Ground radials system for my HF9V vertical antenna

Started by WA4STO, September 22, 2012, 01:15:43 pm

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WA4STO

I've finally gotten off my fat duff and ordered some things necessary for a much better ground radial system for my vertical.

The problem:  I have about 25 radials now.  Antenna works OK, but could always be better.  Unfortunately, I have about five of the radials attached to the antenna ground by way of a little clip and a piece of 18 gauge wire.  Geez... 

The solution (I hope):

 

The pic on the left shows the plate itself.  It's made of stainless steel, has 60 holes drilled for my hoped-for final count of 60 ground radials, and is easily mounted to whatever you have for an antenna support.

The one on the right shows the plate mounted down at the bottom of a vertical (not mine).

I also ordered more ss nuts 'n bolts, as well as a bunch (100) of six inch long metal 'staples' that are shaped like "U"s.  Anybody know what those staples are for?  ((((no, not YOU, Ray!))) :) 

Here's another thought-provoker, maybe:

My vertical is ground-mounted.  Therefore my radials are of "random" lengths and they work well that way.  If I were to mount it somewhat above ground (like, say, on a tripod on the garage roof) the radials would HAVE to be a very specific length for EACH band and not just "random".  Why would that be?

Paul

Those 'staples' are commonly used to 'stake' down the radials in/under the grass.  Metal coat hangers work just as well if you happen to have a few dozen.
Ground radials increase the conductivity of dirt which isn't very conductive wheich means more lossy.  As long as you increase the conductivity it doesn't matter a huge amount how long a particular radial is.  More of them is just better.
When you elevate those radials you can make their length such that they have the required 'conductivity'/resistance.  Which usually means that you won't need near as many of them (more certainly doesn't hurt though).  A 1/4 wave length typically provides the 'right' amount of impedance to 'balance' the radiator.  That's not a very good explanation so don't take it as such.
And naturally, being as cheap as I am, I would have made my own radial connection plate.  It wouldn't be very 'fancy', but then it would be buried so who'd see it?
- Paul

(It ain't easy being as cheap as I am.)

gil

What about using chicken wire and carpet the ground with it around the vertical?

Gil.

WA4STO

Interesting question, Gil.

And I'm sure not an expert on this topic.  I'll bet Paul would have thoughts on the chicken wire ground plane.

At first blush, I'd be of the opinion that it would be hard as heck to get it buried.  Single wires aren't bad, but 20 foot by 20 foot (just an example size) of chicken wire fencing would be a royal pain. 

I saw on qrz.com one time recently that a fellow did exactly that.  He claims that his vertical is working fine, and I can't argue with him; it probably does.

Now where this question gets really interesting is when we start talking about an elevated vertical.  Aside from the obvious difficulty with getting that huge chunk of chicken wire up to roof level (I know you never suggested that, but stick with me for the heck of it) -- then the question becomes "If an elevated set of ground radials has to be a specific length long for each band of operation, what will become of the antenna's 'resonance' if the chicken fencing is in fact ... well ... random.

I don't like the tone of my response to you here, Gil.  Hope it's not offensive.

73


gil

Nah, no problem. It is an interesting question.. You could always staple chicken wire to your roof, but who wants to do that!? There is the corrosion problem too.. I guess the chicken wire would work on top of the ground.. If one had a big yard and could sacrifice some area.. Grass would grow through it.. Anyway, it brings it's whole new set of challenges. Not that radials aren't challenging as is...

I am going through the same problem here, not wanting a bunch of radials behind the house. I might have to.. I could have a diplole at 22ft or so, maybe 30 pushing it.. I'm thinking about this: http://www.radioworks.com/ccw80compact.htm
Or a 43ft. S9 vertical...

I need to finish my magnetic loop project first though...

Gil.

WA4STO

The "Carolina Windom" guy sure has been doing his thing for a lotta years.

The link you sent was interesting and it caught my eye, first by the fact that it's "half the size" of real dipoles (which always makes me wonder how it's managing to get around the laws of physics), and second by the fact that it needs to have a tuner.  Not just any tuner but a "wide ranging" one.

Do you need 80 meter capability necessarily, or would 40 do it for you?  40's going to fit in most back yards nicely and is certainly a lot easier for the back-packing crowd.

Saw an article (either QST or CQ) where an HFPACK sort came up with the very old idea of using a 40 meter dipole, which he fed  with open wire line (itty bitty home-made stuff that didn't weigh 6 ounces all told) which allowed the dipole to work on 40, 30, 20, 15, 10 and 6.  He had a little home-brew tuner built into an Altoids tin.  Pretty slick.  Not for me though; I'm ancient and sure don't get out all that much!  :(

73 de WA4STO

gil

Hello,

QuoteDo you need 80 meter capability necessarily, or would 40 do it for you? HFPACK sort came up with the very old idea of using a 40 meter dipole, which he fed  with open wire line which allowed the dipole to work on 40, 30, 20, 15, 10 and 6.


I might try that... I don't have 130ft. But I could bend the ends.. I saw military fiberglass poles on Ebay, 12x4ft for $8. Shipping is $35, but that is also for two sets.. So, I would get 24 4ft lengths = 3x32ft. 2ft in the ground, that leaves me with three 30ft poles... Not very high, but better than nothing..
80m would be nice... 40 is what I really want most.

Gil.

Paul

:)
In the right circumstances that 'chicken wire' for 'radials' would be very easy to do.  Such as if you ever re-sod your lawn?  It would only take a little preparation before doing that sod laying, right?  Or, lots of those staples, very short 'trim' for the lawn, and wait for the @#$ thing to regrow.
As for the in/on the ground type radials, all that's necessary is to increase the conductivity of the dirt and make good contact with it.  Typically, that means laying wire radials at least 1/4 wave length long.  Longer is better, just a lot more unhandy.  Or, radials that aren't 1/4 wave length long but a lot more of them.  If it's done that way, they are usually at least as long as the vertical element.  It's the "at least" part that's difficult at lower frequencies, not the "too much" part.  A 70 cm vertical on a typical car is a good example of that...
- Paul

(I've 'heard' of it but have never experienced having too much 'ground'/'ground plane'/'counterpoise'/etc.  :))

gil

Here's another one.. If you go to the beach with your QRP radio, should you have your counterpoise wire in the water?
Assuming you're using a vertical.

Gil.

WA4STO

Sure couldn't hurt!

This topic reminds me of the pictures we sometimes see of a DXpedition operator sitting in a beach chair on a few rocks out in the ocean somewhere.   Those rocks evidently constitute a 'rare country' or 'rare DX'.  And you can bet that they have a spectacular ground plane.  Perhaps one of the best in the world :)

O.T.O.H. (warning: wet blanket / ants at picnic / spoiler alert) some experts point out that having your vertical immediately OVER the groundplane is the way to go.  This topic usually comes up with regard to where to place the antenna on your vehicle or RV/motorhome.  They also seem to indicate that radiation pattern will be skewed. 

I mean, so what?  So you get one huge lobe in ANY direction and that's bad how?  :(

Yup; sure can't hurt

Frosty

Thought, for verticals, that you want the ground plane directly beneath and around the antenna for the best efficiency?  If you use a counterpoise wire of any length, isn't your vertical just a dipole that isn't fed at the center?

Paul

Frosty,
In a very broad sense, yes it is the same.  So are most 1/4 wave verticals no matter if they are ground mounted or elevated (typical groundplane types).  Why three or four of those radials around the vertical part?  Symmetry of the radiation pattern mostly, but it'd work just dandy with just one.
- Paul

gil

Hi,

The Buddistick I just got works great with one radial, but it has to be the correct length, to within a couple inches! The counterpoise also has to be at the same height as the base of the antenna..

I posted about my impressions of this antenna in the corresponding forum.

Gil.


Frosty

Quote from: Paul on September 25, 2012, 01:41:13 am
Frosty,
In a very broad sense, yes it is the same.  So are most 1/4 wave verticals no matter if they are ground mounted or elevated (typical groundplane types).  Why three or four of those radials around the vertical part?  Symmetry of the radiation pattern mostly, but it'd work just dandy with just one.
- Paul


Thanks Paul.  Confusion on my part on what/where the ground plane was - the radials or the ocean.

WA4STO

Yesterday, today. tomorrow -- and likely all weekend -- was/will be devoted to fixing my "problem".  Which is:



Try -- if you can -- to avoid looking at the bunched-up coaxial cable (or the water hose for that matter) and focus instead on the source of the REAL problem -- the mess of little black wires, ring connectors and, believe it or not, spring clips that were my initial attempt at providing an appropriate "ground plane" for my 80 meter to 6 meter vertical.

So far, I have the stainless steel ground plate all mounted nicely, and maybe 6 radial wires.  DX Engineering provided a very nice set (2 actually) of ss nuts/bolts/split washers/flat washers/star washers, and even sent along very explicit instructions on how to place each of those sets in the 60 laser-cut holes of the ground plate. 

That way, absolute mechanical dunces like me merely needs to paint by numbers.

Before the weekend's out, I hope, I'll have another pic of the finished product.  Six down, 30-some-odd radials to go.  Argh...