End Fed antenna configuration

It’s really no biggie. Just order some toroids and enamel wire. The 49:1 and 64:1 variations tend to use the 43 mix (FT240-43 or the smaller FT140-43). The Earchi 9:1 unun uses a T130-2 toroid. Buy a few of each. Buy several of the FT240-43. They are especially useful for 1:1 and 4:1 transformers. Get some 18-20 ga. wire (enameled or plastic insulation) and some zip ties. You can put it in a box, or you can saw out some winders from plastic cutting boards and zip-tie the toroids to the winder. That’s what I do.

There are few things as satisfying as using things you’ve built with your own hands. I built a QCX Mini last week and it’s been tons of fun. I built a W3EDP “Junior”, with a 1:1 and a 4:1, along with some 300 ohm twin-lead. It tested fine in the back yard, so now it’s in the go-bag for my next portable op.

Cheers!
Steve

Thanks. I will have to look into that. I have made choke baluns on different toroids but never studied making a transformer.

Great photos on your site.

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Brent,

Here’s the low-down on how to do it really light, and still make lots of contacts on many bands, on high peaks without trees, etc.,

  1. A 16-foot pole is OK. I use a “7M” pole, sometimes fiberglass, sometimes carbon. Whatever you choose should not weigh more than 1 pound.

  2. Use an inverted-L configuration. You sit near the bottom of the pole, and the fed end of the wire runs up the pole, but it’s spaced away from it by several feet, most of the way up to the tip. The wire’s tension bends the thin upper segments of your pole out sideways, so very little of the wire runs close to carbon fiber. Let the pole bend as it will. Forget the doubters - carbon is great, it’s light, and it’s elegant!

    2A) Use thin wire - I use #24 AWG teflon stranded. Heavier wire overloads the pole and is a disaster!

  3. Run the wire out horizontally, or even sloping down, to whatever you can tie to. On alpine summits high above treeline, this may be a pile of rocks, a rock outcrop, or a hiking pole.

  4. Mostly I use 65 feet of wire (total). This is a half wave on 40M, full wave on 20M, 3/2 wave on 15M, etc. You can use a shorter wire as long as you can match it. Sometimes I use 52 feet with my tuner.

  5. I use a homebrew tuner that can match my wire on all bands 60-40-30-20-17-15M. Using it is really easy, but building it was challenging. There is an old post on here about my tuners. Mostly I don’t use or need a counterpoise, but it’s helpful on 60M. I use 12 feet. With shorter wires, you may need a counterpoise.

  6. The KEY POINT is that you can guy the pole much easier than you can carry any kind of tripod or other supports.

    A) As you extend your telescoping pole, wrap a thick rubber band - or 2 - several times around the pole, so it will be 5 or 6 feet above the ground, once the pole is up. On my poles this is usually the top of the third segment. It must be snug, so it won’t slip down.

    B) Lay out three strings or cords on the ground - I use braided dacron about 2mm diameter - each 15-20 feet long. Lay them roughly where they will be when the pole is up. Experience will guide you after a few times.

    C) Tie at least two of the strings around the pole, above the rubber band(s), with the pole still on the ground.

    D) Gather a few rocks to place around the base of the pole, so it won’t get pulled sideways once the pole is up and under tension.

    E) Tie two of your guy lines to rocks located 12-15 feet or so away from the bottom of the pole.

    F) Attach your wire to the tip of the pole. I use a fishing snap-swivel - it’s so easy.

    G) NOW raise the pole, and adjust its position so it will put some tension of the two lines that are
    already tied to rocks.

    H) Now you have a choice - do one of the following:

    I) With the pole standing, holding your antenna wire, quickly pull your wire out in the direction toward where it will be tied. If you are quick, the pole will stay under up and under control, and you can tie off the far end of the wire. This may be all you need, or perhaps you may need to adjust the rocks at the bottom of the pole, or adjust either of the two guy lines. This method is fast, but it works better if wind is light.

    J) If the wind is stronger, tie a third guy line above the rubber band, before you raise the pole.

    K) Raise the pole, and run the third line out to where you plan to tie it, and tie it off so the pole is standing OK.

    L) Adjust the rocks at the pole base, so the pole base will stay put and not swing out under tension.

    M) Take the string tied to the far end of the antenna, walk out to where you plan to tie it, and tie it off. I use 15-20 feet of small dacron line, sometimes much more, so I can choose from the available supports. These are often just rocks, or cairns. Don’t worry much about how high the end if the wire ends up!.

  7. Make any adjustments needed, tune up your antenna, and get on the air!

All of this is easier said than done, but practice makes perfect. You can put up a guyed pole in strong winds that will make the wire sing, and the pole dance and moan! High winds mean more attention to detail is needed. In particular, choose a spot with less wind, hopefully not right on top of a windy peak. Set up downhill, in the lee, even in the rocks 50 vertical feet down! You want to stay on the air and be comfortable! On HF you will work many stations seemingly through the mountain!

The more you do this, the more you learn how to get by with less effort! Some guys slope the pole at a low angle, and just use rocks to hold it up, no guys. This works OK too, and it’s quick.

If it’s really rough, use only a few of your larger pole sections, and use 3 short guy lines. Try to get part of your wire up 10 feet. Only a part of the wire need be above the ground, or above the rocks. In really high winds like we have above tree line, around 3600M here, you may have to put rocks ON TOP OF YOUR WIRE to keep it under control. With a tuner you can still get a good match, use several bands, and get amazing reports, never mind that the antenna looks like a joke, with much of it hardly elevated at all!

After doing it a few times, you’ll wonder why anyone would do anything else. It only takes a few minutes, even on a pile of talus. Remember that at high altitude, for SOTA, less is more.

With an end-fed and a tuner, you don’t need more than 2 feet of small coax from the radio to your tuner - NEVER MORE!!

The bottom line is that all you need to guy your pole is a few small braided lines and a couple of thick rubber bands, and some rocks you find on your summit.

73

George/Carey
KX0R

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You might find that the end-fed wire will indeed hold up the pole conveniently.

The description of this end-fed antenna from Sotabeams shows a reliable method of deploying one using a fiberglass pole without strapping the pole to anything solid. Take a look at the diagrams under “typical setup.” The main difference from your inverted-L configuration is that the radiating element forms two out of the three guy lines necessary to hold up the pole, with the third being a regular guy. Your operating position would then be close to the end of the radiating element “guy” rather than at the base of the pole.

For my setup I’ve replaced the small insulator that attaches the wire to the pole with one of these guying rings. I have then tied a regular guy-line to the opposite side of the ring from that to which the antenna wire is attached. Deploying the antenna is as easy as pegging out the two ends of the radiating element (allowing sufficient slack for the height provided by the pole); lifting the pole and positioning it so that those two “legs” are taut; and then pegging out the guy-line to hold everything in place.

I think this would work with an EFHW antenna. You would need some means of pegging down the wire at the point it exits the transformer box, and you would then use a short piece of coax to connect to your rig.

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This has a lot of helpful information George. Thank you. I am going to be reviewing it further. I especially like the process for guying. Rubber bands sounds like a great idea. Icicle hitches are to cumbersome on a peak. I have some very thin Dyneema line that I am going to use. I discovered my pole for this application is 6 meters and less than 11 ounces (Sotabeams) but I do not use the top section.

I do not have a tuner for the qrp rig and have studied your tuner design before—that’s probably beyond my capability right now in truth. But at least now I can quickly change between 40/20/10 bands now. Some of you are very nimble at that. I never have been.

Thanks Richard, I will look at that too. One thing I like about V configuration is it get the high current portion of the antenna at the apex.

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The Emtech ZM-2 tuner is a great choice. It’s not too big or heavy and it’ll match almost anything. From a bit building perspective, it’s quite easy.

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[How to set up an antenna on a barren mountain]

My idea for such summits is to leave the pole in the backpack, extend it with the feedpoint at the top (coax cable going down to you, the backpack and the radio) and to weigh down the far end of the wire e.g. with your water bottle (the wire suitably extended by rope so as to have a minimal height above ground - I try to have it 1-2 ft above ground at least). As you can only extend or retract the pole and have to stabilize it yourself at all times, you’ll have to lay out the wire / rope / guying weight beforehand, estimating where to place the weight. Too far away, the tension on the pole is too high, too close, the wire will be limp or on the ground.
The pole leans against you or over your shoulder. It should be as vertical as possible with as little pressure on you as possible, but not fall over either. The radio is usually - in my setup - on the backpack.

I tried this already once on an uncritical hill were I could have done it “the proper way”, in expectation of many barren hills to come (but so far, none yet :slightly_smiling_face:).

Does it work? yes
Is it comfortable? no
Does it look ridiculous? absolutely

Hope this helps.
73 de Martin / HB9GVW

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Interesting, that would get me on additional bands. Great, something else I have to buy! And put together!!

Hi Brent,
Most of the times I activate with an endfed wire to a 9:1 unun and a counterpoise wire.
Some few times I’ve setup as inverted L with even an inverted L reflector.

Some few times I’ve setup as inverted vee:

and most of the times I setup as a sloper like this when there are no branches around:

and like this when there are:

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The PAR is kinda heavy. I use a home made efhw using #28 teflon wire. If you make the wire 68 feet long, then attach a two foot stub hanging down right in the center of the wire, you can adjust the length of that stub (will be about 18 inches) for resonance on 20M, and do away with the heavy trap. The stub will be ignored on 40. Have never had any trouble mounting wire inverted-L and then leaning pole against anything, or bracing it in a pile of rocks. EZ. As for five watts, that’s fine. Can work world wide with five watts and an EFHW on CW if band is open. GL 73, Fred KT5X / WS0TA

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First off, you can make the same antenna much lighter. I have been using #28 teflon wire for years without failure. Make the wire 68 feet long and resonate for 40M. Hang a 24 inch stub from the exact middle of the wire, and trim it for resonance on 20M. 40M signal will ignore the stub. 20M needs the stub because it is a fullwave with only two ends, so the end-effect shortening doesn’t apply to one of the halfwaves. Next comment, a pole with carbon in it will detune the wire a little IF the wire runs very close to the pole, but no evidence it diminishes signal radiated. Wire does NOT need to be high when on a mountain peak with the ground sloping steeply away from the antenna. Antenna likely thinks it is very high. I skip coax entirely. It is heavy (forces a heavier than needed pole to support it), cumbersome, and may contribute some loss. Since I am located at the end of the antenna, and the end of an EFHW has no current, I just plug it in directly using the first few feet of the wire as the feedline. An inverted-L configuration puts some of the radiation on the top of the vertical leg, for low angle take-off angle. My antenna weighs two ounces including the winder. My pole weighs 8 ounces, is 17 feet tall, and collapses to 18 inches. Set up time is five minutes or less. Five watts with decent conditions can be heard around the globe. GL 73, Fred KT5X / WS0TA

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I have linked dipoles [60/40/30/20 and 20/10/6] and EFHWs [40/30/20 and 40/20/10]. For everyday [i.e. non big event] HF activations, if I’m not using my new Chameleon MPAS Lite vertical, I usually take an EFHW.

I do not favour the situation where the wire antenna itself is acting as 1 or 2 of the pole guying ‘cords’. Despite having more benign weather than many parts of the world, the regions I operate mostly from [in north-west England and SW Scotland] often have strong and blustery winds especially in winter. I found it stresses my thin-wire antennas at the connection to the balun and links.

So, nowadays I use 3 or 4 guying cords for the pole which means I can ensure the antenna wire has a bit of slack in it. I’ve had no problems after many activations since. The extra weight / volume is nothing and – in very strong wind – it can actually be quicker to erect the pole and tether the end(s) of the antenna separately.

I always use 10m of RG174 coax feeder. The pole or far end(s) of the antenna are rarely somewhere I want to sit. The feeder gives me some flexibility as to where to operate especially in winter. I want to sit in some leeward shelter from the icy wind even if that’s in the heather. The RG174 attenuation is small at HF and is small and lightweight.

73 Andy

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Love this discussion, great insights from all, thanks

73 de Geoff vk3sq

Now that field day is over and I have caught up on work: thank you all. There is a tremendous amount of experience here and it is very helpful for me and I am sure others.

There are some future projects I have added to the list and, more immediately, some antenna, cable, and set up work I need to do over the next couple weeks before my trip.

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I tried the Par trail friendly end fed at the park to cut to frequency and try to contact some activators. No good. The instructions say to adjust for 40 and 20 would fall into the correct frequency. I could get 40 but never remotely close on 20. I changed from an inverted L to a V and saw a significant disparity so SWR was unworkable. Same problem with 20 after adjusting 40.

Fred was correct, the trap is too heavy. And clearly the 20 section is too long or there is a problem with the winding. An antenna where the frequency shifts so drastically based on common configurations is unworkable for SOTA. I know some people use them but this one will not. In any event, I don’t have time to make my own before the trip so will only have 20 and maybe 15. I wanted 40 for closer chasers and early/late activations but maybe next time.

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Brent,
This might help and only requires some wire and 3/4 inch pvc pipe (approx 1"OD).
Remove the radiator it came with and cut a new one for 20M and tune it. Then use about 3 inches of the pvc pipe and wind a coil using enamel wire (22 - 26 gauge) for 50 closely spaced turns. Attach one end to the 20M radiator and the other to about 7-8 feet of wire and tune for 40M.

I have made a few of these and they work well and end up at about 40 feet long. Yes, 40M is a bit narrow but you can tune for your preferred section of the band.
NOTE: This is not my design, it was shown on the PAKTENNA website - they deserve the thanks for this.

Hope this is doable for you Brent and if so that it works as well for you as it did me!

73,
Howard KE6MAK

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Love the idea of rubber bands to hold the guy wires. So simple and effective.

Fred. What pole do you use? Thanks