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AirNav RadarBox and RadarBox24.com => AirNav RadarBox and RadarBox24.com Discussion => Topic started by: ww7y on December 14, 2009, 05:17:39 AM

Title: Homebrew Antenna
Post by: ww7y on December 14, 2009, 05:17:39 AM
Has anyone here built a collinear array for 1090 Mhz?  This is probably what the DPD ADS-B antenna is.  There are several sites on the web with instructions for one of these for the 440 Mhz ham band and 2.4 Ghz WiFi.  Of course you would have to use the demensions for 1090 Mhz but it looks pretty easy.  Any thoughts?

http://www.rason.org/Projects/collant/collant.htm (http://www.rason.org/Projects/collant/collant.htm)

http://wireless.gumph.org/articles/homemadeomni.html (http://wireless.gumph.org/articles/homemadeomni.html)
Title: Re: Homebrew Antenna
Post by: juangelb on December 14, 2009, 10:31:20 AM
HI ww7v

I built several colinears for 1090 based on the following project :
http://www.nodomainname.co.uk/Omnicolinear/2-4collinear.htm
The best performance was achieved with 8 and 10 dipoles, that DPD seems to have.
Needles to say that it works fine, has mutch better gain than a Wimo, does not need preamp, mast head....
The only changes I did to original project, was using copper tubing instead of brass tubing, and recalculated the size for 1090.

The projects that you pointed will work in the same way.
But if You want to built a more easy antenna (less gain), can take a look to this one:
http://www.tech-software.net/1090_ant_02.JPG

Cheers.


Title: Re: Homebrew Antenna
Post by: Mike_Tassy on December 14, 2009, 11:18:45 AM
Hi I built a collinnear out of an old 27 meg mobile whip. Cut off the outer covering, unwind the copper wire and rewind to the correct dimensions.  You can add as many elements as you like depending on the length of fiberglass whip

 Mike

See attached image

Title: Re: Homebrew Antenna
Post by: t1mb0 on December 14, 2009, 07:13:26 PM
My effort was to mimic the supplied antenna, but weatherproof it.
The end result looks like the attached jpg, now strapped atop my chimney to a simple mast mount bracket.

I should add, very cheap, very effective, screenshot of PolarDiag included.
Title: Re: Homebrew Antenna
Post by: OKC-Steve on December 15, 2009, 03:40:28 PM
The DPD is made from mini-coax, and has a plastic rod for strength. That is then shrink-wrapped and inserted into a PVC pipe.  You could probably make one cheaper, but it's cheap enough not to bother.
Title: Re: Homebrew Antenna
Post by: ww7y on December 15, 2009, 07:34:44 PM
The DPD is made from mini-coax, and has a plastic rod for strength. That is then shrink-wrapped and inserted into a PVC pipe.  You could probably make one cheaper, but it's cheap enough not to bother.

I agree Steve, it seems an excellent price for what you get.  I was more thinking of it as a project, just to see the results.  Us hams are always tinkering with stuff.

Steve - WW7Y
Title: Re: Homebrew Antenna
Post by: ww7y on December 16, 2009, 06:36:47 PM
Has anyone here built a collinear array for 1090 Mhz?  This is probably what the DPD ADS-B antenna is.  There are several sites on the web with instructions for one of these for the 440 Mhz ham band and 2.4 Ghz WiFi.  Of course you would have to use the demensions for 1090 Mhz but it looks pretty easy.  Any thoughts?

http://www.rason.org/Projects/collant/collant.htm (http://www.rason.org/Projects/collant/collant.htm)

http://wireless.gumph.org/articles/homemadeomni.html (http://wireless.gumph.org/articles/homemadeomni.html)

Ok, I threw one of these together with some RG-213 Coax I had laying around.  I used 10 Sections and enclosed it in 20mm PVC pipe as a radome.  Have to pick up a female N connector and I will give it a try.  Total time about 3 hours, total cost $7.00 for the N connector.  I will post the results when I get it up in the air.

Steve - WW7Y
Title: Re: Homebrew Antenna
Post by: ww7y on December 17, 2009, 10:24:18 PM
Has anyone here built a collinear array for 1090 Mhz?  This is probably what the DPD ADS-B antenna is.  There are several sites on the web with instructions for one of these for the 440 Mhz ham band and 2.4 Ghz WiFi.  Of course you would have to use the demensions for 1090 Mhz but it looks pretty easy.  Any thoughts?

http://www.rason.org/Projects/collant/collant.htm (http://www.rason.org/Projects/collant/collant.htm)

http://wireless.gumph.org/articles/homemadeomni.html (http://wireless.gumph.org/articles/homemadeomni.html)

Ok, I threw one of these together with some RG-213 Coax I had laying around.  I used 10 Sections and enclosed it in 20mm PVC pipe as a radome.  Have to pick up a female N connector and I will give it a try.  Total time about 3 hours, total cost $7.00 for the N connector.  I will post the results when I get it up in the air.

Steve - WW7Y

Got it mounted on the roof at about 20 feet (not climbing the tower till spring) and it seems to work well.  I'm picking flights up at about 165 NM/190 miles and get planes on the ground at KSLC ( only about 10 miles away).  It is a vast improvement over the supplied antenna and about 50 miles better than the discone I was using.

Steve - WW7Y