2.4ghz (wifi) Antenna

Discussion in 'Tech Talk' started by bjma, May 19, 2010.

  1. bjma

    bjma
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    There was a thread about external WiFi antennas... I have more info.

    I attended the annual Dayton Hamvention this past weekend.

    While it is a ham radio mecca, king of all electronics conventions, Diamond Antenna had thier newest antenna offerings on display.

    They now have a series of 2.4GHz antennas, I saw at least 5 different external antennas (different gain, mounting, etc).

    Google Diamond Antenna
     
  2. RLM

    RLM
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    There are a lot of Wi-Fi external antenna or amplifiers on the market. Without going into the specifics for each, the basic concept is to have an inbound signal strengthened before it reaches the equipment (cell phone or computer). If the choice is an antenna then it’s safe to say that bigger is better. Bigger meaning more reflective surfaces. Kinda like the old roof top outdoor tv antenna. The more pieces of metal rods the better the capturing capability. Or in the case of a satellite antenna, the bigger the dish the better it is at reflecting signals into the LNB.

    There are blueprints online that show one how to make a Wi_Fi antenna out of a Pringles potato chip can. And it works. I personally duct tape a Wireless G USB adapter to a spare satellite antenna for signal enhancement. That also works very well. Research the options as BJMA has suggested and find the biggest piece of metal that you can live with to enhance your incoming signal. The key is what is called db signal strength. The bigger the number the better the system works.
     
  3. Trentheim

    Trentheim
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    Know also that using a Pringles can (which is very cool that it actually works) or a parabolic dish turns your wifi antenna into a "directional" receiver instead of an "omni-directional" receiver. So long as you know where the transmitter is located, you're golden.
     
  4. bjma

    bjma
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    Diamond has OMNI Directional vertical polarized antennas, if you want cheap directional, the old Pringles can antenna is just fine for point to point, but if you want/need an antenna for point to point communications, a retired DirecTV antenna dish would be much better. You can still use the Pringles model as the feedpoint

    RLM, I made a coaxial colinear on 2.4GHz antenna using a piece of brass tube from a RC hobby shop and the center conductor and solid dielectric from a chunk of RG8 coax.

    I assembled the antenna and placed inside a piece of SCH40 PVC. Terminated with an N connector.

    My WiFi card that I use in the motor home, modied by removing that idiot reversed SMA with a NORMAL SMA, then I screw on an adapter to an N and run Belden 9913 to the antenna. If I were to buy new coax, I would go with the Times LMR series, but I bought a spool of 9913 years ago and am still pulling it off the spool.
     
  5. RLM

    RLM
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    QUOTE(BJMA @ May 21 2010, 01:39 PM) [snapback]22201[/snapback]

    RLM, I made a coaxial colinear on 2.4GHz antenna using a piece of brass tube from a RC hobby shop and the center conductor and solid dielectric from a chunk of RG8 coax.


    Would like to see the details on that. If you have a picture, please PM me. Thanks.
     
  6. bjma

    bjma
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    QUOTE(RLM @ May 23 2010, 10:22 AM) [snapback]22214[/snapback]

    Would like to see the details on that. If you have a picture, please PM me. Thanks.


    hereis one:

    http://www.frars.org.uk/cgi-bin/render.pl?...amp;goback=1162

    and the one I built....

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

    The outer braid is a PAIN to work with, so I stripped of the braid, and went to the hobby shop and found a brass tube that fit over the dielectric from a piece of RG8.

    You can adjust the number for the freq, propagation delay of the dielectric... 66% 86% or 99% if you are using Belden 9913. Of course, as you know, the lower the percentage, the smaller the antenna. I used 66% for the smaller over all antenna... If I wanted a longer antenna, I would strip off the Belfoil of some 9913.

    The hardest part of this project was to get good, clean, ACCURATE cuts of tube! I ended up buying a XACTO HOBBY SAW.

    Make a solder jig! I also used 4% silver bearing solder for the strength.

    73 Bob
     
  7. RLM

    RLM
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    bjma> Cool stuff. Not your basic tool box project tho. The quad looks like something that could be done for 440 or 2m too.
     
  8. bjma

    bjma
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    QUOTE(RLM @ May 29 2010, 09:33 AM) [snapback]22300[/snapback]

    bjma> Cool stuff. Not your basic tool box project tho. The quad looks like something that could be done for 440 or 2m too.



    I built a 220MHz repeater in 1980 or so. The antenna was a coaxial colinear that I built using RG-8. It was 13 sections, 12 inches (+/-) per section. I mounted it inside a piece of 3/4PVC and that was covered with 1.5"PVC. Then it was placed on a local water tower. It worked great until I got around to ordering a Phelps-Dodge Super Stationmaster.... then the FCC took away my input, but that is another story.
     

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