Most of the time we feature hokey film footage in our Retrotechtacular series, but we think this hack is as cool today as it was fifty years ago. [Clint] wrote in to tell us about Operation Red Line. It was an experiment performed May 3rd and 4th, 1963, which means the 50th anniversary just passed a few weeks ago. The hack involved sending data (audio in this case) over long distances using a laser. But back then you couldn’t just jump on eBay and order up the parts. The team had to hack together everything for themselves.
They built their own helium-neon laser tube, which is shown on the right. The gentlemen involved were engineers at a company called Electro-Optical System (EOS) by day, and Ham radio enthusiasts by night. With the blessing of their employer they were able to ply their hobby skills using the glass blowing and optical resources from their work to get the laser up and running. With that side of things taken care of they turned to the receiving end. Using a telescope and a photomultipler they were able to pick up the beam of light at a distance of about 119 miles. The pinnacle of their achievement was modulating audio on the transmitter, and demodulating it with the receiver.
[Clint] knows the guys who did this and wrote up a look back at the project on his own blog.
Good old tinkering… aiming a laser with rocks under the table.. lovely
119 miles? They weren’t kidding around there.
119 miles with 125 uW of beam power.
So wait, is that microwatt?
if so that’s damn impressive
Yeah, Johnson Viking II! I’ve got two of those monsters waiting to be restored.
Check this out. http://en.wikipedia.org/wiki/Photophone. Mr Bell made something similar in 1880. I built one in primary school. It was rocking to think I was able to transmit sound over a light beam!
The 119 miles distance is really impressive though.
Hard core hacking! Well done, those men!
(and, true nerds that they were, white shirts and skinny black ties for the win!)
Lasers are one of those things that have never stopped feeling like magic to me. I understand at least at a basic level how they work, and they’re so ubiquitous that I take their presence for granted, but every time I stop and think about it I’m like “whoah.”
“May 3rd and 4th, 1963, which means the 50th anniversary just passed a few weeks ago”
Make that a few DAYS sgo.
Today, mine fits in my pocket, and can accomplish full-duplex voice & UDP-TCP/IP from several kilometers using only a commonly found 5mW key-chain laser cat toy.
:-)
But not over 119 miles though, I think that’s a rather crucial thing here and why they had to use a photomultiplier tube and all.
Also: I have to question your claim of ‘over several kilometers’ using 5mW.
See:
http://hackaday.com/2012/09/22/communicating-with-a-beam-of-light/
Link me to a project using 3 and 10 Watt LED? Bit of a mistake there.
You should have linked this: http://ka7oei.blogspot.nl/2012/09/voice-on-laser-beam.html or http://www.modulatedlight.org/optical_comms/using_laser_pointers.html
And although that doesn’t specify the laser output I fear, but I’ll assume it’s actually in the 5mW range.
Or in other words, I concede and stand corrected :)
“W6QYY”, “W6KAQ”, are those 1337 names? :D
Radio amateur call-signs. But you probably know that.