Mike WN2A sent me the PIC board to generate the CW for my "Lil Slugger" Doug DeMaw transmitter. Then I started wondering about having a light source flash with the CW. Mike recommended some super-bright green LED's. I had a big broken flashlight with me (the benefits of junk!) so I put all the parts together and hung the light in the window of my seventh floor shack. Last night as Elisa and I walked the dog, I looked back from a quarter mile south. The video above shows the scene. The cell phone camera understates the brightness.
The video above shows the rig in action (but with the bulb on the shelf). Note the PLJ freq readout, the SWR meter and, of course, the green bulb.
I half joked with Elisa that I would love to get a reception report on the light beam. This is not all that far-fetched. We have an email address in the CW message, and the light beam is aimed to the south, across the open Caribbean.
All of this reminded me of an article by Rod Newkirk of some light beam communication that he engaged in in Indonesia during World War II. Great story:
If your interested in light communication you may want to talk to Clint, KA7OEI. He knows quite a lot.
ReplyDeleteSee https://www.modulatedlight.org and https://www.ka7oei.com
73, Randy KG7GI
Bill, you will remember that the CW procedures are different for Aldis and Key. Here is some 'old school' info from the UK Navy. https://www.commsmuseum.co.uk/Visual%20Signalling/vissig.htm
ReplyDeleteThanks for the info, but for this I will stick with standard international Morse. I seriously doubt that anyone will actually see it, realize that it is Morse and decode it. But it could happen. I note that Rod Newkirk in Hollandia during WWII apparently was using international Morse when he made his visual contacts (using a flashlight). 73 Bill
ReplyDeleteMost of Maritime Flashing Light is based on procedural code, which gives you an idea of what is coming next. Similar to the use of prowords in voice messages.
ReplyDelete