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Old Apr 04, 2011, 08:22 PM
Engineer for Christ
IBCrazy's Avatar
Amherst, VA
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Originally Posted by badlands View Post
Yea im hoping that works for me, my commercial patch works excellent near the ground, i was hoping my GP patch with its correct (larger) ground plane would work on a tripod up high but it sucked! (was ok on the ground thou)

All good fun testing gear thou...

:-)
Which is why I am developing an antenna replacement for a patch that is not ground plane dependent. I have the design done, I just need to build and test it. It's called the UniQuad... and you guessed it, it only has one quad square. It requires a matching stub to get it to work properly, though.

-Alex
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Old Apr 07, 2011, 01:15 PM
Earth's Mightiest Hero, KC9TBO
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United States, IL, Lemont
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How do you like THEM elements? OK, element.
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Old Apr 07, 2011, 04:21 PM
Engineer for Christ
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Originally Posted by Zahnarzt View Post
How do you like THEM elements? OK, element.
The corners are a bit sharp. That's ok for RX, but in the TX this causes spurious emissions

-Alex
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Old Apr 07, 2011, 05:27 PM
Earth's Mightiest Hero, KC9TBO
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United States, IL, Lemont
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Originally Posted by IBCrazy View Post
The corners are a bit sharp. That's ok for RX, but in the TX this causes spurious emissions

-Alex
Interesting. It will only be on the Rx side. For use on the Tx end, is there a formula that determines the length of the bend? Can you point me to a book I could read about this? Thanks!
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Old Apr 07, 2011, 09:38 PM
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I reference the ARRL antenna book: http://www.arrl.org/shop/The-ARRL-Antenna-Book/
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Old Apr 07, 2011, 10:51 PM
Just trying to get a nut.
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United States, VA, McLean
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I just built one for my 2.4G video...Very straight forward build. Thanks for the awesome instructions.

It seems to work in the house. We'll see how it works in the air. LOLs.

The antenna is enclosed in a plastic sandwich tupperware container for some protection. Anyone see a problem with that?

Thanks again Alex!

JBB
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Old Apr 08, 2011, 02:46 AM
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Originally Posted by scrtsqrl View Post
The antenna is enclosed in a plastic sandwich tupperware container for some protection. Anyone see a problem with that?

Thanks again Alex!

JBB
You wont be able to fit your sandwiches in
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Old Apr 08, 2011, 09:48 AM
Just trying to get a nut.
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United States, VA, McLean
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Originally Posted by mark hitchman View Post
You wont be able to fit your sandwiches in
LOL...


Remind me again, theoretically, range doubles every 3dB?

Thanks.
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Old Apr 08, 2011, 10:46 AM
THEY MOSTLY COME OUT AT NIGHT
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Kaysville, Utah
Joined Jul 2005
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See any problems with this? I'm going to try OMM's balun idea for multipath rejection. Admittedly I'm not well versed in this area, but I'm trying
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Old Apr 08, 2011, 10:54 AM
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Originally Posted by chimaera View Post
See any problems with this? I'm going to try OMM's balun idea for multipath rejection. Admittedly I'm not well versed in this area, but I'm trying
That only works for circular polarization, not linear. For linear it helps balance the antenna, that's all. The build looks great!
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Old Apr 08, 2011, 10:55 AM
Engineer for Christ
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Originally Posted by scrtsqrl View Post
LOL...


Remind me again, theoretically, range doubles every 3dB?

Thanks.
6db doubles range, 3 db doubles signal strength. You need 4X signal strength for 2X range.

-Alex
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Old Apr 08, 2011, 10:59 AM
THEY MOSTLY COME OUT AT NIGHT
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Kaysville, Utah
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Originally Posted by IBCrazy View Post
That only works for circular polarization, not linear. For linear it helps balance the antenna, that's all. The build looks great!

Somwhow I think I should have put that together. Told you I was ignorant Will it hurt or should I remove it?
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Old Apr 08, 2011, 11:04 AM
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Leave it. Any balancing of an antenna is a good thing.
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Old Apr 08, 2011, 12:15 PM
Earth's Mightiest Hero, KC9TBO
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United States, IL, Lemont
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Originally Posted by IBCrazy View Post
I reference the ARRL antenna book: http://www.arrl.org/shop/The-ARRL-Antenna-Book/
Ahh. I have that one. Haven't found a section that directly address spurious emissions related to element geometry, even with a solid PDF search. If you have that earmarked, wouldn't mind knowing what section it is. Anyway, I picked up a biquad from Tim, and it arrived a bit beat up. That's why I made my own element in a freak spurt of free time while I happened to not be at work, and my 3mo old was sleeping!
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Old Apr 09, 2011, 01:58 PM
Engineer for Christ
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Originally Posted by Zahnarzt View Post
Ahh. I have that one. Haven't found a section that directly address spurious emissions related to element geometry, even with a solid PDF search. If you have that earmarked, wouldn't mind knowing what section it is. Anyway, I picked up a biquad from Tim, and it arrived a bit beat up. That's why I made my own element in a freak spurt of free time while I happened to not be at work, and my 3mo old was sleeping!
The sharp bend issue is not outlined in the ARRL antenna book. It is in one of their other publications, though. I can't remember which one. However for an RX antenna, there are no spurs as it is only receiving a signal, not transmitting, so it's not a problem. In fact, the square geometry is just for ease. you can make it a circle, triangle, octagon, ect. It doesn't matter the shape so long as it is one wavelength and symettrical

-Alex
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