Rear Deck Mounted WIFI antenna

**illwill** · 01-18-2005, 08:51 PM

Wondering why nobody has made any pre-made pvc slim cantennas that can mount in the reardeck of the car with velcro to hold it down

**NiN^_^NiN** · 01-18-2005, 08:53 PM

cause they look cantastic

I don't know

**DallasCamaro** · 01-18-2005, 08:59 PM

who here's using a cantenna? I'm just using my little antenna that came with the PCI card right now, but I'm about to remove the FM radio antenna from the car and replace it with a 20-30 inch boom antenna, then install an FM antenna onto the window glass or use a dakota digital underdash FM antenna. I'm not too worried about FM reception, that's easy to get, so I'd rather just have one good big WiFi antenna. The reason I ask about cantennas, is that they are directional antannas. They will give the greatest distance, but in a mobile vehicle, I can't see any reason why you would use anything but an omnidierctional antenna. I want the freedom to park in the street or the driveway, drive around wherever, and still get a signal, without aiming an antenna. Just a thought. I hear cantenna alot here, so I just wondered, but maybe there's an omnidirectional variety I'm not aware of.

**big_cali_dave** · 01-19-2005, 07:41 PM

Because the cantenna is VERY directional. If you put it on the rear deck of the car, you would only be able to see signals in the 15-30 degrees of where that can is pointed. Makes it very hard to aim and drive around at the same time. You really have to stick to omnidirectional antennas with a car, that way you are sure to not miss a signal. There are omnis running up to 12+ db gain. True, you can get more with a parabolic dish or a cantenna, but they would only be useful if you knew ahead of time where you needed to aim the antenna.
Dave

**illwill** · 01-19-2005, 10:59 PM

fab-corp has some cheap 5db omni mag mounts that are 6" tall.. mabe ill get one of those

**grepzen** · 01-19-2005, 11:03 PM

<start laughing>
1) can't netstubmbler (& gps) 'map' WiFi hotspots?
2) can't a servo be used to keep the cantenna 'aimed' at the nearest hotspot?
</end laughing>

no really.. stop laughing.

**big_cali_dave** · 01-19-2005, 11:12 PM

I'm glad you were laughing, cause thats funny. It's an idea I had, Actually I wanted a 3dof parabolic dish on the roof of my truck, controlled with servos and a phidget interface. Then I realized it would be VERY obvious what I was doing, and writing the tracking software would be a pain. Besides, with an amp and a good omni, I think I'll do fine.
Netstumbler won't even pick up hotspots without the directional antenna pointed at them. The GPS plotting is not very accurate, it just drops down the location to an approximate area, so having it train to point the antenna at a hotspot wouldn't work. I have a big parabolic dish with a biquad feed that I use around my neighborhood. The dish gives me about 25 db gain, it was a directv dish. I can pick up signals from 1/2 mile away through buildings.

Anyways, the servo controlled thing could be cool, but it'll be a big contraption and a pain to find the signal.

Dave