Re: TI-H: IR links
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Re: TI-H: IR links
On regulation of radio waves:
-*Anything* anybody on this list builds is going to be illegal.
The 49 MHz frequency band requires no license, but *all*
equipment must be type-accepted by FCC. Just about the only
service you are allowed to build for is the amateur radio service.
-On using microwaves: Microwave bands _are_ regulated and allocated
by FCC as well as various international organizations. The microwave
band people would use would be the 900MHz band, which is called the
"kitchen sink" band by some hams, since it has everything but the
kitchen sink allocated to it. Not wise use for simple data transfer
protocols. In addition, construction
of microwave equipment involves some difficulties. Not insurmountable,
but it *is* more difficult than construction for lower freqs.
-On range of microwaves vs. that of other freqs.: Microwaves have a
shorter range mainly due to the fact that various "tricks" which
work on lower frequencies to bend the radio wave around the
curvature of the earth don't work at higher frequencies. When you
get *really* high, oxygen absorption becomes a problem at certain
levels. The main difference, for practical purposes, is the difficulty
of getting higher powers at microwaves.
BOTTOM LINE: Since anything will be illegal, I'd look into the IR
link more. Alternatively, use the high or low end of the FM band
(around 87 or 108 MHz) and use AM, so that the signal doesn't
show up on FM radios!
--Jon, N9RUJ
jnieho38@calvin.edu www.calvin.edu/~jnieho38
"Outside of a dog a book is a man's best friend.
Inside a dog it's too dark to read!"
--Marx (Groucho, not Karl)
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