Last year, we evaluated how well New Packet Radio would work on our 0.7 cm band.

Winlink email with an 85 kB DFU file took 20 seconds over NPR at Modulation Mode 11 from field to GMail (through the EOC and Winlink Global Email system via Telnet). Winlink reported 156 kB per minute.

The same 85 kB file takes much longer over 1200 packet; 30 minutes at 3.3 kB/min to send with 1200 packet over radio with the RMS radio in the same room, or 4 minutes at 22 kB/min with 9600 packet (or less than 1 second at 746 kB/min with Telnet over 100 Mbps Ethernet).

Feasibly send large file attachments with Winlink (message size limit is 120 kB).

Mode 11 needed very strong signal to get 0% bit error rate (better than -80dBm).

LoRa APRS at 1 W performs comparable to narrow FM APRS at 5 W.
Yet, LoRa gives more accuracy from fewer lost data points. (More about APRS, LoRa)

LoRa modules allow people to use smartphones to send short messages without using the cell network. The Meshtastic app allows people to send messages to all nodes on the network.

We use APRS tracking to help keep volunteers safe in major events. Members need to carry VECTOR radios to do so. What if we could give members small trackers and let you use your own radio?

A small, low-power tracker may make our civic events work easier. LoRa (Long Range) is a proprietary modulation that uses chirp spread spectrum to achieve long ranges with low power use and high immunity to interference. We intend to use the 433 MHz version to test APRS, telemetry, and short messaging.

We need two to four people to help field test mini-trackers in June and July. Anthony VE7XAK has offered to lead the project and set up all the gear.