I knew the qrpkits antenna was coming.
Think about all those dolphins, turtles etc.
Heavier than a plastic bag 
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If Dolphins are so smart why do they keep getting caught with dumb Tuna?
To get back on topic… remember you can tune an aerial but you can’t Tuna fish.
(With apologies to the Regents of the University of California and the 4.2BSD docs. )
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I am now thinking the sota green team may “only operate in sunshine”, leave no trace, only use solar and not pack a fish n chips (or eels for Bath) for lunch on the summit
Thus the only antenna that can be used may be a wire on a balloon
Hi all,
Actually, I am pretty confident that the most recent EFHW Hybrid (traps + links) antenna described by Heinz, @HB9BCB is very close to the best of SOTA antennas. It uses traps for no-frills tuning for 40, 30 and 20m, and two links for 17 and 15 m and thus covers all MTR-5B bands. In an inverted-L configuration, it is rather compact and easy to set-up, independent of the quality/type of ground, and very lightweight. It can be used with lightweight carbon-fiber masts without detuning. The inductances of the traps have a moderate loading coil effect, thus the total radiator length (+ cord) is ca. 16m. The included 1:64 matchbox makes it directly usable with MTRs and other QRP radios without a tuner.
Many of the other antennas recently discussed in this forum, IMHO, are inferior to this design. For instance, the QRPguys trap dipole is heavier and covers only two bands, the “no tune end-fed” is single band, etc.
I really tried many different SOTA antenna designs in the past two years, and Heinz’ design is so far the best of all worlds. The only reason I am continuing with my experiments is that (1) it is fun and (2) the inverted-L is too big for a few very small (or crowded) summits, for which I seek a robust and lightweight vertical.
73 de Martin, DK3IT
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Activations don’t often start in the pouring rain …
… however, more Activations than I’d like seem to end that way. 
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This side of the pond you live with the perpetual threat of rain, and even if it isn’t raining as such you are often in cloud and getting wet with condensation.
Yes, this fact I had to consider in the design of my EFHW impedance couplers, in order to also meet the requirements of typical all-weather SOTA enthusiasts, such as e.g. Jürg HB9BIN, hi.
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Well I have the kits built and tested. I followed the instructions to the t.
The vertical works excellent. I had no issues with swr, although for 30m leaving both switches on 40m provided the best results. Reverse beacon results were respectable on all bands. I will probably increase the number of radials to 8 or even 16 for a little better performance.
The ununtenna, despite the increased amount of radiator, was a much more bulky system and didn’t seem to work as well. Swr was off the charts on some bands (except for 17m for some reason). I honestly not that happy with it, even though the kx3 could tune it. I tested it against the vertical using the rbn on 40 meters, and they were comparable.
Both kits were fun to build. I also have the EFHW tuner and I still have to comment on the antenna attachment system, which is a bolt nuts and a wingnut. I have found just following the instructions is unsatisfactory. The system loosens itself up and falls apart in the field. I now use loctite threadlocker blue on all qrpguys wire attachment points. Just use enough to lock the nuts, but not cover the threads where the wire contacts or the wingnut travels. This eliminates the issue and increases enjoyment.
As much as I like the Pacific antenna trap dipole kit, the qrpguys vertical covers 30m too and is lighter and more compact. I will probably give it 4 more radials as the size/weight 26 awg wire isn’t an issue and give it a chance on my next activation.
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The QRP Guys no tune EFHW has an add to cart button where the coming soon text used to be, so I ordered one.
The assembly manual and description mention no counterpoise being used, as the feedlines acts like one. It will be interesting to see how hot the chassis of the kx3 gets.
The torroid is another new one for me. The directions look very specific to aid the winding process.
Evan
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That antenna and varients of antennas similar to it is already being discussed in a parrallel thread on this reflector here:
http://reflector.sota.org.uk/t/interesting-new-sota-vertical-antenna/16885
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I know about the thread for the vertical, please note this discussion is about multiple antennas, including the pacific antenna trap dipole, the ununtenna, and the no tune end fed. I posted my thoughts on the vertical in your thread already Ed.
I will add a picture of the built qrp guys no tune EFHW antenna kit and the 30/17m dipole from Pacific Antenan after I receive and build them, along with first impressions.
IMHO, if you’re going to do a loaded vertical wire, it would perform better with air-wound loading coil up as high as you can still reach (~6M), off the ground. A vertical with toroids at the base isn’t going to be better than just feeding the wire into your KX1/KX2/KX3 antenna terminals/ATU. Assuming this isn’t a resonant antenna, I don’t see the advantage of its design?
73, Barry N1EU
I thought it was for operating without a tuner Barry.
Barry,
The antenna is designed as a 1/4 wave on 20 meters. It adds the ability to use that antenna via switching at the antenna base.
A set if airwound coils is also larger and heavier, and weighs down the tip of a 20’ crappie pole like the one I use for sota activations. There is some sacrifice to 30/40m performance for convenience and portability made with the design but I’d imagine these are minimal in the grand scheme of things.
Hi Barry, if you are referring to the QRP Guys antenna - it is resonant on three bands - one without ferrite cores (20m) and two with either one (30m) or two(40m). So no ATU needed and hence of interest to those with rigs that don’t have an ATU built in.
OK on your point Evan - I just wanted to ensure that other people reading this thread who may be interested in the QRP Guys antenna, know there is more information/discussion in the parrallel thread.
Finished mine by the way - just have some tuning of the toriods to do, to get it right on my 20/40/60m version.
.
73 Ed.
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If they were traps that shortened the radiator it could be considered resonant on 3 bands. But they’re loading coils on those bands so it’s only resonant on one band.
I keep coming back to questions about this. I have a kx2 with a tuner. Is there an advantage in using a loaded vertical (like the qrp guys one) vs. just running the end of the a 17’ vertical wire directly into my radio? Wouldn’t my radio tuner essentially do the same thing as the torroids?
OK, technically correct - what I should have said was it has a low SWR (looks to be around 1.2:1) on three bands - hence no ATU required.
73 Ed.