Using an Old Satellite Dish as a WLAN Antenna 225
=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.
Jeez....this is an obvious dupe... (Score:5, Informative)
i aint stupid i just dupe it (Score:2)
ahh the good old days of Living Color with Jim Carrey impersonating Vanilla Ice
And the cached version in case anyone needs it. (Score:3, Informative)
Primestar Dish's on eBay (Score:5, Informative)
Steal one (Score:5, Funny)
Re:Primestar Dish's on eBay (Score:5, Informative)
For $15 more you get the real thing (Score:5, Informative)
Re:For $15 more you get the real thing (Score:5, Insightful)
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.
No kidding. Get the real thing. (Score:4, Informative)
I use Linksys WET11 bridges with 24dBi grid antennas made for 2.4GHz (also less than $70 each) and have a rock-solid 11Mbps link a bit over 6 miles away. The trick is to mount your WET11 in a weatherproof box right underneath the antenna, to keep the coax pigtail as short as possible, because signal loss in a long coax is the distance killer. I have only a 3 foot long coax pigtail and run the dc power up the unused pairs of the CAT5 cable to power the WET11. You may have a significant voltage drop at the end of a long CAT5 cable, so you may need to use a +6V or even a +7V DC power supply of adequate amperage to ensure that you still have +5V DC at the end of the CAT5 cable with the WET11 plugged in loading it down. I had to use a +6V, 1.5 amp DC power supply on mine to keep the voltage at +5 volts at the end of my CAT5 cables, or the WET11 wouldn't run.
Re:No kidding. Get the real thing. (Score:5, Interesting)
Chris
Re:For $15 more you get the real thing (Score:3, Informative)
Re:For $15 more you get the real thing *Decibels* (Score:2, Insightful)
Mnem
"Enough technical gobbledygook. Tell me how we kill this thing."
Re:For $15 more you get the real thing *Decibels* (Score:2)
Re:For $15 more you get the real thing (Score:4, Informative)
I don't know why this is news, since it's been out for years.
http://www.trevormarshall.com/biquad.htm is a much, much better way to do it than that crappy can. The stacked "BiQuad" adds 3dbi in itself over a single quad. If you want a slightly better antenna use a ring. People don't make rings because all these antennas are modeled after old HAM designes for at least 9M and there really is no way to make a 9M loop that isn't unwieldy. Think more like UHF antennas for TV's because it's just better than a square by some small margin and it's possible for shorter waves.
I want to get an antenna with perfect measurements etched onto a copper clad board someday because a millimeter at 2.4Ghz will amount to 4 channels.
Channel 6: 2.437Ghz
123mm=2.437Ghz
124mm=2.417Ghz
If you were off by 2mm
126mm=2.398Ghz
The lowest frequency is for channel one that goes from 2.401Ghz to 2.423Ghz.
2mm will put you completely off the 802.11 band, thus you will have a higher standing wave ratio which means you aren't using all those 100mW that you paid hundreds of dollars to buy in cisco hardware
2mm isn't enough to knock a full db off your transmit power, but considering you have to hand bend the wire, and most wire used has a diameter greater than is recommended for an antenna, etching will likely get you much closer to the theoretical 34+ dbi that you could get out of primestar dish.
Whatever you do, do not forget to match your polarity. I suggest horizontal polarity since most interference is going to be verticle. I can't say that my situation is typical (but it may be), but I had a dish on horizontal polarization and sector antenna on a vertical polarization and I got 0% signal at about 300ft. When I fixed the polarization (you probably want to tune it by rotating the dish/antenna slowly then remonitoring the signal level) I got 100% signal and link quality. It really does matter more than you think I don't know why it matters more with a dish than not. Maybe a HAM-op on here will explain it.
Re:For $15 more you get the real thing (Score:3, Informative)
Whatever you do, do not forget to match your polarity.... ...It really does matter more than you think I don't know why it matters more with a dish than not. Maybe a HAM-op on here will explain it.
The easiest way to help you see what's going on is to use polarized sunglasses. if you take two lenses and hold them in the same direction and look through both of them you will see through them. If you rotate one 90 degrees you wont.
It actually matters throughout all frequencies in the electromagnetic spectr
Re:For $15 more you get the real thing (Score:2)
You must remember
The angle of incidence == the angle of reflection
Ask yourself: Have you ever seen a mirror flip your image at a 90` angle? No. Upside down or reversed right or left but vertical and horizontal stay the same.
With a dish you really don't have that much bouncing and refracting as a source for a signal like a normal antenna. You get most of your signal directly from the source
You don't refract a signal with a dish, just reflect. EM can be bent in weird ways but reflecting is all your
Re:Primestar Dish's on eBay (Score:2)
Time to scheme.
Not for long (Score:5, Funny)
Given the fact this story was just posted on Slashdot..not for long.
Somewhere, tomorrow morning, some poor satellite dish dealer in East Nowhere is going to be very, very happy and not know why.
Re:Primestar Dish's on eBay (Score:3, Funny)
I'll sell you a 30" new dish without an LNB (not primestar branded) for $75 CDN. Shipping not included. Add LNB for $10 CDN.
If you're paying $50 US for a heavily used OLD dish, you're being ripped off in a VERY big way.
Re:Primestar Dish's on eBay (Score:2)
Re:Primestar Dish's on eBay (Score:2)
there are many of them still on their pole's on roofs in rural/ semirural areas.
Anyone that pay's for a primestar dish is a fool, they are still around for free, and the people that have them are happy to see them go away.
Re:Primestar Dish's on eBay (Score:2)
Re:Easier than a Floppy (Score:2, Troll)
Re:Primestar Dish's on eBay (Score:2)
You mean post an article recommending using a rare XYZ and then post a reply saying...
You don't own the antenna... (Score:4, Funny)
Re:You don't own the antenna... (Score:5, Informative)
I've already started on one (Score:4, Interesting)
Re:I've already started on one (Score:3, Funny)
What is it like living in the future?
Next time on Slashdot... (Score:4, Funny)
Difficult to locate!?!??! (Score:5, Funny)
Will a DISH Network or DirecTV dish work? I can locate hundreds of these without walking too far. Give me a couple of nights and I can send a bulk shipment you're way for a few thousand dollars.
Now, where did I put my screwdriver?
Re:Difficult to locate!?!??! (Score:2)
Don't forget the wire cutters and the adjustable wench while you are at it!
Re:Difficult to locate!?!??! (Score:2, Funny)
Re:Difficult to locate!?!??! (Score:2)
fucking convince slashdot to fucking cache sites.
fuck
Re:Difficult to locate!?!??! (Score:2)
I once tried this... (Score:4, Informative)
Big Dish... (Score:5, Interesting)
Why beat around the bush? (Score:2)
On the other hand... (Score:2)
Re:Big Dish... (Score:5, Informative)
The main problem with these is getting them high enough for line of sight and also mounted sturdy enough. Mountain to mountain is the best for these kind of links.
With a beamwidth of 1degree or less those 6-10ft dishes have to be held dead still or you loose your signal at any distance.
Anyways.. the record is something like 120+km with two of these things and some VERY modified radios in the cards.
Re:Big Dish... (Score:2)
Re:Big Dish... (Score:3, Informative)
12 Miles at 5Ghz with Primestar Dish (Score:5, Interesting)
http://www.planetc.com/ is the ISP
Re:12 Miles at 5Ghz with Primestar Dish (Score:5, Interesting)
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.
Re:12 Miles at 5Ghz with Primestar Dish (Score:5, Interesting)
How the heck do you sight something like this in? You have to be accurate within a few seconds, don't you? A search pattern would take forever with that narrow of a beam, wouldn't it?
Some of the high-end telco gear has a built-in telescope, but those are precision aligned at the factory.
Re:12 Miles at 5Ghz with Primestar Dish (Score:2)
beamwidth gets wider as you drop in frequency (Score:5, Informative)
How the heck do you sight something like this in? You have to be accurate within a few seconds, don't you? A search pattern would take forever with that narrow of a beam, wouldn't it?
The beam isn't that narrow. Let's do a quick mental calculation. A typical direct-to-home Ku-band dish is going to have a beamwidth of about 1 degree (2 degrees, whatever) in order to be able to isolate the right satellite on the arc. That's at Ku-down, which is about 11 GHz. A given antenna will get "wider" as you go down in frequency, so the beam width at 2.4 GHz for this same antenna is much wider. I believe the beam width and frequency scale inversely, so if you go down in frequency by about a factor of 5 (11/2.4) then your beamwidth (however you want to measure it) goes up by the same factor.
So your beamwidth at 2.4 GHz is going to be something like 5-10 degrees. And it's not a super sharp rolloff, so you'll find that signal easy.
Another way of expressing all of the above is to say that an antenna with a certain gain at a high frequency (like Ku band) is going to have a lower gain at a lower frequency, and the corollary of that gain reduction is lobe spreading.
Hey, maybe someone here can point us to a visualization tool for this -- looking at an antenna pattern for a given antenna, crank down the frequency and watch the lobes spread out and drop.
Re:beamwidth gets wider as you drop in frequency (Score:2)
A typical direct-to-home Ku-band dish is going to have a beamwidth of about 1 degree (2 degrees, whatever) in order to be able to isolate the right satellite on the arc. That's at Ku-down, which is about 11 GHz. A given antenna will get "wider" as you go down in frequency, so the beam width at 2.4 GHz for this same antenna is much wider.
It was my impression that a DSS satellite bathed a large section of the
it may have 10 mile range... (Score:5, Funny)
Hard to locate? (Score:5, Funny)
Re:Hard to locate? (Score:3, Insightful)
I was quickly flamed, parent gets "Funny." Can anyone say double standard?
Re:Hard to locate? (Score:2, Interesting)
Re:Hard to locate? (Score:2)
But satellite tv has no redeeming educational value, and kids running around half naked eating dirt is just funny as hell.
Bah! (Score:3, Funny)
slashdot strikes again! (Score:3, Funny)
Re: (Score:2, Informative)
FCC rules (Score:5, Informative)
Have fun if you get nailed!
Re:FCC rules (Score:2)
Re:FCC rules (Score:2, Informative)
Re:FCC rules (Score:2)
"It's not the volts that kills you, it's the amps."
"Well how many amps are we talking?"
"Enough to push a train
800 Watts? Jesus man, my microwave only does 700 watts and that is enough to cook a chicken. I can only envision 800 watts of microwave energy on a focused beam, on the end of a pointy stick. Look like something out of Ghostbusters.
Re:FCC rules (Score:2)
Canteena for $19.95, shinier and FCC legal ! (Score:5, Informative)
Re:Canteena for $19.95, shinier and FCC legal ! (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.
Re:Canteena for $19.95, shinier and FCC legal ! (Score:2, Insightful)
I can also support a 400mm lens rock solid, exposures at 1/2000th of a second will be as sharp and free from blur as any photo you care to take (given we both use the same film format, no fair if one of us uses 35mm and the other brings out the 8x10 studio camera.)
You need a better analogy, it's eas
Old dish projects (Score:2)
Wardrving aerodynamics will take a hit (Score:4, Funny)
"- Sir, you are aware that you have a huge TV antenna duct-taped to the roof of your mini-van?
- Hun, yeah, I do
- And that there seems to be 2 sets of eyes in the back of the mini-van that look like they belong on ghouls
- I think you mean geek sir. And don't mind the flashing leds too, we are having a lan party.
- In a mini-van ?
- Mmh, yeah.
- Ok, drive safe"
*rolls up window and keeps on following the signal*
Re:Wardrving aerodynamics will take a hit (Score:2)
Hehe, reminds me of the dialogue at the beginning of a Butthole Surfers song....
(Kids in car, singing "I don't give a fuck about the fbi, I don't give a fuck about the cia..."...cop siren goes off, car pulls over and cop starts talking:
- Whatch'a doing?
- Chewing chocolate.
- Where's you find it?
- Mmh, doggy dropped it?
- (pause)...move along.
winegard.com (Score:3, Interesting)
FWIW- I toured the plant, and saw sheet metal stamped into dishes. It was impressive.
Re:winegard.com (Score:3, Funny)
Re:winegard.com (Score:3, Interesting)
You need to find a satellite dealer. They shouldn't have *ANY* trouble getting you a vast selection of dishes, including those made by Winegard (which, surprisingly for an american part, are well priced, and are well built).
Satellite dealers (Score:2)
Me: "I need six satellites, pronto."
SD: "Would that be launched, or unlaunched, sir?"
LAN away (Score:2, Funny)
Call your buddies up around the neighborhood and your ready.
ogg
Hey, the toilet isn't flushing! (Score:2, Informative)
Wonder if he realizes what that vent pipe is for? Are there any studies on the interference factor from 'methane gas' emmisions on WI-FI?
Maybe it's just the bathtub/sink vent.
Why use a mini-dish? (Score:3, Funny)
Plus it is far more conspicuous, and therefore infinitely more cool.
Making your own dish might be fun but.. (Score:3, Informative)
Try this. [pacwireless.com]
Its a 24dB gain antenna (Thats 256 times power folks), its guaranteed to work, it HAS a feedhorn, and all the calculations have been done for you. Not only that, its a grid antenna so there is almost no wind loading. You might pay 50bux or more for a primestar dish on ebay, plus trying to get the can into the focal point, etc. There is certainly a certain apeal in doing it yourself, but sometimes work for the sake of work is no fun at all.
The best thing? Its only 70 bux, WITH the feedhorn and pigtail.
Right now im using one of those, and two 10 foot C-band dishes to make a big triangle network connection. The C-band to C-band dish connection is over 30km long. (Yea I'm in Canada: 30 kilometers = 18.6411358 miles)
Re:Making your own dish might be fun but.. (Score:2, Informative)
Re:Making your own dish might be fun but.. (Score:2)
Either way, there is a wired dish, and a non wire mesh dish, with the same gain. Are the icing issures you're talking about affecting the feed horn? temp. cycle warping?
Re:Making your own dish might be fun but.. (Score:2)
Re:Making your own dish might be fun but.. (Score:2)
I live in Minnesota, and have had one hanging on my roof for the last 16 years. I just took it off two weeks ago when I repainted (it was for an old "wireless cable" system that folded ten years back. Somewhere around the 900 MHz range, as I recall.) It was in fine shape right up until the time I threw it the 25 feet to the ground, unlike the crappy Radio Shack TV yagi mounted on the same mast. I didn't examine its condition when I chucked it in the neighbor's dumpster, but the dumpster is s
Not too hard to find... (Score:2)
Quote of the Day (Score:2, Funny)
Charles Miller
Obligatory Legal Reminder (for US residents)... (Score:4, Informative)
Only the party obtaining the FCC certification is allowed to specify another antenna. You, the user, cannot alter the device even if it meets the requirements of 15.247. Modifying approved transmitters is generally not allowed, with the notable exception of the Amateur Radio Service. A new configuration with higher antenna gain requires a new certification. 47CFR2 [fcc.gov]:
[emphasis added]So unless you have the money to spend on a complete recertification (it's neither cheap nor easy), leave your wifi alone!
Re:Obligatory Legal Reminder (for US residents)... (Score:3, Interesting)
These days, they wait for complaints of interference before they send out the vans, and there are far fewer of them than there used to be. The mentality has changed from being the airwaves police to transferring the responsibility of discovering violations to operators, and the public. The only t
How about trying a Star Choice dish? (Score:2, Interesting)
Re:How about trying a Star Choice dish? (Score:2, Interesting)
The real jems are the old 39 inch starchoice dish's. Over 30 dB of gain! which may be illegal but industry canada isn't going to bother you unless your causing problems with someone eles' communtications.
I've been thinking about setting up a relay system here in western newfoundland, moutain top to moutain top to give high speed internet and maybe telephone services
FCC doesn't care (Score:5, Informative)
The only exception might be certain commercial product vendors who try and sell out of spec equipment to the masses. That is actually worth their time, but some guy with a primestar dish? no way. [ Like linksys getting pressured to take their 2.4Ghz amps off the market because they could interoperate with too many other "unapproved" equipment configurations. Supposedly they can sell them again [smallnetbuilder.com] after making them harder to use with anything but linksys/cisco. arg. ]
There are a number of smaller WISP's that I've come across in the northwest that run 1/2W and 1W amps on their directional point-to-point and point-to-multipoint configurations, but until someone complains that they are interfering, there is no way the FCC is going to proactively come out and bitch.
Wireless users groups across the nation post plans and site configurations using all sorts of unapproved antennas, radios, amplifiers, etc. There is no widespread FCC CRACKDOWN going on. In fact, I challenge anyone to name an incident where a WiFi user (not company) was pressured or forced by the FCC to alter their equipment back into spec. It doesn't happen.
Personally I think this is a good thing. The FCC has done more harm in the 802.11 space than good. Like antenna connectors. Do you know why there is a proliferation of SMA, RP-SMA, N-type, BNC, RP-BNC, MMCX, and any number of other bastardized formats for antennas and equipment? The FCC requires vendors to make their radio's use proprietary connectors to prevent people from easily and usefully extending the range of their equipment with generic antennas. Not that the vendors mind. Nothing like vendor only parts with the associated 400% markup to pad the profit line.
Let the FCC play with the Big Co's and handle licensed spectrum. The ISM bands are where its at.
Easy Dish alignment method.. (Score:2, Informative)
I wonder? (Score:2, Interesting)
DIY (Score:2, Informative)
KI7cx [qsl.net] dish
Primestar [wwc.edu] dish
Bi-Quad feed for primestar [trevormarshall.com] DIY
10 Euro dish with biquad feed [weijand.nl]
Modifying Confier Antennas for Wireless Networking [martybugs.net]
More info: Wireless Leiden [wirelessleiden.nl]
luckily.. (Score:2)
Dish Network dishes, free (Score:3, Interesting)
Re:Could he have used a Low Noise Block converter? (Score:2)
No, because a LNB facilitates reception, not transmission. The LNB takes a certain frequency range and mixes it with a much lower frequency signal, then boosts it so it can be transmitted over a reasonable distance on cheap coax.
Re:do you have any clue (Score:2)
Re:Friggin Line of Sight (Score:2, Informative)
Re:Friggin Line of Sight (Score:3, Informative)
I'm not sure if you're kidding or not, but I'll tell you the reason anyway.
It has a little to do with output power, but mostly to do with frequency. The higher in frequency you go the more readily the energy is absorbed by "stuff."
Ham operators use HF frequencies (loosely defined as about 7MHz - 30MHz). Those
Re:Friggin Line of Sight (Score:2)
Re:Friggin Line of Sight (Score:3, Informative)
So yes it is posible, just remember that you can't encode/encrypt to obscure the meaning of the data. (Although I have never read anything about putting a passowr
Re:Illegal - not (Score:2, Informative)
Re:Primestar dish (Score:2)
Re:Primestar dish (Score:2)
Welcome to Slashdot! (Score:2)
You must be new here. Welcome!