Antenna Supports

[ntilley905]

Hi all! Happy to be here in the new forum!

I recently did my first “all HF” SOTA/POTA activation on Hex Mountain in the Okanogan-Wenatchee National Forest. Right now I have an Elecraft KX2 with the AX1, as well as a KM4ACK 40M EFHW. Hex Mountain was a totally bald summit above tree line, so I only took the AX1 plus my VHF/UHF HT. That being said, especially on SSB (working on my code!) it was a bit of a struggle.

I’d like to pick up something to make use of the EFHW a little easier. I’ve looked both at some Arborist Throw Line like the weaver stuff everyone recommends, as well as a SOTAbeams carbon 6 mast. Any tips between the two? I’m sure I’ll eventually end up with both, but one step at a time!

[SkipRD]

My experience is limited (I've only done two activations where there wasn't a tree handy, and both of those were a short walk where weight/size didn't matter), but here goes. I used an MFJ-1910 33' mast, but not the entire length. (The SOTAbeams mast would be much better.) In one case, there was a 3-foot vertical rock face and I looped a rope around the mast and held the rope in place with another rock; in the other case there was a crack between two rocks and I crammed the mast down that and leaned it over at an angle. My assumption is that it will always be possible to jury-rig some way to hold a mast vertical. In both cases I tied the end of the EFHW to the tip of the mast and sloped the wire down to the transformer. In both cases it worked fine--a flimsy mast is OK because I didn't put any tension on the antenna wire. I ended up sitting on the ground because I forgot to bring my little 3-legged backpacking stool. Add that to your list.

FWIW, a friend uses a Wolf River coil in such cases. It includes a tripod to hold the antenna and he simply throws the radials out on the ground. I've wondered that his system works better than mine and a Wolf River coil setup is on my birthday list (in case my wife is reading this).

Hope that helps,
73 Skip K4EAK

[ntilley905]

Thanks, Skip! That definitely does help. Hadn’t much considered keeping the mast vertical, on this particular summit there wasn’t much other than small, loose gravel, so that would’ve been difficult. I agree that there is probably always a way to make it work though with no tension on the antenna.

Hadn’t heard the Wolf River Coil mentioned in this context before, I’ll have to give it a look. One of the bigger considerations for me is weight, I do a fair bit of backpacking and have gotten my base weight under 10 pounds and so wouldn’t mind being able to keep the radio gear under a few pounds as well. I think the KX2 + EFHW is just around 1 pound and the SOTAbeams mast is something like 6 oz, which is perfect. I’ll have to look into the weight of the Wolf River Coils antenna to see if it’s feasible for those longer days where every pound counts.

[MarkJY]

I realize you are looking for ways to support you EFHW, but just wanted to make another suggestion. Have you considered the CHAMELON ANTENNA CHA MPAS Lite? Supporting a telescoping mast can be difficult, and by the way consider fiberglass instead of carbon fiber. I’ve read the CF mast can interact with your antenna wire. But take a look at the MPAS Lite. Will need a tuner but it seems you have one in your KX2. The MPAS Lite may be a better option for you when at a location where trees are not available. Thomas has several activation videos using this antenna. I have one, but I’ve not activated with it yet so cannot speak to its performance first hand.

Mark
W8EWH

[KO4AWH]

My portable radio works is almost always POTA or SOTA. I typically carry my TX500 and a Tufteln EFHW Antenna with a throwline to get it into a tree. I have a Chameleon MPAS 2.0 and could recommend just the whip but that is not the lightest option and will require a tuner in most cases, maybe your Elecraft has the build in tuner? I fully intend to pick up a carbon fiber mast for cases such as yours but I have yet to do an activation in a spot that doesn't have at least one tree. This does seem to be a common setup when a tree is unavailable and you want to pack light. Let us know what you decide on and how it goes.

Joshua

[N4OOT]

I've use both Chamelon MPAS Lite and sotabeams tactical mast. MPAS is great, still have some issues if ground type isn't cooperative with the spike. For the telescopic mast I use a similar setup to Adam K6ARK (video on YouTube if you want to check it out). Essentially whip some loops on the mast, epoxy and shrink wrap to hold in place. Use tent stakes and 550 cord with a taunt-line hitch or ratchet style clips. If ground is tough, rocks can work. I've also used my pack filled with rocks and lashed the mast to that. Many different options, so more stable than others! Best of luck!

73s,
Seth

[Brian - K3ES]

I have used wire antennas for all of my field activations to date, including purchased and homebrew dipole, 49:1 EFHW, and 9:1 "random wire" varieties. Living in the wilds of Penn's woods, I almost always have a tree available, so a throw-line is my preferred support system (almost always using the throw line to pull up the middle of the antenna into an inverted V). With that said, I did buy a 19' jackkite pole ($40) and a 10m collapsable fiberglass mast ($100+). The jackkite pole is long when collapsed (I can use it for a walking stick), but quick to deploy. I have not yet used the 10m mast for a field deployment, but have carried it strapped to the side of my pack...

I am quite pleased with performance of wire antennas (perhaps better left as a separate topic), but have not yet tried working from a bald hill. In my mind, supporting the mast is the key to successful use. I have managed to support the jackkite pole by leaning it against trees, and by lashing it to a sign post when the throw line was not an option. I have not had to wedge a mast base into rocks, nor have I had to rely on guy lines, but I suppose either could work. I am certain others are better qualified to comment on those methods.

73 de Brian - K3ES

[KK4Z]

Two of my favorite antennas are the Sparkplug End fed and 29.5' random wire antenna with counterpoise. I use a B&M 20' Black Widow fishing pole for both of them https://tinyurl.com/393sby22. I also made a stake for the pole to make it self supporting. The pole and stake weigh 1.5 lbs. You can see construction details here: https://kk4z.com/2022/05/11/vertical-antenna-support/

I also have a MFJ 33' push up pole. I use it with a hitch mount flagpole holder. It fits the 2" hitch at the rear of my truck. You can get those pretty cheap from Amazon: https://tinyurl.com/2m69nbch.

I made a vertical form Chameleon and Buddipole parts. The last time I was out I used this vertical and my random wire antenna and felt the performance was similar.

[KN3A]

I did a SOTA trip in VA in 2021 and had one summit that there weren't any trees. I had a fishing pole that I took along and used guy wires for my random wire. Just this past weekend, I tried something different for just a regular activation - I got a spike (a tent peg) and a $12 mirror mount and put it in the ground and screwed in a MFJ 17 ft. collapsible whip and four 16 ft. counterpoise wires and it worked wonderful. That would be the easiest for me next time I do a SOTA with no trees. I also tried using my Hustler 40 meter resonator and had a lot of success with it as well. This was using QRP CW.

Scott
KN3A

[K1GC]

I do quite a bit of stuff on rock only areas, be it shoreline or mountain top, and I almost always use either a 16' or 23' telescoping mast for a support. I tend to use home made linked dipoles, but the mast can just as easily work with an end fed. It depends a bit on the geology of the area, but in most places in the northeast (and most places that I spent time out west too), the rock offers enough features to find natural anchors to support a telescoping mast. It takes a bit of exploring to find an ideal spot with potential anchor points (meaning cracks) located such that my three mast guy lines have good geometry to support the mast.

Sometimes you luck out and find natural horns, large surface stones or flakes you can tie a guy line too directly, but I very often use retired rock climbing protection for the points. It would be very easy to make some homebrew gear that would work the same way, or buy some old climbing gear on the cheap. I tend to carry a handful of tricams (pictured below), because they are simple, light and also offer a range of crack sizes per piece. Some different sized machine nuts with cord threaded through them could easily work well in many places. However, if you are dealing with featureless rock, then this is all useless.

Ocean side bluff top setup with SOTABeams 7000HDS 23' mast:

IMG_1153 (Small).JPG (151.02 KiB) Viewed 6996 times

Tricams (I usually only carry the smallest 4 sizes)

20211023_121239.jpg (87.29 KiB) Viewed 6996 times