Thread: Mobile Wifi Roof Antenna

Originally Posted by Blaz3

any url's for that antenna ptk?

man do people even read anymore??

GO to the Mp3Car store.

Not to be a nay-sayer, however if you are the least bit interested in WarDriving the all-in-one antenna is not worth it; although the antenna in this review (the original poster) looks to be a good quality antenna.

WLAN
Return loss > 12 dB
Gain 0 dB

The antenna linked in this thread previously at least has a rated Gain of 7.8 dBi.

I have this antenna from FAB-Corp, it's a 5dbi antenna and it out-performs the "9 dbi" ducky antennas. That's because of the ground plane that's built into the antenna.



And if you think $50 bucks is a lot of an antenna, then you're wrong. Low-Loss cable is not cheap. Sure you may be able to get an antenna that performs well but if all of the signal gained from the antenna is LOST through the cable getting it back to the wifi card then what's the point? I'm running an Edimax EW7318-USG with a shortened lead cable on the 5dbi antenna from FAB-Corp. I ran a 12' USB Extension and hooked the card to that. The shorter the distance between the adapter and the antenna the better.

kmfdmk, so I guess a 9dbi gain antenna in the design from FAB-Corp will out perform a 9dbi gain ducky antenna?

How much loss is there due to cables? I want to relocate my antenna to the rear, but I'm afraid that running a cable the length of the car cabin would result in a significant signal loss.

That's a good idea you have there with the 12' USB cable and keeping the distance between the USB adapter and the antenna minimal. The question is, will the USB adapter perform equally to a direction connection on to the motherboard (say, PCI)

Originally Posted by s197PC

kmfdmk, so I guess a 9dbi gain antenna in the design from FAB-Corp will out perform a 9dbi gain ducky antenna?

How much loss is there due to cables? I want to relocate my antenna to the rear, but I'm afraid that running a cable the length of the car cabin would result in a significant signal loss.

That's a good idea you have there with the 12' USB cable and keeping the distance between the USB adapter and the antenna minimal. The question is, will the USB adapter perform equally to a direction connection on to the motherboard (say, PCI)

As for performance, yes the Fab-Corp antenna out performs the ducky antenna. I had no problems with the Fab-Corp antenna with the longer pigtail, I just shortened it to help get even stronger signal. I'll probably eventually install a bi-directional 1/2 watt amp (@ risk of ****ing off the FCC I know I know).

Well the loss per foot depends on the type of cable. A bit of quick googling resulted in this bit of info:

Signal Loss: (For every 3 dB of loss it cuts the signal in Half)
For 2.4 GHz WiFi applications: Signal loss for our 10- foot RG-58 cable is about 1.9 db, and 3.8 db with a 20-foot. LMR-400 equivalent cable: effective loss over 20 feet is about 1.3 db, which is trivial. However LMR-400 is 1/2" thick... RG-58 / LMR-195 is a db loss of 19.1 db over 100 ft, so even though it's 1/4" thick it's going to give you great signal transmission.

As for USB adapter performance, as long as the cable is shielded (a good cable) and perhaps you ground the shield to the case, as well as directly to the car chassis, you should be just fine. Static buildup can and will occur so grounding is necessary to prevent excessive static buildup in the electronics.

I bought this one for my truck, it has a 13db gain. My signal strength went from 20%, 40% to 80%, 100%. I still have some buffering issues at 80MPH, so I am going to buy a booster which will give me a 50 mile range.



The bad thing is it 40 inches tall. i drive a SUV so now I cant make it under certain things without hitting the antenna. Im thinking of changing the antenna rod with one that has a spring so it can flex.

a flex antenna would be much easier - especially in parking garages. Do you know if there are any downsides/signal loss with flex antennas?

Originally Posted by XOHMenthusiast

a flex antenna would be much easier - especially in parking garages. Do you know if there are any downsides/signal loss with flex antennas?

I havent tried one yet but I am thinking of getting one, pulling my antenna off all the time is a mission.

I hear ya- esp. with an SUV that rides high. You could always find a store w/ a good return policy and give it a shot.

Originally Posted by XOHMenthusiast

I hear ya- esp. with an SUV that rides high. You could always find a store w/ a good return policy and give it a shot.

Well thankfully I have a universal mount, so I can just screw diffrent antennas into the base. I have fully intergrated the mount into the trucks frame. So Im just gonna buy the antenna part, not the whole thing.