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AR15.COM
11/30/2012 1:52:16 PM EDT
I'm thinking of replacing my OCF dipole w/ one of these.  I found this page, where they guy had some luck cutting it a little long.



I've got a 4:1 balun, and will be feeding it w/ about 50' of 9913.



Thoughts/experiences?



Thanks,

-Slice


 
11/30/2012 2:08:44 PM EDT
[#1]
I had one where I got one corner way, way up in an old Chinese Elm tree. The antenna really played well. I'd feed it with ladder line for all band efficiency. If it is mounted horizontally try and get it up at least 30 feet. Round is most efficient when it comes to shape, followed by a square, with the delta being last. Any flatter and it approaches being a folded dipole. ETA Keep the OCF dipole for comparison. HTH
73,
Rob
11/30/2012 3:10:32 PM EDT
[#2]
Looks like a sky.burner on 80m at 15 meters high.

If your going to use a.balun use a 1:1. Any impedance mismatch would be magnified by the 4:1.

I would feed it with ladder line.
11/30/2012 4:13:00 PM EDT
[#3]
I have one too and like it a lot.  I'll add my voice to the "feed it with ladder line" crowd.  The losses from SWR mismatches with coax are too great otherwise.
11/30/2012 4:58:29 PM EDT
[#4]
Thanks, guys.



I've already got coax going out of the house, a section of about 15' from the back of the tuner.  Can I use that to get out, then somehow "convert" it to ladder line once outside?  If so, how do I go about doing that?


 
11/30/2012 5:33:36 PM EDT
[#5]
Read this for excellent guidance on loops and baluns.
11/30/2012 7:15:34 PM EDT
[#6]
You can experiment with what you have, see what work best.    Just hook the ladder line up to the end of your coax, see how it works, then put the balun in between, see how that works.     If RF isn't heating up stuff in the shack then it is going out into the air in some direction, what is not in the ideal and impossible to achieve "free space" is pretty fuzzy anyway.
11/30/2012 7:43:37 PM EDT
[#7]
I'd put a 1:1 balun at the coax ladder line junction. I'd also find a way to run the ladder line to the tuner if possible, though, I have heard that the impedance remains reasonable and constant over the frequency span of the loop so the coax loss won't be too bad. I still miss my loop.
12/1/2012 5:29:03 PM EDT
[#8]
I had one before I lost it to wind, I will be putting it back up when all the leaves are completely off the trees here.  I haven't found anything I liked better.  As you go up in frequency from 80 meters, it becomes more directional but in unpredictable directions.  But in those directions, man it really works.  I busted more than one pile-up with only 100 watts and my loop.  
12/1/2012 5:39:51 PM EDT
[#9]
How was yours built, Harry?
 
12/2/2012 10:47:14 AM EDT
[#10]
Very nearly a full wave loop, fed with 450 ohm window line all the way back to the tuner.  I've had the best results with this tuner

On 80 meters I regularly got comments asking me how much power I was running, from contacts within about 500 miles.  I only run 100 watts.  It was a cloud burner on 80 because of the height, about 25-30 feet.  When I put it up again it will be about 40 feet.  
12/2/2012 7:03:46 PM EDT
[#11]
One thing about the horizontal loop is that while it's a cloud burner on it's fundamental frequency, the lobes begin to flatten out as you go up in frequency. 73,
Rob