On Thu, 26 Jul 2007 09:15:44 +0100, Jeff wrote:
"Allodoxaphobia" wrote in message
...
On Wed, 25 Jul 2007 18:12:26 +0100, Jeff wrote:

Note that in almost all places there are legal limitations on EIRP
(Effective Incident Radiated Power). In plain English, the more you
narrow a signal, the stronger it becomes.

Since you did not say where you are, I'll mention the two places I
know for sure. In the U.S. WiFi EIRP is limited to 1 watt for
mobile/portable use (e.g. laptops) and 4 watts for fixed links.

Bear in mind that 2.4GHz is also an amateur band where no erp limits
exist!!

Oh , really ?! cite!

Channels 1 to 6 lie with the 13cms amateur band, which does vary a little
from country to country nut in the UK is 2310-2450MHz, and there is no ERP
restriction in this band just a max power to the antenna, which can have
as much gain as you can muster.

For amateur radio, it's a limit on DC power to the final amplifier, which
you can make as efficient as you want; it's average power, so you can
run 2 KW PEP (peak envelope power) SSB, and gawd knows what kinds of
pulses you're allowed to transmit on the UHF, SHF, and EHF bands, as long
as the average isn't over 1 KW input to the final.

I'm sure it's all covered in the FCC regs, which should be easy to look up
for anyone who's really that interested. ;-)

Cheers!
Rich