iBanjo

I finally conjured up an electronics project which scratched an itch of mine — while simultaneously allowing my buddy and I to design a custom hardware/software solution.

The Problem: ham folks use morse code ‘keyer’ devices to aid them. It’s basically a tiny computer that plays a morse code message in a loop. You program messages into a few memories on the device, then tell the device to play “CQ CQ CQ DE NN9S” in a loop while waiting for someone to hear your hail. Or maybe you program the device to give standard canned responses when you’re participating in a radio contest. Either way, I had this realization that the smartphone in my pocket was essentially a supercomputer; why on earth was I bothering to assemble little IC devices with 5 or 10 flash memories to do this job? My phone was infinitely more powerful.

So really, the question boils down to this: assuming we can write a phone app that plays any morse code we want, how do we convert a ‘beep’ sound into a signal that my radio thinks is equivalent to “pressing the straight key”?

The radio’s connector is quite simple: it sends a small current out of a jack. If the current comes back to it, it thinks you’re pressing down on the straight key (closing the circuit). The straight key is just a physical switch.

So Jack AI4SV (my mentor/elmer) designed a circuit below which uses a common NPN bipolar transistor as the switch; we simply need to tickle the transistor’s base with a bit of current from the phone’s audio, and poof, the transistor closes the radio’s circuit and the radio sends a ‘beep’ out the antenna.

As you can see in the circuit, we take the ~.5V signal from the phone’s audio output jack and transform it into about ~5V. From there, we use a full-wave rectifier to convert the AC into DC, then eventually send that current into the transistor. The capacitor is there to smooth things out.

The other half of the project, of course, was writing an Android app to act as a versatile memory keyer.

Note that neither the hardware or software are finished yet. The software has a long way to go still, and now that the hardware works on a solderless breadboard, we’d eventually like to design and print a tiny PCB to fit in a mint tin. But still, it’s cool to see this stuff actually work in real life!

In the video below, you can see a live demo of the hardware & software in action:

(Disclaimer: I’m one of the ‘old guard’ open source guys. I co-founded the Subversion project back in 2000 and am a proud member of the ASF. These opinions are my own.)

A very popular blog post has been going around lately called Apache Considered Harmful, which criticizes the Apache Software Foundation (ASF) for being impossible to work with. On the surface, it looks a bit like a culture war between older and younger generations of open source hackers: the older generation is portrayed as stodgy and skeptical of distributed version control systems, making the ASF inhospitable to a younger generation used to the fast-and-freewheeling world of git and Github.

One of the ASF’s leaders, Jim Jagielski, then wrote a blog response which seems to say, “We’re not irrelevant; we just have high integrity. We care about long-term health of open source projects, not passing fads or hip popularity contests.”

But I think Jim is truly missing the main complaint.

Backing up a bit: what is the mission of the ASF? Why does it exist? My understanding is simple:

1. to be a legal umbrella of protection
2. to foster long-term, healthy open-source communities

The first goal is achieved by putting all of a project’s code under the Apache license, and getting all code contributors to grant nonexclusive IP rights to the ASF. This guarantees that the ASF “owns” the code, and thus can legally defend it.

The second goal is about encouraging and preserving healthy culture. The ASF has a famous saying: “community over code”. In other words, the ASF doesn’t accept donations of code (or code thrown over walls), it only accepts communities that happen to work on a common codebase. The community is the main asset, not the source code.

The ASF has a great set of cultural norms that it pushes on its communities via political means and lightweight processes. For example, the ASF requires that each community have a set of stewards (“committers”), which they call a “project management committee”; that communities use consensus-based discussions to resolve disputes; that they use a standardized voting system to resolve questions when discussion fails; that certain standards of humility and respect are used between members of a project, and so on. These cultural traditions are fantastic, and are the reason the ASF provides true long-term sustainability to open source projects. It’s the reason I pushed so hard to get the Subversion project into ASF.

Let’s go back to the original “Apache Considered Harmful” post again. Yes, the blog post rambled a bit about the ASF becoming “irrelevant”, but I think that’s just random grumbling around the actual issue at stake: the ASF’s insistence on forcing their hosting infrastructure onto projects. We have repeated examples of mature open source communities trying to join the ASF, which already use git as their version control system — and the ASF is insisting that they convert to Subversion and store their code in the ASF’s One Big Subversion Repository.

I fear what’s happening here is that the ASF elders have tragically confused “be part of our community” with “you must use our infrastructure”. There is no reason for these things to be entangled.

The ASF has teams of people dedicated to running servers for Subversion, SSH, QA testing, email lists, and so on. Ten years ago, infrastructure hosting was a Hard Thing. Getting to use the ASF’s hosting services was considered an attractive perk. These days, project hosting is utterly commoditized: we have Sourceforge, Google Code, Github, and other sites. In a matter of minutes, any two people can conjure up a hosted source repository, bugtracker, wiki, etc. So is it really a surprise that newer communities, ready to join the ASF, already have functional (and possibly superior) tools and infrastructure?

So why oh why does the ASF demand everyone use their Subversion service? They don’t force every project to use the same bugtracker; I wonder if source code is different because it’s the “special” asset being protected. Perhaps the ASF elders think it has to all be in one place in order for it to be protectable and controlled? A simple solution here is to simply require that at least one canonical copy of source code be stored on ASF servers. If that means doing an “hg pull” or “git pull” via cron job every hour, so be it. Who cares where the real coding is happening, or in how many repositories it’s happening in? Irrelevant. As long as a community has blessed a central repository as Official, and the ASF is keeping a synced copy of that somewhere, we should be all set. The ASF’s job is to shepherd communities, not force everyone to use the same software tools.

Ironically, years ago I too was suspicious of distributed version control, and wrote an article about how it tended to discourage ASF-style project cohesion. But in this case, we have examples of communities that are already cohesive and high-functioning, despite using git. They don’t need ASF’s tools; they just need a nice place to park their community. If they ain’t broke, stay out of their development processes.

(Note the ASF isn’t alone in this insanity. Others have told me that FSF projects are forced to use the Savannah collaborative platform, whether they want to or not. Crazy! Repeat after me, folks: your community is not your tools.)

As I’ve mentioned before, I’m very much into the portable, low-power subculture of amateur radio. On business trips, I like to find random hilltops (just like my mentor does), set up a simple vertical whip antenna, and then use my tiny battery-powered radio to start chatting with people around the country. It’s really quite a thrill.

The Yaesu FT817-ND is a really popular radio for this kind of thing. It’s tiny, battery-powered, only weighs a couple of pounds, and puts out 5 watts of power. Backpackers and hikers love it. That said, there’s still a huge aftermarket of “mods” you can add-on to make it more pleasureable to use. I thought I’d share some of these mods here with other aspiring low-power hams.

Here’s a guide to the different additions:

• A: Bulldog morse code paddles. These tiny paddles are made from sewing notions (buttons) and a tiny binder clip but work great and have a magnetic base that sticks to the radio. They’re no longer made, but a newer version screws to the side of the radio.
• B: DSP noise filter. This is an internal module installed for me by the fine folks at W4RT, who specialize in 817 upgrades. It almost completely destroys the static noise floor, just like the noise reduction in my big radio. The change is dramatic and invaluable.
• C: 300hz CW filter Just a standard mechanical Collins filter for making morse-code much more intelligible; offered as an accessory directly from Yaesu.
• D: Speech compressor. Another W4RT mod installed within the hand microphone, it supposedly emphasizes the mids and trebles of the human voice, making my voice much more intelligible to others when using SSB over 5 watts. Others have told me that I sound really clear with it!
• E: Kranker knob. Another W4RT mod which makes the main dial much more usable — both for fine and rapid coarse-tuning.
• F: Peg legs. Cute little foldable feet from Palm Radio, which tip the radio upwards towards your eyes. It’s amazing what an ergonomic difference this makes.

Of course, once I’m actually in the field, I use an Elecraft T1 tuner (about the size of a deck of cards!), and an A123 nanophosphate 4.6AH battery for up to 8 hours of operation in the field.

There are a lot of Sussmans out there, and every month I get emails addressed to ’sussman@gmail.com’ but clearly meant for a different one. I always politely reply with “you’ve got the wrong email address”.

That said, when I search Gmail for such replies, it makes it easy for me to see every wrongly-addressed mail I’ve ever received. The email contents — coupled with the complete lack of context — provide a surreal look on the chatter that goes on between humans. In the spirit of textual surrealism, I picked out individual statements from these emails and composed them into a poem.



I've been thinking about you. How are you? Everything ok?

We will however have recording equipment there and will record the
event.



Well, after successfully carrying the Buddipole on a plane to Silicon Valley and making a couple of 2000-mile contacts on 5 watts (see this blog post), I’m happy to report that I’ve had two more happy expeditions: one to Iowa, another to Oregon. I’m going to start collecting location-specific patches and sew them onto the Buddipole bag as it travels!

During a lovely family vacation to Dubuque, Iowa, I had a chance to sneak out of the hotel after dark with the antenna and Yaesu-817ND bag. I walked down to the west bank of the Mississippi river, and managed to set up a 40m horizontal dipole about 10′ high just before the sun set. Luckily, the bank sloped down 20 feet diagonally to the water, and I think the entire surface of the river acted as a gigantic reflector for my horizontally-polarized signal. Using only 5 watts, I had a lovely ragchew with a gentleman in North Carolina. Only one quick smartphone-picture was made of the antenna’s base before it got too dark:

Last week I was at a conference in Portland, Oregon (very close to the Buddipole makers!) and did a quick Google Earth inspection of the terrain. I located the highest hill in town — Council Crest is over 1000 feet high — and then took a bus up there at dawn. Here’s the equipment just before I left the hotel room, the Buddipole bag and the radiostation bag (containing radio, tuner, analyzer, and 4.8Ah nanophosphate lithium ion battery.)

Once up there, the bus informed me it wouldn’t be back till 4pm, ugh. Oh well. So I took in the great view of the whole city and valley; it was easy to see Mt. Hood on the horizon.

Setup was fairly straightforward. I spent 30 minutes building a no-compromise 20m quarter-wave vertical, with two wire radials hanging down onto the stone walls. After fooling with lengths, I could get the SWR down to about 2:1 to 2.5:1 across the whole band.

The total height was close to 10m tall.

And then I quickly set up the radio station.

During my three hours of activity, I spent an equal amount of time trying to make contacts and explaining myself to all the passers-by. Most people thought I was trying to “sample” the atmosphere or something. Another person who was an EE engineer (but not a radio ham) seemed to think that 5 watts was a ‘huge’ amount of radiation, and I couldn’t seem to talk him out of it.

I did manage to make three contacts on low power — two via voice to Alberta and B.C., and one morse-code contact to Oregon. When the other guy said my morse tone was “drifting around”, that’s when I knew the battery was dying and time to pack up!

Since I was alone up there, I had to spend an hour hiking downward through thick forest trails. My favorite part was the four-way intersection.

…but eventually I made it to the zoo, and from there was able to hop on the light rail back to the convention center!

I’m working hard to convert my social media life away from Twitter and Facebook and over to Google+ instead.

Why? Well, I work for Google and want to see Google+ succeed — the best way to do that is to actually become a daily user. Also, I want simplicity. I can’t deal with three separate social networks; I want just one, and Google+ is a superset of the other two.

A lot of friends have been asking me how Google+ works. “What’s the sharing model?” Here’s my explanation, to the best of my understanding:

• The basic unit of reading and writing is a circle. You need to spend some upfront time defining these circles, but the UI makes it easy to do and the payback is well worth the effort. (And due to Google’s Data Liberation Front, you can take your circles with you if you decide to leave!)
• Reading: You only see posts from people in your circles — nobody else. You can either look at all the circles at once (“your stream”), or you can look at posts coming from just a single circle.
• Writing: Any post you create can be published to 1 or more circles. This provides nuanced sharing — something that’s really hard to do in Facebook. For example, in real life, you wouldn’t necessarily share the same stories with your parents, your co-workers, or your drinking buddies. Remember, however, that the people you post to won’t actually see your post unless you happen to exist in at least one of their circles!
• Being public: Circles can be totally circumvented by publishing to the “public”; in which case, everyone in the world could conceivably see your post when they read “incoming” messages rather than their stream.

This model is nice, since it captures both the Facebook model and the Twitter model.

It captures the Facebook model of sharing via reciprocal friendship, but without explicit friendship requests in either direction. If two people happen to have either other in each other’s circles, then they see each other’s posts. Very simple. No more hurt feelings from unanswered friend requests; no more posts from people you don’t care about.

It also captures the Twitter model. You can do a public post to the world. You can also “follow” the posts any famous person you want (without bothering them) by simply adding them to a “people I wanna follow” circle.

If you haven’t signed up at http://plus.google.com yet, you really should. The Android app is awesome. Any photos I take with my phone are instantly available for posting; no need to explicitly upload them. It’s amazing how big a barrier to entry this used to be!

I’ve been a ham almost a year now, but due to my extremely low antenna (a dipole only 20′ high across my tiny urban backyard), I’ve never been able to make contacts outside North America. I’ve managed to reach 33 U.S. states so far — as well as Canada and a small Carribean island, I still haven’t hit another continent yet. The fundamental problem is that wires strung low tend to reflect energy off the ground, and thus the radiowaves hit the sky straight above the antenna; for real long-distance ionospheric skipping, one needs the radio energy to shoot toward the horizon. This is why I’ve been planning on putting up a higher loop antenna this summer.

In any case, today I made my first breakthrough — a voice contact from Chicago to Italy. Finally!

I thought it would be fun to participate in a low-power “backyard” contest today, so I set up my Buddipole in the center of my backyard, using the same 20 meter vertical configuration that I used on the Silicon Valley hilltop a couple of months ago. I’m still surrounded by other houses and buildings, but heck, a vertical antenna is known to hit the horizon easier than a horizontal one. Worth a shot!

If you look at the photo, you can see the antenna is about 25 feet high. It’s not easy to see that there are also two wire radials sloping down to the side-fences, as well as three guy-lines. The winds were gusting to 20mph today, but the guys held the thing securely, despite the antenna swaying in the breeze just like the tall trees.

At first I used low-power (5 watt) morse code using my tiny radio and a lead-acid battery, and made a nice contact with Salt Lake City, Utah (a new state for me!). I then made a basic voice contact with a guy in South Dakota; there was a busy contest going in that state this weekend. After that, just for kicks, I decided to drag out the BIG radio from the shack and run an extension cord for AC power. I turned up to 100 watts of transmission, and discovered a guy in Italy taking calls. After 20 minutes of hoping he’d hear my callsign, he finally acknowledged me and gave me a 5 & 7 report –not bad for 100 watts! The ionosphere was good for 20 meters today, and you can tell the sunspots are really picking up compared to a year ago when I first started out. In any case, this was a new distance record for me: about 4800 miles.

In the picture below, you can see both my radios, with the tuner in the middle.

A late night blog meditation!

Thesis: I seem to get crushes not just on hobbies, but on the bizarre skills required for them.

Take a look at banjo: is there anything more bewildering than listening to Earl Scruggs play a solo at top speed? To a bystander, it’s an astounding blur of continuous arpeggiation, with accents in just the right places. It’s a bit like watching a tap-dancer go nuts with his fingers instead of feet. When I started listening to bluegrass, I fell in love: I must learn to do that crazy thing.

And so I practiced. And took lessons. And practiced. And practiced. Arpgeggios everyday. I would listen to clips of Earl’s recordings slowed down to half speed, analyzing — note by note — each little trick and lick. After a few months, I noticed one day that Earl was starting to slow down whenever I listened to his albums. Was something broken in iTunes? Wait, no… Suddenly my brain was starting to decompose the stream of notes in real time. The blur was actually a bunch of distinct phrases, some which I knew how to play already. And the more I practiced, the slower his recordings became. It’s fascinating to watch your own brain adapt!

And now ham radio. Morse code is clearly a useful tool — it cuts through static like a katana through whipped cream. It propagates much farther than voice and requires almost no power. But ugh — listen to those folks on the air doing it! It’s a cacophony of irritating high-speed beeps. It’s like my kids banging windows with their little toy wooden hammers. Make the noise stop!

But hey, let’s jump in anyway. Listen to a tutorial CD, learn one letter at a time. Practice hearing each character at slow speeds. Practice, practice, practice, for several months. At some point, I gain the courage to reach out and have a slow speed conversation with a stranger over the air. Never mind that I’m shaking and sweating and so nervous that I’m only able to copy half of the characters coming back to me. Over time, the more I do this, the less nervous I get, and the fewer characters I miss.

Then the same revelation comes back this week: “Man, why is it so hard to find people doing high speed morse on the airwaves these days?” Is everyone slowing down? Oh wait. It’s me. My brain is changing again! Morse code doesn’t sound irritating anymore. The beeps are obviously broken into clear section, clear characters. The tones are haunting… almost relaxing. The whole experience is a bit like a calming vacation.

I turn on the radio, and in voice (sideband) mode, the filter is quite wide. I hear endless grating hiss.

I narrow my filter to 1/6th the width, which is best for picking up code. Suddenly the hiss turns into a whispering valley of calm. It’s a bit like being in an indoor swimming pool: endless harsh echoes of screaming families reverberating around you — and then dunking your whole head underwater. A beautiful solitude. A sound of deep watery solace.

Then turn the dial till a code conversation appears. Listen to the letters float by! Like tiny drumbeats of beautiful tone, perfectly spaced. It almost puts you in a trance.

I know my brain has changed, because I can no longer read emails while listening to morse code. It used to be background noise, but now it’s actively messing with my language centers, competing with my ability to read text.

As my buddy Fitz will testify, I burn through new hobbies like flies on a hot dog. When I got my extra-class amateur radio license only six months after starting the hobby, my co-workers asked me if I had “won yet”, and asked to see my “achievement badges”. I guess there’s some truth there.

My job at Google requires that I do about 8-10 short trips per year (to other offices or conferences). Back when I was in my banjo phase, I obsessed about carrying a banjo on every plane so that I might seek out local bluegrass jams (I even had a folding banjo!). In my photography phase, I carried a giant DSLR and heavy lenses in my carry-on bag, and would taking photographic walking tours of each city. And now, in the era of Ham Radio, I obsess about how to carry an entire portable radio station with me in a gymbag.

And so that’s exactly what I did last week when I visited Mountain View (Google’s headquarters in Silicon Valley.) Into my gymbag went the same stuff from my trip to North Carolina:

• A wee Yaesu 817ND radio. Only does 5 watts of output, but can operate on any amateur band
• A tiny auto-tuner, the LDG Z-11Pro2
• A Heil traveler headset
• My homemade touch-paddle/keyer combo for doing morse code.
• A 5 amp-hour 12V battery, to power the radio and tuner via powerpole connectors.
• An MFJ 259B antenna analyzer
• My brand-new, supremely flexible Buddipole Deluxe antenna construction kit.

The final gymbag was ~20 pounds, and was thoroughly swabbed and inspected by the TSA in both directions of travel. I guess they’re ok with sealed lead-acid batteries, because, well… they’re sealed.

The real star of this writeup is the Buddipole. After my own homebrewed antenna experiments failed to pan out in hotel rooms last autumn, I discovered this product. It’s not so much an antenna, but an erector set for improvising any sort of antenna you wish. It comes with a fantastic cookbook (written by fan NE1RD) that shows a zillion different tested configurations. Within a tiny little 2-foot long bag, you get a tripod, 10 foot mast, multiple radiator elements, counterpoise wires, guy lines, and changeable coils.

(This is not me, but the creator of Buddipole, holding the bag:)

The idea is that you can build a straight horizontal dipole (up to 26 feet long!), and “tap’ the coils to change the electric length. Or you can build a vertical antenna, with either rigid or wire counterpoises at random angles. Or you can make up your own Y or L shaped designs — whatever works for you! With an antenna analyzer at hand to adjust your invention, you can get it tuned perfectly. Or if not tuned perfectly, the autotuner helps span that last little bit of impedance mismatch.

Hams love to see how far they can reach with their signals — what they call ‘DXing’. They also love to take trips to remote islands or jungles and set up portable stations, what they call a “DXpedition”. My own DXpedition started when I got up at dawn and headed over to a tiny salt-water lake in the public park just north of the Google campus. Some folks at Ham Radio Outlet had recommended it to me, since an antenna over salt water gives nearly perfect ground reflection.

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I showed up and started by building a 10 meter vertical antenna, with two 30 degree counterpoises.

And here you can see me holding the tiny radio, hooked up to the antenna.

Alas, the 10m band was mostly inactive, and I had to start my workday. So after 7 hours of meetings, I teamed up with another ham co-worker (N1VF) and we scaled the hill just between the campus and the lake. Quite a view up there! We then built a full-sized half-wave 20m vertical antenna, since vertical antennas tend to have low takeoff angle and hit the horizon better than horizontals. Of course, on the hilltop we already had a 360 degree view of the horizon. In the photo below, you can see my buddy next to the antenna. We have 3 guy lines coming off of it, and 2 wire counterpoises (about 17′ long each) drooping down to the ground.

We then sat on the hilltop for an hour, as the sun slowly set over the ocean. Nobody replied to our CQ hails on morse code, but we did hear a guy in Colorado talking to a guy in Australia, both with directional beam-antennas. Pretty neat. Eventually we made voice contact with a guy in Wisconsin; apparently he was able to pick up our tiny 5 watt signal because he too had a beam-antenna pointed towards his friend in Hawaii. The highlight of the hour, however, was when we made voice contact with a ham just outside Fairbanks, Alaska — that’s about 2500 miles away. For 5 watts, not too shabby!

After packing everything away, I managed to grab a snapshot of the setting sun as we went down the hill.

Overall, I consider the expedition a success. Alaska is a hard state to “achieve” in the game of ham radio, and I’m proud to have it in my logbook. The Buddipole really impressed me to no end. I will heartily recommend it to anyone who ever travels, camps, whatever. I plan to use it quite a bit for Field Day next June.

As I mentioned before, one of the joys of ham radio is to invent engineering challenges and then solve them as cleverly as possible. And it’s a great excuse for hardware hacking. Over the weekend, I built a teensy morse-code radio (on a single fixed frequency!) called the Rockmite… but I’m still trying to debug why it’s not working.

Meanwhile, a much simpler project arrived at my door: a tiny circuit board that turns any two pieces of metal into morse code paddles. By simply making touch-contact with the metal, the resistance triggers the ‘dits’ and ‘dahs’. My goal was to combine this with my existing keyer (a device that creates perfectly-timed morse code, which sits between your paddles and your radio.)

Here’s a short video showing the two circuit boards hooked up by temporary wires:

I first tried fitting the keyer board, paddle board, and a 9V battery all into an altoids tin, but alas — the keyer board’s controls were too tall for the tin, and I didn’t feel like disconnecting them and mounting them directly to the walls of the tin. But then I had a great idea! If the paddle board only needed 6V to operate, I could stack two coin-cells together. And then the coin cells and paddle board could be stuffed into the keyer’s existing black plastic enclosure!

Notice how the two coin cells are tucked into a slitted styrofoam peanut. To change the batteries, I just yank the electrodes out of the peanut, drop new batteries in, then re-stuff the elecrodes back in. Meanwhile, I hooked up the batteries to a toggle switch added to the back of the device. I had to drill an extra hole for the paddle wires to come out as well. Here’s the finished product:

And finally, a short video where I demonstrate how it works:

A huge thanks to Dale N0XAS for the picokeyer circuit and to Sumner WA1JOS for his touch keyer board. Great fun to combine them!