LoG antenna trick
- Andrew (grayhat)
- Posts: 287
- Joined: Sat May 28, 2022 5:56 am
- Location: JN63pn
LoG antenna trick
What follows is a small trick which allows to maximize the performance of the LoG (Loop on Ground) antenna, I won't add details about the antenna since it has been discussed on SWLing, but if one doesn't know about it, the infos about such an antenna can be found on Matt Roberts' page, here
http://www.kk5jy.net/LoG/
anyhow, let's start with the antenna topology shown on Matt's page
now, let's say we hold the antenna on ground using four plastic stakes, but instead of locking the antenna wire to the stake, we'll use four nylon cable tiers to form some loose loops tied to the stakes at one end and the antenna wire passes through those loops, now, let's refer to the image below, the red dots are our stakes with tiers, notice that one of the stakes (the #1) is moved to one side, this has a reason to be; remember that we used the tiers to hold the wire, so the wire itself is free to slide through the looped tiers, now, let's say our LoG antenna main lobes (the side arrows at #2 and #4) are oriented toward E/W, if we gently pull/slide the antenna wire moving the feedpoint from point #1 to point #4 (refer to image) the main lobes of the antenna will be rotated by 90° (toward #1 and #3) so they will now point to N/S, and, given the quite wide lobes of the LoG, using such an approach we'll be able to cover the whole 360° horizon and aim our LoG toward the direction of interest, sure it won't be a remotely controlled thing, but this simple trick may help pulling out some more DX signals !
.
http://www.kk5jy.net/LoG/
anyhow, let's start with the antenna topology shown on Matt's page
now, let's say we hold the antenna on ground using four plastic stakes, but instead of locking the antenna wire to the stake, we'll use four nylon cable tiers to form some loose loops tied to the stakes at one end and the antenna wire passes through those loops, now, let's refer to the image below, the red dots are our stakes with tiers, notice that one of the stakes (the #1) is moved to one side, this has a reason to be; remember that we used the tiers to hold the wire, so the wire itself is free to slide through the looped tiers, now, let's say our LoG antenna main lobes (the side arrows at #2 and #4) are oriented toward E/W, if we gently pull/slide the antenna wire moving the feedpoint from point #1 to point #4 (refer to image) the main lobes of the antenna will be rotated by 90° (toward #1 and #3) so they will now point to N/S, and, given the quite wide lobes of the LoG, using such an approach we'll be able to cover the whole 360° horizon and aim our LoG toward the direction of interest, sure it won't be a remotely controlled thing, but this simple trick may help pulling out some more DX signals !
.
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Re: LoG antenna trick
Excellent tip!
I use stakes with short ropes attached to them for that:
(Sorry, bad pics, didn't mean to picture the stakes that morning and quickly realized that trying to take pics of a LOG is kind of ...ummm... difficult. )
I use stakes with short ropes attached to them for that:
(Sorry, bad pics, didn't mean to picture the stakes that morning and quickly realized that trying to take pics of a LOG is kind of ...ummm... difficult. )
- Andrew (grayhat)
- Posts: 287
- Joined: Sat May 28, 2022 5:56 am
- Location: JN63pn
Re: LoG antenna trick
Yes, ropes will work, although they may tend to "wrap/garble" while nylon tiers will remain a bit more rigid
Oooh, c'mon, I don't think someone will pretend that all the pics here should be ready for some gallery exposition
And since we're at "LoG" and "tricks", another trick if the LoG is installed in a garden/yard is to use a length of garden hose and slide the LoG antenna wire inside the hose and seal the hose ends to avoid that water may accumulate inside it, that way, when mowing the lawn there won't be problems with the antenna wire laying on the ground
Re: LoG antenna trick
Simple yet effective ideas. I have the needed materials and I am getting ready to assemble this LOG soon, so timely post.
- Andrew (grayhat)
- Posts: 287
- Joined: Sat May 28, 2022 5:56 am
- Location: JN63pn
Re: LoG antenna trick
If you don't have a 9:1 balun with galvanic isolation, you may pick one of those
https://www.nooelec.com/store/balun-one ... bones.html
they'll work just fine, by the way you'll need an enclosure, also, a cheap and good cable for the LoG is the "RG6" (sat/tv) coax, it will work much better than a run of RG-58 and will cost less
Re: LoG antenna trick
Not to over-think anything.. but 'ground level' really means - what? 2-inches, 4-inches, or ?? above ground?
Looks like something fun to try.
Thanks!
Looks like something fun to try.
Thanks!
EM64rp
- Andrew (grayhat)
- Posts: 287
- Joined: Sat May 28, 2022 5:56 am
- Location: JN63pn
Re: LoG antenna trick
on the ground means on the ground, and... yes, the first time I saw that I thought it was some other "magic antenna", it isn't, mind me, just set it up... errr lay it down properly and you'll see... hear, I mean, just ensure to lay it down on grass/dirt and keep it away from buried pipes, wires and other buried conductive objects and ensure the feedpoint transformer is "by design" since those are the main issues with such antenna
check this for an idea
https://youtu.be/wMb8i5QajW0
Re: LoG antenna trick
Testing YT embedding BBCode here (having a rough start on this, 'youtu.be' URLs will not work)...
Here's a video I shot last year using the passive 20m LoG antenna before I shot the pics above:
That's 16,000km away from my secret LOG testing ground, on a day with no particularly elevated condx. OK, I know I don't have to tell just of all you how great these things are!
Here's a video I shot last year using the passive 20m LoG antenna before I shot the pics above:
That's 16,000km away from my secret LOG testing ground, on a day with no particularly elevated condx. OK, I know I don't have to tell just of all you how great these things are!
- Andrew (grayhat)
- Posts: 287
- Joined: Sat May 28, 2022 5:56 am
- Location: JN63pn
Re: LoG antenna trick
The link seems to be working, and the video shows what an antenna laying on ground can do; then... if you're going to shot some more of those, it would be a good idea having the ability to switch in a second antenna (even a miniwhip or whatever) to show the kind of difference the LoG makes
Re: LoG antenna trick
That's exactly what I bought this switch for.