18 Nov  2006    News for NTIA/ITS HF Propagation Models (WINDOWS version)

18 Nov  2006   1. A minor change was made to plotting Distance and Time
                  options in the Point-to-Point models. Previously, if you
                  plotted a variable that did not change, (e.g TANGLE for
                  and isotrope antenna), a division by zero could have occurred.
                  This has been fixed.

               2. It seems that sometime after the 05.0119W version I made a
                  change that lessened the loss when the frequency was well
                  above the MUF (and MUFday < .0001). This would sometimes
                  give rise to a reasonable value of REL, when no communication
                  would be expected. This was especially true for HAMs that
                  tend to use very low required SNR values. I corrected this
                  and added more loss when MUFday < .0001. This will only
                  affect circuits that are well above the MUF. MUFday is the fraction
                  of the days of the month that the operating frequency will be 
                  below the mode MUF.
                  This change was performed in both VOACAP and ICEPAC.

               3. Look for some changes in REC533 in the future that have been
                  requested by the ITU meetings held in Geneva in October.