[aprssig] PHG - dBi or dBd ?
hessu at hes.iki.fi
Mon Sep 29 07:08:48 CDT 2008
On Mon, 29 Sep 2008, Chuck Kimball wrote:
> I've noticed that aprs.fi is using dBi for it's display of the info
> provided by PHG.
> In looking through Bob's and most other references of PHG they only
> specify dB not specifying dipole or isotropic.
> So which is it? Do I need to reprogram my digis with dBi numbers?
The APRS Spec addendum 1.1 clarifies the specification that it is dBi:
"The Antenna Gain in the PHG format on page 28 is in dBi."
The PHG circles do not very accurately represent true coverage, so if they
*roughly* match with your mobile (half-sized circles) or fixed station
(full-sized circles) coverage, and if it's hard to reprogram the digis, I
wouldn't go through an awful lot of effort to change the configuration.
- Hessu, OH7LZB
More information about the aprssig