[Laser] What's the freq?

[VE7DXG]

Thanks for the replies. So I figure I'll log this QSO as 470THz, should be
close enough.
Since some of you were asking, here is the setup:
2 Ramsey kits. I have a children's telescope, the transmitter ducttaped to a
piece of styrofoam on the telescope. I aimed the telescope at a nearby tree
and aligned the transmitter to the field of vision. Adjustments to the
ducttaped styrofoam mount were made by using pieces of gravel, blades of
grass and spent cigarette butts. It took less than a minute at the 3km
distance to be aligned.
VE7DDR had no telescope, just a camera tripod. The only real difference is
that he uses electrical tape as opposed to my duct tape for securing the
transmitter to the tripod. Once he saw my beam, I had to turn off my laser
as it was too bright to aim for. I switched on the car headlights and he had
me in about 2 minutes.
The receiver is once again just a plain Ramsey. We found some plastic
"reading magnifiers" (about 12X8" plastic Fresnel lenses) at the Dollar
Store and mounted them in a cardboard box. Focusing is done by hand, moving
the receiver diode back and forth till it turns red. Smokers have a distinct
advantage in this process...
Of course we kept in touch on 2m FM during the whole test.
After some fine tuning we were reasonably close with the aiming so I did not
have to run back and forth between TX and RX.
The beam was about 4-5' wide at my end, although it's kind of hard to say,
because in my ultimate wisdom I set up right under a streetlight.
We used AM through the built in little mike on the Ramsey, it worked just
fine.
Anyway, we learnt a lot and maybe this weekend we'll shoot for a longer
path.
73,
Gabor, VE7DXG, CN88cx

----- Original Message ----- 
From: "Andrew T. Flowers, K0SM" <flowersa@alltel.net>
To: <laser@mailman.qth.net>
Sent: Monday, July 21, 2003 6:51 PM
Subject: Re: [Laser] What's the freq?


> Gabor,
>
> Congratulations on your first contact.  I made my first laser QSO with
> the Ramsey kits back in the June contest.  Were you using any lenses or
> just the bare phototransistors?  How bright were they at 3km?  I'm sure
> we would like to hear the details of how you aimed it--most of the
> "pros" you mention were in your shoes at one time.  I'm still stuck on a
> tripod here, so I won't be doing anything of great distance yet, even
> though the receiver is capable of it.
>
> Andy
>
>
> Jim Moss wrote:
>
> >same physics as radio!
> >
> >wavelength = 300,000,000 / frequency
> >since red = 632.8 if HeNe, if diode 630 or 635, or 650 or 670nM
> >wavelength = 474 THz
> >
> >Jim
> >N9JIM/6
> >
> >
> >--- VE7DXG <ve7dxg@seaside.net> wrote:
> >
> >>This weekend VE7DDR and myself made our first laser QSO.
> >>We were using the cheapo Ramsey Laser Communicator kits over a 3km path.
> >>There is lot to improve yet, but it was great to see the "flash" from
the
> >>darkness when we found each other with the beam.
> >>I don't think I describe the setup we were using after seeing some of
the
> >>pictures the pros took of their setups...
> >>Anyway, for my log, what is the frequency of a red laser (same as you
have
> >>in a pointer pen)? Is it something like 450THz?
> >>
> >>73,
> >>Gabor, VE7DXG
> >>
> >>
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