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Author Topic: gap eagle or steppir big IR  (Read 568 times)
NEWHAM77
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« on: March 25, 2008, 10:03:52 PM »

Hello all, my QTH has almost no soil just rock. What antenna would be best a Gap Eagle up five feet or a Steppir Big IR vertical with the radials not buried but on top of the ground ?  Thanks
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W7ETA
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« Reply #1 on: March 25, 2008, 11:20:05 PM »

People bury radials so that they don't trip over them, or because they need to mow the lawn.

73
Bob
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N6AJR
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« Reply #2 on: March 26, 2008, 01:16:40 AM »

I have a gap voyager for 40/80/ 160, and a 3 ele steppir for hf.  I would like to add the 6-80 meter steppir vert with a lot of radials.  the gap voyager is good on 160 and where it is resonant, and only 3 radials required. but the steppir is by far the better of the bunch.
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K6AER
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« Reply #3 on: March 26, 2008, 07:40:52 AM »

Three to four elevated resonate radials for each band will get you about 80-85 % efficiency with the counterpoise. When a vertical is mounted on the ground the radials no longer become resonate due to ground losses. You will need many more radials but at about 60-70 radials you approach a point of diminishing returns for you radial placement.

The SteppIR vertical is a quarter wave for each operating frequency or a ¾ wave vertical on bands higher then 15 meters. Efficiency is what you would expect for a full size vertical. The big selling point is the antenna is remotely adjustable for all bands.

The Gap antenna is shortened antenna design with lots of linear loading on the various bands with the selling point that it does not need radials due to its center feed design. I have tried several of these antennas and found they are about 3-6dB less efficient than a standard ¼ wave length vertical with radials. Another word there is no free lunch. If you buy an 80 meters version the bandwidth is so narrow and the efficiency is so low you might as well not have the 80 meter add on. An end fed wire will yield much better results on eighty as compared to a very limited 80 meter vertical.
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KB9CRY
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« Reply #4 on: March 26, 2008, 08:13:18 AM »

Steppir crushes Gap big time.
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WB2WIK
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« Reply #5 on: March 26, 2008, 10:37:23 AM »

>RE: gap eagle or steppir big IR  Reply  
by KB9CRY on March 26, 2008  Mail this to a friend!  
Steppir crushes Gap big time.<

::I agree entirely.  Provided you have an adequate radial field under the SteppIR "BigIR," it will work considerably better than the Eagle on every single band, especially on the lower bands 20m and down.

This isn't a fair comparison, since the BigIR is quite a bit bigger than the Eagle, and absolutely requires an elaborate radial system.

WB2WIK/6  
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K2DC
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« Reply #6 on: March 26, 2008, 12:00:07 PM »

I had a Gap Eagle for several years at a previous QTH a long time ago before I put up my first tower and small beam.  As Mike pointed out it is fed above the base with lots of linear loading for multiband operation and no connection to the shield of the coax, only ferrite chokes to keep antenna currents off the feedline.

I had mine up at about 25'.  It seemed to work reasonably well on 20M and up, but on 40M it absolutely stunk.  I also had a 40M inverted vee only a few feet higher and 40M DX was typically 2 S units or more higher on the wire than it was on the Gap.  As for performance on 20M and up, I was satisfied at the time.  But when I put the little Force-12 C3SS at 40', it was like a whole new world opened up.

I've never had a traditional vertical with radials (adjustable or otherwise), but I'm sure that the Step-IR with a reasonable radial system would run rings around the Gap.  Not to knock the Gap, but it is a compromise antenna.  The Step-IR with good grounding and radials is not.

GL and 73,

Don, K2DC
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K3MOV
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Posts: 504




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« Reply #7 on: March 26, 2008, 12:01:07 PM »

See this DX Engineering site for how to put down radials without burying them "How to put radial wires down without digging" (http://www.dxengineering.com/techarticlepopup.asp?ID={9D191972-822A-41D9-9409-44DD19CBA21C}). Hopefully, you have enough soil to be able to use lawn staples.
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K3MOV
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« Reply #8 on: March 26, 2008, 12:10:23 PM »

Search for the DX Engineering site on Yahoo! rather than Google.  Don't know why, but it doesn't come up on Google.
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WD6S
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Posts: 19




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« Reply #9 on: March 27, 2008, 07:46:11 AM »

I have the radials for my Hustler vertical on top of the ground at our desert cabin, where the ground is rocky and sandy. They work fine. I could not bury them if I wanted to. The only problems are the wind sometimes re-arranges things a bit (not that much) and varmints like to chew on some of the wires. I was using rope to guy the antenna and something chewed one of the lines into several two foot pieces.
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K7UA
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Posts: 37




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« Reply #10 on: March 27, 2008, 09:08:13 AM »

I have had a BiggIR for about three years.  I used it on all bands until I put up a SteppIR Yagi.  Now I only use it on 80,60,40 & 30M.  It has worked very well, especially on 30 & 40M.  I have an improvised ground system.  Without going into the lengthy details, lets just call it 16 radials.  Not enough for some people, but it has worked well for me.  Mine are buried.  Only so they are out of the way.  73,  Bryce K7UA
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N5YPJ
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« Reply #11 on: March 27, 2008, 06:52:28 PM »

Funny how these critters out here in the desert like synthetic fibers.
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