To Ground Plane, or not to Ground Plane? That is the question...

[Shockwave]

All I can say is if this worked so good, they would be selling like hotcakes on 2 meters. The 5/8 wave groundplane with 5/8 wave radials would look just like a small version of a Starduster on 2 meters. Oh no!!! I just shared my million dollar idea with everyone

 

[Marconi]

All I can say is if this worked so good, they would be selling like hotcakes on 2 meters. The 5/8 wave groundplane with 5/8 wave radials would look just like a small version of a Starduster on 2 meters. Oh no!!! I just shared my million dollar idea with everyone

I agree completely Shockwave, but I would be surprised if there aren't already a lot of collinear 2 meter antennas sold that fit this scheme. Maybe they won't look like a Starduster, but they could produce their collinear ideas by using sleeved designs and make em' look like a long stick. Except for a matcher, that would be very similar to the SD design electrically, IMO.

I'm just giving NB the benefit of the doubt with his claim, because I know in fact and show evidence in my album of another guy doing something similar and making similar claims---at least with modeling. True or not, fact or not, if you will look at it, Yates talks about his idea which sounds very similar to our new friend Needle Bender. Check out image 3 in row 3. http://www.worldwidedx.com/members/...ing-10-meter-verticals-nm5k-demo-version.html

I believe what NB says he sees, so if he'll kindly show us some pictures of his setup, that will help support that part of his story. And after that we just have to have faith in what our brother tells us, or wait and see what else he says.

Meanwhile, 'Doc is trying to get us all to grinin'. He wants to keep us all on the straight and narrow, getting us to look at db gain like the value of the US dollar.

Hey 'Doc, we're talking serious theory here, can't you tell.

 

[Marconi]

@Marconi
About the effectiveness expected by military or commercial use...
I totally agree those are my thoughts. If it was 100% effective they would use it.

Could one say...the imax isn't the best there is, without radials ?

I agree Henry. Personally I like my A99 better than my Imax.

About the impedance changes of >1/4 wave verticals and height.

You pointed out a new thing for me ! so thanks for that.
Ill be testing it on the gear here this afternoon..

Henry, I'm not sure how we got off into this topic, but I may have misspoken when I posted about impedance vs. increasing height---decreasing impedance. I was referring to impedance very broadly in that context. If you want to try and duplicate my results that's great, that doesn't happen too often that I know about. I may need to be more specific about how I defined impedance relative to my answer “decreasing.” My tests were a long time ago and I haven't checked my notes yet, but I was likely just recording SWR readings back then. Let me know what you find and maybe we can make a new thread to discuss this, concerning new information I have using my analyzer. I don't want to Shanghai this thread any more than I already have.

@Shockwave:

We are speaking about the same.
You can say the imax has a different impedance matching unit than any other.
This is logical, cause without radials you need to match other values..
As i see it, it is not that the matching unit compensate the "lack" of radials it is the matching unit matches the impedance which is present due to the "lack" of radials.

Six of one, half a dozen of another.

It is only logical that a 5/8wave without radials would have a significant more loss cause the matching unit is planned to work with radials so there will be more loss..

You design antennas, could you plot the difference between the imax with or without radials? I guess dB figures would be the same as given earlier for a 5/8wave.. And i agree the difference is very small.. with the first radials attached and will become less when after that you add more.

Henry and Shockwave, this issue is one that dwells on my mind a lot when I'm thinking about antennas. I have a different take on the issue of what happens when we add radials. We don’t talk about what radials do or how they do what they do, we primarily discuss if we should slant them at some angle, make them horizontal, or if they will improve gain, stop TVI, or make a better angle of radiation for talking DX. We even talk about radials generically most of the time and tend to forget that different radiator lengths are affected differently by properly placed radials.

Every time we add a radial to the mix of a functioning GP the amount of current per radial is reduced and without thinking about it, that might sound like a bad idea, but it’s the only way to go if we want to mitigate the destructive effects of radials on the radiator’s natural pattern. The main reason for this idea is considering what happens when we are able to transmit with our antenna over sea water. We’re operating over a near infinite highly conductive ground plan and we don’t need radials that mess up the pattern plus we will see remarkable gain. I'm not implying we will see similar gains by adding elevated radials as if we were over sea water, but with my 1/4 wave Marconi testing with 0 - 6 radials, I have seen significant gains using a field strength meter to compare actual near field signals. I did some transmitting with each addition and I was also seeing some gains on-air. I'm still hoping to try and duplicate this effort, if I get to feeling better.

If I can find my notes, I will post that old hen scratching.

About my remark about the radials for a 1/4 or 3/4 wave. Perhaps i wasn't clear enough in my previous post. I wasn't try to say they will produce equal results.

I was trying to point out a 1/4 wave or 3/4 wave depend more or less on radials.
You are saying :
"What can be used for counterpoise on a 1/4 wave will provide a completely undesirable high angle radiation pattern on the 3/4 wave."
Wouldn't the length of the radiator provide that high Angle when used a counterpoise for a 1/4 wave on a 3/4 wave ? and not the radials as a main thing ?

Anyway thanks for your input it is highly appreciated !

Enjoy the (rest) of the weekend,
H.

 

[Marconi]

Henry, here are the original notes on 03/20/06 of my field strength measurements on my Marconi antenna.
Admittedly this is not scientfic, but this is the way I did the comparisons while adding radials. Next time I do this I will also record data while adding radials starting with 0 - 6 one radial at a time.

In this process, I first tested the antenna with all six radials installed,

3-1/4 waves slanted down plus 3-72" horizontal.
3-1/4 waves slanted down.
3-72" radials horizontal.



I used a Heathkit PM2 meter with a remote coaxial antenna on a 10' wooden dowel that I can setup on a wooden ladder. This gets the top of the coaxial antenna up to about 20' and was located about 40' away from the antenna.

First thing is to calibrated the meter for medium deflection (5 on the scale) using the Marconi with no radials at all, presumed to be the weakest antenna tested. I found this setting was way too strong and had to reduce the sensitivity down to less than (1) else the stronger antennas buried the needle over (10).

Images below, Marconi, FS meter with remote coaxial antenna attached. The Marconi shown has one 1/4 wave radial missing in the image.

 

[Henry HPSD]

Thank you Marconi !

Good to see the notes!

Didnt had time today as i was bussy with a 4el vertical yagi wich wouldnt lissen to me..
But as soon as i am home for a hour or so.. Ill put on the analyser and see whats going to happen.

(ill put that on another thread as i am already poluting this one, for wich my appologies.)

edit:
Hello guys did do the test.. seems like only the resonant frequency drops a bit.
going from 10 feet to 30 feet made about 100 khz difference...thats all..
If you want to see the minivna analyse plots drop me a mail and ill send it towards you.
Kind regards, Henry.
73 H.

 

[Marconi]

Will, I know this nice thread has sort of died out, but I'm curious as to what else is going on with you, and if you got your questions answered among all the words?

 

[n8fgb]

So should I buy the freaking GPK or not?

No, just move your guy wires up to the base of the antenna. run 108 inches to insulators, and there you are. Ground radials.
Rich

 

[Marconi]

Hey Mr. Needle Bender, we're waiting to see some pictures of your Super Imax. I was counting on you to help prove me right. Where'd you go?

 

[1342]

i have one of my own questions similar to yours and i will probably not get an answer unless it was already answered?has anyone tried isolating an imax 2000 from the mast and installing a maco gpk under the feedline to the mast?would this not work?being isolated from the antenna would not change the impedance would it?

 

[GnG8d]

Says who? I have it on my Imax. It must help.

I have it, so it works?

 

[Needle Bender]

Hey Mr. Needle Bender, we're waiting to see some pictures of your Super Imax. I was counting on you to help prove me right. Where'd you go?

sorry my compeuter was broke down for awhile. i cant get pics to loadup but its kind a like that steep picture you put on hear they are the top guide wires of four secktions and are reel steep going down. i mesurred thenm out to twenty two and a half feet for the guide wires to the insulaters

 

[ChrisBama351]

I put insulators in my top guy wires and used dacron for all the rest. my top guy wires are 23 foot long to the insulator and come off the top u-bolt and now my imax hits 2 pounds more everywhere, specially long range. static dropped and ears came up to. my buddy a mile away and me both run 2995s, he has an enforcer and he used to get me everywhere we talked but now i get him a lot of places.
i threw away that radial kit. had a couple guys want to buy it but i wont sell somthing that dont work, not even to an enemy

No, just move your guy wires up to the base of the antenna. run 108 inches to insulators, and there you are. Ground radials.
Rich

So all 3 quotes have 3 different length radials made from guy wires. Does radial length matter? I thought They were supposed to be in 1/4 wave lengths? If my length is right can I just go ahead and attach it to my anchoring post/rod for the guy wire? Do I need to use insulators?

sorry my compeuter was broke down for awhile. i cant get pics to loadup but its kind a like that steep picture you put on hear they are the top guide wires of four secktions and are reel steep going down. i mesurred thenm out to twenty two and a half feet for the guide wires to the insulaters

 

[HomerBB]

For raised radials it is usually 1/4 wavelength radials.

 

[bob85]

I remember this, NB was talking about 5/8wave radials on his imax, putting insulators in his top guy wires 5/8wave down from the antenna to make a sort of 5/8 starduster,

i think the idea is it may act something like a vertical extended double zepp & give some of the edz's gain.

i can't imagine how that would work unless the antenna was properly isolated to force current into the extended radials.

 

[TIN_CAN]

Well I have had a gpk for the imax for a year just never put it up as to close to metal roof, so now I am adding another 10' section of tower to bring up to 40' + 8' mast and will install the gpk. I do not have any TVI in my own home or my neighbor's, even when I fire up the sweet 16. I just have the tower grounded at base and no choke at base of antenna and near flat match on ch 1-40 so seems to work good as is, but will try the gpk and see if it improve floor noise or anything...gpk radials are at 75 degrees hope to have up as soon as we have some nice and not windy weather.