[Laser] Big Reflector

[Cliff Buttschardt]

This is an excellent idea.  I contacted the local roads department some time
ago and was told that they would save an old, mangled stop sign for me.  The
one I obtained had only the mounting holes torn out due to high winds.
Cliff K7RR

TWOSIG at aol.com wrote:
> 
> I use a STOP sign down the street.  The percent of reflectivity is not as
> good as an expensive retroreflector, and I cannot move it to a different
> location.  There are lots of them arround and they are provided by tax monies.  You do
> need to be polite and turn the laser off when there are cars on the road.
> 
> The one I use is 30 inches across. Which is about the beam width of my Ramsey
> LBC6 transmitters at 800 feet.  Reflectivity is pretty good, too.   At night,
> I can see the reflected beam from a single LED.
> 
> If I can align my transmitter to hit a stop sign, and get the receiver
> sensitivity to detect the signal from it, I figure that I am ready to try four times
> that distance LOS.  Which reminds me, there is another stop sign down the
> road 5 miles.
> 
> James
> N5GUI
> 
> In a message dated 6/17/2004 2:02:46 PM Central Standard Time,
> stjohn at ocsnet.net writes:
> Why not nine or sixteen retroreflectors, all on a portable plywood board?
> Each
> one reflects, and all back to the emitting source.
> 
> Anyone do this?
> 
> Tom Upton  AD6N
> 
> Kerry Banke wrote:
> 
> > Just  a note on using beam expanders.  One setup I use has  a laser pointer
> > expanded out to 50mm.  I have what I would call  a very good pointing setup
> > with  fine micrometer adjustment and have found that for LOS it's about as
> > tight of a beam as practical for my setup.  Even with a 24X scope It takes
> > a little time to  to hit a 2" retroreflector at 4 miles using a very slight
> > manual raster scan.  Maybe the bigger issue is that a change in temperature
> > in direct sunlight causes the beam to walk off the target.
> > Kerry N6IZW -
> >
> > At 12:14 PM 6/16/2004 -0400, you wrote:
> > >Richard,
> > >
> > >Keep in mind that you'll need to test your expander using a very distant
> > >target.  A perfectly collimated beam should have a diameter of 6" right in
> > >fron the of the transmitter, and 6" a mile away.  I used a white factory
> > >building 3/4mi away and a 20x spotting scope to make my adjustments.  Keep
> > >in mind that aiming something like this on a LOS path will be pretty much
> > >impossible.
> > >
> > >I hope that helps!
> > >Andy K0SM/2
> > >
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