How to Self-Spot Off-Grid for SOTA/POTA Using HF

FT8 – the Marmite Mode

Over in the UK grocery stores sell a product called “Marmite”. It is a dark, sticky, yeast-based product with a very strong flavor. Aussies have a similar product called “Vegemite”. These products are either loved or hated; so when the adjective “Marmite” is attached to something it means people are highly unlikely to be indifferent about it. FT8 is probably a “Marmite mode”. It has strong adherents and vehement detractors.

Personally, I have never really been attracted to FT8. A few years ago I tried it just to find out what it was all about. I even completed a QSO with it. Since then FT8 has grown to be an enormous success and probably has more users than any other mode.

So why doesn’t FT8 ring my bell? Well, it’s all to do with the way I like to operate – out in the field, in what I call my “Big Blue Sky Shack”. I prefer to hike down a trail into the bush and be alone with nature. That style of operating is incompatible with carrying a laptop that adds weight and another source of limited battery power to the field rig. There are no comfy picnic tables in the back country – nowhere to spread out a lot of equipment where it won’t get dripped on from the tree canopy above. Personal preference? Yes, absolutely; “your mileage may vary”.

Spot Me Please!

I am an avid Parks On The Air (POTA) enthusiast. I have been using the Internet to self-spot on the POTA website when I am out on an activation. Some parks have no cellphone coverage and so in the past I have had to rely on calling CQ and asking hunters to spot me. It can work, but it can also take longer to complete an activation that way. I may have plenty of time to complete the activation, but my field rig’s battery does not always have plenty of charge!

Busting Through my Own Taboo

But, this week, I busted through my personal FT8 taboo in a way that was very gratifying and certain to be repeated. The reason? By employing FT8 to self-spot a POTA activation I was able to eliminate my use of the Internet to achieve the same goal. And it worked! For the first time in well over a hundred activations I accomplished my objective without the Internet. (Of course, I realize the POTA website played a big part by directing hunters to my frequency; it’s just that I was able to self-spot over HF instead of the Internet).

SOTAmat

So, how did I do it? The answer lies in a phone app called “SOTAmat” (pronounced “SOTA MATE” as in Summits On The Air autoMATion). Yes, it still involved my phone, but the process is conducted entirely offline. I switched my Yaesu FT-891 over to Data/USB mode and hooked my phone to the radio via a small interface circuit. Then, after selecting a frequency and entering my park reference number on the SOTAmat screen, I pressed the soft key to send the FT8 code that would get me spotted on pota.app.

The FT8 code is transmitted 4 times to ensure it is correctly received and picked up by PSKreporter or RBN (Reverse Beacon Network). The cleverly encoded 4-character FT8 message translates into everything POTA needs to publish the spot. And does it work? I received my self-spot through another phone app called “Ham Alert” almost immediately (yes, that notification did use the cellphone network and Internet, but was non-essential). Then, as soon as I started calling CQ, the hunters responded right away.

FT8 to Spot, CW to QSO

My location was POTA entity VE-5651, Hibou Conservation Area on the shore of Owen Sound Bay, Ontario. This was my sixth activation of the park and was undertaken to test another antenna configuration. A HamRadioOutsideTheBox reader had made a suggestion to try my usual 4 radials oriented in the direction I wanted to radiate my signal – in my case that is southwest. The antenna was a quarter wave vertical whip mounted on a spike.

After successfully spotting myself on pota.app using SOTAmat and FT8, I switched to CW for the actual activation. Here is the map of spots recorded by RBN, the Reverse Beacon Network, during the activation. Note these are RBN spots, not my actual contacts.

Back in the shack, post-activation, I modeled the antenna using EZNEC. The predicted propagation pattern closely matched the results obtained in the field. Here is an image of my radials out in the field:

And here is EZNEC’s description of the expected propagation pattern:

As you can see, this radial pattern provides a little bit of front/back gain, but not as much as the single radial discussed in my last post. The radials were oriented southwest to provide coverage of the lower 48 states from my QTH in southern Ontario. RBN recorded several spots in Europe and, indeed, 2 of my POTA hunters were in Europe; one in the UK and one in Italy. These contacts were either long path or off the back of the antenna.

Never Say Never Again?

I will probably never become an FT8 enthusiast but I have found real value in using the mode through SOTAmat for self-spotting my CW activations. There is a very beautiful, but hard-to-find Ontario Provincial Park about an hour’s drive away from my home that has no cellphone service. I am already planning another activation there with the confidence that I will be able to self-spot and operate entirely over HF.

NB: Planned POTA activations can be entered on the POTA website in advance. When RBN receives a spot from a CW or digital operator it matches the planned activation to the RBN spot and adds the activation to its own spots page. I usually prefer the spontaneity of self-spotting while actually in a park ready to transmit.

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