pangea

Hi all,

I just made ~20db+ gain directoinal antenna for only 30 bucks and it works great.

As you guys all know, the problem of dish+USB combination is that many of transmit signal from USB adapter spreads out all over the place. Also dish+directional antenna (like bi-quad or wave guide one) costs a lot due to expensive pigtail and still ends up with significant signal loss thru pigtail.

So I just bought $5.00 8db+ gain directional antenna and soldered pigtail to USB adapter antenna, and just put it on the dish focal point. Now you don't have signal loss thanks to USB cable, and you don't waste transmit signal by using directional antenna. For me, it worked great.

I bought 18" dish antenna from ebay for only $20. (You might get it for free)
Airlink101 8db+ directional antenna was only $5 at Fry's.
And I got Netgear wg111 54g USB adapter for free after rebate.
Bought 15' USB Male-Female cable for $5 at ebay.

I had hard time soldering pigtail to PCB. Solder was so easily taken off, so I had to use super glue to support pigtail after soldering. Directional antenna from Airlink101 was perfect for 18" direct tv dish, since you can put it on the arm which holds LNB. Directional antenna stays perfectly at the focal point of dish. You have to make a weatherproof box to protect USB adapter, if you're going to put this antenna outside. I just used tupperware and sprayed a white paint to avoid overheating from the sun light, and made drainage holes at the gravity bottom, just in case water gets in or of condensation.

I hope I can post some pics, but my digital camera is broken. I live in a campus housing, and my house has weak leaking signal from the computer workstation area (~500ft away). The connection was come and goes, so I had to subscribe expensive cable. Now I have stable connection, and it is free with student ID. LOL

wrzwaldo

http://www.usbwifi.orcon.net.nz/

And you don't have to fiddle with a pigtail!

pangea

Yeap that site helped me a lot.
But, USB wifi adapter mostly uses built-in omni-directional antenna, so I think directional antenna matches best with dish combination. I checked this before I soldered directional antenna to USB adapter. When I just placed USB adapter at the focal point of dish where LNB is, the signal gain was not as good as directional antenna + dish combination. USB adpater usually doesn't have external antenna connector, so I had to solder it. Yes, it is pain in the axx, but I had solder and iron anyway, so I gave a shot.

Scruge

What type of antenna was on the usb to begin with? LTCC chip or etched on pcb?
I'm surprised your results were improved with the 8db element. If the dish was a true parabolic it should have focused all signal at a single point.
If the reflector had been a corner reflector I could understand the improvement.

wrzwaldo

@ pangea

Your USB device happen to have an FCC ID #?

pangea

directional antenna
NETGEAR USB adapter
18" satellite dish

My radio knowledge is shallow. USB is netgear wg111 802.11 g adapter. I counldn't find any ceramic chip antenna or hirose connector. It looked like some diversity type (however the antenna was not etched on PCB). Dish was direct tv 18" one. It's oblique shaped parabolic dish such that it reflects signal at the off-centered focal point. Yes, parabolic will focus signal at a single point. My idea was to concentrate transmit power using directional antenna. Reception may have no difference, but what about Tx? The improvement may be because of difficulty of putting USB antenna precisely on the focal point. On the other hand, directional antenna that I used is more forgiving.

At least it was fun to make it.

pangea

Sure it had. It was on the sticker, but I threw it away while I was disassembling it.

wrzwaldo

Any of these look familiar?

I'm betting 1 of the bottom 2...

pangea

Yep, wg111 v2, bottom left one. Though my one doesn't have u-fl adapter.

Scruge

Ah, it makes more sense now after seeing what you were working with.

wrzwaldo

You took the shield off and there was no connector? And those antennas are etched onto the PCB.

SignalSeeker

Pictures, come on. I am a guy, I am visual.

Justin

pangea

I took the shield off, but found no hirose connector. There was small capacitor (I'm not sure if this is capacitor, the square one) instead.

Airlink101 directional antenna has an extra TNC to SMA convertor. I cut the TNC part off and soldered it onto PCB. I originally sordered before capacitor, but while I was playing around with it, the PCB print came off. So I had to solder pigtail after capacitor, and it came off again!! Gosh, I thought that I totally screwed up at that point. I finally soldered at the corner of the chip (where antenna feed goes) and poured super glue then let it dry for an hour. Then I glued pigtail wherever it touched PCB. It is still not that secure, so I would not put much strain on it. Pigtail shield was soldered to ground. I don't know if I had to leave that capacitor. It works somehow.