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laser ham radio

steve001

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The new green (532nm) laser pointers are nothing like IR and visible red lasers (640nm-700nm)

The Green DPSS laser is a very complicated photonic/optical device. They make excellent CW transmitters. Power outputs range from 5mw-20W. QRP? Not really. Remember high school physics. E=H/Lambda (wave length. To avoid physics, this equation states that Energy is a function of wavelength. Higher frequencies or wavelength are far more energetic.

A cheap 5mw laser has a range of 5000meters or 7500 feet. A 100mw green laser is visible up to 75 Kilometers (125,000 feet, or 50 miles.) Needless to say this is absolute line of sight.
http://www.eham.net/articles/15790
 



Hemlock_Mike

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Ok Steve there good buddy --

What's your QTH ? I'll send you a CQ with my DL125 !!! ;D ;D

Mike (WA0BMP)
 

Kenom

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why mike am I totally not suprised your a hammer?
my dad is too.
K7wes Helena.
 

Hemlock_Mike

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Kenom --

I got my ham ticket 47 years ago !! Remember the BIG tubes and high voltage ??
You could almost heat a house with a killowatt final amp ;D
Ahhh for the good old days of plates glowing red hot with 2000 volts at 1 Amp :eek:

Mike
 

Kenom

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god, My dad still has some of that older equipment. Now he's lookin at doing packet. Wonder if you could do packet over a laserbeam?!>?
 

Hemlock_Mike

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Packet is computer based and would require the use of repeaters and reflectors. Fog, clowds, rain etc would limit functionality in real use. The 2 meter band still seems best for packet communication.
I think we're a bit off topic here.........

Mike
 

Benm

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I don't see why anyone would want a DPSS laser for communication.. a red or even near IR would work just as well, and yield equal s/n ratio at a given power level.

It's perfectly feasible to set up a communication link using diode lasers, phototransistors and some optics, but obviously true line of sight paths would be required. Nice if you and your buddy both live in a scyscraper facing eachother, useless otherwise.

As for packet radio: Laser links could be much faster, it should be possible to reach over a megabit using diodes from dvd drives and proper modulation.

A cheap 5mw laser has a range of 5000meters or 7500 feet.
I know everything in america is bigger, but 67 cm feet are a bit excessive ;)
 
L

likewhat

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I went to a talk once about laser communication. It was from some physicist from a large aerospace company. The way they transmit the data is likely identical to data transmission methods that are currently used in fiber optic communication. Most of the issue comes with keeping the laser pointed at the detector when it is a plane transmitting to a satellite via a laser, or a UAV over a battlefield transmitting to a tank that is driving.
 

Benm

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I can imagine that using these on mobile targets would be a real pain, especially on something relatively wobbly such as a tank or airplane.
 







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