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Old July 27th 07, 02:19 AM posted to comp.sys.laptops,sci.electronics.design,rec.radio.amateur.antenna
Dave Platt Dave Platt is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 464
Default Help with Wifi antenna

In article ,
Rich Grise wrote:

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. ;-)


I thought that the FCC had abandoned the "DC input power to the final"
standard quite some time ago (a decade or more, I think).

Most of the transmitter power standards for hams are in in 97.313,
which describes all of the limits in terms of PEP. Duty cycle,
modulation, and final efficiency are apparently no longer relevant in
most cases.

For most bands, and most operator classes, "legal limit" is 1500 watts
PEP. There are plenty of exceptions based on band, operator class,
and modulation (spread spectrum in particular) but these limits are
almost always defined in terms of PEP, which is referenced at the
transmitter-feedline connection.

There are some time-averaged and/or ERP limits described elsewhere in
Part 97, but these all seem to have to do with deciding when a
particular station must go through an evaluation for just how much RF
it's exposing humans in the area to.

--
Dave Platt AE6EO
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