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FLAT COILS-VS-ROUND COILS

Help with installing an Antenna, or just choosing the right antenna to go with your radio, or your mobile.

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FLAT COILS-VS-ROUND COILS

Post by Guest » Thursday, 10 November 2005, 22:39 PM

WHATS THE DIFFERENCE BETWEEN ROUND-COILS ANTENNAS VS FLAT-COILS ANTENNAS


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Post by Stormbringer » Thursday, 10 November 2005, 23:35 PM

The Flat coils are "Flat" & the Round coils are...well, "Round"! Seriously though, I'm no antenna expert, but, the way I understand it......its the radiation pattern coming off the coils that make the difference. The signal transmits 360 degrees off the round coils, whereas the flat coils direct the signal off the sides? I dunno for sure however! Is there an antenna specialist in the house!?!

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Post by spiderman716 » Saturday, 12 November 2005, 19:18 PM

flat coils generate more audio because more surface area to transmit from :shocked:

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Post by Roadrunner » Thursday, 21 September 2006, 8:57 AM

In theory, the flat coil should be a little better due to what is called the "skin effect" which means the signal travels on the outside surface of the coil. The larger the surface area is, the more effieicent the antenna. But in the real world, at 11 meter freqs. & low power, you wouldn't see much of a difference.

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Post by Amp|-|ibious » Thursday, 21 September 2006, 12:10 PM

Hey guys, I didn't want to change your alls subject. I am having SWR problems with my base antenna. With just the radio on my swr is find through out the am channels but after turning on power my swr is higher on 1 than on 40... 1 being at 1.6 and 40 being at 1.4. Any suggestion how to get it below 1.3?


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Post by North Texas Mudduck » Wednesday, 08 November 2006, 18:30 PM

well im looking at a blank wall trying to picture your setup

give some ideas to put in our head to kind see what your setup is
and antenna

basically give us the who what when where

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Post by Amp|-|ibious » Thursday, 09 November 2006, 11:28 AM

Sorry about that, it use to be listed at the bottom of each post. Not sure what happened to it but here it is. I have a SWP Galaxy 2547 with a Excalibur by Coily. Thanks for the help :D

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Post by jessejamesdallas » Thursday, 09 November 2006, 18:20 PM

Amp|-|ibious wrote:Hey guys, I didn't want to change your alls subject. I am having SWR problems with my base antenna. With just the radio on my swr is find through out the am channels but after turning on power my swr is higher on 1 than on 40... 1 being at 1.6 and 40 being at 1.4. Any suggestion how to get it below 1.3?
Sounds like your radio and amp are a miss-match. I would sugest taking the radio and amp somewhere so they can be matched together.

I had a similar problem with one of my mobiles once, and took the box and radio over to Peakaboo's, and he set the amp to match-up with the radio...after that, problem went away!
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Re: FLAT COILS-VS-ROUND COILS

Post by Sly Dog » Thursday, 21 December 2006, 5:54 AM

Anonymous wrote:WHATS THE DIFFERENCE BETWEEN ROUND-COILS ANTENNAS VS FLAT-COILS ANTENNAS
For all intensive purposes there is an significant difference between the 2 types as far as transmit.

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my 2 cents

Post by Century21 » Thursday, 21 December 2006, 9:58 AM

I have always heard the Flatter coils, because of the skin effect produce a lower angle of radiation.
And for the man with the SWR problem, if you still have it. How are you measuring it, off the radio or a meter after the amp.
With the meter after the amp, SWR in most cases dont change with an increase in power, even when your watt meter shows it, Simply because alot of people have rf coming back on the shield of the coax. Atleast what i been told.

And if your using the built in one on the radio, If its accurate, which most aint, then your need to tune the input on the amp. People like carrying amps and radios to little shops and have it done. But when they take it home they see something different. And they always will. Surrounding objects, line voltage, SWR changes, cant be duplicated in a shop. Pay someone to come to your house with the right equipment and do it.


Just my 2 cents

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Post by mopar2ya » Sunday, 11 March 2007, 15:40 PM

The construction of the coil is merely aesthetic. Choose whichever you think looks pretty. The radiation pattern of the antenna is not determined by the shape of the conductor in the coil.

A coil in an antenna is there to cancel capacitive reactance by providing an equal amount of inductive reactance thereby making the antenna purely resistive. Nothing more, nothing less. Cut it out of a beer can, string paper clips together, wind it out of a railroad rail, it still does the same thing.

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Post by Slowdraw » Saturday, 31 March 2007, 22:05 PM

The shape of the wire, like Mopar2ya said has next to nothing to do with angle of radiation and just a very little to do with efficiency.

Flat wound coils "can" have a higher "Q" (think lower loss here) in most cases due to the fact there is less surface area facing each other between windings resulting in lower capacitance between turns. This allows one to use just a little less wire for the same inductance. At the size of the coils that are used on antennas like the Predator, Monkey, etc., the difference would not be noticeable outside a laboratory.

3 things in respect to loaded antennas (anything shorter than a 1/4 wave whip) that do matter.

Coil shape: There is an ideal proportion for highest Q and lowest loss, that is twice as long as it is wide or a 2x1 shape factor. An example would be a coil that is 8" tall by 4" wide. Again, with the larger coils on the higher end antennas, a little deviation is a moot point, it won't matter.

Coil position: The higher the coil is from the base of the shaft, the less current flows through it and therefore will have lower resistance (Q) losses. power= current(squared)*Resistance..... in other words... if you could measure the current through the coil, and square it, and multiply it by the resistance of the coil, you would have the power lost by the coil.

There is also more loss due to your ground system, which is never perfect, if the coil is closer to the base or feed point of the antenna. This is usually the LARGEST LOSS of any mobile antenna system.

Coil surface conductivity: Most people are aware of this one. A shiny gold plated surface would be ideal, but costly. (I'd pay for this, but who makes one?) Copper, next for a few days until it corrodes. Aluminum would be next best. Hams prefer cadmium plated aluminum, but nobody does this for CB'rs? Why not? Never bother with a shiny chrome plated antenna coil. It looks pretty, but chrome makes a great resistor. Remember the Predator (NOT THE PREDATOR 10K) antennas the truckers used to like many years ago. There was a reason the SWR was flat for so many channels.. It made a great dummy load!

This is probably wordy enough that most ppl won't read it all the way through, so I'll end it here. If anyone cares for more info, I'll write some more. There is still a lot of misunderstood information out there about antennas.

Examples: 2.5/1 swr may mean your antenna is great and you have a really good ground plane for your short efficient antenna. There is a way to achieve a perfect match.

A 1/4 wave whip above a perfectly conducting ground plane would have a 1.5 to 1 SWR reading.

The higher Q or lower loss an antenna is, the narrower the operating bandwidth of the antenna will be. (Beware antennas that show flat across 120 channels) Ground losses figure can into this. I had to learn about this and the two items above, the first time I put an Audio King on the roof of my van and the SWR was 3 to 1!

There is an ideal length of coax, but probably not for the reasons you think!

I can go on, but I run the risk of putting ppl to sleep... LOL

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Post by mopar2ya » Sunday, 01 April 2007, 8:15 AM

******************************************. Who are you? I think I recognize the writing style, I just can't put it together....

LOL!

Mopar

On edit... Sorry... I was reading your posts trying to figure out who you were and saw that you wish to remain incognito. So I edited out my guesses. Anyway, good to see you posting, you are obviously very well informed and I will be watching and learning from you I think.

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Post by clutch » Sunday, 01 April 2007, 19:02 PM

go ahead and keep teaching that's one reason i joined

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Post by Slowdraw » Sunday, 01 April 2007, 20:28 PM

If you know me, you should know my handle... LOL You can always PM me and I'll let you know if you are right.

I'll post more about antennas if I see a good question, and I don't mind ppl disagreeing with me. If you do have a different point of view, please support it with book knowledge, not anecdotal evidence....

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Post by Shaft » Sunday, 01 April 2007, 20:39 PM

Slowdraw wrote:If you know me, you should know my handle... LOL You can always PM me and I'll let you know if you are right.
I had only heard stories about you and guessed who you were from your first post.
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Post by BOOTYMONSTER » Sunday, 13 May 2007, 9:20 AM

mr coily went from flat to round coils and its now a 10k wannabe/lookalike ....................for what ever its worth .
of course.............................
theres nothing like the real thing baby <<<<<someone should use that in a song . :twisted:

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Post by MOONSHINER » Tuesday, 22 May 2007, 11:12 AM

BOOTYMONSTER wrote:mr coily went from flat to round coils and its now a 10k wannabe/lookalike ....................for what ever its worth .
of course.............................
theres nothing like the real thing baby <<<<<someone should use that in a song . :twisted:
i noticed that, kinda looks like a 10k copy to me...

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Post by 209 first class » Saturday, 22 September 2007, 5:19 AM

10k copy? i hope you guys dont think 10k invented this style of antenna. (center loaded whip) :D i dont know who did, but in the city library there are ham books from the 50's-60's with those kinds of antennas. 209
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Re: coils

Post by Circuit Breaker » Saturday, 22 September 2007, 5:21 AM

spiderman716 wrote:flat coils generate more audio because more surface area to transmit from :shocked:
Um, no. No antenna in the world is going to make your audio louder because it has absolutely nothing to do with the audio chain.

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Re: coils

Post by BOOTYMONSTER » Saturday, 22 September 2007, 7:35 AM

Circuit Breaker wrote:
spiderman716 wrote:flat coils generate more audio because more surface area to transmit from :shocked:
Um, no. No antenna in the world is going to make your audio louder because it has absolutely nothing to do with the audio chain.
true dat CB .

it seems nobody in the past 20 or 30 years has made a "new" antenna that hasn't been done before . the seemingly different ones to us newbies just seem to be different aspects of old designs combined in shinny new ways that the old timers so gleefully point out to temper our enthusiasm and make us feel ashamed for our excitement . my point was that a major maker switched his design from flat coils to round and now his current antenna looks like a 10 k .

its all good 209 , just felt like tossing a rib bone at ya . :wink:
if everybody wanted the same thing there would only be one mic,one radio,one amp and one antenna . this hobby has many options for many opinions .



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I need a new anttena!!!!!!!!!!!

Post by 403 » Sunday, 16 March 2008, 19:52 PM

Were do yo suggest i buy one from???10k is what i want!!!My 102" whip is not doing the job!!!!! :cry: :cry:

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RE FLAT COILS-VS-ROUND COILS

Post by Foxhunter » Sunday, 08 June 2008, 23:43 PM

Anonymous wrote:WHATS THE DIFFERENCE BETWEEN ROUND-COILS ANTENNAS VS FLAT-COILS ANTENNAS
That sounds like a trick question. :wink: To a "junior" operator still learning like myself one difference is obvious and that would be strength----I'd think the tubular design would be much improved. Perhaps the question could be what is the ADVANTAGE of the two design methods. As another post-er stated that naturally skin-effect will always come into play with a radiator or ground---but without an actual circumferential measurement the "apparent size" of a flat-coil can be deceiving. Take any small tubular section of pipe, a copper pipe coupling for instance and cut it lengthwise and unroll it----wow----now it's a "wide looking" flat piece. I went thru that whole argument with a co-worker over his MonkeyMade vs my Predator10K and demonstrated that my "tiny tubes" as he called them, were slightly more surface area than his "wide-looking" flat bands. The appearance is deceiving but measured and electrical length leaves no guesswork. Tubular designs are much stronger structurally so that is a definite difference and advantage.

Now I wouldn't be sure though either what effect, radiationally, the flat, "2 sided" bi-directionally opposed MM-type antenna would have as opposed to the omni-directional shape of a tubular coils such as the 10k-type. That's really had me wonder and have any of our antenna engineers here considered or know what the advantage one might have over another in that respect. That is my humble observation only and have read at-length on antenna theory vs antenna fact and realize that even antenna engineers and experts disagree in many instances.

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Post by KI4MSJ » Monday, 09 June 2008, 3:17 AM

Can't he just retune with the amp in line?
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RE FLAT COILS-VS-ROUND COILS

Post by Foxhunter » Monday, 09 June 2008, 10:15 AM

Anonymous wrote:WHATS THE DIFFERENCE BETWEEN ROUND-COILS ANTENNAS VS FLAT-COILS ANTENNAS
:!: Back to the original topic: Anyone who really understands antenna design/theory care to tell us, for comparison's sake, DOES ONE DESIGN HAVE AN ADVANTAGE OVER ANOTHER in regards to either flat or coiled shape and resulting performance ???

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RE FLAT COILS-VS-ROUND COILS

Post by PONY EXPRESS » Monday, 10 November 2008, 19:10 PM

Anonymous wrote:WHATS THE DIFFERENCE BETWEEN ROUND-COILS ANTENNAS VS FLAT-COILS ANTENNAS
Here you go on Flat vs Round .here is what the BIG BOYS do on antennas

The coil in front is made from 1/2 inch ROUND copper tubing. That first element is 82 feet long and the boom is 74 feet long. This antenna is a 19 element log periodic, 4-30 MHz, but it works fine on 75 meter phone. It weighs 1600 pounds and sits on top of a 100 foot self supporting tower. The antenna is fed with 1 5/8 inch hardline! (10 to 14 db gain)
You do not have the required permissions to view the files attached to this post.
Its not a real radio unless it has tubes and USB/LSB on the front panel ....



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RE FLAT COILS-VS-ROUND COILS

Post by jessejamesdallas » Monday, 10 November 2008, 19:41 PM

Foxhunter wrote:
Anonymous wrote:WHATS THE DIFFERENCE BETWEEN ROUND-COILS ANTENNAS VS FLAT-COILS ANTENNAS
:!: Back to the original topic: Anyone who really understands antenna design/theory care to tell us, for comparison's sake, DOES ONE DESIGN HAVE AN ADVANTAGE OVER ANOTHER in regards to either flat or coiled shape and resulting performance ???
Let me put it as simple as I can....
Ever see a "TV Antenna" or Car Stereo Antenna, or Beam Antenna, made from Flat Stock Aluminum?...There is a reason!

Heck...Even Satellite TV Dish's are round...

I did read a post one time on this by the way..How true it is, I'm not sure, but it did make some since.

The post stated that flat coils radiate the signal off the edges of the coil, and Not the surface area like what some antenna builders would have you to beleive...And round coils, since there are no edges, do radiate the signal off the entire surface area. (like I said thou...I don't know just how true that statement is, but it made since when I read it)

I've used both flat, and round coiled antenna's, and like the round better if for no other reason, they are lighter in weight than the Flat coiled...and catch less wind.
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Post by drdx » Monday, 10 November 2008, 20:17 PM

I doubt you'd see the difference in performance between the 2, as I know I haven't. In the big antenna picture I've loaded and talked on everything from regular antennas to aluminum foil, to balcony rails, to gutters and they all work if you can get a match.

CAUTION, USELESS RANT ALERT: How about no coil at all? Maybe a shortened whip with a capacity hat, or some linear loading? Maybe an aerodynamic fat element short coil free design with a small capacity hat for good measure? Who's with me here? Coil loading is the LEAST efficient form of making the antenna a good load, so why is it so popular? Convenience I guess, but just as everything else has evolved, I'm hoping antennas will too. Hopefully one day the coil will be a symbol of what we all did before we saw the light. I think it will be linear loading, but that's just a guess, but I do know that eventually someone will invent the new standard, it has to be just a matter of time. Just think, 25 years ago when mobile amps were just a few hundred watts and everyone thought that was the limit, and look at them now. Radio wise, I think we may have stepped back in quality, but there have been strides in capability especially on ham rigs.

The antenna is the last and most important frontier of performance, so why dwell on the present? Move forward. The coil to the antenna is our kryptonite. We just have to get past it. The theory and laws of physics won't change but we will be able to squeeze the most out of it one day. I'm hoping for some new space age material with a radiation factor (like a velocity factor in coax) that offers full length resonance but at a much shorter height. Maybe some miracle material that at 2 feet radiates like 9 feet of our currently used materials. Fatter elements tune shorter so there has to be some better thing to use. Once we get there we'll be onward to mobile antennas, maybe collinear designs, with actual GAIN in a mobile. How about that for possiblity?

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Post by 'Doc » Saturday, 06 December 2008, 6:56 AM

The shape of a coil only affects the inductance and/or reactance it produces, which is the whole point to having a coil at all. No matter what the shape of a coil, some are 'better' than others, that coil doesn't radiate any more than an equal length of wire/tubing will (not the straightened out length, but the length/height of the coil it's self). Anything having sharp points or edges is a sort of 'no-no' with RF. Those sharp points/edges tend to produce sparks at lower voltages than do rounded points or edges, and sparks means that energy isn't being radiated as -useful- RF.
An antenna, all antennas, have nothing to do with the quality of the audio signal being radiated. They can't affect audio, the radio does that. The only things you need worry about with an antenna is will it 'fit' where you want to put it, is the matching of that antenna to the feed line/radio sort of easy. And most important, is it's radiation pattern going to put a signal where you -wish- it would go... at least part of the time?
And lastly, the only good reason to have a coil in an antenna at all is to shorten that antenna to some usable/reasonable length.
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Re: coils

Post by pacbtech » Monday, 16 February 2009, 14:55 PM

Circuit Breaker wrote:
spiderman716 wrote:flat coils generate more audio because more surface area to transmit from :shocked:
Um, no. No antenna in the world is going to make your audio louder because it has absolutely nothing to do with the audio chain.

I'm glad I'm not the only one who saw that mistake.

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Re: FLAT COILS-VS-ROUND COILS

Post by linearone » Monday, 30 March 2009, 15:51 PM

dont tell jo gunn that lol....
Its CB radio, plug and play technology, its just not that hard folks...



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Re: FLAT COILS-VS-ROUND COILS

Post by Pro-Tech » Monday, 30 March 2009, 18:45 PM

I visited Dubbs CB shop last week on I-70 in the Land of Lincoln, just west of the Indy border. And they only carry and sell flat coil antennas like Browning and Monkey Made. These gentlemen bragged of thier membership in the HAM world and are antenna scientist. They informed me after testing and expierementing that only flat coil antennas recieve better than the round. And they will only sell flat coils. They also do not believe in selling fiberglass antennas for ten and eleven meter radios, but will sell HAM fiberglass antennas. Very nice and intellegent people there and was impressed with the store lay out. The also wanted to test all the different models of the Bad Boy brand so I left them with one of each. I'm going to be passing back through there in a couple of weeks and I can't wait to see thier test reports. 8)

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Re: FLAT COILS-VS-ROUND COILS

Post by jessejamesdallas » Monday, 30 March 2009, 19:00 PM

Pro-Tech wrote:I visited Dubbs CB shop last week on I-70 in the Land of Lincoln, just west of the Indy border. And they only carry and sell flat coil antennas like Browning and Monkey Made. These gentlemen bragged of thier membership in the HAM world and are antenna scientist. They informed me after testing and expierementing that only flat coil antennas recieve better than the round. And they will only sell flat coils. They also do not believe in selling fiberglass antennas for ten and eleven meter radios, but will sell HAM fiberglass antennas. Very nice and intellegent people there and was impressed with the store lay out. The also wanted to test all the different models of the Bad Boy brand so I left them with one of each. I'm going to be passing back through there in a couple of weeks and I can't wait to see thier test reports. 8)
They only sell Browning and Monkey Mades? Wish you would have dropped off a Predator 10K while you were at it! But, there's not allot of difference between the 10K design and the Bad Boy design, so I would be intrested in what they have to say about the Bad Boys...Personally, I think they must be getting a real good deal from Monkey Made, if that's one of the only antennas they sell...
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Re:

Post by Master Chief » Thursday, 02 April 2009, 9:37 AM

mopar2ya wrote:The construction of the coil is merely aesthetic. Choose whichever you think looks pretty. The radiation pattern of the antenna is not determined by the shape of the conductor in the coil.

A coil in an antenna is there to cancel capacitive reactance by providing an equal amount of inductive reactance thereby making the antenna purely resistive. Nothing more, nothing less. Cut it out of a beer can, string paper clips together, wind it out of a railroad rail, it still does the same thing.
Mopar was the only one to get this right! Thank GOD, I was worried! There is an advantage to a larger diameter conductor, but yes, you can make an antenna out of paper clips or 1" tubing and BOTH will work! A flat conductor will have more SURFACE AREA than the same size round conductor. Since the energy flows only on the surface, a larger surface area is better.

More audio folks? An antenna does not create or diminish audio. A coil does not change your angle of radiation. A coil does not radiate in the way you think it does. If you have no idea what you are talking about, you should resist the urge to submit a reply!

You would be much better with a full length radiator than any coil type antenna. The larger the radiator, the better......to a point. Driving down the road with a 8', 1" diameter copper wand doesn't make much sense......but on the battle line it sure does!

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Re: FLAT COILS-VS-ROUND COILS

Post by Foxhunter » Thursday, 02 April 2009, 11:02 AM

I guess if you're "gonna do coils" you could go all the way !

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As far as Masterchief's comments go-------if the flat coil's antenna coil surfaces radiate on both sides inner and outer surface of the flats, then certainly the flat coil stock has more surface area to radiate from. If the antenna were to radiate from only one side the outside of the flats , then still the flat coil has more surface area, not much but is certainly measurable.

Specifically for a MonkeyMade MM9, even if only the one outside-facing coil surface were radiating, it still has more surface area than the Predator 10K coil. Although I like my Predator antennas, the measurements are correct and the MM's have more surface area either way.

In the end:

Coils = Loss

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Re: FLAT COILS-VS-ROUND COILS

Post by Master Chief » Friday, 03 April 2009, 12:07 PM

Foxhunter wrote:As far as Master Chief's comments go-------if the flat coil's antenna coil surfaces radiate on both sides inner and outer surface of the flats, then certainly the flat coil stock has more surface area to radiate from. If the antenna were to radiate from only one side the outside of the flats , then still the flat coil has more surface area, not much but is certainly measurable.

Specifically for a MonkeyMade MM9, even if only the one outside-facing coil surface were radiating, it still has more surface area than the Predator 10K coil. Although I like my Predator antennas, the measurements are correct and the MM's have more surface area either way.
Where did I say the coil radiates? I didn't. Especially the "inside/outside" foolishness! I'm talking about surface area. A 3/8" flat stock will have more surface area than a 3/8" round conductor. However, a 1" round conductor will have more surface area than a 3/8 flat conductor.

My point is, whether the stock is flat or round doesn NOT matter. Its about the surface area. Coil radiation is minimal at best.

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Re: FLAT COILS-VS-ROUND COILS

Post by Foxhunter » Friday, 03 April 2009, 16:26 PM

Master Chief wrote: Where did I say the coil radiates? I didn't. Especially the "inside/outside" foolishness! I'm talking about surface area. A 3/8" flat stock will have more surface area than a 3/8" round conductor. However, a 1" round conductor will have more surface area than a 3/8 flat conductor.
My point is, whether the stock is flat or round doesn NOT matter. Its about the surface area. Coil radiation is minimal at best.
I didn't say the coil section radiates "extensively" or rivals the whip section as the main radiator did I? Did I say you said that either? But it is there in many instances despite what a coil's "job is" and can be easily checked with a voltage present on the coil section of these type antennas---period. That may not their purpose but just the same it is measurable.

And since we are not discussing "whips" or "shafts" or "tips" and the thread is about "flat vs round coil" sections, I wanted to comment on the difference in overall surface area on the coils between these two type of popular designs----if I "have your permission" there Captain.

Foolishness? Leave your insults for someone else really. I felt like mentioning the simple observation that a piece of flat stock has two bi-directional surface areas (an inner & outer) rather than a tubular piece of metal that only has one outer surface----hence more surface area total for the flat stock coil.

Many may not have taken the time to measure the two antennas side-by-side to notice the fact that a Monkey Made has more total surface area than a Predator. And since these seem to be the two most popular "flat vs round" coil antennas going, I felt like mentioning it. Excuse me if you didn't read what I was saying correctly or perhaps I should've worded it differently, for "comprehension" reasons.

LOOK: If anyone is interested in reading a good comparison article with real data on two of the more popular "coil" antennas I was attempting to mention above (the Predator and Monkey Made antennas) here is a decent review article here: (it also provides numbers against the 102-whip and Francis 5'5" stick)

CB Radio Antennas, Which one is right for you? CBradiomagazine
http://cbradiomagazine.com/Feb%202007/C ... %20you.htm" onclick="window.open(this.href);return false;

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Re: FLAT COILS-VS-ROUND COILS

Post by Master Chief » Saturday, 04 April 2009, 0:33 AM

Foxhunter wrote:I didn't say the coil section radiates "extensively" or rivals the whip section as the main radiator did I? Did I say you said that either?
You sure did, and I quote, "As far as Masterchief's comments go-------if the flat coil's antenna coil surfaces radiate..."
Foxhunter wrote:But it is there in many instances despite what a coil's "job is" and can be easily checked with a voltage present on the coil section of these type antennas---period. That may not their purpose but just the same it is measurable.
We don't disagree and if you go back and read it again, you will see that.
Foxhunter wrote:And since we are not discussing "whips" or "shafts" or "tips" and the thread is about "flat vs round coil" sections, I wanted to comment on the difference in overall surface area on the coils between these two type of popular designs----if I "have your permission" there Captain.
It's Master Chief, not Captain. Now who is insulting who?
Foxhunter wrote:Foolishness? Leave your insults for someone else really. I felt like mentioning the simple observation that a piece of flat stock has two bi-directional surface areas (an inner & outer) rather than a tubular piece of metal that only has one outer surface----hence more surface area total for the flat stock coil.
Time to back this one up! You stated a flat conductor radiates on the surface ("flats") facing the outside, and not on the surface ("flats") facing the inside. Then you follow this up with a comment that a round conductor does not. I didn't know physics worked differently where you live. But I have an open mind so please educate me.
Foxhunter wrote:Many may not have taken the time to measure the two antennas side-by-side to notice the fact that a Monkey Made has more total surface area than a Predator. And since these seem to be the two most popular "flat vs round" coil antennas going, I felt like mentioning it. Excuse me if you didn't read what I was saying correctly or perhaps I should've worded it differently, for "comprehension" reasons.
You're excused, but I understood exactly what you were trying to say, so no comprehension problem here. I don't doubt that the MM coil has more surface area than the P10K, but who cares?! I'll bet they both work the same, but I'd take a P10K over a MM any day! The reasons are simple; the P10K is a solid performer and does not rip mounts off your vehicle. The P10K is lightweight and should you ever need to rebuild it, you can get the parts. The P10K comes with excellent support. But who cares why I would buy one?
Foxhunter wrote:LOOK: If anyone is interested in reading a good comparison article with real data on two of the more popular "coil" antennas I was attempting to mention above (the Predator and Monkey Made antennas) here is a decent review article here: (it also provides numbers against the 102-whip and Francis 5'5" stick)

CB Radio Antennas, Which one is right for you? CBradiomagazine
http://cbradiomagazine.com/Feb%202007/C ... %20you.htm" onclick="window.open(this.href);return false;
This article, written buy someone who states he's, "not an antenna expert, nor trying to pretend (he has) the knowledge of an antenna engineer, is entertaining at best. Its full of opinions but isn't backed by any technical data. If you were to take this article as written, the P10K wins (bandwidth and SWR are better than the MM). His OBSERVATIONS state that both antennas work great. Its too bad he didn't go all the way and actually test them.

Since we are supposed to be talking about coils, let's get to it! Coil designs can vary widely......and so can their performance......
My friend Ron builds the Scorpion Antenna and wrote, "We have wound and tested every size wire at just about every thread pitch you can imagine and testing confirms that #10 gauge wire at 6 TPI on a 3 inch coil always produces the strongest signal!" See those results here: http://scorpionantennas.com/test.html" onclick="window.open(this.href);return false; . He also knows and is friends with Charlie from Hi-Q Antennas, who is the undisputed HF mobile antenna maker. Charlie tested the coils for Ron using something other than a "MFJ 259-B and an external swr meter". If you doubt Charlie's abilities, know that he builds antennas for the military...... http://www.hi-q-militaryantennas.com/" onclick="window.open(this.href);return false;

What does this have to do with the MM and the P10K? Their coil designs are very different. The close spacing of the MM coil lends itself to arcing (not a myth). The P10K coil is spaced out and doesn't have complaints of arcing. Its my understanding, and I'd have to talk to Kale again, but I believe Kale went through a number of coil designs himself, before settling on his production configurations. Based on user reports, Kale got it right. Its my OPINION that the P10K has a better coil configuration over the MM. I'd like to get the chance to prove it if I can get my hands on a MM antenna.

While there is no doubt the MM has a larger surface area coil, it doesn't mean its a better design. Even the review you listed pointed that out. The Wilson 5000 has a larger diameter coil than the Wilson 1000 and performs better. Sometimes the bigger coil is better! In the case of the Wilson 5000, it was designed by an antenna engineer.

Maybe we can get someone who is qualified to test the two coils......

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Re: FLAT COILS-VS-ROUND COILS

Post by Foxhunter » Sunday, 05 April 2009, 20:35 PM

Master Chief,

We ALL know what is inside a hollow tubular antenna-----a chewy caramel center!

And another thing everyone knows is that ALL electronic components have smoke inside. When improperly used or abused, the smoke comes out and they have to be replaced. The MORE smoke, the higher quality the component was and the more expensive it is to replace. :albino:

Really, Master Chief my apologies to you if you'll accept them, I was unclear in my prior post and maybe offensive in my second to you. I'm more in agreement with your statements than anything to begin with in the first place and didn't mean to appear somehow to be commenting on your posting in an adversarial or disagreeing way at all. Was trying to elaborate or build on what you said not disagree, that's all-----in my own somewhat limited way. I did a poor job trying to convey what I was trying to describe.

As stated above and from many other sources, it is true that RF does not like sharp edges and that rounded surfaces are much more conducive for effective surface emission. 100% agreed also and have stated many times prior as well about the problem with arcing at high-powers with the flat-coil antennas. There is a CB shop in Virginia that has a "wall of shame" of various bad and damaged products. The "centerpieces" in the collection are an exhibit of Monkey Made antennas that all have burned edges and arc-over spots between the coils! For those QRP-ers it shouldn't really be an issue at all, but if you are into QRO-ing there can be a fatal flash-over. Scary.

I own a Monkey Made MM9 as well as two Predators, a Browning coil and another K40 now also. Although there are qualities I like about the MM9 I think if I were "stranded on a desert island" I would opt to take a Predator with me.

As far as the "skin effect" on the surfaces as it relates to physics. Although I wish I had his knowledge, I like to frequently have lunch or dinner on a regular basis with an old friend who is a physicist. We meet and love to discuss the world, culture, science and astronomy & cosmology. I myself do have many well-rounded interests, but don't specialize enough to have a completely thorough intricate knowledge of antenna theory and electromagnetic radiation (as it relates to antennas). I have begun understand it fairly well, but not completely. There are still many facets.

We do know that there is a downside with sharp edges to a conductor, that's clear. But despite the flat-type possibly having a greater surface area, it can be offset by the fact that RF and currents like rounded surfaces.

However there is an effect that occurs within the "inside surface" of a tubular section that is different than the one along the tube's outer surface. An EMF field is present within the tube and it partially negates and hampers it's ability to efficiently emit/receive signal. In a sense, it is partially "trapped" or shielded and there is a definite interaction between the voltages within and the metal material itself that makes up the tube, especially depending on thickness. Anything thicker than "skin deep" plays a role of partial "shielding" and is not invisible to RF. I can only say that the inner and outer surface areas, square inches total, can not be simply added up to sum a total surface area that is completely RF "viable".

To digress a little I'm glad that we have the people that we do writing and contributing to the many threads and topics. I wish I knew it all but admittedly have still much to learn. Still trying to grasp a new idea or concept every day that I was previously unaware of or unsure of the day before.

It seems that from reading that the HiQ antennas are definitely of high-quality and I do admit though I don't own one. It would seem that Mr.Alan Applegate seems to give an excellent description of his and the resulting performance. I do take a lot of stock in what the gentleman has to say and would consider him of "expert" status when it comes to the field in general. He has been very kind to me personally and has provided much via his website to the hobby and to me personally via email exchanges on many occasions, and I am thankful.

I would agree the CBRadiomagazine article is simply a review, although it does provide some side-by-side comparison data. Albeit only some. Like all things online much of it must be taken with some precaution. I only cited it because there are few like it at all, and that's surprising!

I am clearly not a big fan of "manufacturer's claims" either, or by those who wholeheartedly promote-----due to a personal financial stake or vested interest. I would really like to see actual unbiased antenna-field, lab quality antenna comparison data on the most popular antennas on the market. Something of a "Consumer Reports" for antenna buyers to actually read true comparisons instead of promotional literature, hearsay or disinformation claims between rival companies or representatives. It would dispel many popular beliefs I think and manufacturer claims.

In the end, ALL coils (and traps) equate to nothing but loss and inefficiency. So all the popular "coil type" coil loaded antennas are a serious compromise at best. No real comparison to a straight whip antenna, period.

Even with the above in mind about the coil antenna not comparing at all to the straight whip, look at what the US Army Radio Wave and Propagation manual has to say about even the whip. So if a typical whip is a poor choice even to begin with, what does that say about the seemingly popular "big coil" type antennas ?
US Army Radio Wave and Propagation Manual
Whip Antenna
----The worst antenna to use is the whip antenna. The term whip in our case means an antenna that is (15) or X=feet in length. The only good thing that can be said of a whip is that it is convenient for mobile or mobile at-a-halt situations. We can improve our whip (in the AN/GRC-142) by adding sections to its normal 15-foot length. We should add three more sections (for 2 -12 MHz use) or until our whip approaches a quarter wave (234/f) in length. Because the mast base loses some of its rigidity, you may have to guy the whip. The reason the whip is so poor is because of the loading coils used to match the transmitter to the antenna. Most of the power is consumed doing the matching.
To cite Mr.Applegate for some additional information, the chief factors to consider in antenna selection, design and construction for those who might be interested.
K0BG / Antennas, Commercial

The number one factor with respect to efficiency is ground loss (Rg). Minimizing ground loss is priority one!

The number two factor is length. An antenna's radiation resistance (Rr) is a factor of the square of the overall length. Shorter lengths also require more inductance in the loading coil. Think of it this way; half the length, less than one fourth the efficiency.

The number three factor is loaded coil Q. Once coil Q surpasses about 350, there is little advantage to increasing it. If the Q is under 150 (as most commercial antennas are), doubling it can more than double efficiency in some cases, and at least 50% in most cases. In equations, Q losses are referred to as Rc (resistance, coil).

The number four factor is matching. The fact is, if your antenna doesn't require matching, you either need a better antenna, better mounting, or both!

The number five factor is construction. Some commercial antennas are so poorly made and/or designed, a blind man would rate them an F! So, if you're favorite antenna is listed here as an F, you'll know why.
http://www.k0bg.com/" onclick="window.open(this.href);return false;
Now-a-days I mainly keep these to ward-off intruders in case of a break-in.
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Re: FLAT COILS-VS-ROUND COILS

Post by Master Chief » Monday, 06 April 2009, 12:05 PM

No problems here Foxhunter. "Foolishness" is a hot word that can spark a person's emotions...and should be used sparingly! I'll own that one. You are a good man!

I agree with everything you said in your last post. I think it is interesting that K0BG uses a Hi-Q antenna also. I'll see Charlie (Hi-Q) in a couple of weeks and I'll have a discussion with him about the coils. Charlie has done many many many many tests on many many many coils. He -IS- the coil king!

You are also correct about "sharp edges", but I'm not saying that the MM has a bad designed coil (other than the spacing between coils, which the local shop you mentioned has pointed out......despite the CB Magazine article). Ther are advantages (surface area) and disadvantage (sharp edges) of a flat conductor. As far as GROUNDING a radio station, you WANT a flat conductor!

At the end of the day, I'd also take the Predator over any other "big coil" antenna. It is a design that is tried and true and has proven itself over the years! I know some have had issues with water ingress and this is a problem. A small weep hole at the bottom will fix this problem as well as a simple design change where the whip enters the body. Unfortunately, this design change would mean the whip would not be as adjustable......I vote for the weep hole.

While I feel the predator is the best of the best "big coil" CB antenna, it could be made even better with a larger coil. But would that be practical? Kale really did his homework. As K0BG pointed out, any coil Q above 350 doesn't show much of an increase in performance......I wonder what the Q is of the Predator? I've never measured it. One advantage to the CB "big coil" antennas is that they were designed for one band which allows their builders to get the right coil to match the band. The ham antennas must cover MANY bands! What works on one frequency will be a compromise on another.

As far as many of the users out here, they buy what they think LOOKS good. The majority of CB operators don't know or don't care about what is better or right. They don't care that their audio is distorted, they can't be understood, that they are splattering all over the band, that their receivers are deaf, etc. They will buy what everyone SAYS is the best, without doing their due diligence. Its too bad as CB radio has gotten its bad press because of these operators.

It is my hope that someone picks up the Predator line from Kale, who is not doing well because of health issues. My guess is that he doesn't make much money and does it more for the love of the art than the money. Could you build one for $65.00? You know he sells them to his dealers for less than that. Unless he has access to a free CNC machine that can kick out parts by the hundreds, his labor alone wouldn't make it worth it. Let's just say that I'm glad i have a couple!

FINAL WORD:
If you have a choice between the MM or the Predator, get the Predator......its a better antenna. As far as flat verse round, it depends on the design of the coil. You can have a good designed flat coil and a bad designed round coil (seen those too!). The flat coil on the MM arcs......this is BAD. The round coil of the Predator doesn't......this is GOOD! :cheers:

Enuf said.

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Re: FLAT COILS-VS-ROUND COILS

Post by Slowdraw » Wednesday, 08 April 2009, 7:06 AM

>The number four factor is matching. The fact is, if your antenna doesn't require matching, you either need a better antenna, better mounting, or both!

I think that this is a golden rule that is the most forgotten by a lot of CB'rs. Probably not by the ones reading this thread.

What is important, I think, about an antenna loading coil design are 2 things.... Height above ground and Q, both of which effect antenna loss. The higher the coil is mounted above ground, the higher the RF voltage is and and the higher the instantaneous radiation resistance and the less the coil losses enter into the total antenna loss. This to me is the absolutely most important factor in a loaded antenna construction. Use as long an initial shaft as you can get away with!Also, according to antenna books I've read, more signal is radiated from the high current portion (below the coil) of the antenna than the low current portion. Very little signal is radiated from the coil, very damn little. (Sorry MM) Top center loaded antennas are often considered the best compromise between coil size and coil location. The higher a coil is above ground, the more inductance is needed to tune the antenna to resonance, for a particular length and minimal losses. Hams often use a coil at the very top of an antenna with capacity hat to add more reactance and keep the RF voltage at the top of an antenna lower than a Tesla coil's. :-) This works, but makes for a complicated and fragile antenna.

I've sometimes read that flat wire coils have a slightly higher Q than round wire coils due to the fact of lower capacitance between coil turns. (Less conductor area exposed to the next wrap.) This in practice yields very little gain in Q though, plus an an added problem of arcing when the weather and power levels are just right.

The ideal shape factor is an important, but neglected design rule for many antennas, including a couple of Kale's. We've discussed this a couple of times, but he just smiles and says "Hey, they work!" Can't argue with that.. LOL The ideal shape for best "Q" (ie. lowest loss) is 2 to 1. That is twice as long as it is wide. Most of his coils conform pretty close to this shape factor. Maybe it is a good idea, if you need more inductance, to break the coil up into 2 coils as he does with one of his designs. And yes, he personally winds all his coils by hand.

Another important factor, is the coil surface resistance. Too many coils were made (and still are) with chrome plated coils... YUK! Note that they will always be easy to match and very broad banded. Copper is great, but corrodes easily. Aluminum is probably the best unplated or unvarnished surface. Tin plated copper (Typical ham antenna) is o.k., but pretty lossy on higher frequencies. Chrome is the absolute worst.

Top loading is a good thing too. Anything that shortens an antenna without the added loss of loading coils will help improve the efficiency of an antenna. It will also make the input impedance lower (as it should) and require more work in matching.

If you read this far, sorry about the rambling. Blame it on my age :-)

Slowdraw

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Re: FLAT COILS-VS-ROUND COILS

Post by 'Doc » Wednesday, 08 April 2009, 7:51 AM

A mechanical advantage? Maybe.

An electrical advantage? No. Meaning, the idea of a particular shaped coil radiating 'better' than another shape is just not worth considering at HF. There is no practical electrical difference.

If 'looks' is what you're after, pick the one you think is 'best'. If electrical performance is what you're after, waste your time with some other aspect of the antenna (such as it's color?).

Now if you really want a 'different' loaded antenna, why not a 'pancake' style coil? Dang sure ought'a shorten the thing! 8)
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Re: Re:

Post by Double D » Wednesday, 15 April 2009, 12:33 PM

Master Chief wrote:More audio folks? An antenna does not create or diminish audio. A coil does not change your angle of radiation. A coil does not radiate in the way you think it does. If you have no idea what you are talking about, you should resist the urge to submit a reply!
I wonder where all these myths came from... :aaargh:
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Re: FLAT COILS-VS-ROUND COILS

Post by Gummybear » Wednesday, 15 April 2009, 16:35 PM

I think this has too be the most informative posting i have seen in a while on here. There should not be any confusion on any of this antenna stuff now.

Now we just need a step by step manual on proper antenna setup from start to finish. Then no one can or will ever mess up installing a antenna properly. at least not anyone from this site.



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So foxhunter, what do you use for a antenna then?
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Re: coils

Post by 209 first class » Thursday, 27 August 2009, 21:57 PM

spiderman716 wrote:flat coils generate more audio because more surface area to transmit from :shocked:
coils dont transmit..... read any in depth antenna book and you will learn coil loaded antennas radiate most of the signal directly above the coil out the vertical element. even the wilson fiberglass top loaded antennas have a brass element above the coil. where did you learn coils generate more audio? 209 massachusetts
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Re: FLAT COILS-VS-ROUND COILS

Post by 209 first class » Thursday, 27 August 2009, 22:18 PM

.

LOOK: If anyone is interested in reading a good comparison article with real data on two of the more popular "coil" antennas I was attempting to mention above (the Predator and Monkey Made antennas) here is a decent review article here: (it also provides numbers against the 102-whip and Francis 5'5" stick)

CB Radio Antennas, Which one is right for you? CBradiomagazine
http://cbradiomagazine.com/Feb%202007/C ... %20you.htm" onclick="window.open(this.href);return false;[/quote]
======== there are no signal tests, and no proof in that article. just because an antenna has lower swr, does not mean it is more efficient ,lol. its a selling gimmick. so..if i take a round tube, and pound it flat with a hammer, it has more surface area ? it will have the same surface area... if a coil is any thicker than the vertical radiator, its not adding anything. what makes a coil efficient is the spacing,material and dielectric. everyone will try to tell you different, but know for a fact any antenna with a coil is not as efficient as its full length original size. all coils induce loss. some are so close u almost couldent tell, but will never equal. 209
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Re: FLAT COILS-VS-ROUND COILS

Post by Texas Mobil 219 » Friday, 28 August 2009, 2:04 AM

Its a 10K world.
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Re: FLAT COILS-VS-ROUND COILS

Post by drdx » Friday, 28 August 2009, 5:34 AM

Texas Mobil 219 wrote:Its a 10K world.

I thought you were MR. "108 INCH WHIPS RULE". You mention them and have them in your signature. I just thought I'd bust your chops a bit on that. Have a good one.

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Re: FLAT COILS-VS-ROUND COILS

Post by 209 first class » Friday, 28 August 2009, 7:25 AM

no, its not a 10-k world. its a world where people suggest an antenna they like, or an antenna they carry in thier store, or thier friend says is the best. the worst is that the 10-k is less efficient than the 1/4 wave whip. its a fact, period. the sad part is no one offers proof, i offer info to the contrary available in antenna textbooks. lets say i marched around proclaiming the k-40 was the best antenna with no proof, would you take any of my other advice ? i guess it personally bothers me when people give opinions that have no factual basis. ("it works better" and "it transmits better" ). how bout some receive measurments? you will never see any... and if you do they are flawed. any antenna adjusted with coax and a meter will not show its true measurements. most people do not even know for accurate readings on cb receive/S meter you need a radio with the rf gain before the agc circuit,not after. and u need the control antenna set to about 3 on the meter. after about 5 s units, the agc comes into operation like a compressor/limiter and evens the readings out some, ruining those fine differences. please do not follow any of my advice,or suggestions . check it in a book and see what is correct. 209 massachusetts
2zero9 workin this top secret station in massachusetts.



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Re: FLAT COILS-VS-ROUND COILS

Post by drdx » Friday, 28 August 2009, 7:36 AM

The only thing that cracks me up more than this is those coil loaded BASE antennas. If you think coils are that great, then build yourself a coil loaded beam and rule the world. :lol: I can just see it now, we'll have huge AM broadcast towers with coils that look like something the Jolly Green Giant would run on his rig. :lol: Start thinking outside the box. If you need something shorter, try a capacity hat and a shorter whip. I think all forms of loading beat the coil. I run a 10k and know it is a compromize. There is no such thing as a free lunch and that applies to antennas too.

-drdx
Yes it's me, Dollar-98, drdx, the original all *Censored*, shot cawla on workin this no-fade technology.

-drdx




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