At 9/4/2007 11:21, you wrote: >That is true. I was only talking about cases where the equipment IS the >problem - spurs, adjacent channel rejection, frequency stability, Etc. > >Here are the recommendations: ><http://www.wprc.us/wprctechguidelines.html> > >Joe M.
Hmmm... 5 kHz deviation & 15 kHz spaced channels? Must need a lot of geographic separation between adjacent channels. The transmitter noise spec. is nice, but you forgot to specify the noise measurement bandwidth. I doubt it's dBc/Hz (the usual spec.) with those numbers. My own personal standard (for my equipment, not for coordination) is -80 dBc in a 16 kHz BW, which works out to -122 dBc/Hz. You have a spec. for the pre-emphasis curve, but don't specify what happens above 3 kHz. We've found that lack of post-limiter filtering can cause as much adjacent-channel interference as overdeviation. I've got one of Kevin's AP-50s lying around for the next one of those we run into. W.r.t. RX specs, are you saying your spec. for -85 dB total BW is 60 kHz? BTW, our specs are at http://www.tasma.org/devdata.htm Bob NO6B
