[Laser] Getting Started

[jim car]

Hi,
    My name is Jim. A friend, Brian (KI4JQA) and I
(KG4SGP) are interested in putting together a laser
transceiver. We would like to use the set up for LOS
and non-LOS communications. I'm planning on using a
PGP type receiver using a BPW34 diode, TL-07 and a
frasnel lens (probably some where around 8.5 by 11
inch or bigger). Of course it will all be completely
shielded. We are interested in cloud bounce in the end
but are going to work in small steps to achieve that
goal.
    I've done some research on set ups and it seems
that PGP type front ends seem to be the agreed winner
on sensitivity when huge bandwidths are not needed. So
I think I'm pretty set with that type of receiver but
I'm definitely open to any thing having no experience
my self.
    I’m getting kind of stuck on the transmitter that
I should use however. I have heard that 20-30mW is
needed for cloud bounce. I know you could time
integrate a signal, but has any one ever bounced a
signal off of a cloud and heard it in real time? What
kind of equipment would that take to that with a 100Hz
or 3000Hz bandwidth?
    The actual laser I’m thinking of using is a laser
from a DVD or CD writer, because I've read on this
reflector that those lasers are near the 20-30mW or
even 50-100mW category. I might start off with a less
powerful laser, such as a laser pointer or similar.
I'm planning on using a shunt type circuit to modulate
the laser.
    Any comments, questions, or conversation would be
greatly appreciated.
Thanks!
   Jim - KG4SGP



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