Dual antenna Alfa

[damocles]

So I currently have this adapter:

http://dx.com/p/802-11g-54mbps-high-...k-dongle-35688

It works quite well I must say. But I lost the omni directional antenna. And so A good opportunity to buy a new adapter which might be better. I read a lot about this and decided I want to go with the in a lot of topics covered Alfa AWUS036H.

I found this model: http://dx.com/p/alfa-1000mw-802-11b-...-silver-112006

Price: US$ 21.10 with free shipping. Is this a real alfa AWUS036H? I kind of like how it looks with the dual antenna!

[Jimmy87]

It does look like it, and it has the Realtek RTL8187L chipset according to the website.

[maverik35]

You probably end up spending 20 bucks more and in the end you will have 2 same things: The important thing is the chipset...I'm almost positive that the one you bought is a alfa clone with rtl8187L chipset.

This chipset RTL8187L has the "Works right out of the box" status for any BT3, BT4 and BT5 distros. It is an excellent choice when it comes to "plug and works" status in Backtrack. So in my very personal opinion, "Do not buy another one, unless you want to have 2 pieces of excellent wifi in your arsenal.

If you want something more, you have to keep in mind several things:

1. Tx power
2. Rx Sensitivity (very important aspect)
3. Noise affecting the signal when RECEIVING, not TRANSMITTING.
4. Any signal block like aluminum shades in windows, cement, rf noise that might sometimes shift to the 2.4Ghz frecuency, distance, trees, etc.

As to the antenna, you have 2 choices and nothing more: Omidirectional and directional.

The Directional, depending on how close the covered angle is, the better Tx/Dx is. As to the Omidirectional, in case you want to transmit around (sometimes need a signal booster and an external antenna to send signal outside several yards).

Both antennas can be external or small ones connected directly to your Wifi. The external antenna, you will need a cable, but dependig on how far is the antenna, you might want to use LMR400 cable.

Up to 3 meters, you can use LMR200, this, due to the signal loss in cable. You might end up having no signal at all (using a cheap cable or one that does not support frecuency loss good enough).

Any way, I can keep writting, but in the end, it all comes to 1 thing: CHIPSET supported...

Let me ask you one thing: If you have a 2 watt Tx, which by the way might end up frying your wifi device unless you use a signal booster, Do you think you can grab some signal back from AP if is far away and with blocking around it?....

I do not understand why people keep insisting in having so much power if will not be able to Rx some decent signal back from AP when AP signal is weak or Link Quality is below 50%..

The second important thing is Rx Sensitivity....This can be fixed but still indexed to the distance, noise and blocking of signal...But sure you can improve it..In this matter, I personnaly, from my experience, the best wifi device I've used is the Ubiquity...Not even Alfa have the Rx Sensitivity as Ubiquity.

Again, is my very personal experience and point of view.

Third important thing: Cable and antenna. Again it depends on distance from wifi device and external antenna. I have 4 external antennas: 2 HP 16dbi yagi antenna, 1 24dbi grid antenna and 1 HP 24dbi parabolic antenna, all connected to the same pole, and with LMR400 cables (4 cables of 6 meters each. I use any of them, just connect my Alfa 500 or my ubiquiti pcmcia, in my laptop. But I know the Rx is my limitation...The key here, the magic word here is called LINK QUALITY...

I hope this can help you.

Luck.