Thanks to Tony G4WIF for alerting us to this really nice video from the fellow who made all those great “Secret Life of Machines” videos. This video on LED’s makes me want to improve the lighting in my work shop. And I think I need some more high wattage resistors. I’m really glad Tim Hunkins is making more videos. His look at the Secret Life of Radio was a real masterpiece.
Category: Light Bulbs
Science Fair Light Beam Communications in 1960s
Hi Bill! This Bob Schubert, KC4FNE in Blacksburg Virginia just wanting to say hello and taking the opportunity to say “Thanks” for the SolderSmoke Series. I have to let you know your podcast accompanies me as I do my early morning exercise regime. Before SolderSmoke, I would begrudgingly get out on the track every other day. Now I’m out there just about every morning listening to a new episode. I’m not sure what I will do once I exhaust all of the episodes? Normally I would cover my obligatory 2 miles in 45 minutes, now I’m looking for excuses to stay on the track so as to complete a one-hour or so episode. When I’m listening to it in the car, I find myself circling the block just so I can finish a podcast. It has also prompted me to purchase the SolderSmoke book. I’m thoroughly enjoying the book as we seemed to have both grown up close to the same timeframe and our early lives led as “geeks.” If you interetsted in what an “old geek” is up to now, point your browser to http://www.lumenhaus.com/ This is a solar powered house done by a team of architecture and engineering students/faculty I was involved with. If you ever find your way to Blacksburg and are interetsed in our Lumenhaus, I would be happy to provide a tour.
I’ve included a photograph of me taken at Orange County High School in the mid-60’s with a science fair experiment “Talking on a Light Beam.” While not quite in the 478THz range of the high-power LEDs it was up there! While modulating the filament on a flashlight I would be hard-pressed to go 95ft much less 95 miles.
Best, Bob Schubert KC4FNE
Our book: “SolderSmoke — Global Adventures in Wireless Electronics” http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20
Oscillating Light Bulbs
Oh man, this is some fascinating stuff: old light bulbs found to be oscillating at VHF! Wayne, VA7AT, stumbled upon this phenomenon at age 13 while engaged in Knack activities. Now Joe Sousa explains the physics behind the emissions that caused Wayne’s light bulb to interfere with the broadcast of baseball games. How long until AA1TJ has one of these bulbs on the air, making contacts? There is much in this that would appeal to Michael: light bulbs, weird physics, translations from German… You gotta love the BNC connector plugged directly into the bulb. Check it out the radio museum article here.
Hi Bill
There was a question posted on Antennex E-mail discussion group talking about how a vacuum type light bulb will oscillate and radiate RF at about 100MHZ. This answered the question I had since I was a boy of 13 experimenting with a light bulb in series with an electrolysis bath (aluminum electrodes with table salt dissolved in water) and 117vac. The bulb dimmed with the electrodes apart and at a certain position the radio I had on blanked out with fissing sound. I had to shut down the experiment quickly because the neighbors were listening on their favorite baseball game and cussed loudly .
I now know what happened on that fateful day. Here is a site I found about the oscillating light bulb http://www.radiomuseum.org/forum/rustika_lightbulb_fm_measurements.html
Wayne VA7AT
Our book: “SolderSmoke — Global Adventures in Wireless Electronics”http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20