Low Power Transmission
Now I am testing APRS with BAOFENG UV-5R / iPhone. I found one potential concern during this experiment. Since I am considering to use APRS during hiking and it will be a long operation during hiking. It could be more than a several hours. To save the power, I try lower power.
From my home, digipeaters near my home can pick up the signal even if I transmitted 1W. So I started using 1W output power to track during my commute. It seems that it works well near home, however some packets are not recognized if the location is close to my office. I saw a couple packets are missed, probably around 50% is not recognized. (It can recognize packets sent by digipeaters.)
Here is my best guess. Since APRS is using the same frequency (channel) to send a packet, it is possible to conflict some packets almost at the same time. If other stations sending them with higher power / efficient antenna, a weak signal which was sent by lower power / inefficient antenna might be overridden. This is probably a nature of FM signal and traffic on APRS channel near my office is much more than around my home.
To understand more, I think I need more data with different power. I will continue to correct more data to understand this.
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