Which antenna best for panel antenna

There is a municipal wifi transmission antenna about .5 km from my roof. Can get a line of sight, but the antenna they are using is pointed downwards on a plaza and I THINK it is a panel antenna. I am approx perpendicular to it. Sorry I cannot get photos do not have the right equipment for that.

Have plans for several homebuilt antennas and some dish antennas available on the net. On the dish antennas is there any rough guide to which are best for the, is it, 2GHZ? frequency of wifi? Can the tv satellite antennas be modified for use? Or is another antenna better since I am not sure I can get precise alignment to their antenna. Others nearby appear to be accessing this transmission with simple home made cam antennas. Also I have a tree I might need to trim that seems to be covering a part of the field between me and their antenna.

I realize this is sketch information and will try to provide better later, if I can. They have been uncooperative in giving details of their setup because the really, contrary to the pr campaign, do not want people using it for free, only businesses.

Reply to
everyman
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If one looks around on Google drawings will be found for various antennas. I suppose that the most successful would be the parabola. In general it receives parallel RF input and focuses it in much the same way that when capturing light rays. The focus has to be found, and is a little touchy but it could be calculated or found by experimentation. But, at 1/2 Km. I would have no problem connecting up with my USB device on a six foot cable which carries only data to the USB PORT. I travel and use many free hotel and other Wi-Fi APS at that distance with pretty good luck....Luck!!!

Reply to
Jose Cuervo

Hi You can try any Highly Directional Antenna that is intended to work with

2.4GHz signal. Jack (MVP-Networking).
Reply to
Jack (MVP-Networking).

It doesn't work the way you seem to think from the subject line. It's all about the signal strength and the signal quality from the access point to your client device, and back again. You can improve the signal receive strength and the signal send strength through a good antenna, doesn't matter if it's a panel, parabola, can or whatever. Look at the dbi rating. If that's accurate, there's absolutely nothing to do with which type of antenna it's associated with. Some of the inexpensive panel antennas you can buy on eBay are good deals. If you want to build your own, lots of info available.

Reply to
Rôgêr

nice try. this guy probably works for the company which brags about giving residents free access then tries to obstruct people who want to use it, haha. Tell you and your workers you will be getting a STRONG signal sometime soon.

Frank wrote in news:dpgbmo$15k$ snipped-for-privacy@domitilla.aioe.org:

Reply to
everyman

Guess you do not know the answer to the question: what design characteristics make for a good 2GHZ, probably dish, antenna. I wrote one company that sells these things and their "salesman" did not even know. It is very funny, whenever there is relatively new technology that crops up how most people using it do not really understand it, and some think they are guardians of some kind of secret key that only the noble are privileged to use.

"Jack \\(MVP-Networking\\)." wrote in news: snipped-for-privacy@TK2MSFTNGP15.phx.gbl:

Reply to
everyman

You falsely assume I have not thought of that factor, which is easily provided for. Like I said they will be getting some STRONG signals sometime soon, with or without good answers from this group. We'll see how that effects their secret operation.

Rôgêr wrote in news:43bb8b15$0$18436$ snipped-for-privacy@news.astraweb.com:

Reply to
everyman

"Jose Cuervo" hath wroth:

Wrong. High gain (24dBi) parabolas are difficult to turn into useable antennas if you try to build your own feed. Getting the dish illumination correct is difficult and always a compromise. It's also not cost effective as commerical 24dBi parabolic dish antennas can be found for $60-$80.

Yep. Now try this experiment. Pretend your transmitter is an incandescent light bulb. Hang it at the focus of the dish and try to guess how much of the light hits the dish and reflects in the direction you want to talk. Then, guess how much does NOT hit the dish and is lots to parts unknown. Do you see the importance of a proper feed now?

See:

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Focus and phase center are different animals. Because the RF source at the feed is NOT a point source (isotropic radiator), you'll need to find a suitable compromise. For example, where do you put a tin can feed so that the RF is focused for maximum gain?

Various people have posted plans for just shoving a USB antenna into a coffee can and improving the gain substantially. These work mostly because the gain of the typical USB dongle is so lousy, that any type of reflector will constitute an improvement. You can probably get a

6-8dBi gain improvement with anything from a pie tin reflector to a coffee can. Incidentally 6dBi is double your range.

Oh, it also has to be portable? Why are you looking at a dish antenna? Same with coffee cans. These are not very portable. Wanna disclose exactly what you're trying to accomplish and what you have to work with so we can offer some useful suggestions?

Reply to
Jeff Liebermann

This question, or one suspiciously similar to it, was covered in excrucitaing detail about two months ago. See thread at

formatting link

Reply to
Lem

If it is a "Panel Antenna" and you are perpendicular to it then you will probably be outside its "Beam Width" and unlikely to be able to connect via this antenna.It is probably a directional antenna used to provide wifi access for those in the Plaza.

If this is true then they will prevent your access no matter how you try to connect to it.

Reply to
Frank

Have you tried a USB wireless dongle? If there is any sort of signal it should see something, with a bit of luck it will identify it, report signal strength and whether it is encrypted. If you get this info you may need some form of access rights like account info to access it. You can put simple ali foil reflectors, or more complex dishes, around USB wireless dongles to get "some" increase in signal strength.

Reply to
ato_zee

I'm already married, I don't shit from you. I tried to give a good answer. Don't like it? Fuck off.

Reply to
Rôgêr

Hmm.. Taking into consideration that I was involved with my first design of Antennae in the late 60's (yeah that is 40 years ago), and doing it On and Off since then.

There is No General Best-Designed Device. Antennae are measured by their Gain and the difference between them is in the amount of directionality and other parameters that a more of the physical nature of the specific environment (how, where, and what is the mounting arrangements, and the way it is connected to the Wireless source).

The home build Antennae that proliferate on the Internet has to do with what the Hobbyist is capable to build with the parts that are available to him, and the person technical knowledge. It has nothing to do with "Best Design". For 2.4GHz signal, the Dishes are actually not a good solution, 16 elements Yaggi would be nice ;)

Therefore, from practical perspective your question is moot question. If you want to buy an Antenna, compute the Directionality Angle, buy the highest dbi that you can find (afford), and make sure that the type of Antenna that you choose can be physically installed safely in your specific environment, and connect correctly to your Client WIFI.

If you want to make one, make what ever technically you can find parts to, and have the mechanical know how.

You want to try something inexpensive this might help,

formatting link
Jack (MVP-Networking).

Reply to
Jack (MVP-Networking).

Mr. Spoke, glad you are still here! More inline...

Jeff Liebermann wrote in news: snipped-for-privacy@4ax.com:

Yes so for such a connection would you use another design than parabolic? Also I have plans now for a parabolic that uses a usb adapter card at the focus point. Others have said that the USB cable can be extended further with less loss (how is this?) since I have to go about

4 meters to my computers, unless I move them all, in which case i have to only go about 2 meters, would it be better to use a usb client adaptor at the focal point of the parabola? At least with usb, I don't have to buy separate adapters for each computer, nor do I have to put up a wifi AP router, since I can connect directly to the dish. What do you advise, Dr. Spock?

AHA, learning more from you with each sentence. I notice that the usb client cards are rated at much lower power than the pcmcia cards. Why is this? So, should I forget about USB and go with antenna to AP router to pcmcia card? But does this not increase security problems since I will have signal emanating from my room?

Thanks alot for your very astute comments here. Grasshopper.

Reply to
everyman

Jeff Liebermann wrote in

Thanks for your reply. I am trying to ascertain now if USB is better than PCMCIA and if so/why? I know that USB is more portable, but what about signal strength and losses over usb wire vs. coax cable. As you can tell I am new at this. :-( Also, see above, most usb adapters are rated at much lower power output than some of the hi powered pcmcia cards.

news: snipped-for-privacy@4ax.com:

Reply to
everyman

Sorry for my earlier attitude. Frustrated lately.

Ok, so design is not it. As I said in last few posts, I have plans for a homemade parabola with good tested db gain with a usb adapter as its focal pickup point. Since there are a few tree branches in the "fresnel zone" though I have a line of sight approx. 75 degrees to the side of the transmission point, I wonder if the parabola is best. Just guessing I would think that it's design would allow for more precise targeting of the signal or am I thinking backwards since a barbecue type antenna might pickup more off target signal, maybe even bounced signal plus more interference? Just seems from the look of it that a good satellite dish would be better since it focuses the waves. And I think they are the choice for longest distances are they not?

Jeff Liebermann wrote in news: snipped-for-privacy@4ax.com:

Reply to
everyman

No. At 0.5km from a rooftop to the side of an unspecified antenna, methinks you'll need all the gain you can get. Parabolas have the highest practical gain at about 24dBi max. What I wanted to point out is that *BUILDING* your own parabolic antenna is not a trival exercise. I suggest you purchase a commercial wire grid dish.

Same problems as previously listed. Think light bulb again. If the USB dongle radiates in all directions, how much of that signal will hit the dish and go where you wannit? Without an optimized feed, a USB dongle at the feed is a crap shoot. If you're lucky, it will work. If you're not, it's a waste of electrons.

The official limit on USB cable is 5 meters total. However, there are active (amplified) cables and adapters that will much further. I recently installed one in a trailer that was about 12 meters long.

I'm not sure. I would use a USB radio, but attach a coax cable pigtail in place of the built in antenna. The pigtail would then go to a proper 2.4GHz dish antenna. What will require some soldering expertise and a bit of waterproofing but should work.

Most PCMCIA cards have seperate RF amplifiers with diversity antenna switches nearby. The larger board real estate also allows more complex antenna designs. There's no room for that in the USB radios.

No. You apparently have too far to do in cable. Coax losses at

2.4Ghz are horrible and should be avoided at all cost. Basically, your radio should be near the antenna. If you wanna be fancy, get an access point that has a "client mode" such as WAP11, WAP54G, DWL-900AP+, WET11, and mount it at the antenna in a waterproof box. There used to a nifty set of photos on the Sveasoft web pile, but it seems to have evaporated.

No. The signal is radiated from the antenna, not the radio. The real security issue is someone steals the dish antenna with the radio attached. I just hate it when that happens.

Reply to
Jeff Liebermann

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