15/08/2014

Tutorial: How to build a satellite dish Wi-Fi cheap and functional

Tutorial: How to build a satellite dish Wi-Fi cheap and functional


After a week of investigations by the network they've built a couple of cheap directional antennas; the details below. I'm not teleco, so some technical data may be incorrect or little adjusted to reality. This type of antenna comes to us to constitute a link point to point with a neighbor, for example, or to concentrate all the signal from a small antenna in a given area. The best links to remote satellite antennas are always used, with which you get better result by concentrating all the waves in one spot.


From Omni-directional antennas (that meet its mission well) which bring the AP (access point) can focus your radio's coverage through the use of a satellite dish or with any conductive metal that has a curved shape. After searching among the Junk I found a leaky pan of unos32 cm in diam. I served well, because its shape reminded commercial antennas.





Cut a piece of the measure that we want, as we want to concentrate the radius of coverage in minor or major RADIUS (measured in scheme), using the rotaflex, rectangular-shaped (it could be round, depends on the result you want to obtain and the antenna you have, but I thought that it was best to aprobechar all possible from the pan size).
I cut two pieces to make two antennas, and thus put in each one of them my Conceptronic C54AP removable antennas, so that with one with access point to point from the roof, and with the other sign up directly from the attic down, managing to concentrate all the signal with that Antenna House. To do this I have caught and desoldering wires going to the plate in the AP and placed a slightly longer cable (1 mt, no more,) to be the access point on the roof though requires some experience in welding, to connect to the satellite dishes homemade.
To lengthen the cable, it is important to use quality cable if they are going to be several meters (the LRM400 would be ideal), and joints should be cut sufficiently the inner cable so we can then put the mesh on top, so that it is not air central thread, since it lost signal in this way, and we could lose the signal that we have gained with the cable...




Knowing that the Omni-directional concentrated their power mostly horizontally, I placed the antenna finally in the most optimal way, vertically, in the corner of the roof since there are direct view from there (this is important, because at that distance and to get good speed is almost indispensable to achieve direct vision with the antenna of the neighbouring 200 MTRs). In my case, part of the signal was reflected by the roof of other houses, be they on a hill, but only in part to being the home which wanted to route the signal with the 2nd antenna more altitude than mine, about 15 ° and 200 meters of distance.
In the diagram indicated the radius of coverage. I've tried the antena-cazuela (only one connected) with a notebook, since I have no field meter, and it doubles the comparative connection quality whenever you're in range. On the other hand, if you put yourself in the back signal loses quite a few meters, making it a test of the effectiveness of the material to reflect the waves.
Antenna with which connect to 150-200 meters of distance is an omni-directional, small, that came with a card "get Net Wireless LAN mini-PCI", but the card is the Conceptronics C54D with standard 802.11 g, and placed on the balcony of their house (direct view) with 15 meters of cable's best (used by a telecommunications company, with triple layer of aluminium and steel cable meshcopper coated) got speeds leads 36 Mbps, which is not bad. That Yes, it loses enough to put it inside house walls, to lose the connection in some points. I can't imagine the speed that we would get if put other "casserole antenna" on this side...
I've done another test to 1,5 kms away (from a nearby mountain) and I get 11 mbps using a pot of nesquick for direct emission and reception; a pretty nice scope. Instead of doing the entire roll of the manual, I have caught and made more or less hole where mark and there I've got the small antenna of the card, which I have lengthened with a cable.
Conceptronic C54AP details provided by the support by email:

Power (Watt): 100mW and integral antenna is required; Number of Ports & type: 1 * 10 / 100Mbps Ethernet; Number of Antennas (gain dB max): 2 * 2dBi; Maximum emission power: 18dBm; Minimum sensibility with BER: 83 dBm for 11b @ 8% (PER); Packet Error Rate of 10-5 (dBm) 66 dBm for 11g @ (1000-byte UDP's) frame Error Rate = 10%; chipset Atheros, and the manual, fairly concise, certainly, for newbies. Maximum speed: 54 Mbps; Price: approx. €81 to 25-1-04.
<>1-9-04 Update: I have finally discovered that this AP, as well as being very limited, has two flaws:
-Is unstable with mixed networks (I have added a customer with standard antenna 802. 11b other marks and hung continuously.) Will have to change this card by a conceptronics 802.11 g) and
-Only works with one of the antennas at a time, so sent by the two but not at the same time, so the antenna pointed toward the House cut the service abroad. What garbage software has this AP.