Link is in my post to the free modeling software mmana-gal, tiny program , easy to use, works very well.
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Loop Antenna Plan
- Thread starter xm49north7
- Start date
Thank You Marconi for the modeling work, Good to have confirmation of my numbers , very close for sure, These are good numbers, feel free to tweak and see if you can get more out of here, I did get some higher numbers by dividing it up the middle with another wire, a smaller loop and a u shape, but it was nt worth the effort for building for another theoretical db. This general shape has worked well for me in the past I found it just by hand tuning in the air, so now that I can model in software I wanted to see if I was on the right track, and it seems that I am, I am still puzzled by why it would not have higher db with straight sides, I have run loops both straight sided, like this one, and some that were out of kilter a little, they all worked well, I do find for some reason that I seem to get a little better results with the feed more towards the bottom, and the software validates this, but in pure antenna theory, it should be dead center. Bt software and real work prefer it towrds the bottom 1-3, not the half way point. I have one up and fed for horizontal, but have no locals horizontal to try it with, a buddy is in the process of building a flat side 3 el beam, so I will know more in the spring when we get his flatsider up.
It may be a cheap program and easy to use...but it has a major flaw!!!
Sorry but NO WAY a single loop antenna has 9.5+ DBI gain which would be 7+dB gain over a Dipole!
Can't happen! That's the gains of a 3 element yagi or if everything is done correctly, better than a 2 element Quad.
A single loop antenna if done correctly with impedance matching correct is at BEST 3dB over a dipole...period!
If this were as your program states correct, every manufacture for the last 75 years would have been building them, plus broadcast would be using them.
I am sorry North 47 but true!
I commend you for building and using your own antennas, however that program has some major design issues.
Well maybe that's what MACO, Gizmochee, Antron, and Solorcon use to model their antennas
All the Best
Gary
Sorry but NO WAY a single loop antenna has 9.5+ DBI gain which would be 7+dB gain over a Dipole!
Can't happen! That's the gains of a 3 element yagi or if everything is done correctly, better than a 2 element Quad.
A single loop antenna if done correctly with impedance matching correct is at BEST 3dB over a dipole...period!
If this were as your program states correct, every manufacture for the last 75 years would have been building them, plus broadcast would be using them.
I am sorry North 47 but true!
I commend you for building and using your own antennas, however that program has some major design issues.
Well maybe that's what MACO, Gizmochee, Antron, and Solorcon use to model their antennas
All the Best
Gary
xm49nirth7, try reading the first section of this Website by W8JI and see if it makes any sense as to what we might see in results for a Horizontal CFD dipole at 145' feet at 3.72 MHz. Here we see W8JI discussing the results of a model with high accuracy ground over medium real earth...using Eznec.
https://www.w8ji.com/end-fed_vertical.htm#IMAX
Do you have the manual for your software? If so, then look up Average Gain Results using Free Space for the model. This FS feature will show, among other things, if there are over-stated gains or under-stated gains in the model that can effect gain results. A great tool you will find helpful in getting more reliable models.
https://www.w8ji.com/end-fed_vertical.htm#IMAX
Do you have the manual for your software? If so, then look up Average Gain Results using Free Space for the model. This FS feature will show, among other things, if there are over-stated gains or under-stated gains in the model that can effect gain results. A great tool you will find helpful in getting more reliable models.
not sure where you read over nine dbi, my model reads 6.15 dbi, which is around 4 dbd, which is well stated in most articles on quad loops, about double your standard vertical dipole, which really is what a loop is. Two dipoles in phase. I can attest to the effectiveness of loops, and concur that this seems to be the case in use. I do not have any trouble with these gain numbers. . Loops perform very well. I am surprised more people do not try them. Bi-directional with better pattern than a dipole, some gain , great receive. Loops sit in a sweet spot for me of having a bit of everything, I have had most every kind of antenna up. Loops have been very effective for me.It may be a cheap program and easy to use...but it has a major flaw!!!
Sorry but NO WAY a single loop antenna has 9.5+ DBI gain which would be 7+dB gain over a Dipole!
Can't happen! That's the gains of a 3 element yagi or if everything is done correctly, better than a 2 element Quad.
A single loop antenna if done correctly with impedance matching correct is at BEST 3dB over a dipole...period!
If this were as your program states correct, every manufacture for the last 75 years would have been building them, plus broadcast would be using them.
I am sorry North 47 but true!
I commend you for building and using your own antennas, however that program has some major design issues.
Well maybe that's what MACO, Gizmochee, Antron, and Solorcon use to model their antennas
All the Best
Gary
Last edited:
xm49, BJ was questing the model results that I posted. I should have describe the details better. This modeling business can get confusing.
I made the models based on the limited details in W8JI's article. In part I was hoping the article would help clear-up the issue about gain, being way too much, that BJ raised with you, saying:
My link to W8JI's article may have opened up in the middle of his longer article, so it is possible no one as seen the section at the very top of the article yet.
Just scroll up to the top of he article in the link.
Here the link is again.
https://www.w8ji.com/end-fed_vertical.htm#IMAX
My 2 models were CFHW dipoles at 145' at 3.72 MHz at 128' feet in length. Again, these are similar to the antenna W8JI was describing.
One was a horizontal over Real Earth
One was a Vertical over Real Earth
I made the models based on the limited details in W8JI's article. In part I was hoping the article would help clear-up the issue about gain, being way too much, that BJ raised with you, saying:
[B said:
My link to W8JI's article may have opened up in the middle of his longer article, so it is possible no one as seen the section at the very top of the article yet.
Just scroll up to the top of he article in the link.
Here the link is again.
https://www.w8ji.com/end-fed_vertical.htm#IMAX
My 2 models were CFHW dipoles at 145' at 3.72 MHz at 128' feet in length. Again, these are similar to the antenna W8JI was describing.
One was a horizontal over Real Earth
One was a Vertical over Real Earth
How high are you mounting the loop?Sounds like you really like them.
Constructing another breakover to install a L2. Is there a sweet spot for elevation?
I have them around one full wave length, 36 feet to the feed point, higher is always better, up to about 1.5 wave lengths. 54 feet. After that you trade some dx for better local. I think any antenna for cb radio does very well at 36 feet to the feed. Loops will work at any height on a vertical feed, have even got out well with bottom wire 8 feet off the ground. I really do like a loop, have had 5/8th, dipoles, j-poles, 2 el beam, 4 el beam, a moxon, the loop has been my favorite to date.
Current antenna at 37'. Have some play in build of new tower pending stability.
Just hope that when I get it all working there's propagation.
Just hope that when I get it all working there's propagation.
Here in eastern ontario, skip starts around april 15 runs to about sept. 15, Get the odd contact in the winter , but few and far between.
Few weeks ago had sporadic skip, made two contacts up yonder to Canada awl the way down here in TX.
That is a good trip for sure, I have not had a contact in Texas yet, Have made most of the East coast as far as Florida On my 12 watt bearcat 980, on the full wave loop, last summer was great, got out many times every day.
Keep swapping from my 980 to McKinley, just can't make up my mind. Both run well paired with 450LD.
980 got a D104M6B, the McKinley has stock mic.
Antenna.....gonna love this......
A StarBuster, started from scrap aluminum tubing and an old star duster hub. Broke the hub, built another from scrap. Broke the top element, took the 102" off truck and mounted.
Does pretty good at 1.1:1.
Listening to OTR on 19 AM rt now on McKinley.
When new breakover is built, with L2, the 2970N2 gets to come out and play.
980 got a D104M6B, the McKinley has stock mic.
Antenna.....gonna love this......
A StarBuster, started from scrap aluminum tubing and an old star duster hub. Broke the hub, built another from scrap. Broke the top element, took the 102" off truck and mounted.
Does pretty good at 1.1:1.
Listening to OTR on 19 AM rt now on McKinley.
When new breakover is built, with L2, the 2970N2 gets to come out and play.
- No one is chatting at the moment.