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Choice of 10M Antenna Support for SOTA

Thanks- yes I guess just use trees except if there aren’t any. I have read that some some folks use a carbon pole to “push” the wire over a tree limb, instead of tossing weights, slingshots, etc.

And as far as I know, the carbon poles have worked fine for folks on radials- just wouldn’t be right to build a vertical.

Currently I’m leaning towards this

7.2M and very light- not too much of an investment to start out with.

Thanks all and 73
W6AHH

If you want to work 40m between 10am and 3pm you will be doing short skip contacts, which is where you can make use of the NVIS principle. And the sweet spot for NVIS on 40m is 5m exactly (1/8 wavelength). This has been proven by experience, my NEC modeling and few articles out here on the internet.

Marek

I am using a 3.3m fibreglass fishing rod. It collapses to 70cm. It is light, and was cheap (maybe about $25, I can’t remember exactly). It clips onto my backpack just like a hiking pole.

The eyelets to guide the fishing line make great attachments for the feedline and the feedpoint.

I also use a fishing rod support stake to stand it up in the ground. And brass swivels to attach guylines. Come to think of it, fishing accessories are a good source of parts and ideas for antennas.

I haven’t deployed a Dipole for SOTA above about 6ft in my last 20 or so outings… from the east coast I typically have QSO’s to AZ, NH, SC, TN. Being low, it’s easy to deploy / recover.

How quick you can set it up when it’s cold/windy… does it stay up, do you need to mess about with it to get a good match. A quick to set up antenna that is not bothered by ground changes may well be worth lower efficiency…

Wayne,
There are some cheaper options if you are willing to wait for shipment from China. Try searching for “Telescopic fishing rod” on banggood. Results include:


With the lower prices, you can afford to buy more than one unit, just in case you managed to break one later in a high wind situation. Specify one of the longer lengths when you order - I have been using some 7.2 m poles, but the top metre is too flexible to hold an inverted V but might be OK for a light vertical wire.

Peter VK3PF

Yes it is perfecly fine to have antenna as low as 2m, but what has to be noted is that you are getting substantial amount of attenuation by ground proximity.

If you have the antenna 1/8 wavelength high, so on 40m band it is 5m, you are getting NVIS patern but not much loss. If you go higher, the elevation agle gets lower and you will get closer and closer to freespace pattern and gain. If you go lower you are getting more and more ground attenuation.

That is the theory, you would say, because you are making contacts - yes you do, but maybe you work only 50% chasers you could have worked if you had the antenna at 5m. Of course this might not apply in countries with low chaser density, so you maybe work them all no matter what your setup is, but in Europe where you can easily make 20-40 chasers in half an hour, it makes a difference.

To support this, I give an example: When I activate SOTA with kit transceiver running of low sensitivity NA612 mixers and having no preamp, I work about 10-15 chasers. With my KX3 I am getting 20-30 chasers on average. But if there were only 10 chasers out there, I would be likely to get all 10 on both setups no matter how I improved my station. So during your field test consider if your sample is statistically sufficient.

But dont get my wrong I have nothing against low antennas, it is only about what are your expectations. If you want rapid-deployment (RADAR) and do not care about how many contacts you make as long as you activate the summit, this is the way to go. But if you are like me and enjoy little pileup, at expense of setup taking longer, higher antenna is way to go. We should say all the facts and let everyone decide what are their expectations.

Lastly, a bit of reading on the NVIS height topic with a graph:
http://www.w8ji.com/nvis_n_v_i_s_antenna.htm

Marek

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I haven’t seen a significant reduction in the number of QSO’s logged since I have moved to a very low dipole. I have also experimented with a wire reflector at +5% length to the radiator with little increase in the signal report.

Without too much thought to the matter, I seem to always make the required number of QSO’s to activate, I consider the quality of the chasers equipment to also be an important consideration. While the activator may deploy a compromised system, the chaser (usually) has the advantage of antennas at good height, gain antennas, base station rigs (with good receivers), and significant power on TX.

I just spent a few days in Colorado, If I lived there I would be using a push-up pole most of the time operating above the treeline. Traveling there with my usual 'east coast" radio kit, I didn’t have a pole with me. Each activation seemed even more compromised… I did 5 SOTA activations, KX3 on 5w, link dipole. Lowest signal report I gave out was a 57.Lowest received was 3x3. Didn’t take the reflector. One activation was only on FM. I made 45QSO’s on the other 4 activations. I spent a total of 130mins of operating. 40m band did seem “dead”, 90% of the contacts were on 20m

East coast, in the forested dense summits of the North-east it’s just too much trouble to mess with trying to deploy a link dipole using trees to 30feet. 15ft is possible and as data suggests is probably a reasonable compromise for the future especially as band conditions deteriorate further.
Good discussion, thanks for sharing your thoughts and data.

Richard // N2GBR

Hi Peter unfortunately both the links you give come up with “Sold Out Currently!” for all lengths.

FYI Wayne - when you have a pole that the top section is to flimsy to support a dipole, you can simply unscrew the bottom of the pole and drop out and remove the centre section or sections. Hence a 7.2m pole might be a strong support at around 6m. Removing the unused sections will reduce the weight to be carried marginaly. If you simply fasten or drop the dipole support down to the lower and stronger sections and leave the weaker sections in place, you can attach a SOTA flag to those upper sections.

In any case don’t expect to be able to support the centre of a dipole at the full height of a fishing pole unless it is specified as a heavy duty pole.

Ed.

Hi Wayne.

My advice is to accept that sooner or later you’re going to break stuff. With that in mind you might prefer not to spend too much, especially before you know what suits your style. Also, in high wind you might be put off extending that $$$ pole fully and miss some QSOs. There are some pretty good fibreglass poles around, and I’d have thought a local sporting goods supplier would be able to help.

As for carbon fibre, I’d like to measure just how good an RF conductor these are. Carbon fibre is often used for parabolic reflectors for mm-wave in my line of work and I’m told this makes a fairly effect mirror before they add the aluminium coating!

I’ve been using 5m fibreglass poles for a long time. I still have my first pole in good condition and have used it since December 2006! It cost £5/$7.50 in 2003 :wink: It supports a dipole in inverted-V for 60m/40/m/30m or a vertical for 30m/20/m/17m/15m/12m/10m (loaded on 30/20m).

I have a 6m and 7m fibreglass poles to try but just haven’t got round to using them yet.

Important pole deciding questions are how long/rigorous are the summit hikes you want to carry it on and what kind of antenna will it be supporting?

I own a variety of poles, from flyweight carbon poles to the hefty, but fairly compact, Sotabeam 10m pole. They all work well depending on the application.

73, Barry N1EU

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Very good point, for example the DXWire poles are rugged but bit heavy to be carried for long walks.

Marek

I have an 8m pole which supported a 0.64lambda 10m vertical. It was significantly heavier than my 5m pole and in addition I had a 50W 10m PA with me as well. The extra weight of the pole, PA and extra battery was very obvious.

Choose carefully unless you have a porter to help carry the gear.

The 10m DX-Wire Mini-mast is not too heavy to carry (1.3 kilos) and relatively short when collapsed (also sold via SOTABeams by the way) but it is still twice the weight of the 6m (shortened to 5m) no-name pole that I bought at Friedrichshafen 3 years ago for €30 if I remember correctly. So far I have used the 5m pole on about 95% of my activations and only used the 10m one on 5% when I really needed it to get a longer (e.g. 80m) antenna out.

I’d definitely try to team up with another activator for your first activation Wayne, use their gear and discuss with him or her what they would recommend for an antenna support.

Ed.

The more replies … the more poor Wayne will get confused :wink:
But here we go :
I use this 6m fiberglass pole from Decathlon (sports good store in Europe), cost 15€ (17$)

If folds down to 58 cm so fits nicely on the side of my backpack , and weighs only 556 gram.
(I see it was on sale for only 5€ now, should have bought me some more !
https://www.decathlon.de/angelrute-telepocket-s-600-id_8044451.html )

I have used it as a vertical (5m radiator and one 5m radial above (not ON) the ground), but lately I only use my homebrew link dipole for 40-6m.
I don’t use the two top sections , so center of my dipole is around 5m above ground, the ends are abt 1m above ground. It must work very well, since I made 100 QSO’s in 1h15m on my last trip … all on 40m !
Read my report here :


it contains several pictures where you see the pole in action, and on one picture you will see a yellow “thing” in the background, that is a plastic cup with a 25cm steel pin, it keeps the pole up without guy lines (it’s also a fishing accesory from Decathlon), and fits in my backpack. I only use the dipole, nothing else, to keep the whole thing up.
If I can’t get the pin in the ground (happened very few times) , I use some bungee cords or other solution.
73 Luc ON7DQ/KF0CR

Yep that one shows out of stock at €5 - the nearest I can find at €14 is this one:

I use my 37 inch telescoped crappie pole as my walking stick until I set it up as the antenna.

Lenght can be a feature. And they only cost $20…

Pete
WA7JTM

I find that a 5m or 6m travel pole fits inside your average 38L 60cm rucksack. It is light, hidden from others when walking and more than adequate for supporting a link dipole for 40m and up. Some use a similar length pole for lowerr bands than 40m even. I would only consider carrying a 10m pole if I was going on 160m.

73 Phil

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I use my 10m for supporting 17m and 20m verticals. The same as Phil regarding dipoles. I hope to do 160m this summer.

Normally I use a 7m pole which is fantastic for general activating,

Jonathan