G0KSC LFA - TH6 10m yagi comparison by VK2GGC
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- Опубліковано 10 лют 2025
- Comparison between a G0KSC Loop Feed Array 10m Yagi and a TH6 at club station VK2GGC Australia during 2012 ARRL 10m contest. Ant 1 = LFA, Ant 2 = TH6, taken by VK2PV. READ COMMENTS BELOW FOR MORE 10m VIDEO ACTION
Note the difference in weak signals noise reception at 2:45 min - 2:48 min
Audio taken from an Icom 7600 speaker (not via speaker jack) to simulate real working conditions.
While on average the LFA produced 4-6 signal points better performance than the TH6 (on both RX and TX), the most significant differences were in low level signal work.
Please note: The photo of the two antennas side by side shows them in opposite directions. This was taken later in the day after the comparison tests.
Footage for R&D purposes only
Excellent video. I've been convinced of the performance of the LFA that it is all I build now. 73
Nice! Not much difference in signal, but the S/N ratio is strikingly better with the LFA. Also, you are a smart 10m operator, since I see you have CB channel 6 at the ready to check propagation. I have used it for years as a beacon for conditions; with some of those guys running 10kw or better, it lets you know the band will be open before most people realize it. 73 de NV6R
After more than 2 years of operation this antenna is still out performing every 10m yagi in Australia (for a single stack). In the first year of operation we achieved first place in the ARRL 10m contest. Does one need any more proof than that ? We clearly hear stations that other VK yagi operators cannot even hear. In my view and experience this is THE best 10m antenna around. Peter - VK2PV (LFA is operated at club station VK2GGC)
In addition, If I did have a 6 element monobander to compare with I would have put that up too. I did find the antenna remained very stable in all weather conditions, however, given we don't get snow in this part of Australia I can't comment on that aspect. Hope this info helps. Peter
Agree ! 27.025 is the best beacon around. Those guys are 5/9+ here while everything else is a 5/2 !
Hi all, some good feed back and comments here. Firstly, your correct. I am not comparing apples with apples. I am comparing a TH6 with a 36' long LFA. The video confirms what the computer modelling states, that it should work better. It is for people wanting to improve on their 10m antenna systems without having to go through the process of building or buying. A TH6 is a common all rounder and is used as a benchmark only. As the video states - for R&D purposes only.
Cheers, Pete, VK2PV
Would have to disagree here my friend. The performance of the LFA (Noise floor and SWR) did not change between a 40 degree day and a cold wet and rainy night. Furthermore, the SWR tuning could be done at 1.5m above the ground and varied little, if any, when errected to 35 feet. It was extremely stable in my view and experience. Maybe that comes down to build quality, not sure. cheers, Peter.
Peter, great video. To me, th LFA is the clear winner on 10 meter. That is my next antenna. Joe N2CEP
What is the boom lenght of both antennas?
Great antenna
I will try and fix but at bottom of iPhone page select 'desktop'. Should be ok to view now.
Great demo and an amazing difference but a th6 is only 4 el on 10m on a 20' boom.
That LFA looks like a 30' boom.
Not really comparing apples but I wouldnt have expected such a difference, well done.
So what you get is higher gain on the LFA but lower noise. Win Win! de W4ABC...
Where did Boris get that the LFA was a YU7EF design? The LFA was first introduced by G0KSC. Second, the LFA is not an unstable antenna, unstable antennas are generally very low impedance and have far too much spacing between elements, the LFA does not. I have photos of 432Mhz LFAs covered in snow which are still working moonbunce!!
There are photographs of lfa antennas installed on German aircraft of the Second World War
@@gusgar9212 I guess you don't understand the concept of an LFA, what it means and what is involved. You may want to do your research
TH6 is 24' long and the LFA is 36' long. Peter
From my point-of-view, that is not a fair comparison as a multiband 4 active elem on 10m won't be as good as a 30' boom optimized monoband long yagi. I've seen other comparisons where the LFA was about a dB better than a monoband with same number of elements and aproximated boom length. The loop seems to be less prone to common mode than dipoles. I believe LFA will make a dramatic change on VHF, UHF EME antenas, but I still have to compare. It is on my wish list.
Both antennas pointed at the stations in question? How do you know this?
Because I stood underneath them and took compass headings.
YOU SEE THIS IS IT HOW DO YOU KNOW THIS AND ALSO WHATS TO SAY AN ATTENUATOR WAS NOT IN LINE TO MAKE THE OTHER LOOK BETTER FOR SALES OR EVEN BETTER STILL YOU KNOW SOMETIMES HOW YOU CAN JUST MOVE A FEW FEET AND THE SIGNAL FOR NO REASON WILL GET BETTER ? THE TOWER MIGHT JUST AT THAT TIME BE IN A BETTER SPOT WHO KNOWS WHY BUT IF YOU ARE OR USE A MOBILE RADIO IN A CAR ITS 5/5 ONE WAY BUT DRIVE OR MOVE ABOUT 20 FOOT AND ITS 5/9/ WHAT YOU THINK ON THIS REPLY SIR ?
Due to the back ground music UA-cam bans the video on phones in some countries. As mentioned, select the 'desktop' option at the bottom of the screen when viewing from a phone. That has fixed the problem in the past. Cheers.
Still can't watch the movie on my iPad. Can you fix this please. 73's m0hdd
you need to speak with UA-cam for that, sorry
Correct, the TH6 is active on 4 elements on 10m only. But at the end of the day you have a large 6 element antenna up in the air taking up realestate. The significance here is the low noise between the two, not the gain difference. The CM is significant even this far down on the band from VHF and UHF.
Exelent test,tanks veri good signal greating from golf the mexico73
Here is a bit of cheating, first the TH6 is Multiband the LFA is Monoband, it is obvious that there will be divergences due to the amount of elements that they receive ... here they must make the comparison between TH and the LFA with the same number of elements in monoband and then if you have to see and hear the differences between the two.
He puesto que no me gusta por estar bloqueado a los dispositivos moviles....
MORE 10m VIDEO ACTION
I have posted a few youtube videos of VK2GGC operating on 10m during the last year since the LFA was moved to tower 1 at a greater height, and with less coax loss. Performance is better than outstanding. In fact, I would go as far as saying every single time we call out on 10m there is someone who says it is the first time they have ever spoken to VK.
It is not uncommon for us to work East Coast USA mobiles 5-7 plus, and in the past two years since installation we have worked all 50 US states during the 10m ARRL contests. We actually achieved the ARRL "Worked All States" (WAS) award for 10m in a single weekend of operation.
For final proof on how well this antenna works check out this footage of Last Man Standing station K6H, from Hollywood studios. They didn't even believe we were in Australia during a recent chat ! ua-cam.com/video/OGU500ztLiI/v-deo.html
And for other 10m action have a look here:
ua-cam.com/video/eG2sC__WEro/v-deo.html
ua-cam.com/video/_FwagMRp8k4/v-deo.html
ua-cam.com/video/ja5XrN5zOXk/v-deo.html
73's, Peter VK2PV and the VK2GGC team
LFA is YU7EF design, very optimized antenna with bad characteristics when antenna is wet, covered with snow or surrounded with other antennas. Better avoid this design.
There are photographs of lfa antennas installed on German aircraft of the Second World War
You have no clue what you are talking about - TROLL
Where did Boris get that the LFA was a YU7EF design? The LFA was first introduced by G0KSC. Second, the LFA is not an unstable antenna, unstable antennas are generally very low impedance and have far too much spacing between elements, the LFA does not. I have photos of 432Mhz LFAs covered in snow which are still working moonbunce!!