The 1000S has a spectrum analyzer in it and the 1000A probably does not. However there were a few 1000A units (or just plain 1000 ?) that had spectrum analyzers in them. 73 Gary K4FMX barry tuttleman wrote: > anyone know the difference(s) between IFR 1000A vs IFR 1000S? > tnx, > barry > carson city nv