[Laser] Re:: heliograph vs. laser indeed!

[Chuck Hast]

On 6/17/07, Chuck Hast <wchast at gmail.com> wrote:
> On 6/17/07, Charles Pooley <ckpooley at sbcglobal.net> wrote:
> > Chuck Hast <wchast at gmail.com> wrote:
> >
> >   >Perhaps if like minded technical people in other countries want to get
> > >involved, they can start their own micro launcher groups, I have been
> > >following this of late, I did not realize that ITAR had you screwed to
> > >the wall, but perhaps other groups starting up in other countries might
> > >be the way to do it.
> >   ----------------
> >   As I understand, ITAR prevents me from "exporting" technology to noncitizens, and that even means tallking privately with noncitizens above some level of specivity (our famous First Amendment has acquired a major exception).  I still can publish openly, as in a book, website, etc in which all have equal access.
> >
> Don't you love it when the constitution acquires ticks? I can
> understand national
> security but we are talking about something that is common knowledge.
>
> >   Non-US versions of Microlaunchers?  I'd welcome it.  It would have do be done without my involvement, unless I (we) were to get an export license, but I've always assumed that's too lengthy, complex, expensive a process.
> >
> Yes, I have been involved in those, such a mess, I think it is designed to favor
> the big boys like all else in this sector.
>
> >   I think the inner Solar System is spacious enough for all.  And anyone doing this will help all and help the "cause"--developing means to explore space in ways other then the massively expensive "collectivist" means now in use.  In future Youtube videos I will be going on and on about this.
> >
> Politicians like "collectivist" activities, why does the IRS give
> small businesses
> such a bad time? but if you are employed by a large company no big deal.
>
> And am pretty certain that most of them do not at all like the idea of
> little guys tossing devices into space over their heads and outside of
> their normal routes (big, heavy, laborious, expensive)  And if those
> devices actually do productive work, that case great amounts of dis-
> persion on the bureaucratic operations that they so much love.
>
>
> >   Laser questions I've recently been seeing:
> >   Cannibalizing a CD/DVD is certainly practical even if you can't get laser data.  Perhaps by analizing a write head (which could have a 50 mw laser in it) could be operated to see the current the laser is running on.  Or operate at 2x the threshold lasing current.  It may be worthwhile conducting a line of discussion re operating write heads.
> >
> >   Also another path could be taken:
> >   These lasers are available as OEM parts.  If necessary, buying groups could be organized.  I wouldn't mind being able to buy some of the 405 nm blue ones from Nichion.  But the main interest on my part is for 650 nm up to 30-50 mw.
> >
> My only worry about the 405nm lasers is that they are getting into a area of
> increasing atmospheric absorption whereas the 650 diodes are in a very good
> part of the window.
>
> >   Or the roughly 3 mw 650 nm ones in the cheapest of the pointers will do.  These are very easy to get, and by noting the running current of these, a driver circuit can easily be built.
> >
> I am building a terrestrial link that has 4 lasers around a 4 inch PVC, pipe.
> The idea being that even though the atmosphere causes fading and beam
> deviation, by having 4 of them aimed at the far end, at least one of them
> should illuminate the target. Also 4 at 5mw is a total of 20mw...
>
> >   On the detector side, I will be experimenting with some of the available APDs and Geiger mode APD's.
> >
> >   Can't right now for budget reasons.  It will await initial financing of Microlaunchers.  Then I will be doing some indoor and outdoor mountan-to mountain experiments here in southwest US.
> >
> >   Aperture required for this can be 25 mm (beamwidth about 30 microradian).
> >
> >   Maybe we could have a competition involving the smallest recieve*transmit product of optics diameter over some distance.  The range will be then prportional to receiver optics diameter for a given bandwidth.
> >
> I live in Florida where we have to use towers and roof tops but as long as
> there is a free and clear path I am interested. One of our interest is in using
> FSO as a alternative data link after a tropical storm, the TS will  leave a area
> of clear air after it for some days, by using FSO links I believe that we can
> take some of the pressure off of the antenna recovery teams and get high
> speed links up taking advantage of several days of clear air before the summer
> thunderstorms return. Even then the links MAY go down only for a few min-
> utes during a heavy storm, they do not last long, so they may still be even
> a long term solution for some activities.
>

By the way, here are some pictures of what I have been working on:

www.kp4djt.org/wch/index.html

The pix are sort of big so if your link is a bit slow it may take a bit to
load. All of the RT unit head stuff can be found under most toilets...


-- 
Chuck Hast  -- KP4DJT --
To paraphrase my flight instructor;
"the only dumb question is the one you DID NOT ask resulting in my going
out and having to identify your bits and pieces in the midst of torn
and twisted metal."