The AM Forum

OK, so my dream antenna if I was to move to Texas would be a full wave 240 ft loop of wire, 60 ft square. Would this work? It could also be a 1/2 160 m loop. Or I can trap it to make it a full wave at 160.

Would this work? Does length even count in wavelengths with a loop? I could wire up the entire 2.5 acres of property and use a 2.5 acre loop.

I've got a friend in Texas who's quite a welder and he'll weld me together 4, 40 ft tilt over poles for the support.  The railroad uses them for jacking up their control point antennas and a bit of wire won't be near as much wind load as a UHF yagi or VHF folded dipole array. I've studied how they do it and I'm sure my design will work as well. They would be easy to tilt over for maintenance just remove the bolt or pin and walk it down, and walk it back up and put the bolt through it.

I wouldn't need to worry about ice weight in the winter as a problem since San Antonio rarely sees ice.

Traps I don't know how to make. I'm sure Google probably knows but I haven't looked yet.

40 foot high poles to elevate the loop?
You might want to "re-calculate"... Don, K4KYV has a couple of approaches to 160M. A full length dipole 90 feet in the air and a broadcast style tower, isolated from ground, and the radial field. I forget the height.
You can choose the Vertical for longer distance (DX) or the dipole for local.....500-600 miles.
If you have the space, you should go BIG and TALL.
Fred

I don't have the funds or resources to go to 90 ft. A 90 foot tower is way out of my affordability. New or used I doubt I could afford one. Unless I go into the tower removal business in the area and offer to take down and haul away towers free for those that have Dish and no longer need over the air antennas. I guess that's a cheap way to get some Rohn 25. If people will bite and just want their towers removed for free. Some may still want money for the hardware even if you take it down for them.

The length of the loop is important.  I use full size loops here.  To find the length, divide the freq into 1005 and this is the length in feet.  My loops are in the vertical plane.  The top side in up at about 80-90 ft.  The lower side is only about 10-12 ft above the ground.  They are fed along the low side with a 1/4 wavelength of 75 ohm coax and then 50 ohm coax (any length) to the shack.  The exact shape is not critical, doesn't have to be an exact square.

Fred

A full-wave horizontal loop at 40 feet would be a good local coverage antenna on 75 meters (out to 300-400 miles). If you feed it with open wire line, you can use it on several bands.

My antenna at my vacation house is a rectangular loop of about 320 feet that essentially follows the property line of the yard. It is fed with open wire line at the midpoint of one long side to an air balun mounted in a waterproof box just outside of the shack. About 8 feet of RG214 coax couples the balun to my tuner. I also have an MFJ current balun in series for good measure. It works great on all bands. I primarily use it on 75. The only problem is it is more of an NVIS antenna as it is only about 25 feet above the ground. I use six poles to support it, one in each corner and one midpoint on the long sides. One in the front yard is also a flagpole.

In my studies of loop antennas I determined that a resonant length is not essential or maybe even desired. One paper I read actually showed better results for a non-resonant length. So just put something up and make it a long and as high as you can.

I wonder how many of you guys use loops and if you like them. I am about to put one up but my expectations are checked by my experience at the Monterey Bay Area Radio club. A few years ago I helped put up a beautiful 75m loop. Three of us did it. Horizontal,  up 55 - 60', relatively square.  Fed it with ladder line but not much of it. It was a chore. This is former Ft. Ord land, scrubby, thorny, rocky, rattlesnakes.

We never did have a QSO where it was better than the 75M inverted V dipole up about the same height. It really wasn't much quieter either. We could tune it for other bands but it sure seemed like a lot of work and wire for what we achieved. I guess we were expecting something dramatic and did not get it.

Nevertheless, I'm going to try one again.

Once upon a time, when we were awash in sunspots I had a vertical 20M delta loop fed 1/4λ from the apex. It was wonderful.

If and when I move down there it will most likely be a dipole or inverted-v to start with but I've always wanted a loop. I've heard a lot of good signals from loops.

I had a 40 meter vertical loop for years and thought it worked well. After a number of years the wire insulation started to look grungy so
I decided to replace it with some better stuff so I took it down. Before getting the necessary wire, I threw up a dipole in the interim. Seems the dipole worked just as well as the loop. The loop never went back up.

Hmm, since the topic has changed in favor of a dipole, what if I took two dipoles or inverted V's and fed them out of phase to 'screw' the signal into the ether. Kinda like the Satellite guys use to talk to satellites. I'll have the real estate to do either. I've already been told he don't care how many antennas I put up or even if I need some of his property to do it. Does that work on HF? If so does it prove any advantage?

Sort of a HF turnstile antenna; makes a great omni directional antenna. Save money on feedline.

I hear you on the towers, however a tower to just hold up the center of a dipole could be done real cheap.  

Like you, a new 90 foot tower is out of the question, but I was able to land 2 used towers for super-cheap.  I bought 5/8 inch Dacron to guy the 90 foot tower, so it's non conductive and no insulators required.

One of the towers is a military unit 24 inches on a face.  The other is Rohn 45.  Built the tower on the ground and tipped it up in one piece and use 2 sets of guys, one at the top and one at about 50 feet.  

I've also put up that military telescoping mast at 90 feet.  You need more guys, but it definitely works.

I say this because a dipole with the center at 90 feet is a really, really good general purpose antenna.  Work Europe on 75 meter AM during the fall/winter months, and coast-to-coast is no problem at night, but the local signal is excellent also.  What I'm using now is a coax fed fan dipole for 160/75 with the center at 90 feet.  The ends come down to about 60 or so feet - held up by ropes in trees.

If there's any way to get up a single high center support, it's probably the biggest bang for the buck.

Anyway, just another idea.

I have a 290 foot 80 meter loop hanging between 6 or 7 trees, mainly because that's where the wire could be hung easily.  It's sorta triangular in shape and is fed with about 50 feet of 450 ohm window line directly into a balanced tuner.

It out performs my 100 foot dipole, noise-wise, and just about anyone I hear I can talk too, using no more than 100 watts,. 

Monday nights I load it up on 20 maters for the Monday 20 Mater AM net and usually have no problems with mid westerners and west coasters. Locals, not so much.

I like my loop....

Cool, that's what I'll start with only one center support, and since I'll only be using one I'll be able to go higher than 40 ft. The satellites will most likely be trees to get started. The area is all low cedar so that will put the ends up at about 20 feet. I've got plenty of wire to string up thanks to W3JN, so a 75/160 fan is also possible. Now I just have to consider what I'll have to do to relocate.  In my current position I need to do a lot of research and I'll have to start some balls rolling before I leave.

Don't waste your time on the two dipoles. A single dipole at 40 feet is already omnidirectional (or nearly so). Nothing to be gained but more complexity.

If you really want to put up two dipoles, put up two spaced about 40-50 feet apart and phase them. With switching and matching your can have three patterns: unidirectional in two selectable directions, bidirectional (lower take off angle) and nearly omni and mostly high take off angle.

Agreed!  

There is less than a dB difference between a loop and single dipole when modeled.   A dipole is easier to support, takes up less precious "antenna field" interaction space and its "effective" height is higher than a loop due to less ground coupling, thus somewhat lower take-off angle.

The ultimate antenna for 75M - the poor man's ass kicking array:  As HuzMan said, a pair of coax-fed dipoles switched and fed  +90 or -90 or 0 degrees in-phase. This will give us unidirectional gain of 4-5dB  in either direction with a reasonable low angle and a 20dB front to back for better receiving - PLUS feed them in-phase and produce a strong high angle cloud burner local signal.

I'm not kidding - a pair of 75M phased dipoles at 60' is possibly the best free lunch in the 75M/ 40M world there is. To surpass this would require a 3el rotary Yagi at 90' on 75M.
Considering it's almost like quadrupling our output power in the favored direction, you'd think it would be a more popular antenna system.

T

Loop antennas are known to have better signal to noise ratios and I would have to say that in my experience that holds true. My vacation location is near the coast where there is a higher power line noise level. The loop does much better than a previous dipole. A couple of other loop users I have spoken with give the same report.

Even on a smaller lot you can get a lot of wire up there with a loop. My shore lot is about 120x60. I run a loop around almost the entire perimeter, total length about 320 feet. It does not have to be a resonant length. Make it as long as you can.

Interesting.  I've heard this often and respect these opinions.

I have often wondered why a loop would be quieter. After all, does it know when to discriminate noise from real radio signals?  I could see it happening if the pattern were altered compared to a dipole.

I have a pair of closed, parasitically coupled loops for 75M at 190' high, used for Europe and western USA.  In my own experience I've seen little difference in noise levels between the loops and other high 75M Yagis I use here. Go figure.


Here's a short discourse about noise and loops. It goes to show that this debate will probably go on for a long time... :-)




Posted on  a reflector:

"I have used a 75 meter loop antenna here where I live for the past 5
 years. It works very well. I live right in town on a lot surrounded by
 other homes. I started with a dipole but was advised that a loop would
 hear less noise. It turned out to be quite true. I am now a convert to
 the loop antenna. Have no idea of the physics of how it works, but it
 sure does work well on bands between 75 and 20 meters. It actually seems
 to work best on 40 meters."


[response]

"It is not true. Only in the cases of corona buildup, etc, on the
 elements would that be the case.
 If you hear less noise with the loop, vs the dipole, it's due to
 the change in pattern. Not due to any qualities of the loop itself.
 Noise is RF the same as any other signal, and follows all the same
 rules. It's no different than an actual signal.
 If what you/they say is true, and the loop received less noise, it would
 also receive less "desired" signals. Or in other words, everything
 would be down vs the dipole.
 The most likely explanation is the change in pattern less favored
 the direction the noise is coming from. Either that, or the noise is
 local to your shack, and for some reason the loop's feed line is better
 decoupled than the one feeding the dipole.
 If I had to bet, I'd say it's the change in pattern.
 There are no magical anti noise properties with loops."



[Photo courtesy the HuzMan]

I agree with the corona discharge type static being reduced with a loop vs an antenna that has open ends.  So, this would be static that is being produced right on the antenna rather than noise that is being received on the antenna from some other source.

Fred

Yes. Had em. Will have em again some day. Phed Phased Dipoles Phantastic.

Sterber Curtain?
Lazy H type stuff?

I had a friend here who put up a Sterber Curtain for 10m nominally and swore he could
load it on 160m just fine, it was pretty long, quite a few sections...

I personally like the phased dipole concept, the trick though is to put the thing up in the right orientation the first time, since there ain't no second time!

HLR has a very strong sig-a-nig-a-nal with his phased array, whatever it is.

          _-_-

How Cool!
Where can I learn more about doing these phased dipoles ?

As far as loops go, I am inclined to agree that for the low bands, loops are a total waste of time, unless you can get them up high!
Tom, W8JI, has shown that the more wire you have out at low heights (under a wavelength), the more loss you will have.
Perhaps this is why they are reported to be "quieter" ?

Hey Bro, I am an Audiophool too, you know, like direct driven electrostats by Tubes, B&W 801's, Krell, Threshold, Sumo Gold, stupid stuff like that.

I wouldn't say that low (somewhat undefined) loops are a waste of time. On the fundamental frequency, they are great for high angle coverage on links 0-300 miles. Just depends what you want.

Some good info on phased dipoles at the link below.

http://www.eham.net/articles/27922

My mind has been changed on my dream antenna to a phased array, I had heard praise of loops but the information posted here has changed that. And running a diaper pole I can actually go higher since I only have one support to erect to start instead of 4, or however many it takes to construct a loop. And those supports would have to be a tower of some sort because as I said the area is all low cedar the majority of trees are 20 feet or less. There's just no way I can get a loop high enough to even be effective for local talk let alone 300 miles or more is impossible without constructing said towers.

Thanks guys for the info. Expertise is why I come here.

Even before I read this stuff, I have had a few low loops up, over the years.
All were simply insulated wire, strung through trees for support.
Of course, they all broke, and I was nearly always forced to go back to a Dipole.
I never seemed to miss a lick with the dipoles, local or dx.

Then, I found this

Which is the Best 160m Antenna ?

In a nutshell: vertically-polarized antenna for transmitting, using separate antennas for receiving.

From W8JI on qrz.com:

"The fact is....... an Inverted L with 20 or more radials at least 50 feet and hopefully 100 feet long will absolutely smoke any normal height loop antenna or dipole antenna at nearly any distance on 160 meters. The possible exception is between 20 and 200 miles.

"As a matter of fact a low full wave loop has no gain, any horizontal wire has increased earth induced loss as it is made longer when close to earth.

"Do not make the radials shorter just because you have fewer radials. They really need to be as straight and long as possible, but lengths over 100 feet don't help much. Even 20-30 radials 60 feet long make a fairly good ground.

"Nearly all especially successful stations on 160 use a vertically polarized antenna of some type for transmitting. That's just a fact.

"I have a full size 160 dipole at 300 feet, and it is never really much better than a 1/4 wave vertical at any distance in any direction. As a matter of fact, the dipole is 10-20 dB weaker than the vertical off the dipole ends. The dipole only beats the vertical broadside to the dipole, and then only rarely!! And this is with the dipole 300 feet above ground.

73 Tom"


http://forums.qrz.com/showthread.php?t=260716&highlight=beverage

The facts are that antennas are almost always about tradeoffs. The tradeoff with an Inverted-L is likely reduced signals on shorter range links. This might not matter much since usually signals are strong on short links anyway. Losing a few dB isn't going to matter. The other tradeoff with an Inverted L is the requirement for a ground radial system. The payback is stronger signals on longer distance links. Each person must weigh these tradeoffs for themselves. What sort of contacts do they want to make? How much time, effort and money will be put into the antenna system? How often will they use the band in question? Will/can the antenna be used on other bands? A hard core DXer on 160 meters will answer these questions and weigh the tradeoffs differently than someone looking to make a few short range AM contacts on 160 meters during the winter months only.

There will be many naysayers out there, but my antenna works surprizingly well!
It kicks ass on 40 and 75 and even works surprizingly well on 160.
But............. You need heavy feedline and a balanced tuna with serious cajones to make it work. Don't even think about using anything made by MFJ if you are considering running any serious power! ! ! ! The whole trick is to get as much of the RF as you can to the feedpoint of the antenna. Depending upon what power level you are running, the feedline current can become pretty brutal, especially on 160. I primarily use it on 75, but have been known to occasionally pop up on 160..........


Frank

Even an 88 ft doublet is quite short for 80 meters, as can be seen here. http://www.w8ji.com/short_dipoles_and_problems.htm

Your antenna is only 60 ft long.

W/O seeing the modeling results of this antenna/feedline combo, here is what it looks like to me is going on.
You may have "hit" on a good feed line length, that combined with your wide range tuner, is allowing you to force feed power into it.

But just because we can feed power into it, doesn't mean there is not considerable loss in the matchbox/feedline.

You can easily be losing 3 to 6 db with this combination on 80 and below, and that is before the loss of the overly short dipole is added in.

If it were me, I would start over, and instead use the wasted bottom folded dipole wire to add some length to the top dipole. Zig Zag it to fit your yard if you have to, but more length in your flat top is what you need.

The antenna is longer than 60 feet electrically. There is 120 of wire involved. The losses have been well covered in other posts here over the last 10 years. The losses are minimal and probably indistinguishable from a full-sized dipole. Frank has made 1000s of AM QSO on 80 meters, some coast-to-coast. The losses are minimal and probably indistinguishable from a full-sized dipole. About the only improvement he could make is to increase the height above ground.

Call me when you can engineer a 160 antenna that makes people know who to turn it over to next :P

Yeah, I just saw that. The furnished PDF File loaded on my screen sideways, and I don't read very well that way.
It is a bent in half 120 ft flat top, electrically.

The spacing between the top and bottom 1/2  of the dipole could be played with on the computer model I suppose, to try and get the most benign low bands impedance curve.

+1 ! ! ! ! !  ;D  ;D  ;D

What you need to do is use your commputer and your modeling software to print out as much worthless paper as you can and stack it beside the porcelain convenience for "those messy cleanups........."

Then turn the computer off and start modeling with wire! ! ! !  You'd be amazed at what you might discover! ! !

If half of the people out there took the time they spent computer modeling in search of the "holy grail" and actually built some antennas you would have a lot more QSOs out there.

No one said it better than the words of Derb! "Put as much wire as you can fit up as high as you can get it and feed it with ladder line, and a good tuna and no one will have trouble hearing you!"

"Nuff said! ! ! "

I have only been a Ham for around 25 years, not nearly as long as many of you.
I agree with you that computer modeling has taken a lot of the good old fashioned fun out of just going out, and actually building something, then seeing how it actually works, on the air!

However, that being said, I still think computer modeling does have a place, in the overall scheme of things.

Hell, I remember back in the old days, when we made Yagi's, we simply cut the reflectors and directors about 5% shorter then the driven elements, spaced the elements evenly across the boom, and went out hunting DX.

Yes, these antennas "worked", and some worked real well.
However, they would be no match for the computer optimized Yagi's of today.

Same with your antenna.

It seems you have a great design, from what all the guys here have said.
Now, what IF that great design you have come up with, could be made even better, by computer modeling.

What IF computer modeling could come up with something a "little more user friendly", while still keeping your basic design.

One variable I saw on your design was the feed line length.

The computer can tell us what are the best lengths of feedline in a short period of time.

The problem is RF is a "Theory" computers think of things "Literately" Not what if? But if, then. You can't exercise the good old imagination with a computer. It just doesn't happen that way. The software is only going to do what the programmer told it to do, nothing more. Computers (currently) cannot think for themselves. They're getting close, but not quite there yet. You have to throw some wire in the air and experiment, who knows it might defy your computer software. That's why I'd trust the word of someone who tried it over someone who just modeled it on a computer.

Here is an example of a W5GI "Mystery" antenna, that is claimed to "confound computer modeling"
This is because Computer modeling has revealed it to be the poor antenna that it is.
There is no "Mystery" here, Computer Modeling clearly shows what is going on.
The only "Mystery" is why people even consider it, when there are so many other antennas that actually work as claimed, to be had.

The Computer is an awesome design too, for people (not me), who know what they are doing with it.

I don't have computer modeling software, nor do I know how to use it, so I started this thread http://forums.qrz.com/showthread.php?414706-Anyone-Care-To-Model-this-Simple-Antenna&p=3020488#post3020488

I am curious what Modeling has to say about this antenna

How does modeling work with my 160m Isotron??


klc

I'm thinking of putting it on my Ford Explorer.

http://www.w8ji.com/e-h_antenna.htm

About antenna modelling:

Back in the 80's I put up my first 150' tower with 4 cleared acres and acquired an 18,000'  roll of #5 copper clad aluminium wire for $100.  This was JUST before computer modelling was mainstream.

I tried every antenna known to man for 75M, 40M and 20M -  vertical arrays, wire logs, wire Yagis, V beams, loops, Lazy H's, Sterba curtains, rhombics, stacked dipoles, etc. My main goal was a big signal into Europe, the USA and locally on AM for 75M.  I went thru ALL 18,000' of wire experimenting over two years.

What I found was for local work, a simple dipole at about 1/4 to 3/8 wavelength above ground was best.

For DXing, a Yagi worked great.  For real animal gain, then a combination of Lazy H's or Sterba curtains with parasitic reflectors was tops.

Stacked Yagis were always good too.


Now here's the point:   Later I got Mini Nec  and much later, EZNec V5.0 computer modelling programs. (MiniNec 1988)  I would have saved hundreds of hours of real whirl experimenting if I had used the modelling earlier. I tried antennas that were obviously too low to the ground for low angle performance - and many that were phased incorrectly. The modelling would have told me all this. And modelling would have optimized my designs instead of climbing and pruning for days.

A recent experience, 2013:  I wanted to put up a more effective local antenna for 75M AM for use out to maybe 300 miles.  I decided to try a 300' horizontal  dipole flat top at 90' fed with open wire. It modelled out to have maybe 2.5dBd gain at 60 degrees takeoff angle over my exisiting  1/2 wave dipole at 60'.  A no brainer to effectively double my signal strength locally.

But guess what?  I assumed there would be no interaction to my other antennas. It was to be erected in the clear, away from the other antennas. But before starting the project I decided to model all the other antennas in the field to make sure there were no pattern distortions. Turns out no matter where I put this big 300' wire on 4 acres, it did some damage to my other antenna patterns.  The worst was the high 75M 2 el loops for 75M.  The 300' wire caused the loops to lose most of their 5dBd gain and develop a hole for European coverage. The loops in turn negatively effected the 300' wire causing any local gain to be eliminated.

Looking at a bird's eye drawing of the antennas on paper looked fine, but the modelling showed it as a disaster. Years ago I would have certainly put this up and wondered for days why I wasn't seeing the old performance - or worse, never realizing what happened to my gains.

So, modelling, if used as a tool to verify and confirm ideas, can be a valuable tool for a ham. It can also be a good educational tool of what to expect from the many, many antenna designs out there to better tailor them for the best fit to our QTH and performance goals.

EZNec V. 5.0 for Windows is what I currently use and it can be mastered in a few days. It can be downloaded and tried free for 30 days.

http://www.eznec.com/


Tom, K1JJ

Are you implying models aren't accurate?  GIGO.  There is no reason the Isotron can't be accurately modeled.

Correct me if I am wrong, but has not modeling of the Isotrons and Tak Tenna's, etc, etc shown them to be, what they really are ?
I think I read somewhere that all these devices really are are deliberately unbalanced loads, designed to make the feed lines radiate.

" Correct me if I am wrong, but has not modeling of the Isotrons and Tak Tenna's, etc, etc shown them to be, what they really are ? "

No, the modeling doesn't even approach the true usefulness; they make excellent bird perches.... ..


klc

(http://i00.i.aliimg.com/wsphoto/v0/717350592_1/Mini-12-font-b-Ceramic-b-font-Charcoal-BBQ-font-b-Grill-b-font-baking-font.jpg)

Tak Tenna's make excellent BBQ !

There's also nec2c (Command line) and xnec2c (GUI) for Linux. Both are free. I am the lead packager for the Fedora Linux Amateur Radio SIG. I know both are in Fedora, because xnec2c requires nec2c, and for other distros the source can be found HERE (http://www.qsl.net/5/5b4az/pages/nec2.html)

I have never had any luck figuring it out.

Well............. You have been a ham for 25 years, Hmmmm..........
Seems like you have spent most of those years modeling antennas and not building them. If you took the time you spent modeling antennas and used it to build a few of them, you might actually be on the air instead of arguing about it on a forum   ::)  ;D

Keep in mind that antenna modeling software only knows what was programmed into it at the time that it was written. It can't figger out new scenarios on it's own, it can only compare the info that it is given to what was written into it. If you ask it to analize a scenario that was not written into it it cannot possibly give you an accurate answer.

Antenna discussions here are always a big source of pissing and moaning. Then when I throw my antenna into the mix, most of the computer modelers swear that it can't possibly work. Well.........I don't like being piss-weak, so I put out a pretty serious signal with my antenna that can't work. If you doubt me, you can ask any of the major players on the east coast!

Even a wet-string dipole works way better than no antenna at all! ! !  Get up off of your modeling program and trying to create the perfect world, put some wire up in the air and get on the air.

That's it, short, sweet, and simple. Nuff said! ! ! that is the end of this discussion for me! As Murphy said: "Never argue with a fool, sooner or later no one will be able to tell the difference"! ! !

Frank
AKA  KB3AHE

10-4, over and out!

I can vouch for that, I've heard Franks signal, as well as operated his station. If he can hear it, he can work it. With an antenna that doesn't work.

Frank, no one is "arguing" with you, so please don't get defensive.
Several here have said you put out a great signal with the antenna, and I am trying to figure out WHY you do.

With absolutely NO disrespect intended or Implied towards Frank, or his Antenna, for the life of me, I can't understand how this can be possible.

Steve, G3TXQ, is a well known antenna/computer modeling expert, the designer of the K4KIO Hex Beam, and a regular on QRZ.

Here is what he found, when I posted the schematic of it, and asked for someone to computer model it -

 "What do you need to know?

Radiation patterns and extreme impedance variations very similar to a simple 60ft doublet!

Fed with 100ft of Wireman 551: 6dB feedline loss on 80m and 19dB loss on 160m. Losses would be less with some open-wire line formed from large diameter wire.

Steve G3TXQ


I have a very very small lot, and could really use a smallish, easy to build antenna, like this one!

I think the idea behind Frank's antenna is to minimize feedline losses by using homebrew very heavy gauge openwire feedline and a tuner using 3/8" copper tubing and strapping connections throughout.

A dream version of his antenna would be to have the amplifier mounted up at the center of the antenna and the final pi-network directly coupled to his low impedance antenna. In this case, I bet his short dipole would be within two dB of a full size dipole on 75M.  

And, if the antenna conductors themselves were of sufficient diameter, there would be little loss compared to a full size dipole.  So if we can minimize the tuner/feedline losses thru heavy conductors, we are almost there.

Theoretically, we could use a 75M dipole that is only one foot long made of superconductors that exhibits close to zero ohms. This would work as well as a full size dipole. Just imagine a 3el 75M Yagi that you could hold in your hand.  The radiation pattern would look the same as a full size antenna.

Bottom line is it's all about how much we control the losses when we shrink down antennas below full size.  Since superconductors are not yet practical, brute conductor thickness is what we have to work with.


T

Every antenna couples power into both radiating electromagnetic modes (which comprise the far field) and non-radiating modes that decay exponentially with distance from the antenna (which contribute a portion of the near field).

For a given amount of total power that leaves the antenna, an electrically short antenna has a larger ratio of near field to far field. The larger near field is dominated by non-radiating electromagnetic modes that decay exponentially with distance from the antenna.

The near field produces heating losses (e.g. ground losses) in the vicinity of the antenna.

Even if the antenna's conductors, the feedline, and the tuner have zero losses, the larger near field to far field ratio of an electrically short antenna will limit its radiation efficiency compared to a full size antenna.

Sometimes nearby conductors couple to the antenna, and become part of the antenna (just as the parasitic elements of a yagi are part of the yagi).

The shorter a dipole antenna is, compared to full length, the larger the near field amplitude will be.... and the larger the fraction of the total RF power that will end up heating the ground and other nearby objects.

Stu

Yes, that would be nice, to have the amplifier mounted at the feedpoint.
I used to own a Henry 3K Ultra, I think it was?
It had a remote controlled RF Deck. The idea was to place the amp right at the base of the antenna, and control it from the shack.
It only had a single 3CX 1200 tube in it, but it was an "export model".
I traded/sold it to W0AD, some years back.

Stu,

What if a severely shortened, loss-less antenna is in free space or on an infinitely tall tower... does all of the near field power eventually get radiated?

T

Tom

If the surroundings are lossless, then energy is stored in the non-radiating modes, but it is not converted to heat, and not radiated... analogous to an ideal capacitive load across an AC voltage source. Therefore, all of the power that leaves the transmitter is radiated (nothing is lost in the wires, the transmission line, the tuner, or surrounding objects).

In practice, the shorter the length of the antenna is compared to full length, the more difficult it becomes to avoid resistive losses due to currents induced in surrounding objects, and hysteresis losses as well.

Stu

After many tries to minimize coupler/feedline/radiator losses and some on the air comparisons I conclude the following.

Given giant stupid size inductors vacuum variables #8 feeders and #8 near doublet center tapering toward ends to #10 to save weight.

120' antenna center @ 80 feet ends 60'

160 meter signal reports were generally down 6 dB in guess meter strength compared to a friend 15 miles away with a full sized 160 horizontal radiator at 110 feet.

Really not bad.

I know 3 operators in this general area who put a good amount of time on 160 in the last 10 years with shortened doublets, 75 meter size and less. Bill Russel, The Slab Bacon and myself.

This is not for anyone who is not willing to build a coupler. Even BC-939 coils got hot at QRO. Try that with a high pass T into a 4:1 BalUn and the SWR may be good but not much will go out the pipe. 

The very same setup supported only at the very ends at about 33' average height still worked but it took legal limit to make a Ranger sized signal.

Here in New Jersey (Jersey is a place in England) 160 AM operation is much different from what's found out West. Cloud burner antenna work fine. Some of the guys with vertrickles can reach out and touch people further away but are usually down in signal level from others close in. The vert antenna really shine close in during the daylight hours though.

This is not a 160 DX operation requiring the best low angle stuff just to have fun. I have worked across the pond on ssb with the 33' high 75 meter doublet on 160 fone. THAT just proves the patience of some 160 DX hounds. It took about 10 repeats.

I'm noticing many online amateur antenna discussions land up with general "you can't do this or that" based on un-quantified obstacles. Put the antenna together like a race car. Minimize losses anywhere possible. Works. May not work well but it beats being stuck on the internet typing stuff about radio with other guys who aren't on the air.

The shortened antenna can be a way to get on 160 for those of us who don't live on farm sized lots but can have at lease one high antenna support.

The same small lots usually land up being a nightmare for inverted L because the radial field will be incomplete in size and the signal will need to pass right through houses, people, wheelbarrows, dogs, cats and toasters. House wiring lands up being part of the counterpoise also. I've heard many a PW inverted L from small lots. Out West you guys are generally geographically spread out and most likely NEED the low angle antenna just to work more than a couple other AM folks.

K3L 2005 used a 60' center fed doublet. See writeup on this site. See log on this site. Note the 75 meter portion of the log. That outing was put off the air for many hours because of thunderstorms and RFI. Still not bad for a half sized radiator. Stu is right on the money concerning the intensity of near field radiation. Expect extra debugging of interference prone consumer junk electronics.

I'd rather get on 160 with a loaded lawn chair and learn something than sit at the old compuker writing the whole idea off due to software pushed to limits with incomplete/inaccurate input.

Nailed it, Dave.

When all is said and done, usually more is said than done.

I did some sims on Frank's antenna back in 2007.



Tom, KLR did some sims later and got different numbers, more loss IIRC. I never resolved the disparities.

I am still amazed how well the mobiles used to get out on 160m AM with low power. This was the early 70's, in the Detroit metropolitan area. This activity was quite common before 2m FM took over. On 160, in that area, and at that time, the mobiles were on 1806, crystal controlled. These transmitters typically had a 6V6 or a 6AQ5 in the final, and Heising modulated. The AM car radio with a converter was the receiver.

Those guys were running 5-10W DC input, and used a mobile antenna that might have been 2% efficient.  During the day, those guys got out quite well over at least a 30 mile radius.

The base stations were often at 1835, and inverted L antennas were Kings. I recall many times hearing something like, "Go vertical as high as you can, and then go horizontal". A typical L was about 3/8 wave, and fed with a series capacitor to tune out the reactance.

I took that advice after upgrading in 1974 from a Johnny Novice. With 25 watts (input), I did OK. It was all new to me, and any contact was so exciting. One December evening I worked stations coast to coast, and as far south as Texas. I was so excited, stayed up all night...

I found a write up from that time written by my Friend Larry, WB8FGK. It is on his QRZ home page

Jim
Wd5JKO

Interesting discussion...     Yep, Slab certainly does well with his shortened antenna and 500 watts. A big gun up here for sure.

Stu,

So, it appears that the shorter from full size an antenna is made, the MORE important its height above ground and isolation from surrounding objects becomes.  This shows why an 1/8 size mobile whip on 75M has so much problem close to the ground when surrounded by other cars, power lines, ground loss, etc.

It also shows why a shorty dipole needs to be up in the clear as much as possible, even more important than a full size one. This is also a reason why some guys get out huge signals with low, but full size dipoles despite being at 30' on 75M.

From what you said it appears that in free space, a radio wave can begin as a point source and still radiate all of its energy. It does not need a large 1/2 wave wire to "guide" it. BUT, when the same point source is brought into the real whirl with houses, ground, etc., the near field starts to couple energy and waste power when low to the ground.


Happy Thanksgiving, everyone!  (a hearty TimTron beeelchhhh to all!)

T

Tom
et al.

Yes... I agree with your statement below except for one small misunderstanding: "It does not need a large 1/2 wave wire to "guide" it."

The current flowing in the short dipole antenna (obviously) only extends for a small fraction of 1/4 wavelength on either side of the feed point. If there are no capacitive hats at the ends, then the current is maximum at the feed point and zero at each end. This spatially confined current does not couple efficiently to radiated electromagnetic modes (the far field), but it does couple efficiently to non-radiated, exponentially decaying modes (which are part of the near field). The efficiency of coupling between a short dipole and the radiated modes (the far field) is approximately 100% x [l/L] x [l/L], where l is the length of one side of the short dipole, and L is 1/4 wavelength. This formula is valid when l/L is less than 1. The coupling efficiency to non radiated modes (i.e. the non-radiated  part of the near field) actually increases as the antenna gets shorter than full length; but that requires a bit of calculus and electromagnetic field theory to prove.

So, for example, if each side of the short dipole is 1/8 wavelength long, the coupling efficiency of the short dipole to the radiated modes (the far field) is approximately: 100% x [(1/8)/(1/4)] x [(1/8)/(1/4)] = 25% of what the coupling would be with a full sized dipole.

The tuner/matching network/load coil  attempts to make up for this by increasing the amplitude of the current that flows out of the feed point by a factor of 2, compared to the feed point current of a full size dipole. [2x the current => 4x the power; 4 x 25% = 100%]

If the losses in surrounding objects (which are exposed to the near field) are low, then you can just increase the feed point current to make up for the weak coupling of the antenna to the far field. But this higher current, and other factors that have to do with the distance the current extends from the feed point on either side of the dipole, increase the amplitude of the near field. Therefore, for a given surroundings, a larger and larger fraction of the total transmitter output power will be converted to heating of the surroundings, instead of being radiated.

For l/L less than 1 (i.e. a short dipole), the increased near field losses may be totally acceptable.

For example, in my new home, I use a dipole on 40m that is only 25 feet long on each side ... i.e. l/L is approximately 25 feet /34 feet = 0.74; and the efficiency with which this antenna couples to the far field is about 100% x 0.74 x 0.74 = 55% of the efficiency with which a full sized dipole would couple to the far field. I use a tuner to make up for the mismatch (i.e. to increase the current flowing into each of the 25 foot long dipole sides at the feed point). Therefore, I have some increased loss in the tuner, in the feeder, and in the 25 foot wires vs. a full length dipole... and the near field of the antenna is larger than it would be with a full length dipole. Overall, the associated losses (vs. a full size dipole), and the RFI  are acceptable... considering that this is a longest antenna I can put up. Also, it is definitely not "in the clear". It actually running across the 2nd floor of my house, at ceiling height. Therefore, the losses associated with the near field are larger than they would be if the antenna were located high up, and in the clear. On 40 meters, the antenna seems to "get out" reasonably well, based on signal strength reports.

If I tried to use this same antenna (a dipole, 25 feet long on each side) on 75 meters, then l/L would be 0.39, and the coupling of the antenna to the far field would be 100% x 0.39 x 0.39 =15.6%. Using a tuner, I could probably push my transmitter's output power into this antenna... but the currents at the feed point would be (roughly) 2.5 x as large as they would be with a full sized dipole, and the near field amplitude (volts/meter) would be higher than with a full sized dipole by a factor of more than 2.5 (because the coupling efficiency to near field modes actually increases as the antenna gets shorter). Of note, this antenna works fairly poorly as a receiving antenna on 75 meters. I can load into it using my tuner (I can obtain a 1:1 SWR on the transmitter side of the tuner)... but I haven't yet tried using it as a transmitting antenna on 75 meters.

Happy Thanksgiving to all!

Stu

Well, that "Bad News" is Frank's Antenna is not doing very well, when subjected to Computer Modeling by some well known, and respected Antenna Guys http://forums.qrz.com/showthread.php?414706-Anyone-Care-To-Model-this-Simple-Antenna/page2

The Good News is that his antenna can very easily be improved!
Instead of doubling the wire back on itself, all he needs to do is to allow the same amount of wire to droop down vertically.

Happy Thanksgiving Everyone!

Yes, the "Skirted Dipole," as some call it.

I've always liked the results of hanging the ends down vertically when the flat top is short.  It appears to load the antenna well and pull the current out as desired.

Bob, K1KBW has up a shortened 160M dipole at about 70' high doing the skirted thang. On 75M, he is one of the loudest locals in New England.  On 160M, he does rather well locally too, considering it's only 1/8 wave high on 160M.


Stu, thanks for the info, OM!


T

Hope to hear that antenna on the air soon from your station Chris.

Thanks Steve!
I too am "lot challenged", and that's why Frank's Antenna appealed to me so much.
A 60 ft flat top looked like something I might be able to squeeze in here.

When discussing antennas, one has to keep in mind that after WW2 there was tons and tons of surplus coax out there cheap on the surplus market, and the ARRL adopted it's use with open arms. Thus leading to 52 and 75 ohm charactoristic impedance becoming the "world" standard for feedline. With 75 ohm somewhat "falling from grace" as the surplus market started to dry up. Most older forms of balanced line / open wire fed designs then becoming less favorable.

And then you get into the "appliance operator" false myth that open wire radiates. When in reality you have much more feedline radiation problems with coass then you will ever have with parallel feeders. I got to witness this phenomenon first hand well over 20 years ago when Derb used to live at his mothers, and had a run of ladder line (the crappy brown stuff) running right next to a $50 K-Mart B&W TV. It didn't as mich as put a line in the picture!

With that being said, most hams (especially appliance operators) turn their noses up at the thought of balanced line fed antennas. Feeding a dipole (or whatever) is the key to using 1 antenna on multiple bands! One year when we were doing the Farfest special event station at the Howard County fairgrounds, we needed close to 100' more feedline than we had to get from the back of the stable where the antenna was to the operating position. So we made "ladder line on the fly" We stapled 2 100' runs of #12 THHN to the wooden pillars that supported the roof of the building. Several appliance operators laughed at us and swore that it would never work. We kicked ass and took names that weekend on 40 and 75! ! !

Now, in a long previous discussion, Stu (AB2EZ) said "Why would anyone want to use a shortened antenna?" I replied to him "Because some of us don't have a choice!" That was the end of that discussion as he usually tends to take the long way around the block, and I am a big KISS advocate. Keep it as simple as you can. I have about 65' of horizontal run to put whatever I use for an antenna in. A compromised antenna beats the living hell out of no antenna at all! ! ! ! ! ! ! ! !

Now, with all of the above said, Jim (JKO) makes a very good point, the little short mobile antennas that used to be used on 160. Any length of radiator is resonant on any and every frequency, just not at a 50 ohm nominal operating impedance, or perfect radiating efficiency. The tricks to making it work are:

1. Figure a way to make it's charactoristic impedance look appealing to the 
    transmitter. (match)
2. Eliminate as much loss/inefficiency as you possibly can.
3. Eliminate as much of I/R losses in the feeders as you pussibly can.
4. If you are one of those who can't sleep at night unless you are running 
    coass. And you are insistant on running it in a high SWR application, always
    sin in the direction of too low of an impedance! ! ! In a low impedance
    situation (say 10 or 20 Ohms) The only losses are the I/R losses and most
    likely they will be neglible it you are any good at installing connectors.

    But if you decide to use it in a high impedance situation, you are screwed,
    blued and tatooed! ! Keeping in mind that coass is a big capacitor and the
    interconductor capacitance is pretty high the capacitive reactance will eat
    your RF for lunch! ! Your transmitter output will be pissed away heating up
    the coass, leaving very little left for the antenna!

The idea of a 60' flat top with 30' on each end hanging vertically works quite fine, But.......... One must remember that the loose ends are quite hot and somewhere near the max voltage point of the antenns, please take adequate safety precautions. If you have plenty of height, it becomes a non issue.

The thing that I like about my antenna is that all of it is up in the air, out of harms way. I may occasionally offer suggestions based on my lnowledge and a bit of head-scratching conjecture, but I will label them as such. If I tell someone that "this works" it is because I have done it and I know for a fact that it works. I have built a handful of these antennas for other people, and several others have made them themselves, and I know for a fact that it works. Yea, there have been plenty of naysayers, but EVERYONE that is usung one loves them.
Mine has been up for so many years that the UV has just about disintegrated the plastic dog bone insulators! It's pretty much piss-beat. I guess when I get through with my cancer treatments, I'm gonna have to get up off of my ass and build a new one. That one was just an experiment gone right and only originally built for testing, that was many years ago........ If it aint broke, don't fix it ;D

...-.-
10-4, over and out.

The Slab Bacon (Wit da fat meat shakin)

Speaking of Cancer, I have lost many friends to that chit.
One ex Marine hard ass (who hated recreational drugs) was so sick from the Chemo and Radiation, he was about ready to give up.
I begged his wife to ration out AND HIDE his pain Meds, cause I feared he would save up the narcotics, and take his own life.
One day, I came over, and smelled a familiar smell, the smell of Weed!
Sure as chit, the Ex Marine was smoking the very Marijuana he hated so much!

Well ... The weed helped him deal with the awful sickness from the Cancer Treatments.
Proof that even an "Old Dog", can learn new tricks.

For me, I find that the mind is like a Parachute, it works best, when it is open.

It took me awhile to embrace Computer Modeling, since I too come from the "put as much wire as you can fit, as high as you can put it, and feed it with open wire line" school of thought.

Remember, I am a 7 (Licensed In Seattle), the land of big ass trees, that are everywhere.
But, I always wondered why my big ass 160 and 80 meter flat tops were deaf on the higher bands.

Or why my full wave low band loop did not play as well, or any better then a dipole.

Today, I look at Computer Modeling the way I look at the 3M Company.

3M don't make products, they make the products we all have better.

And, just like Computer Modeling showed me years ago exactly why my loop was inferior to my dipole, G3TXQ has found you additional gain (from less loss), and an easier to feed antenna, with one very simple change!

Only you know your situation, and if the suggested drooping ends will be safe, or not.

But more then anything, I hope your health gets better, and you beat this Cancer.

Chris











...-.-
10-4, over and out.

The Slab Bacon (Wit da fat meat shakin)

[/quote]

Keep in mind the feedline transforms the single digit radiation resistance with a short 160 doublet. Helps with matching.

Drooping ends in my case probably makes for miserable RFI and patterns on the higher bands. That would also put the voltage max right near some unhealthy trees. Recipe for fire where it would be difficult to nip in the bud. I'm not folding my antenna, it's just a center fed wire.

I have enough support and room for only one wire. Other stuff in the area would just make problems.

Glad to see the sour grapes guy on QRZ is still well enough to type. Hint. Want respect? Get on the air with something that works well instead of sad, marginal performance. Show us how it's done.

Some of that thread is pretty good otherwise. 

I see very few hard numbers or details in that QRZ thread. I'm not sure how anyone could draw a conclusion. Let's use a number that was posted - the feed point impedance of 12-j380 ohms at 3.8 MHz (this is almost exactly what I got in simulating Frank's antenna). Using the VK1OD TL calculator, you get a transmission line loss of 2.154 dB in 70 feet of Wireman 554 (pretty sure this is what Frank is using).

If you put 30 foot vertical ends on a 60 foot long single horizontal wire, you get a feed point impedance of 35.291-j128.09. This results in a feed line loss (same conditions as above) of 0.4 dB.

Assuming the losses in the tuner are identical for both arrangements (I didn't check), you could gain as much as 1.754 dB using the "ends hanging down" approach. Getting away from the absurd three digits after the decimal point and returning to the real world, let just say 1.8 dB. If we use 6 dB per S-unit, this difference amounts to one-third of an S-unit. That's not much when rag chewing over 300-400 mile links with received signal strengths in the 20-40 db over 9 range (the normal application of Frank's antenna).

In the past, I used what started life as an 80 meter dipole on 160 meters by adding vertical sections on the ends. So, I'm fully aware of the utility of this approach. We know antenna design is almost always about tradeoffs and what the designer is willing to accept given space, time, money, application, etc. Seems to me that Frank has traded off a small amount of gain for a small antenna with no portions near the ground to create a safety problem. This is pretty reasonable to me. YMMV.

Bacon

I don't recall ever asking the question that you attribute to me (quoted below).

Can you provide a reference to the thread in which you claim I said this?

Many times I have pointed out that short antennas are not as efficient in radiating the transmitter's power output (into the far field) as a full length antenna, even with a lossless transmission line and a lossless tuner. Many times I have pointed out that very short antennas are very inefficient with respect to the portion of the transmitter's power they can radiate into the far field, and that their near field levels (volts/meter) are much higher than that of a full length antenna.

However... I don't recall ever suggesting that someone who is operating with limited space to put an antenna should not use a short antenna (rather than nothing at all).

I am using a short antenna in my current QTH: i.e. a 50 foot (total length) dipole... which I use quite sucessfully on 40 meters, 30 meters, 20 meters, and 10 meters.

Stu

Are you neglecting to add TUNA LOSS, into this ?
Plus, you are only considering 80 meters.
Things get MUCH worse on 160

Everything is a trade off, and in the end, we must all do that which we feel is the best compromise, for us.
Franks Antenna works for him, but not everyone has the heroic tuna he has, and not everyone will want to even use true OWL.
Some will want to use lesser Tuna's, and 450 ohm store bought ladder line.

In a past life, I used to sell RV's. In the RV Sales Business, we used to say "There is an ass for every seat".
This does not mean that "Frank is an Ass", of course.
This simply means that different people want different things, from their RV.

Tuner losses were covered in previous posts. Or you can run them yourself from the numbers below.

Of course things get worse on 160 meters. There are no free lunches.  ;D  I think that fact was well established and I don't think it was ever "advertised" as a 160 meter antenna. Frank uses this antenna only rarely on 160 meters. Functionality on that band was more of a freebie than a design requirement. Frank thought he would give it a try, just to see what could be done. In other words, it's really an 80 and up antenna that will give you something on 160 meters in a pinch. There are many better options (in most instances) for 160 meters. But any antenna is better than no antenna.

Hope to hear you on the air soon.

Thanks Steve!
Right now, I am in the process of getting my 40 - `10 meter antennas "all set"
I think it is really cool that you guys here have "kept AM alive" !
I hope to join some of youon 75/80 someday, maybe even 160!

I own 2 big Dentron Tuners, and a Millen Transmatch, and I am "not scared" to use OWL.
In fact, my home is cement block, and I plan to drill some holes right through the cement blocks, and use threaded metal rods, to come into the shack!
No XYL here to tell me what I can, or can't do.
I will do what I please, in the last 1/3 of my life.

Age here is 59, so that means that 2/3 of my life is over, when you think about it!
I fully intend to "Ham It Up" for the years I have left.

I like your attitude!

Enjoy it while you can.

Thanks Steve!
I own a small roof cleaning company here in the Tampa Florida area.
I make a living, and that's about it.
But if I had more money and free time, and my business would run w/o me, here is what I would like to do.
I would very much like to get me a RV, hit the road, and Ham it up!

Maybe do like a Ham out west did ?
He found a spot where there was an old abandoned rail road tracks, that used to serve a Silver Mine, on the side of a Mountain.
There are telephone poles along the tracks, with wires running for miles!
He had to repair some of the wires, but he drives up there, and hooks into miles of wire, fed against ground!

The long wire antenna he used has gain lobes, some well in excess of even a Beam!

That's the kind of shit that I would like to do someday.

Or park my RV near a saltwater beach, with an Eagle One Vertical, as close to salt water as I could get.

I live pretty much Inland here in Florida. But those Hams lucky enough to live on salt water kick ass.
I knew a Ham down in Boca Raton Florida, on the east coast, with a Hustler Vertical he had mounted on his Dock, right over Salt Water!
When he called CQ on 40 at night, I swear 1/2 of Europe waited in line to work him!

LOL, one time, during field day, I intentionally drove to the Top of the Sunshine Skyway bridge. It is about 200 ft high, over Tampa Bay!

I had an Kenwood TS 50 in the mobile, and a 20 meter Ham Stick.

I let the air out of my tire (had a few cans of compressed air).
The cops came, and I told them I was "waiting for a tow truck"

That bought me about 2 hours of operation time!!!!!!!!!

I called "CQ CQ Field Day, this is KA7NIQ Maritime Mobile" LOL

In the middle of Tampa Bay, 200 some feet up, and armed only with a TS 50 and a Ham Stick, I was able to hold down a frequency, until I simply got worn out!

So, I simply put the valve back in the stem, inflated my tire, then drove away!

I have always wondered what it would be like to operate on the Great Salt Lake, in Utah ?

You may want to insulate the threaded rods from the cement block.  Use some plastic tubing.  Cement block can store moisture during the rainy season.

Fred

Thanks for the Tip!
LOL, now I am wondering where to get some threaded Copper Rods!

Why threaded??


klc

So the rods will stay in the blocks tight, and maybe the washers will keep the termites out ?

Why copper??

But, if you must, there are places online that sell threaded round copper rods.
There are even more places that sell plain round copper rods and you thread them yourself.

Low resistance, and I can't afford Gold  ;)
Plus, my old Millen Transmatch has a copper chassis

Seriously Pete, do u think I will be OK with regular home depot threaded Rod ?

Don't let Pete give you a hard time. He's been using the same crummy 572Bs since 1968.

The difference between copper and threaded rod from Home DeLowes will be minimal. You're only talking about 6 inches or so, right?

I have a Dentrol Clipperton L that uses 4 - 572B's  in it, and they are original!
But then again, they are Cetrons  ;)

Yeah, just enough to go through the cement blocks, no more then 10 inches.

" So the rods will stay in the blocks tight, and maybe the washers will keep the termites out ?  "

Just one word...



klc

That's how I have seen it done out West. I saw a LOT of wire antennas fed with real, home made OWL back when I lived in Seattle.
Probably because of the abundance of tall trees out there, and also because it the late 70's/early 80's, and more old timers were still alive.'

These Hams drilled right through the walls, and used threaded rods to get the OWL through the walls.

I do remember seeing flat washers on the rods.

I just can't recall if they were Copper or not.

There used to be a place in Seattle called Boeing Surplus!

The amount of surplus electronic stuff in there was mindboggling!

Johnson KW Matchboxes were pretty easy to come by, back then.

And there were always heroic home made truly balanced tuners of great power handling floating around.

Me I am done with dipoles and their variations. Yagis as well. Also tried a small magnetic loop. Last year I threw a line up into a tree with my spinning reel and fishing pole (forget the slingshot. The reel thing works MUCH better) It is a 80M long wire 137 feet up no more then a 40 ft average end fed with a 67 foot single wire feeder which comes off at a distinct right angle. I use a HB tuner which is a basic Pi network with 13 taps. From the first moment I used I it has worked. Better then my A3 cushcraft did, or my inverted L or my inverted dual band Vee. Only my 20m ground mounted vertical gets as much love. Why do I like the longwire (and the 20M vertical for that matter) so much? Because my son they work. When I talk people hear me. 20 or even 30 over sig reports compared to " I can just tell you are there sori I cant read u". Even my antique Cw sets one or two tubes get out on this rigging. Never had it so good. I listen on a beverage on my lower band stuff. Finally after 30 odd years I have an antenna that doesn't need improvement. If I go on 160 with my  ARC5 I use the built in inductor to make it work which BTW is exactly what it was designed for , feeding a "short" long wire and I don't use the tuner with either ARC5 (160M and 80M AM phone) . Sometimes we think exotic is always better. Sometimes it doesn't work out that way. Sometimes the old stuff works best. On 20M the 20M vertical made from plumbers 3/4 inch copper pipe, a soup can lid and a 94 Dodge Ram antenna will crack any pile up when running my slop bucket rig barefoot.(TS830S) So while you are all shaking you heads that Canadian station (who just got in ahead of your 2500KW linear feeding a stacked yagi at 150ft) running barefoot would more then likely be me. As I age I have become totally results oriented. Seem strange for sure the best antennas here cost virtually nothing to build and outperform all the exotic crap I ever bought. However for me from this QTH it is so. My AM rig is a DX60B and I run it barefoot on 40M and use my Hb 811A amp on 80M to help out a friend who lives in a S9 noise level QTH
Don   

I think if most tried that at higher power, there would be a lot of RF floating around in the shack...

I myself am lazy, I have dipoles for 80 and 40, coax fed, no tuna.

Yep, non center fed antennas seem to have feedline radiation problems.
Especially at high power levels.

 Unless you run a counterpoise and an elaborate ground....but if your wasting wire on a counterpoise ..may as well double up the  feedline and split the antenna in half !! I dont know how I did it as a novice living at home..I was only allowed 1 wire through the window so it was a  random wire  about 75ft long. I grounded all the equipment to the house ground and that was it. It was a basement shack..I never ran any  real power so I didnt notice any rf bouncing around the shack ...but I know now that it was there !  

Rick

Boy, I sure got some nasty lip bites in the early days of end fed wires.

Nothing like smelling burned spit in the morning...  :o


T

Ouch! Lip burns !  Glad I didnt get any of those....I was only running CW back then...would have been something seriously wrong !

Rick