[aprssig] PHG - dBi or dBd ?

Robert Bruninga bruninga at usna.edu
Mon Sep 29 08:51:00 CDT 2008

>> Do I need to reprogram my digis with dBi numbers?
> The APRS Spec addendum 1.1 clarifies ... dBi:
> www.aprs.org/aprs11.html

The most common error of all digis I see is the failure to
understand Height above Average Terrain.  And it has nothing to
do with height above sealevel!  If the mountain is at 3000 feet
above sea level and surrounding area is at 2000 feet, then the
HAAT is only 1000 feet.

Too many digis use their altitude instead of HAAT.


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