I’ve been having fun with mountaintop VHF ham radio for decades, way before Summits On The Air (SOTA) was a thing. It is an activity that I enjoy very much during VHF contests, Parks On The Air (POTA) activations, SOTA activations, and just goofing around in the mountains. Most of this activity has been on the 2-meter band, but any frequency above 50 MHz can be fun.
My philosophy with ham radio is to have fun doing ham radio things and tell people about it. If they think VHF SOTA looks like fun, other hams may try it. At the same time, I want to be open about the challenges that may be encountered. Doing SOTA activations using just VHF can be difficult, even frustrating. (This is one of the reasons I like doing it.) So this post is a cautionary tale, focused on three essential principles.
1. VHF SOTA is easy to do, except when it’s not
A VHF SOTA activation can be as simple as taking a $30 handheld radio on a hike up a summit and making a few contacts on 146.52 MHz or another simplex frequency. The radio is compact, lightweight, and completely self-contained, ready to go! This is arguably the easiest way to do a SOTA activation if the summit is near a populated area. For example, Genesee Mountain (W0C/FR-194) at 8284 feet overlooks the greater Denver area, so hike to that summit and you should have plenty of stations to work on 2m FM.
Now, try that same approach in a more rural part of the state and you may run into trouble. This is when VHF SOTA is challenging and potentially frustrating.
Which leads us to the second important principle…
2. You need to have chasers within range to contact
This is obvious, but you do need stations that are within range to work. This becomes more difficult in areas that have low population density. There may not be many radio hams within range of your chosen summit; they may not have 2m FM gear, they may not be listening to your frequency, and they may not even have the radio turned on.
Before activating a summit, consider the likely range and how many chasers might be around for you to contact. Take, for example, Aspen Ridge (W0C/SP-084) on the west side of South Park. The hike up is easy, and the elevation is substantial at 10,740 feet. The map shown above has a circle with a radius of ~25 miles, which is a conservative rule of thumb to get us started. Making radio contacts within this radius should be a slam dunk from this elevation, but it does depend on the actual terrain.
From the map, we can see that we should be able to work stations in Buena Vista and Salida, which are small mountain towns with a corresponding small ham radio population. Some of these folks make it a habit to monitor 146.52 MHz to see what activity occurs on the calling frequency, which helps. But it helps to get the word out to the target audience that you will be on the air. The basic idea is to “send invitations” for your planned activation. The local radio club (Chaffee Lake Amateur Radio Association) has a groups.io list, so you could drop an email message there. If you know some of the hams in the area, you can always reach out and ask them to be listening for you. It is always good to post an ALERT and then a SPOT on SOTAwatch because some chasers may see that. Also, keep an eye on SOTAwatch for other SOTA activators that are on other summits. During the summer months, it is common to encounter tourists, campers, hikers, or off-road enthusiasts on 2m simplex.
Looking at my Aspen Ridge logs, I see that I’ve worked K0MGL at his home station near Florrisant, at about 60 miles, with some mountains in the way. So the 25-mile radius shown on the map is quite conservative. (Much longer distances are possible.) Now, I probably would not be able to work K0MGL with just a handheld radio and a rubber duck antenna.
Which leads us to our third and final principle…
3. Every decibel of signal strength matters
VHF radio often gets described as being limited to “line of sight,” which is a helpful model but one that is incomplete. (See The Myth of VHF Line of Sight.) I often make VHF contacts beyond line of sight, bouncing signals around the mountains without knowing the actual radio path. These VHF SOTA contacts happen at the fringes of radio coverage. That is, there is just enough signal to complete a contact, but small changes in signal strength can make the difference between success and failure. So you should optimize your station as best you can.
First up is ditch the rubber duck antenna and get an antenna that is a half-wave in length on the 2-meter band. See A Better Antenna for Dualband Handhelds. Make sure it is a half-wave and not just one of those extended rubber duck antennas that are a quarter-wave. Those work a little better than the typical rubber duck, but the half-wave is far superior.
Another half-wave option is the roll-up J-pole antenna, such as the N9TAX Slim Jim antenna. (There is a slight difference in construction between a J-pole and a Slim Jim antenna but they are so similar, I consider them the same.) You can purchase this type of antenna already assembled, but it also makes for a fun project to build one from scratch. (Just search on the web for “2 meter j-pole antenna plan.”) You’ll need some way to support this antenna, such as a non-conductive pole or a rope strung from a tree.
The next step up in antenna performance is to add additional gain and directivity. I use the Arrow II 2m Yagi antenna, which provides about 6 dB of gain over a half-wave radiator. I normally just hold this antenna in my hand, but you can also set up a mast to support it.
Another option is to increase your power level. The typical HT puts out about 5 watts but a mobile radio can go up to 50 watts, a 10-dB improvement. While antenna improvements help on both transmit and receive, increased transmitter power only makes your transmitted signal stronger. However, if the other station is also running 50 watts in a vehicle or at home, more power from the summit tends to balance things out.
The key point here is that even a few decibels of improvement can yield more radio contacts.
Wrap It Up
So there we have it, three important principles to keep in mind when pursuing SOTA activations using VHF. I have had a ton of fun doing this, but I also know it can be frustrating. The most fun occurs when I make a long-distance contact that I did not expect. (My best DX from a SOTA summit using 2m FM is 245 miles.) Keeping these principles in mind helps to set expectations while providing some ideas for improving your odds of success.
73 Bob K0NR
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