I think your results are valid for you and your location, no matter what any book says. There are so many nuances of location, soil quality, materials, etc that there just aren't any firm answers that hold in all cases. We can generalize, but antennas continue to be at least as much art as science. Which is why I enjoy watching your antenna experiments on YT. As a fairly new ham, I really learn a lot from your work. Thanks! 73!
Hi Abraham, glad you like the videos & are learning from them. Just because I run a TH-cam channel, that doesn't mean that I know any more than anyone else! I am also learning from my videos!!! You are very correct in the fact that there are a lot of variables. Upon reflection, I think that the radials are coupling to the antenna on the first test (even though they are not physically connected). If I'm correct about that then it will have given my first test (without radials) a boost & messed up my results. It would be interesting to try WSPR testing two antennas simultaneously (one with radials, one without). I reckon that I could get two setups around 50 meters apart with the space available in my field. A possibility for the future!
Interesting test their James, I love comparison tests like this. I too wondered if the radial system could couple to the antenna whilst disconnected but I suppose you'd have to set up two systems isolated from one another. Great stuff mate, love it. 73s from Steve G6JEF.
I'm debating setting up two 20m verticals approximately 50m apart at the field & doing that experiment as a follow up to this video. "Watch this space" as they say!
Definitely possible the radial system is coupling to the antenna. Until recently I had a 1/4 wave ground plane in the loft for 11m which had just two perfectly matched radials, but only worked properly with the loft ladder down. If I collapsed the loft ladder and pushed back up into the loft to put away, it being aluminium and about 2.5m in length, became another radial and directed my signal more northerly, but upsetting the balance of the grounding and raising the SWR a little.
Excellent, I hadn't considered that possibility for people using loft antennas but it makes sense. If it's causing your signal to become directional, I wonder what the front-to-back ratio is?!?!?!
Would be interesting to see a side by side comparison with simultaneous TX using two identical WSPR TX like two WSPRLites and comparing the results with DXPlorer
My thoughts exactly. When I get time I will probably do a follow up to this video & set up two 20m verticals around 50m apart (one with the radials & one without) & run two WSPR systems simultaneously to see what happens.
You will probably find with the 1st single radial set up it was still coupling into your buried ground radials. I recommend you repeat the test but with the 1st setup should be well away from your earth mat. I think you will then see a bigger difference in efficiency.
This was filmed quite some time ago so I forget the exact wording in the book. I think it was to the effect that radials are as important to a 1/2 wave vertical as they are to a 1/4 vertical. If that is the case, then we would expect to see better TX (and by default probably better RX) with more radials. Plenty of people have done experiments with 1/4 wave verticals to prove this but I've not found anything to show this for a 1/2 wave vertical. Commonly accepted wisdom amongst the majority of the amateur radio community (which isn't always right to be fair) seems to suggest that radials are not important for a 1/2 wave vertical, as long as you have some sort of counterpoise (in some cases, people just use the braid of the coax). While the author of the book is a highly respected DXer, what is in the book goes against what I have been taught & my (admittedly very basic & probably quite flawed) experiments seem to suggest that having a number of radials makes very little difference on a 1/2 wave vertical. I'm wondering if I've misunderstood what the author was trying to say? I'm really not sure what to make of it if I'm honest.
those are not radials. Thats called a counterpoise. They do different things. This is not an end fed, its a vertical. Verticals are not voltahle fed, end fed horizontal wires are voltage fed If it must have a 49:1 it is horridly out of match Radials are VERY POOR for HF, they waste much power into lossy ground. Earth at HF is a lossy dielectric. This system is a disaster. A grounded vertical 1/4 wave is 50 ohms. There should be no 49:1 transformer needed. It is either shorted or very high impedance.
![เปิดบ้าน โคตรสวย ป๋องกพล รู้จักตั้งนาน เพิ่งรู้ว่ารวย!!! l [Nickynachat]](http://i.ytimg.com/vi/tmgCF_2HfYI/mqdefault.jpg)
Excellent!
Thank you for running this test!
That, my friend, is a real head scratcher.
I think your results are valid for you and your location, no matter what any book says. There are so many nuances of location, soil quality, materials, etc that there just aren't any firm answers that hold in all cases. We can generalize, but antennas continue to be at least as much art as science.
Which is why I enjoy watching your antenna experiments on YT. As a fairly new ham, I really learn a lot from your work. Thanks!
73!
Hi Abraham, glad you like the videos & are learning from them.
Just because I run a TH-cam channel, that doesn't mean that I know any more than anyone else! I am also learning from my videos!!!
You are very correct in the fact that there are a lot of variables.
Upon reflection, I think that the radials are coupling to the antenna on the first test (even though they are not physically connected). If I'm correct about that then it will have given my first test (without radials) a boost & messed up my results.
It would be interesting to try WSPR testing two antennas simultaneously (one with radials, one without).
I reckon that I could get two setups around 50 meters apart with the space available in my field. A possibility for the future!
Interesting test their James, I love comparison tests like this. I too wondered if the radial system could couple to the antenna whilst disconnected but I suppose you'd have to set up two systems isolated from one another. Great stuff mate, love it. 73s from Steve G6JEF.
I'm debating setting up two 20m verticals approximately 50m apart at the field & doing that experiment as a follow up to this video. "Watch this space" as they say!
Definitely possible the radial system is coupling to the antenna. Until recently I had a 1/4 wave ground plane in the loft for 11m which had just two perfectly matched radials, but only worked properly with the loft ladder down. If I collapsed the loft ladder and pushed back up into the loft to put away, it being aluminium and about 2.5m in length, became another radial and directed my signal more northerly, but upsetting the balance of the grounding and raising the SWR a little.
Excellent, I hadn't considered that possibility for people using loft antennas but it makes sense. If it's causing your signal to become directional, I wonder what the front-to-back ratio is?!?!?!
Would be interesting to see a side by side comparison with simultaneous TX using two identical WSPR TX like two WSPRLites and comparing the results with DXPlorer
Hi - good stuff ! I do think the presence of the big ground radial system will have improved the result for the first run.
My thoughts exactly. When I get time I will probably do a follow up to this video & set up two 20m verticals around 50m apart (one with the radials & one without) & run two WSPR systems simultaneously to see what happens.
Maybe try rf choke at antenna to stop radiation of feed line, making the radials do the work?
You will probably find with the 1st single radial set up it was still coupling into your buried ground radials.
I recommend you repeat the test but with the 1st setup should be well away from your earth mat.
I think you will then see a bigger difference in efficiency.
Those were my thoughts. If you haven't already found it, there's a part 2 to this video where I tried exactly that.
I think you arrived at the answer yourself with the last comment you put on screen
an interesting question: given documentation in the book, what results would or should we expect, better rx, better tx? any ideas on that?
This was filmed quite some time ago so I forget the exact wording in the book. I think it was to the effect that radials are as important to a 1/2 wave vertical as they are to a 1/4 vertical.
If that is the case, then we would expect to see better TX (and by default probably better RX) with more radials.
Plenty of people have done experiments with 1/4 wave verticals to prove this but I've not found anything to show this for a 1/2 wave vertical.
Commonly accepted wisdom amongst the majority of the amateur radio community (which isn't always right to be fair) seems to suggest that radials are not important for a 1/2 wave vertical, as long as you have some sort of counterpoise (in some cases, people just use the braid of the coax).
While the author of the book is a highly respected DXer, what is in the book goes against what I have been taught & my (admittedly very basic & probably quite flawed) experiments seem to suggest that having a number of radials makes very little difference on a 1/2 wave vertical.
I'm wondering if I've misunderstood what the author was trying to say?
I'm really not sure what to make of it if I'm honest.
Did you account for your ground conductivity? Even without a ground stake the conductivity of earth could impinge on your results!
those are not radials. Thats called a counterpoise. They do different things.
This is not an end fed, its a vertical. Verticals are not voltahle fed, end fed horizontal wires are voltage fed
If it must have a 49:1 it is horridly out of match
Radials are VERY POOR for HF, they waste much power into lossy ground. Earth at HF is a lossy dielectric.
This system is a disaster. A grounded vertical 1/4 wave is 50 ohms. There should be no 49:1 transformer needed.
It is either shorted or very high impedance.