marsbar

I have this small dongle, works great, but not very long range. Is it simply to cut the PCB on the onboard J-pole antenna and connect a coax, or do some components need to be altered? Looking at the bottom, I suspect a resistor and a LED is missing! Would be nice to add a LED.

I am writing this with the shown antenna from 2-3km. I made some more improvements today: 1.A round ferrite was treaded onto the coax, I believe this will eliminate some noise and RF feedback 2.Some aluminum was wrapped around the modem to shield it. This worked very well. (From beer can) There is no proper shielding as per today, so I am thinking of making my own metal box for the USB modem. If you look at amplifiers, these are placed inside a milled solid aluminium block, there must be a reason for that. LNB's for satellite systems also have metal shielding around the circuit board. So some room for improvement still!

Actually, this bi quad antenna gave exactly same result as the patch antenna I am using now as a feed. I am going to make more of the patch antenna, because its very solid and super easy to make! All you need is a long M6 bolt, washers, nuts.... some shhet metal that can be soldered. Tip: Look for old flat TVs in order to find sheet metal you can use.

Okay, bought a smaller waterproof box and made an LNB like setup. This eliminated my 1m antenna cable. Connection speed increased from 5mb to a whopping 121.5mbit. Signal strengt did not improve though, 1m cable is not much loss using a high quality cable. But distortion and noise got better as a long antenna cable picks up all kinds of noise. The problem now is the connected computer is too slow, having only a slow USB port... Okay, this is it, no more time to fiddle with this antenna. On to next project! ?

Okay, bought a smaller waterproof box and made an LNB like setup. This eliminated my 1m antenna cable. Connection speed increased from 5mb to a whopping 121.5mbit. Signal strengt did not improve though, 1m cable is not much loss using a high quality cable. But distortion and noise got better as a long antenna cable picks up all kinds of noise. The problem now is the connected computer is too slow, having only a slow USB port... Okay, this is it, no more time to fiddle with this antenna. On to next project! ?

The cantenna was pretty useless as feeder horn, I tried this and speed doubled and signal increased by 25%... will do a permanent change as the rain stops...

Any recommendations on daily use surfing cards?

Inside my water proof box A small hole is drilled in the bottom in case of water, its 1mm so difficult to see.

I am looking for ways to improve my setup. Is there any difference in the fake ALFA and the real deal? I have to admit, I have the fake one from DX.com... (Shame on me?) Any suggestions or is my connection lost in Noise? I get like 40 strong AP's. I get 1Mbit up and 1Mbit down. Still, better than no internet

Here is some more info about my setup. When making a long range Wi-Fi connection, it's advisable to place the antenna and Wi-Fi USB adapter in a waterproof box outdoor. However, the USB cable cannot be more than 5 m due to signal loss and voltage drop. Previously I used cat. 5 as a USB cable, but 5m is not long. It worked sometimes with 10m and 6m, but sometimes the computer would not recognice the item when you plugged it in. So what I did was I bought two adapters from e-bay, and used some recycled cat. 5 cable. There are 8 wires in a Cat. 5 cable, 4 pairs. One pair is used for the signal, and 2 pairs are used for plus, and 1 pair for -. Thus, voltage drop is kept as low as possible. I have tested it with 20m cat 5 cable, voltage drop was under 0.2V so no problem. I soldered in two missing electrolytic capacitors, 10uF 16V across + and -. The ad says maximum of 45m (150ft), but I had only use for 20m. Besides voltage drop on 45m is a bit high for the USB modem. Tip1: To get the cable with connector in a gland, you can cut the gland in one side. (Note glands should at all times be in bottom of a box to avoid water ingress!) Tip2: Peel of the outher sheath of the cable in a length of 20cm. Then you can insert the cable in a window and close it. Cat. 5 cable is 0.25mm2 thick, so 20m gives a voltage dop of: [ 0,0175 * 20 * 2 ] /0.25*3= 0,93 Ohm (2*20 because of + and - wire that are both 20m long, and 3 wires are used in paralell) U=I*R=0,25*0,93=0,23V USB output is normally 5.25V to compensate for volage drop in cable, so this should be ok for an ALFA adapter drawing 250mA 5V.

I will post some connection pictures when I get back next week!

I simply used an usb cable I cut, I kept the lead as short as possible. At first I used 10m. Then I,sometimes got some trouble connecting. I then reduced it to 6m. I believe 5m is the maximum length of an usb cable.

Some more info on my setup: Cat. 5 cable length is 6m. + and - is transffered via 6 wires, USB communication on pair blue and white. Two capacitors approx. 10uF is connected in both ends of + and - to avoid noise from power supply into communication pair. A 1m coax is soldered directly to the tin can, center of wire is 30mm. It's 0,5mm thick. Question: What is the best length of antenna element? I see some places Ø should be 3mm and length 31mm. I am considering using the patch antenna instead of the cantenna for feeder. Would this improve signal? The coax from the USB adapter to cantenna is 1m long. I need this cable because of water tight box. Antenna is placed outdoor... Cables enters the box in the bottom to aboid water ingress. Coax cable is professional type, double outer braid.

Unfortunately no open APs... but you know what I am thinking of. Reaver did not work... and I painted it military green for comuflage. But grey would have worked better I assume...

Here is my parabolic antenna. The focus was calculated using the with of the antenna. Length of coax center was 31mm, but cutting it to 30mm gave better signal. Then I added two washers. Inside the water proof box there is a fake ALFA USB WiFi adapter from DealExtreme.com. I get 100% signal from an AP 500m away. From 2km I get 75%. Unfortunately there are 40 APs and some are very strong sending out noise on the same channels... Any tips to improve the system? Will original ALFA adapter help?