[600MRG] YaND Navtex Decoder Software

[Frank Lotito]

 I was recently introduced to the world of NAVTEX DXing." I primarily monitor 490 and 518 KHz using the YaND software package , version 6.4 by Dirk Claessens.  I downloaded the software package from http://www.ndblist.info/datamodes.htm.  As recommended in the user manual, I installed this software in the main directory C:\ in lieu of the normal default directory C:\program files (X86).  The computer's O/S is Windows 7 SP1 64 bit with 8 GB of RAM.  The sound card is a "no frills" card.  My receiving system is the same system I used for HF RTTY.  For RTTY I use the MMTTY software.  
 
I have three questions you may be able to help me with:
 
(1) The YaND "INP. LEVEL" meter always sits on zero, but the other two meters seem to be properly working.  The spectral display (signal amplitude) almost fills the entire screen and successful decodes for minutes on end are the norm, at least for nearby NAVYEX stations. Any suggestions?
 
(2) On moderate to strong received transmissions the spectral display is characterized by two peaks as it should for two-tone FSK  modulation. However the left peak is 4X to 5X wider than the right peak, and around 60% the height of the right peak.  I have tried receiver band widths ranging from 2200 Hz down to 600 Hz and saw no effect.  Any suggestions? My receiver is an Icom 746PRO, and the receiving converter s the KF5CW up-converter from the LWCA web site.  
 
(3) I have yet to find the time to try YaND on HF NAVTEX.  Am I correct in assuming YaND works on (decodes) all SITOR-B type transmissions?
 
I have not been successful in finding a means to correspond directly with Dirk Claessens on these matters.
 
73 Frank K3DZ / WH2XHA