> I have found an IR beam for monitoring a boundry in a security

I bought some brass-sleeved IR laser diodes + collimating lenses
from Oatley Electronics in Oz (http://www.oatleyelectronics.com/ )
for only $10 each. To drive them you only need a constant current
source, which can be modulated for voice or data. If a 38kHz
carrier is used then there are a variety of cheap IR receivers that
can be used

> Remember sunlight will have a VERY bad effect on your
> IR remote distance.
> -Roman

The only way I ever got a decent range (40ft) outdoors with
LEDs was to have 4 in a parabolic reflector, and the receiver
at the bottom of a tube with a violet filter to block as much
stray sunlight as possible. This makes the transmission angle
very narrow though

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.