Help out SOTA/POTA activators with your SparkSDR station

[Brian Mathews]

You can provide a valuable service to SOTA (Summits-On-The-Air) and POTA (Parks-On-The-Air) activators with your SparkSDR based station by running a skimmer (monitor) 24x7 when you aren't using SparkSDR for other work.

A common problem for SOTA/POTA activators is getting "found" on the air (spotted) while they freeze in the snow and wind on a mountain top.  Because of this, SOTA is one of the few amateur radio sports that allows cell phones to be used for self-spotting.  But what happens when there is no cell service (and no local APRS station) available to self-spot in the field??

There is a new off-grid self-spotting solution in Beta called SOTAmat: it uses an iOS / Android mobile phone (no computer needed) to send specially encoded FT8 or PSK31 tones over HF (optionally cable-free with the mobile phone speaker into the radio's microphone).  The mobile app encodes a special FT8/PSK31 message that gets picked up by SparkSDR skimmers around the world (we need yours!), who forward to PSKreporter, get decoded by SOTAmat, and spotted on POTA or SOTA.   Since FT8/PSK31 on HF goes long distances with low power, it works when APRS and Cell aren't available.  

Since we are using FT8 for something it wasn't designed for, it turns out that the *only* reliable FT8 skimmer that works is SparkSDR.  SparkSDR is able to parse callsigns and suffixes from FT8 "free text" messages and forward to PSKreporter.  Other FT8 software (such as WSJT-X and other SDR's) do not pull free-text callsigns+suffixes and often only report on "CQ" messages (which can't encode the suffix information needed by SOTAmat).

HOW YOU CAN HELP:

If you have a SparkSDR receiver, simply run it 24x7 whenever you aren't using your radio for other work.  We want more worldwide skimmers monitoring FT8 and PSK31 from multiple locations on 40 meters, 20 meters, 15 meters, and 10 meters.  Those 4 slices (4 bands) and 8 virtual-slices (FT8 + PSK31 for each) are possible with a slice bandwidth of 96K samples/second.  If you don't have a multi-band antenna, then run whichever slices make sense for your antenna.  Make sure each virtual slice is configured to report receptions to PSKreporter (tick the checkbox for each). 

The SOTA activator freezing in blowing snow on a mountain top will thank-you when your monitoring station hears their special message and facilitates the triggering of a spotting command.  Right now there are barely enough monitoring stations, but more skimmers means better reliability of getting the message through!

For more information on how the system works, check out https://SOTAmat.com

Attached is a picture of the leader board of SparkSDR monitors as of 9/2022 (1st place is in Alaska and he is far from everybody!  Your shack might have an easier time hearing SOTA/POTA people than Alaska!):

Thanks!