NetStumbler.org Forums - View Single Post - how do i find out how much db my antenna is

Thorn · 07-25-2002

The simple (and NOT the most accurate) way is to get a reading using a card w/o an external antenna, and a AP or another card. Next plug in the antenna, and read the signal. Subtact the first reading from the second. The difference is the rough gain of the antenna. Don't forget that the readings tend to be in negative numbers since we're dealing with radio waves.

First reading: -90
Second reading: -75

-75 - -90 = 15. Diffenence is 15dB gain.

Hope this helps.

07-25-2002	#2 (permalink)
Thorn Did you do the math? Join Date: Apr 2002 Location: Villa Straylight Posts: 10,358	The simple (and NOT the most accurate) way is to get a reading using a card w/o an external antenna, and a AP or another card. Next plug in the antenna, and read the signal. Subtact the first reading from the second. The difference is the rough gain of the antenna. Don't forget that the readings tend to be in negative numbers since we're dealing with radio waves. First reading: -90 Second reading: -75 -75 - -90 = 15. Diffenence is 15dB gain. Hope this helps. __________________ Thorn "Read Altas Shrugged. Compare it to today. Repeat as necessary"