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Using an Old Satellite Dish as a WLAN Antenna

Posted by ryuzaki0 on from the rolling-your-own dept.

=m8s=Dark Underlord writes "I was browsing for wireless stuff and came across this link that shows how to use an old satellite dish as an 802.11 antenna." The directions tout the range as being 10 miles given line of sight. We've had other stories about building antennas, but I think these are cooler because of their focused nature, but a Primestar dish is a little tougher to locate than a Pringles can or a floppy disk.

11 of 225 comments (clear)

  1. Jeez....this is an obvious dupe... by Geraden · · Score: 5, Informative

    The Original Slashdot Article

  2. Primestar Dish's on eBay by TheMysteriousFuture · · Score: 5, Informative

    Looks like you can pick up a Primestar dish on eBay for about 50 bucks (current auctions here). Shipping looks to be about $20. Anybody know of other sources for acquiring these dishes?

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    1. Re:Primestar Dish's on eBay by ajlitt · · Score: 5, Informative

      I've picked one up at Goodwill for $5 (actually a DirecTV dish) and it works great with the cantenna.

  3. Big Dish... by nitrocloud · · Score: 5, Interesting

    My grandparents have a satelite dish that's about 10 feet in diameter... so should that give access to about 30 miles away? (I know it wouldn't, but it'd be neat to crank the amps)

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    Karma: Good, or bust!
  4. 12 Miles at 5Ghz with Primestar Dish by ArkiMage · · Score: 5, Interesting

    Where I work our internet connection is via a WISP that uses this "technology". We have a Primestar dish on an elevated pole aimed at a mountaintop 12 miles away. 5Ghz and also a backup 802.11b radio with Yagi antenna that needs an amplifier to go that distance, but does so fairly well. The less-informed employees think the "dish" points to a satellite, not noticing the odd angle it's mounted at :)

    http://www.planetc.com/ is the ISP

    1. Re:12 Miles at 5Ghz with Primestar Dish by MemoryAid · · Score: 5, Interesting
      As I recall, most of the satellite dishes these days have an offset feed, so it is not obvious which way they are pointing. In fact, they usually point a little higher than it appears. That is, a vector normal to the center of the dish points lower than the main lobe of the antenna pattern.

      During a trip to Fairbanks, Alaska last year, it struck me as odd (well, odd looking) that the satellite dishes were pointing at the horizon. The offset-feed dishes looked like they were pointing at the dirt.

      If you want it to appear that your dish is pointing to a satellite, you could mount it with the feed horn on top, giving the appearance of a skyward view.

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      Language students: Don't try to learn English here. This ain't it.
  5. Hard to locate? by christopherfinke · · Score: 5, Funny

    Satellite dishes aren't hard to find; just visit any trailer park or upper-lower/lower-middle class neighborhood, and I guarantee you, there'll be a dish stuck on the corner of every other house. The kids'll be running around half-naked, there'll be a car or two on the lawn, but getting satellite tv still seems to be first priority.

  6. Re:You don't own the antenna... by Anonymous Coward · · Score: 5, Informative

    Primestar was purchased by Directv, who made the old primestar dishes "useless". Directv sent new satellite dishes and receivers to anyone who was subscribing to primestar.

  7. FCC rules by Anonymous Coward · · Score: 5, Informative

    Hey, guys, this would violate FCC part 15 and other applicable rules. Specifically, we are referring to ERP (effective radiated power).

    Have fun if you get nailed!

  8. Re:Canteena for $19.95, shinier and FCC legal ! by v1 · · Score: 5, Informative


    I shopped around a month ago for wifi antennas too, and found there's a lot of rip-offs and a few hiddeen gems. Cantenna doesn't come with the pigtail, which doubles the price. Add a "mounting bracket" (it's a camera tripod) and the price is now triple.

    For about the same money, check out the real thing by Pacific Wireless: http://www.rangeextender.com/224pagransy.html

    24db gain, versus the cantenna's 12. Adding 12 more db of gain amounts to 16 times more signal than the Cantenna, and it even comes with a weatherproofing kit and is meant to mount to a pole outside where it belongs. I don't think a Cantenna would last one season outside where I live, and it certainly won't mount on my roof using that camera tripod.

    I think the Cantenna is meant for people that want to just experiment, war-drive, look for waps near their house, etc. If you really want to establish a long-distance or "shooting through trees" link, the Pacific Wireless looks to be the real deal.

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    I work for the Department of Redundancy Department.
  9. Re:For $15 more you get the real thing by djh101010 · · Score: 5, Insightful

    Exactly my thoughts - I have several DirectTV dishes lying around that I was going to use for a 1.1 mile 802.11b link, and it just wasn't worth the hassle. The offset feedhorn makes mounting (and the math) inconvenient, and to me it wasn't worth the risk of, ahem, going beyond the 24 dBi of gain that the FCC allows. Better to be able to point to published specs for each piece of gear, and cable losses, and explain how you're not exceeding the legal limits. Yeah it's cool and all that, but what's the gain of these? (I don't know either). is it worth taking a chance?

    For what it's worth, two Linksys WAP11's in bridge mode, and two directional 24dBi gain antennae, and my link is rock solid at 1.1 miles.