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Geoffrey S. Mendelson · October 18th 07, 05:04 AM posted to rec.radio.amateur.homebrew

wrote:
Just to chime in on this topic, I think some incorrect information was
passed along regarding legality of transmission power - the FCC does
in fact limit unlicensed maximum transmission wattage on the 2.4Ghz
range, however the use of high gain antennas is NOT illegal. You can
use extremely high gain directional antennas to achieve links over a
20+ mile LOS link, and still be within legal limits for unlicensed
operation. Think of it as using as talking thru a funnel - all it is
doing is using that same power more efficiently and more focused. Now
if you are talking about running the signal thru and actual signal
amplifier, then yes, that would be illegal.

Unfortunately, this is also incorrect. The limit is for EIRP. The more focused
the beam, the higher the EIRP.

The exact limit the U.S. is 1 watt EIRP for mobile devices and 4 watts
EIRP for fixed (point to point) links. That's a combination of transmiter
power plus antenna gain plus feed line loss.

Ham radio is limited to transmitter output power, which is quite different.

It could be worse, the limit here is 100mW EIRP.

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
IL Voice: (07)-7424-1667 U.S. Voice: 1-215-821-1838
Visit my 'blog at http://geoffstechno.livejournal.com/