -2144,11 +2144,11 @@ elseif strcmp(mapping_for_tcv.method,'switchcase')
           z_axis_av = nanmean(z_axis.data(round(numel(z_axis.data)/3):round(numel(z_axis.data)*0.85)));
         end
         if z_axis_av > 0.12
-          gdat_data.gdat_params.source = '23'; % zaxis +23cm
+          gdat_data.gdat_params.source = '23';  % probe array at z = +23cm
         elseif z_axis_av < -0.12
-          gdat_data.gdat_params.source = '-23'; % zaxis -23cm
+          gdat_data.gdat_params.source = '-23'; % probe array at z = -23cm
         else
-          gdat_data.gdat_params.source = '0'; % zaxis = 0
+          gdat_data.gdat_params.source = '0';   % probe array at z =   0cm
         end
         t1=sprintf('source set to ''%s'', can be ',gdat_data.gdat_params.source);
         t2=sprintf('''%s'', ',mhd_source_list{1:end-1});
@@ -2156,7 +2156,7 @@ elseif strcmp(mapping_for_tcv.method,'switchcase')
         fprintf('%s %s %s',t1,t2,t3)
       end
 
-      % load data dependent on source
+      % load data dependent on requested source
       if numel(gdat_data.gdat_params.source)>=2 && strcmp(gdat_data.gdat_params.source(1:2),'23')
         aaLFSz23_sect3=tdi('\atlas::DT196_MHD_001:channel_067');
         aaLFSz23_sect11=tdi('\atlas::DT196_MHD_001:channel_075');