Long wire not straight.

Wanting to put a longer long wire up but have a small garden
At the moment i have a 10m length running almost North to South and it works well.
Wanting to put a 20m length up but it would only go like a reversed 7 but the extra would be running almost East to West.
Would this work would it be ok.
Thanks in advanced.

I have found nothing beats more wire in the air.

I was running a shortened (23m-ish), loaded, 80-10EFHW and in addition to 80m bandwidth being non-existent, I wasn't really happy with my signal reports or incoming signals.  Keeping everything else the same, I changed to 40m of wire for a full length one, dog-legged at 90 degrees at the end of the garden, and everything improved dramatically.

Thanks for the reply.
What i was bothered about was the shape it would have to go like a 7 backwards.
Don't know if it would be firing at each other if you get what i mean.
Not into making aerials but hope to succeed lol.

Learn how to model antennas in software like EZNEC or one of the free versions and do azimuth and elevation plots modelling it over simulated real ground. It'll give you an idea of how it should perform and you can then build it and compare.

Northern Crusader wrote:

Learn how to model antennas in software like EZNEC or one of the free versions and do azimuth and elevation plots modelling it over simulated real ground. It'll give you an idea of how it should perform and you can then build it and compare.

If i had the garden size i would try to experiment but i haven't.
Also i am disabled so that put's a limit on what i can do.
I think i will just try it but it can only go one way and that would give it the reversed 7 so no 90 degree more like 80 or 75.
Plus to old to start learning new software the gray cell's don't absorb much anymore.

How much can you get down the length of the garden before you need to bend it?

There are plenty of completed models out there for the EFHW, for example, and you could grab those and the software used and simply change the wire orientation....BUT remember with a multi-band antenna, the [pattern changes per band, as the effective height above ground changes relative to wavelength.

A good place to start reading is here.....but personally, for the cost of the 20m of wire you're talking about, I'd grab a mate you can get some signal reports off on your favorite band, where you're not always a 59, put the new one up, and try it again...that's what I did.

https://www.qsl.net/kk4obi/EFHW%20Straight.html

https://forums.qrz.com/index.php?threads/efhw-antennas-radiation-patterns-vs-frequency.692671/

I appreciate a disability is going to make this more of a PITA than for some of us, but that's why we have mates! 

Still on the 10m long bit of wire but it IS working.
Just had a qso with ke55ee in Pensacola Florida on the 20m band.
Do i need to double the length lol might try it but will save the old 10 meter length.

I have an end-fed wire 20m long (ostensibly a 40m end-fed half-wave) which is configured very similarly to yours. I’ve used it on all bands from 160m to 6m with considerable success - I’ve been heard in Japan on 160m, in the USA on 6m, worked Market Reef on 160m and Australia on 30m - all with no more than 40 watts. It runs south-east to north-west for about 50% of its length disguised as a washing line (!!) and then north to south for the other 50% stapled to a wooden fence, and is only about 1.5m above ground. Hope that gives you some encouragement to try your wire!

G0RQQ wrote:

I have an end-fed wire 20m long (ostensibly a 40m end-fed half-wave) which is configured very similarly to yours. I’ve used it on all bands from 160m to 6m with considerable success - I’ve been heard in Japan on 160m, in the USA on 6m, worked Market Reef on 160m and Australia on 30m - all with no more than 40 watts. It runs south-east to north-west for about 50% of its length disguised as a washing line (!!) and then north to south for the other 50% stapled to a wooden fence, and is only about 1.5m above ground. Hope that gives you some encouragement to try your wire!

Are you running an end-fed with a 9:1 or a 49 or 64:1 as you would for an EFHW, or something else entirely?

I ask because 20m is roughly a half-wave on 40m, which means you'd have several thousand ohms of impedance there that a 9:1 would struggle to match with any normal tuner, but if you ran a 49:1 or similar, I'd love to know how you were getting 80m matches (Or 160m) as typically EFHW's won't give an efficient match on anything lower than the fundamental frequency they were built for through a 49:1.

I've run full length and shortened/loaded 80-10EFHW's, and they won't work on 160m, as they effectively become a quarter wave on that frequency, presenting low impedance making the 49:1 useless as a matching transformer.

Prior to that, I was running just a random wire into an AH-4 tuner, and whilst it tuned everywhere, it was way less efficient than the EFHW I have now.

Could get interesting.

My wire is fed via a 49:1 Balun which is earthed via several copper rods driven into the flower bed. I can get a good match 160 - 6m using the internal tuner on my FT-920, which in itself is a surprise as built-in tuners are normally not too brilliant. I think it’s a case of what I call the “Bumblebee Effect” - according to all the laws of aerodynamics the bumblebee shouldn’t be able to fly; the bumblebee doesn’t know that, so it carries on flying. Similarly, my antenna doesn’t know that according to antenna theory it shouldn’t work, so it just carries on working!

G0RQQ wrote:

My wire is fed via a 49:1 Balun which is earthed via several copper rods driven into the flower bed. I can get a good match 160 - 6m using the internal tuner on my FT-920, which in itself is a surprise as built-in tuners are normally not too brilliant. I think it’s a case of what I call the “Bumblebee Effect” - according to all the laws of aerodynamics the bumblebee shouldn’t be able to fly; the bumblebee doesn’t know that, so it carries on flying. Similarly, my antenna doesn’t know that according to antenna theory it shouldn’t work, so it just carries on working!

What length is the wire ?.

21.5m - roughly a half-wave for the 40m band. 

I keep thinking about experimenting with other lengths, but always come back to the old saying: “If it ain’t broke, don’t fix it!”

At my previous location I had a wire loop in the attic. A friend and I installed it by simply putting down enough wire to go around the complete perimeter (I’ve no idea what the final length was) and then connecting it via a Balun of unknown ratio to the coax to the rig. Between that antenna and the current wire in the garden, since 2012 I’ve worked 94 countries of which 28 have been on 6m, 108 four-character grid squares on 6m, 28 US states, and 6 Canadian provinces, all with 40 watts or less. I also have “1000 Miles per Watt” awards from the QRP ARCI group in the USA for 40, 20, 17, 15, 12, 10, and 6m all with 500 milliwatts of SSB. 

I haven’t posted this to boast, more to demonstrate that even with compromise antennas you can still have fun and work some good Dx.

"Bumblebee Effect", haven't heard that one in a very long time!

(August Magnan, circa 1930's entomologist, widely held misconception that bees shouldn't be able to fly.....except they do? Modern thought, reasoning and investigation shows that they move their wings back and forth, not up and down and hence their flight is easily explained. Sort of a 'crappy helicopter'! )

No offence Keith, you'll need to update your analogy



I still say that any antenna is better than no antenna, you can work radio with an antenna and do nothing without one!

If you get an antenna working and you're happy with it then jobs a good'un. Some people swear blind by magnetic loops and the ubiquitous 'Tak-Tenna', others will argue to the hilt about efficiency and 'recommend' other avenues.

Start delving into the intricacies of antennas and you open a proverbial can of worms and a quest for the holy grail. You could even be dragged down into the argumentative world citing EZNEC etc. modelling, (often without ever building the damn thing!), and the affray that usually follows.


Got to admit though, I'm slightly confused as well and 'er' on the side of Jeff's statement.
Probably because I also couldn't help myself and started reading about antennas!

(Although I have a Ham friend running a similar setup to you Keith and also swears by it!)



Alan mate, you're doing alright so far with your bit of wire and tuner, (judging by your contacts made with your spangly new Ham callsign ) If you're happy, then all's well. If you're after a bit more 'performance' you're heading on a long arduous path my friend. I'll bet though, that like me, you want ALL the bands on one antenna setup!


My 'fan' or 'nested' dipole array wiggles, bends, wobbles it's way inside my attic space, (just to fit in!) One band runs one way, another in a different direction and so on. There's a lot of copper up there!

Is it fantastically efficient? Probably not.
Does it work? Astoundingly, yes!

With a 450ohm feedline, through a 1:1 current toroid, RG213 and then my homebrew Pi-Network ATU it does a lot.
But it doesn't do 160m at all and I still struggle with 17m SWR.
(Greedily I can operate 80, 40, 20, 15, 10m and still operate 11m to boot!)

Is it for everyone? Definitely not.

Although mine is completely hidden from view, (handy in a village environment), not affected by weather and corrosion and a darn sight easier to reach, (despite my disability), than if it was strung across the house and gardens.
It suits me well



Alan, bend your bits of wire to fit your plot. You might hit a winner!

(Also worth reading some information though, especially as I sit here staring at a weird binocular 16:1 balun I built and some expensive termination resistors. That terminated loop wasn't as good as first envisaged or had been led to believe! Was fun experimenting though......and that's what counts )



Alan, Keith, Jeff, my very best to you all. An interesting thread, (to me anyway )

Victor

G0RQQ wrote:

My wire is fed via a 49:1 Balun which is earthed via several copper rods driven into the flower bed. I can get a good match 160 - 6m using the internal tuner on my FT-920, which in itself is a surprise as built-in tuners are normally not too brilliant. I think it’s a case of what I call the “Bumblebee Effect” - according to all the laws of aerodynamics the bumblebee shouldn’t be able to fly; the bumblebee doesn’t know that, so it carries on flying. Similarly, my antenna doesn’t know that according to antenna theory it shouldn’t work, so it just carries on working!

Ha ha...yeah.  First rule of antennas - everything affects everything, and every install is different.

My iCom would absolutely not match 160m on my 40m long 8010 EFHW.

I’ll have to try it again with the LDG, though even if I got a match, I’d be concerned about cooking the transformer if I ran QRO.

If you have an analyser, i’d love to know what impedance it sees at the end of the feedline on 1.8MHz into that transformer and wire.

Oh, and just to be clear....I wasn’t remotely having a dig....just seeing if there was some magic I was missing re getting and EFHW to work well below it’s fundamental frequency the wire was cut for.

Even one of the gurus on these things (Have a look at Steve Ellington’s YT channel) implemented a switch to take the transformer out of cct to get 160m as a quarter wave wire.

I’m completely screwed here for space to get a 160m antenna up, but there is a net or two I’d like to get on.

The analyser showed on 160m SWR = 2.2, R = 34, X = 28. The worst was 40m: SWR = 5.0, R= 34, X = 77. On 6m, SWR = 2.6, R = 19, X = 13

The best band that it seems to work on is 30m where SWR=1.3, R=44, X=11. I’ve had quite some success on there with both CW and data modes.

G0RQQ wrote:

The analyser showed on 160m SWR = 2.2, R = 34, X = 28. The worst was 40m: SWR = 5.0, R= 34, X = 77. On 6m, SWR = 2.6, R = 19, X = 13

That’s fascinating.....40m should have been near perfect, as presumably that’s where you tuned it as the fundamental for the wire length you’re using; but 160m is a bigger shock, as from those numbers it appears completely usable even with no tuner, which matches your practical expereince.

I’m now intrigued.....will have to sweep mine at the weekend snd compare.  With the current wire being a loaded 23m(ish) long, it was tuned on 40m, then the inductive load and tail added and that tuned on 80m.

For your 40m measurement, is the reactance inductive by the fact the 77 is positive? i.e. 34+j77?

Oh, and have you choked the feedline at the transformer, or is it likely to be being used as a counterpoise? (They say to choke it at 0.05 wavelength at the lowest frequency, but rather than chop into my Heliax, I choked it at the transformer and ran a 4m counterpoise off from the ground terminal, as well as the ground rod for static bleedoff).

Re 40m - you’re correct - 34+j77. There are no additional chokes on the feed line, nor is there a true counterpoise wire. The earth terminal on the Balun goes to a short wire connected to the three copper rods in the flower bed outside the shack window. The rig is also connected by a short thick wire to the central heating radiator so that may be acting as a counterpoise, though.

A friend ran EZNEC plots on a couple of bands for me -I’ll see if I can find them and post them on here.

probeer dit