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I built one of these with an old dish a while back and was surprised how well it worked. I used it as a cheap proof-of-concept antenna for a 0.7 mile point to point wireless link and connected it to my laptop and NetStumbler to test signal strength. Fun project
Pete

You can build one of these things out of a sardine can, and if you hook them up to an old dish, you get a lot of gain. http://www.seattlewireless.net/index.cgi/SardineCanAntenna http://www.trevormarshall.com/biquad.htm

I do! hell, the wifi setup on my laptop puts out 604mW. I have a 200mW Z-COM, Prism2.5, PCMCIA Card connected to a 5.5dBi Antenna(1), 4.8dBi gain after connecter and cable loss are calculated in. If you were to connect this card to a converted PrimeStar dish with a biquad feeder(2) (27 - 31dBi gain) you would have an EIRP of 159 watts... In other words, don't point it at your gonads!

(1) http://www.wlanparts.com/c=So0zbsGg2Glh7swrUjbpMQG KP/product/RV24-5RD
(2) http://www.trevormarshall.com/biquad.htm

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BSD Podcasts @ http://bsdtalk.blogspot.com/

Satellite dish and a can or Satellite dish and a Bi Quad

First, the connector on the Lucent/Avaya/Orinoco/Proxim equipment is known as "MC" or MC-Card". Cisco and others use MMCX, which is just a hair bigger and slightly differently shaped. IIRC, the Senao card uses MMCX, and you should consider it for your trip because it has higher output power and better receive sensitivity than any of the others.

Second, yeah the card's integrated antenna is crap. Anything external that's even close to the right band will do better. I disagree that external mounting is a big deal. For stumbling, an omnidirectional antenna is good because you just mount it and leave it. But for using hotspots at truck stops and such, you can manually position a higher gain antenna for best signal. The directionality will help a lot if you're at the edge of the parking lot, or if you decide to surf from the Flying J while parked at the TravelAmerica. Obviously, it's easier to aim an antenna if it's inside the vehicle with you. This also helps minimize losses from long antenna cables. I'm not worried about metallic window tint on your Vanagon interfering with the signal. :)

For antenna designs, the cylindrical waveguide cantenna can't be beat for simplicity, but it's never wise to point weird-looking tubes out the window of a vehicle, moving or otherwise. (Print out a copy of this Ask Slashdot posting, or something else to indicate that you're nonmalicious in the event that you get questioned.) I can't emphasize this enough, our society is pretty paranoid already, but the police are trained to recognize potential threats, and a scruffy dude pointing a metal tube at things is pretty high on the grab-your-gun index.

Trevor Marshall's Bi-Quad antenna design is absurdly compact, reasonably directional, and very easy to build. Marty's instructions clarify a lot of the things Trevor didn't show in detail. If you have an old double-wide jewel case around, you can build the little biquad into it for a totally nonthreatening appearance.

As for extended roadtrip suggestions: Consider a battery isolator and dual-battery setup, if it's within your budget. I was in the market for such a unit recently, and Hellroaring seems to have the best-designed product with a ton of helpful app notes and install guides.

If most of your portable gear runs from AA's like mine does, you might be pleased to know that many of the recent NiMh chargers run from a wall-wart, instead of building the entire power supply into the charger unit. Presumably, this makes the UL listing process easier by moving the mains supply out of the unit, to a transformer that can be separately listed and doesn't need to be re-qualified each time the charger gets revised. It benefits you, because the wall-wart steps down to 12 volts and the charger takes it from there. Ergo, it's dirt simple to make a car cord for such a charger, and it's more efficient than running through an inverter.

While on the subject of vehicle DC wiring, check out the Powerpole connector. It's become the standard in the amateur radio community for 12 volt supplies, because lighter sockets suck. Powerpoles are genderless, polarized, and very reliable if crimped correctly in the first place. Crimp+solder is even better.

If you're the paranoid/prepared type, ghost your laptop's basic setup onto a spare drive and keep it (wrapped in antistatic foam) elsewhere in the vehicle. You don't want to be stuck 1800 miles from home with a crashed drive in one hand, freshly reinstalled laptop in the other, trying to figure out how to download the drivers for your wireless card when said card is your only means of internet access.

Good luck, have fun, drive safe, and post some pictures from your trip!

The main problem with using a Low Noise block is finding one for 2.4 GHz. The stock ones are built only to receive at 10Ghz.

The best solution is to put your transceiver right at the focal point with an improved antenna. One of the best feed antennas would be a BiQuad.

Here is a link to using a 2.4GHz BiQuad feed for Primestar dish

Some links:

KI7cx dish
Primestar dish
Bi-Quad feed for primestar DIY
10 Euro dish with biquad feed
Modifying Confier Antennas for Wireless Networking

More info: Wireless Leiden

http://www.trevormarshall.com/byte_articles/byte1. htm

QUOTE.. And this leads us nicely into the real world. The designers of the antennas for PCMCIA cards face a real problem. It is not easy to form antennas onto the small circuit board inside the bulbous plastic cover that sticks of the end of the PCMCIA card. I won't go into the technology here, but below is plotted a typical sensitivity measurement for a laptop equipped with a PCMCIA WLAN card. The effective gain of this antenna is low, less than 0 dBi (typically -4 dBi) and it is very directional.

This link is something very interesting for anyone who wants to make a parabolic antenna for 13cms/2.4GHz. The BiQuad design works well as a feed or as a stand-alone antenna.