1. <script src="//ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
      
       <script>   
       $(document).ready(function(){
           var ncs_callsign = <?php echo json_encode($ncs_callsign); ?>;
          
           if (ncs_callsign == 'NONE' || ncs_callsign == null)
           {
               $("#nav_bar li:nth-child(3)").hide();
               $("#NOW").hide();
               $("#NCS").hide();
           }
           else
           {
               $("#nav_bar li:first").hide();
               $("#nav_bar li:nth-child(4)").hide();
               $("#WAIT").hide();
               $("#IF").hide();    
           }
          
           var logger_callsign = <?php echo json_encode($logger_callsign); ?>;
          
           if (logger_callsign == 'NONE' || logger_callsign == null)
           {           
               $("#LOGGER").hide();  
           }
           else
           {
               $("#nav_bar li:nth-child(2)").hide();  
           }       
       });
       </script>

Here's what happens.  Initially, both ncs_callsign and logger_callsign are null and the comparisons work fine and the html ids in the first section of both comparisons are hidden.

However, if the ncs_callsign changes to NONE and the logger_callsign changes to a valid value, the ncs_callsign comparison fails and the ids in the second section of the ncs_callsign comparison are not hidden.  But the ids of the first section of the logger_callsign comparison are hidden.

The other case is also a problem.  If the logger_callsign changes to NONE and the ncs_callsign changes to a valid value, the second section ids of the ncs_callsign comparison are hidden but the first section ids of the logger_callsign ids are not.

Summary - unless both ncs_callsign and logger_callsign are null, the comparison with value of NONE fails while the one with a valid value works ok.

Any ideas are welcome before I go completely nuts.