(As is my usual, this article has a bunch of links – click on as many as you wish to receive the full experience)
by Vince (VE6LK)
In May of 2023 I embarked on a two week vacation to Hamilton Ontario that co-incidentally happened to include a side trip to Hamvention just outside of Dayton, Ohio.
For a guy living in Alberta, Canada, this would prove to be quite the trip and it created memories to last a lifetime. I also was told that I could play radio during the trip provided my wife would get to see some of the many waterfalls in the City of Hamilton, the area we’d call home for our two week trip.
Yes, I did take a brief detour to Niagara Falls while on the trip as it is only an hour from Hamilton.
And thus the planning began. I started overlaying POTA entities that overlapped on waterfalls so we both could visit and enjoy in our own way. It also meant I had to figure out what radio gear and, most importantly antennas, to bring along.
I landed up mostly running with low-slung antennas. By this I mean something between 4 and 10′ off the ground and horizontal in orientation. But it’s what I discovered about this simple approach that made it appear like pure magic to me – I made great contacts at what I would consider to be beyond NVIS distances including one from OH to UT!
Unlike many others who have defined kits and detailed plans they will use for an activation as they know the layout of the destination park, I prefer to arrive and work with what I’ve got based on the situation at hand. I did exactly this at K-9446 the day before and just around the corner from Hamvention. This approach is both an advantage and not, however it means I need to have enough flexibility in my kit to have some freedom of choice in approach. I also don’t wish to break my back nor needlessly contribute to the coffers of an airline via baggage fees.
Both to help me figure it all out and to document it in case of loss on the trip, I took some photos and posted them to Twitter showing most of the gear I packed. I ensured that anything with a battery was packed in my carry-on to not run afoul of airline security restrictions. Feedlines and anything non-electronic went into checked baggage and transceivers along with batteries were in my carry-on or backpack.
Along with the radio gear and bits for it, I figured that I’d pack an EFHW (or two, they’re small!) and my Comet HFJ-350M vertical kit. During one of my early activations I broke a piece of this kit and my inner potty mouth made a brief outward appearance, ahem.
Of course I couldn’t travel to the world’s largest hamfest and not open my wallet. I came back from Hamvention with a new vertical from Elecraft (the AX1), a 41′ EFRW from Tufteln, a 3D printed paddle key designed and built by Adam Kimmerly K6ARK, and a choke from Tufteln. The antennas would prove to be smart acquisitions given their small size and performance.
It’s with all of this background that I discovered the joy of a low-slung wire – – out of necessity.
Not wanting to repeat a broken antenna experience, I set out to string up a wire antenna for my activations. I’m not equipped with a throw line or a Weaver throw weight, just some bright pink mason’s line cut into different lengths along with my Gerber multi-tool. I do not possess the pure skill that Thomas has with his line and weight (it is most impressive to see Thomas in action as I did on the Sunday of Hamvention), so this means that I would not be aiming for top branches but rather things I can reach – about 8 or 9′ high – and de-tangle if need be.
Comparatively, in Alberta many of my activations are with a push-up flagpole and drive-on mast due to sheer simplicity and the lack of tall trees. I usually land up with some sort of a sloper arrangement.
At one end, it the antenna would be loosely attached to a tree or bush limb, or perhaps a signpost in the parking lot.
Depending on the length of your antenna wire, you may need to adjust your vehicle’s position in the parking stall to get the antenna to fit. The wires -antenna and counterpoise- route around the strut to their end points. You can see a short video of my set-up at K-9446.
At the other end the antenna would be hooked on the strut of the hatchback or perhaps temporarily affixed onto the vehicle’s broadcast band whip antenna. I’m un-fussy about how to use the vehicle as an end support provided I’m not scratching the finish and I can walk under it without an unexpected clotheslining 🙂
I operated on 40m, 30m, 20m, and 15m while running 5W into either an EFHW or EFRW. Hunters gave me reports, more often than not, 559 and above. And what caught me off guard was how well they performed in what I previously considered to be a substandard arrangement.
By now you are thinking, “Hey, Vince, can you wind back the tape and tell us about NVIS?” Sure, I’ll take a run at explaining something I partially understand.
NVIS (pronounced nih-viss or enn-viss) stands for Near Vertical Incidence Skywave and is most often experienced below 8MHz. The short version of this is that the closer you place an antenna to the ground, measured in wavelengths for a given band, the more likely it is to exhibit NVIS tendencies in how the signal is propagated. That’s to say your EFHW at 10′ (3m) will behave differently for NVIS on 80m than it will for 40m given the height above ground hasn’t changed as you switch between the bands.
“Can I use a low-slung antenna to my advantage?” Well sure you can of course! With POTA, SOTA and other programs, we set up our antennas to work with the stations we wish to contact. I don’t know about you, dear reader, but I’m opportunistic when I do these activities and am happy to make a number of contacts from anyone with a license and then move on to my next activity.
At it’s core, the question of “do I put a low-strung antenna up” is a question of strategy as it depends what you are after and how much gear you want to carry. Maybe the bands are running short, or you are out early in the day and want to run at a longer wavelength than the middle of the day. There are as many different ways to do this as you can imagine.
Given my location during this trip was in the Eastern Time Zone as I was activating in Ohio and Ontario, I expected good response given the population distribution on this side of the continent. I can’t wait to compare the differences when I get back home.
It’s all part of the experiment we call Amateur Radio.
Portable operations gives us the gift to experiment as we set up each time we operate. If you are like me and like experimenting to learn, portable operation is an easy way to learn. All you have to do is experiment while in the field, and note what you did along with your results. To repeat results in the future, refer to your notes.
You may discover a joy just like I did!
First introduced to the magic of radio by a family member in 1969, Vince has been active in the hobby since 2002. He is an Accredited examiner in Canada and the USA, operates on almost all of the modes, and is continually working on making his CW proficiency suck less. He participates in public service events around Western Canada and is active on the air while glamping, mobile, at home or doing a POTA activation. You can hear him on the Ham Radio Workbench podcast, follow him on Twitter @VE6LK, peek at his anemic YouTube presence (subscribe!), and view the projects and articles on his website.