How to be US FCC legal
How do I determine if my wireless systems are legal? And, if I need to throttle them
down, is reducing the Power in the pfSense gui to be lower than 99 a good method?
I use both CM9's and some Atheros-based 400mW mini-pci cards.
802.11g auto speed. 400-series coax (~3ft., and a few 12+ft.).
I have various antennas: Omni's from 6 to 15 dbi. Panels 8 to 18 dbi. Parabolics 19 to 24 dbi.
Some locations have Signal Filters with 2-3db insertion loss (this is bi-directional loss).
And, a few Linksys WRT54GL (at default tx power) with 6dbi omni and 14db panel.
I have read about a tip to turn off tx/autotx on the directional antenna to receive only.
I also have a few Atheros-based 900MHz 700mW 802.11g mini-pci cards, are fcc limits the same for 900MHz as 2.4GHz?
But, I don't yet know what steps I need to take. Any words of wisdom, instruction, and/or educational links are appreciated.
Also, Where may I find a value priced signal strength meter with N-Female coax connector?
you can use any combination you want…..just will need to turn down the radio on the atheros card on the higher db antennas.
If my output is 26dbm, and I need to limit it to 24dbm, what would I set the Power to in the pfSense gui? (100*24)/26 = 92 ?
If you need 24 db EIRP then you need to calculate your output, meaning radio output in mw - convert mw to db, subtract any insertion loss / connector loss / filter loss /spiltter loss /cable&pigtail loss etc. then add antenna gain.
For the 400mw cards this will not be correct. they do not show output power in mw, but rather output power in mw +10dbi (astleast some do this). so mw to dbi +10dbi -"whateverloss" +antenna gain = dbi
then you can do dbi to EIRP ( www.e-zy.net is a nice place for wireless calculators )