[ADXA] Inverted L and the Snow
Mark Graves
mgraves at avecc.com
Sat Jan 11 13:33:11 EST 2025
Look up 3Y0X Peter 1 antennas and their published models. They determined that the ice and snow was far enough away from conductive earth just to make a low band Yagi laying on the surface ice without having detrimental effects.
It makes me wander if my mountain top verticals are actually elevated being installed over rock and sandy “soil”?
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________________________________
From: adxa-bounces at mailman.qth.net <adxa-bounces at mailman.qth.net> on behalf of Michael Nettles <kb5wbh at gmail.com>
Sent: Saturday, January 11, 2025 12:11:09 PM
To: w5znjoel at gmail.com <w5znjoel at gmail.com>
Cc: ADXA <adxa at mailman.qth.net>
Subject: Re: [ADXA] Inverted L and the Snow
Thanks for the info. We have alot of knowledge in our club. I like reading about past experiences. I'll have to look that QST article up too.
Best DX,
73
MIke kb5wbh
On Sat, Jan 11, 2025, 6:51 AM <w5znjoel at gmail.com<mailto:w5znjoel at gmail.com>> wrote:
I remember that article, and it contains some very good ideas.
It also generated some confusion over the difference between a good DC ground system for things like lightning protection versus the purpose of a ground radial system for a vertical type antenna. The purpose of a radial system, whether it is actually on the ground or elevated (another one of those intense religious debates!!) is to reduce ground losses. You don’t need a ground rod for that. The earth is a great big resistor and will suck up (a southern technical term for absorb) all of the current that flows along and then into the ground from an antenna. An effective radial system will greatly reduce the “sucking up” and reflect these, adding a little gain and lowering the radiation angle. A good radial system should perform the same whether it is in ground, on the ground, laid out on top of rocks, or elevated. Radials do not have to be buried in the ground in fact, if they are buried too far beneath the surface you will have the same result as being under fresh water. That great big resistor “Earth” will come in to play. I have around 16 miles of radials (YES miles) under my 160 and 80 meter transmit antennas and none were buried. I’ve described my technique before which is not unique, but a method used by those who have a lot of radials.
While talking about “ground”, when Steve, N2CEI, decided to build a 160 meter contest station at his Live Oak, FL QTH the first installation of Beverages just didn’t work well at all. No matter what we tried we just could not achieve the performance we should have. Then out of the blue one day Steve threw out a BOG (Beverage on Ground), and the performance was equivalent to one normally installed 5 to 7 ft above the ground. We didn’t give this much consideration but accepted it for what it was. I flew down and we began installing a system of BOG’s. During the installation Steve said “Its real easy to drive an 8 ft ground rod all the way down because there is about 5 ft of sand on the surface before you actually get down to real Earth……HELLO!!!!! A Beverage is a lossy antenna by design. It needs Earth losses underneath it to perform as it should and sand doesn’t provide that. In fact, it’s a pretty good insulator. I told Steve no wonder the Bev’s didn’t work well at 5 to 10 feet above the ground because, effectively, that was a Beverage 10 to 15 feet high above “Earth”. With the Bev’s laying on the surface or a few inches above it at his location was effectively 5 feet high, above “real” ground. So, the entire array of Beverages at N2CEI are about 4 inches above the surface. No worry about deer getting into them because there aren’t any there, just watch out for the little prickly cactus all over the surface and pigmy rattlesnakes that like to hang out among the cactus!
Now, with all of this said, whatever your situation, the only way you will determine the optimum conditions for your station at your location is to try something. If it doesn’t work as expected, revise it or if that doesn’t work, try something else. Some of your efforts will take time to optimize so focus on your effort, document what you’re doing so you will know the result, and organize your time. You won’t lose anything by missing an episode of Oprah or The View and the experience you gain from your work will be most rewarding for your station. Remember, develop a plan then work the plan. Set those goals.
Now, GET IN THERE!!!
73 Joel W5ZN
From: BILL KENNAMER <k5fuv at prodigy.net<mailto:k5fuv at prodigy.net>>
Sent: Friday, January 10, 2025 3:40 PM
To: 'Michael Nettles' <kb5wbh at gmail.com<mailto:kb5wbh at gmail.com>>; 'ADXA' <adxa at mailman.qth.net<mailto:adxa at mailman.qth.net>>; w5znjoel at gmail.com<mailto:w5znjoel at gmail.com>
Subject: Re: [ADXA] Inverted L and the Snow
Check out the article "Improving earth ground characteristics" in December 1976 QST. I do that in addition to my radials.
FUV
On Friday, January 10, 2025 at 09:27:01 AM CST, <w5znjoel at gmail.com<mailto:w5znjoel at gmail.com>> wrote:
I remember, once upon a time, I was having a chat at some radio event with Roy Lewallen, W7EL, the developer of EZNEC. A guy walked up and said “I have a question about ground systems and radials, and I realize that ground systems and radials is a lot like talking religion….” Roy interrupted him right there and said “That’s an easy answer and I don’t even know you’re question, I don’t discuss religion!!!!”
OK with that out of the way, the short answer is no. It won’t help the ground system on any antenna. We’re talking about fresh water (in any form), so the only real impact it will have is if you have a ground radial system that is under fresh water by a couple of inches you effectively don’t have any radials. Of course, salt water is an entirely different animal.
With that said, this is a religious question so opinions vary greatly and someone here may offer a different perspective (opinion). As a close personal friend of mine, Larry Price, W4RA (sk), told me on more than one occasion “You’re entitled to your opinion, even if it is WRONG!”
73 Joel W5ZN
From: adxa-bounces at mailman.qth.net<mailto:adxa-bounces at mailman.qth.net> <adxa-bounces at mailman.qth.net<mailto:adxa-bounces at mailman.qth.net>> On Behalf Of Michael Nettles
Sent: Friday, January 10, 2025 9:10 AM
To: ADXA <adxa at mailman.qth.net<mailto:adxa at mailman.qth.net>>
Subject: [ADXA] Inverted L and the Snow
Since we are in the middle of the current Snowmagedon I have a question for you guys. W5ZJ and I talked about it this morning too.
Does all this snow help the ground system on an Inverted L?
73
Mike kb5wbh
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