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[aprssig] Re Net28

Stephen H. Smith wa8lmf2 at aol.com
Tue Jun 15 02:55:06 UTC 2010

Dave Baxter wrote:
> In any case, I was under the (mistaken?) impression, that much of HF
> APRS used a PSK type modulation, where the USB/LSB problem does not
> exist, as it's the changes of phase that convey the information, not
> relying on discrete frequencies and shifts.
> Or did I skip something, again......
> 73.
> Dave G0WBX.

The main modes that are sideband-sensitive are classic RTTY and it's 
derivative AMTOR.  

Until recently, APRS on HF exclusively used classic 300-baud AX.25 
packet using FSK NRZI coding that is not affected by sideband sense. 

The more recent development of APRS over PSK63 uses (obviously) PSK,  
which is also unaffected by sideband sense.



Stephen H. Smith    wa8lmf (at) aol.com
EchoLink Node:      14400    [Think bottom of the 2M band]
Home Page:          http://wa8lmf.com  --OR--   http://wa8lmf.net

*** NEW ***  HF APRS Using PSK63

JavAPRS Filter Port 14580 Guide

"APRS 101"  Explanation of APRS Path Selection & Digipeating

Updated "Rev H" APRS            http://wa8lmf.net/aprs
Symbols Set for UI-View,
UIpoint and APRSplus:

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