radioAe6rt

Jeff Pulver, WA2BOT, and Internet Voice over IP pioneer, suggests starting an Internet tradition akin to amateur radio Field Day. Jeff describes Internet Field Day “as an annual activity that would bring together members of the Internet Community who wish to become better skilled at Post-Disaster Communications together with a community of people who have a history of being active in the space, the worldwide ham radio community.”

Traditional amateur radio Field Day exists as a annual event to prepare and exercise portable communications systems for a day we hope never comes: natural or manmade disaster. Once a year as a community activity, hams pack up their gear and operate in the field for 24 hours under power off-the-grid. Practice makes perfect - systems and procedures undergo hardware- and bit-rot unless they are exercised and used. Jeff’s idea being that emergency ad-hoc Internet data networks, which obviously can also bear voice traffic, can participate in this off-the-grid drilling and field exercise.

Nice job, Jeff.

[tags]disaster communications, disaster preparedness, ham radio, emergency communications[/tags]

My thanks to John, WI6O, for being my very first CW QRP contact. John is in Moorpark, CA and I’m in Pasadena. Not a vast distance at 45mi, but good to be heard.

My power was 2 watts, using my kit-built NorCal40a on 7.020MHz. John was also running QRP at 5 watts with his Elecraft K1 (which I would also like to build).

The NorCal40A runs off 10 AA batteries, into a 70ft (1/2 wavelength at 40m) long wire as high up in the tree as I could get it. All this took place in my front yard tonight, and which proves I can do a portable Field Day with this rig and a thermos of hot coffee.

Thanks again, John!

[tags]ham radio, qrp[/tags]

The latest addition to my radio library is Experimental Methods in RF Design. From the first chapter, we understand what good hands we are in with these authors.

[tags]ham radio, rf[/tags]

For the last year I’ve been into operating continuous wave using Morse Code. While it sounds odd, I believe there is something pleasurable from a brain chemistry perspective when processing Morse Code. Something like a focussing opiate.

Code is not just fun - this is not about fun, but rather pleasure. Code is not quite like music, because code is work, and the way I listen to music is usually not. Code is definitely not like listening to and processing human speech, because code is much simpler than human language.

But taking in Morse Code actively feels good. It’s pure, simple, and feels like orange juice for the brain. It would be interesting to see a brain scan during listening to speech, listening to music, and listening to code to see the similarities and differences in which parts of the brain are stimulated.

[tags]morse code, cw, ham radio[/tags]

For some time I’ve been interested in developing richer forms of group communication, thereby adding to the already accepted communications methods we already enjoy- email, IM, voice over IP, Web 2.0-stuff, etc.

For example, while at EarthLink, we discovered (probably rediscovered) the value of video presence, whereby thumbnail video of a small (6) number of coworkers were transmitted to every other coworker, so we could “be together” visually if not physically. We weren’t looking for the effect, but rather we backed into it while looking for something else[1]. 24×7x365 video thumbnails of a half dozen guys hacking code together. And while one may claim this “always on” video channel is obviously useful and would serve to cohere the group members into a tighter weave, that would be lazy - it is not obvious, nor was it clearly useful until we tried it for a few months, and from there, for the next five years. So Buzz comes into the office, turns on his camera, and we all get to see him in a room-filling (not headshot) view. No audio channel, just video. Buzz is there for us, and we for him. So to text (literature, prose) and audio (voice, singing) modes, we add video (sight).

One wonders what else could be added to the mix of communications methods we use to stay close to coworkers so that we can produce more interesting and useful products or to just stay closer to associates or family. We might consider adding bio-generated audio in the form of our human EEG (brainwaves). Pitch-shifted because the baseband time varying signals are in the sub-10Hz spectral region. Pitch-shifting puts the baseband up into the audio region where we can “hear” the brainwaves, or at least a representation of them.

Listen to some here, from my net acquaintance Jim Peters’s brain. Look for the files starting with hb (e.g. hb4.mp3).

Eerie stuff, isn’t it? So we all plug in, subject our EEG output to the same pitch shifting algorithms, and we listen to each other’s brains, so to speak. Maybe patterns would emerge, some suggesting that Buzz is thinking really hard, or Buzz is happy, or Buzz is relaxing after a period of mental gymnastics. Whatever it means, the pitch shifted audio sounds like something — there is order and continuity — so let’s exploit that.

This could be extremely interesting. Think of it as putting your head to someone’s chest and listening to their heartbeat - they’re in there in some sense. Listening to brainwaves over the network could provide the same sense of experiencing that person in a real biometric sense.

OpenEEG provides a place to start.

[1] “Now, a few words on looking for things. When you go looking for something specific, your chances of finding it are very bad. Because of all the things in the world, you’re only looking for one of them. When you go looking for anything at all, your chances of finding it are very good. Because of all the things in the world, you’re sure to find some of them.” Daryl Zero, The Zero Effect

[tags]groupware, social software, eeg, moods[/tags]

SolderSmoke offers podcasts of discussions of QRP construction projects. Very, very cool.

[tags]ham radio, qrp, radio kits[/tags]

I want to plug these two books, because I value them at the same level as Jackson’s Electrodynamics or Corson and Lorrain’s Electromagnetic Fields and Waves

• Paul Nahin’s Science of Radio
• Dave Rutledge’s The Electronics of Radio

When I think about antennas, I often end up thinking about Maxwell’s Equations and radiating dipoles. I can’t help it, and rightly so, and which is where Jackson’s text comes in. But after Jackson, which is dense and of biblical authority, you want to read something a bit more practical and accessible.

The two books above are great complements in the quest to understand RF phenomena. Nahin treats the history and basic physics of radio, while Rutledge treats a real working analog radio, the NorCal40a. You can buy the NorCal40a in kit form, assemble it, operate it, and read about every aspect of its theory of operation in Dave’s book. Wow. So cool.

RF science is genuinely hard, because you’re dealing with time varying propagating fields in real world physical systems. Here, real world is shorthand for extremely complicated and begging for first and second order approximations. These two books get us started in those approximations and the radio physics they describe.

[tags]rf, radio frequency, radio, electrodynamics, ham radio[/tags]

I’m looking for sources of interactive line of sight maps, such as this sample which shows what can be seen (sort of) from Contractor’s Point in the San Fernando Valley, CA.

Anybody?

[tags]maps, line of sight maps,rf propagation, ham radio[/tags]

Last fall I built a NorCal40a 40m CW transceiver as a QRP rig and trail radio (ham radio). The rig includes the optional KC-1 Keyer, which allows me to use a paddle key instead of a straight key.

For trail use, where the radio, power supply, tuner, antenna, and key would be stuffed in a backpack and hauled in, I wanted all the components to be as light, small, and rugged as possible. The power supply is a set of 10 AA batteries mounted in inexpensive battery holders of the type readily found at RadioShack. The tuner built from kit is the Emtech ZM2, and the antenna a half wavelength longwire made from a single strand of 21 gauge speaker wire, with a quarter wavelength counterpoise made from the same. To store the antenna, I roll it up on a 12″ spool made from a length of old broomstick.

To store the rig, I found at Target a plastic, shoebox-sized box with lid in which the entire rig fits. The box fits nicely within either a day pack or larger backpack. Total weight is about 5lbs., which is fine for day trips. On longer, hike-in trips, where you’re carrying food plus everything else you need to survive, 5lbs is a bit heavy. Priorities.

Paddle touches are pretty personal, and if you don’t like the touch and action of a paddle, you probably won’t have the fun with it you could be having. I have a very nice Begali Simplex paddle that I use with my home, essentially nonportable, radio. This paddle is not going on the trail with me, at a hefty 3 pounds itself. Besides, this paddle is a work of art and mechanical princess, and should be used in friendly environments, not outside or stuck in the bottom of a pack. While the Begali may be able to take this sort of abuse, I won’t subject mine to it.

So for trail use, I considered using a Paddlette BP, but couldn’t get comfortable with how the key would perform, based solely on an inspection of the product photos. It looked larger than what I wanted. This may be a great trail paddle, but I never got around to trying it. I actually did try a Vibroplex Code Warrior, Jr.. While this was a nice key, it, too was too large and heavy for my backpacking considerations.

Eventually I settled on the Palm Radio Mini Paddle and couldn’t be more pleased with the product. It’s very small and light, and has a terrific action. I operate it by grasping the paddle body with my left hand as I would grip a bicycle handlebar, rest that left hand on my right knee, and operate the paddle with my right hand, which is also resting on my right knee. This configuration provides enough stability to comfortably and accurately generate clean code.

The Mini-Paddle action is clean, crisp, and sure and the construction compact and rugged. When not in use, the paddles can be stowed inside the paddle housing to protect them and reduce the paddle’s stowage space requirements - both very important features. Space requirements for the paddle are about the same as a pack of chewing gum or pocket knife.

This is a great little portable paddle, easy to handle with crisp, firm keying action.

[tags]ham radio, cw, telegraphy, morse code[/tags]

Some time ago I ran across Jim Kortge’s pictures of the 2n2/20 20m rig he built using ground plane construction techniques.

Absolutely gorgeous work.

Wow.

[tags]ham radio, ground plane construction, radio kits, radio[/tags]