APRS: RF vs Blackberry

I had to run an errand over my lunch break so I decided to run an APRS experiment.

NG0R-9 : Kenwood D700 @ 50w transmitting every 3 minutes
NG0R-12 : Blackberry Bold running APRSBB sending every 45 seconds (the default)

There is an APRS receive gateway here in Kingston, MN so coverage should not be a problem. The trip today was a maximum of 12 miles in a straight path to the receive station.

Red is the RF beacon
Pink/Purple is the Blackberry

I was surprised at how much of my trip was missed or not received on the RF path. I expected to see more cell phone/data drop outs because there are numerous black holes in my area on the AT&T network.


The weird part is that I was heard by three stations ranging in distance from 12 miles away to 129 miles away. I would have expected the two closest sites to be able to hear my whole trip.

The table below show that with the D700 in my truck I have seen APRS paths as good as 200 miles over the past couple of weeks. Those are some pretty extreme distances as 20-40 miles is more common.

Links:
Blackberry APRS client:
http://aprsbb.bluearray.net/

APRS Maps & Data:
http://aprs.fi/info/NG0R-9

This data really surprised me as I figured that I would have better APRS coverage near my home since there is are two nearby receive sitez. It makes me want to do some more experimenting.

73 de NG0R

Posted on August 17, 2010 at 5:57 pm by John · Permalink
In: Uncategorized