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[GEORGEMINK]

I'm putting up an end fed non resonant antenna in my back yard next weekend.

Fed with a 9:1 unun. I can either put up a slopper fed from the bottom of the pole going up 25' and then running out and back down to my privacy fence post so sorta an inverted "L" with 107' of wire. Or I can put up 2 supports and run 135' of wire at 25' in an inverted "U" up 23', over to the other pole 92', and then back down 22'. I live in a HOA and might not be able to get away with the 2 poles, but I'll try! lol I've had a vertical antenna up at 21' for a couple of months now and nobody has said anything so I know I can get away with the single pole.

Since I don't have an antenna analyzer I'm just wondering if any KNOWS how the inverted "L" or "U" configurations affect wire length. Typically would it need to be longer or shorter than the known lengths that are non resonate of 107' and 135' that I plan on using.
 

[W7XTV]

Buy an antenna analyzer before building this antenna (or, really, any antenna).  Don't guess.  Know.  You'll know exactly what your R and X are on each band at the coax feedpoint, and can figure things out accordingly.  All homebrew antennas are unique,regardless of how similar to someone else's setup might be.

And don't forget a good ground system.  Treat a non-resonant end-fed non-resonant wire like a vertical.  Lots of in-ground (32 or more is preferable, as long as you can make them) or resonant above-ground radials, preferably 2 per band.

But if you can run 135 feet of wire, why not shorten it a bit and use it as an End Fed Half Wave with a 49:1 unun?  That eliminates the need for an extensive radial system, and it'll work on 80 thru 10, including WARC bands.

[W1VT]

EZNEC is now a free download!  It can be used to model the different options so you can chose what is best for your needs.

[GEORGEMINK]

EZNEC is now a free download!  It can be used to model the different options so you can chose what is best for your needs.

I did not know that! thank you!

[KA4DPO]

Just build an L-network tuner on a piece of wood.  All you need is a tapped, or variable inductor and a variable capacitor.  No guesswork, no lossy transformer, and no RF all over the shack.  Use Ebay, hamfests, wherever to get the parts, and it is pretty inexpensive.

[N6TTV]

In my experience using 9;1 unun  with non resonant end feds the most important thing is length of the wire. 41, 55, 83, and 107 are good. Avoid 135 since that is a half wave length on 80m. If you want to use 135 ft go to a 49:1 unun. I have made a lot of contacts using those lengths with a short counterpoise  thrown on the ground. Palomar Engineers has a whole pdf on their web site about these antennas. 73, Carl, N6TTV.

[N8NK]

I've spent two years documenting the work I've done with Multi-Tap UNUNs with end fed antennas. It's all on youtube if you'd like to see. I gain nothing but pleasure in trying to inspire others to build antennas. My channel is not monetized. No ads.
I'm Chuck, N8NK, and my youtube channel is called: N8NK QRP
A link to the 'EFHW & UNUN' playlist is:  https://www.youtube.com/watch?v=lTb3sFydpPQ&list=PL3CPduOS04Ncrid9dWw-p5fWFQkvMLKIi

[K6CRC]

No where near an expert here, but I have a system that works.

Inverted L from one corner of lot to a support halfway up the other side of the lot.
GigaParts 31ft push up pole in the corner
84 ft of wire (WireMan 26ga copper coated steel antenna wire), about 30 ft up, and 54ft out to a 15ft re-used TV antenna support on the other side.
At base of pole, 8 radials in a 90 deg pattern, 8-20ft long.
BalunDesigns 9:1 Unun connects antenna wire to radials and feed line coax.
Run of LMR-400 to my office/shack. Line isolator, important to keep RF from shack, then 8ft of LMR-240 to my IC-7300.
Info on BalunDesigns website give best/proper wire lengths for these types of antennas.

Using internal tuner, get low SWR on all bands, except 80M. Use the 'Emergency Tuner' feature in the 7300  to match antenna, but with reduced power <50watts

Works well, have 9 band WAS and 250+DXCC contacts. Not very efficient, I realized, but short of a divorce-inducing tower/beam the best I can do.

Recommend buying a quality Unun. I have several home brew ones, but BalunDesigns worked the best.

Check out their website for information on antennas such as the one I use. A great resource.

www.balundesigns.com

[W7XTV]

Just build an L-network tuner on a piece of wood.  All you need is a tapped, or variable inductor and a variable capacitor.  No guesswork, no lossy transformer, and no RF all over the shack.  Use Ebay, hamfests, wherever to get the parts, and it is pretty inexpensive.

The problem with L-networks in the shack isn't necessarily excessive RF from your own transmitter, although that's certainly possible without proper grounding.  The biggest problem is bringing the antenna wire into your house, where noise from all your digital devices will be all over the bands.  That's one main reason why a 9:1 unun and the end of the wire are put outside, as far from the house as possible.  I've used both methods and find the unun preferable, even though it isn't as efficient.

Of course, you could build the L-network into a weatherproof box and install it outside in place of the unun.  Losses solved.  Trouble is, it would require going outside to change bands -- not fun this time of the year in most areas of the Northern Hemisphere.  An automatic ATU would fix that problem, but I find it rather silly to spend $500 to tune $10 worth of wire.  I'll stick with the unun.  Losses aren't that bad (1 dB or less) on all bands other than 10 and 12 meters.

[GEORGEMINK]

Thanks for all of the suggestions and feeback.

So I had to Nix the two pole setup, going with the single pole and the 107' "L"

[K6CRC]

Should add this.
I had a MFJ remote tuner, with and without a 4:1 Unun before.

Advantage of the remote tuner was some increase in efficiency and the ability to run 80M with full power.

Seemed that I was constantly retuning the MJF.  It worked as it was suppose to, Factory checked it out.

Just for this set up, didn't make much difference in performance. Others may have had difference experience.