View Single Post
  #9   Report Post  
Old July 16th 11, 11:50 PM posted to rec.radio.amateur.antenna
Jeff Liebermann[_2_] Jeff Liebermann[_2_] is offline
external usenet poster
 
First recorded activity by RadioBanter: Jun 2007
Posts: 1,336
Default Curtain Quad - Real gain or antenna snake oil?

On Sat, 16 Jul 2011 12:43:16 -0500, amdx wrote:


Hi Jeff,
Why didn't the loop sizes shrink, when the author went from 1296Mhz
to 2400Mhz. First thing I thought about was etching it on a PCB.
But then saw he built the higher freq antenna with the same loop
lengths.
Mikek


I'm not quite sure what you mean. However, I have a guess(tm).

His curtain quad calculations and NEC2 deck are at:
http://home.comcast.net/~ross_anderson/CurtainQuadFigure11.htm


If you scroll down to the bottom of the NEC deck, you'll find the
line:
FR 0 1 0 0 1332 0 'simulation is at 1332 MHz
That's the operating frequency. Change it to 2442 MHz and you have a
2.4GHz antenna.

The element dimensions in the NEC deck are in wavelengths. This makes
it very easy to use a design on different frequency. In order to
obtain construction lengths, simply multiply each element length by
the free space wavelegth. For 2.4GHz, that's about 12.5cm.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558