Over at G4ILO’s blog, he responded to the recent Wired article about ham radio by asking “Is technology good for ham radio?” with his answer being “no”.

G4ILO’s Blog: Is technology good for ham radio?

The statement which caused me to blow milk out my nose was this one:

The more high-tech ham radio becomes, the less magic there is.

I must admit that such statements cause me to roll my eyes. Ham radio wasn’t ever magic. It seemed like magic, because it allowed you to do something which you couldn’t imagine doing without it: communicate with others over hundreds or thousands of miles. It’s hard not to think of this as magic, a quote attributed to Einstein (but as far as I know unverified) goes:

“The wireless telegraph is not difficult to understand. The ordinary telegraph is like a very long cat. You pull the tail in New York, and it meows in Los Angeles. The wireless is exactly the same, only without the cat.”

That makes it sound very much like magic, but it’s really not, and moreover, it never has been. On my desk I have a copy of The Principles Underlying Radio Communication, a really nifty little book put out by the U.S. Army Signal Corp. The first edition was published in 1918, and you can read it online via Google Books (my own copy is dated 1921).

If you bother to read this book, it isn’t magic or alchemy: it’s engineering and science, harnessed in the service of human communication. You’ll learn about currents and resistance, about Ohm’s law and batteries, about capacitance, magnetism and inductance. And because this was in the days just after WWI, you’ll see the use of alternators to generate radio waves, and the first hints of the use of vacuum tubes (the most cutting edge of technologies for its time). Amateurs were following right along through all this. If you surf the QST archive available from the ARRL, you can see that dedicated amateurs were tracking these amazing developments with incredible rapidity and skill. The history of amateur radio is one of technological adoption, not historical preservation. It was about challenging one’s self to do something that seemed like it would be beyond the realm of what could be done by individuals, working on their own with resources limited by what they could afford.

To me, amateur radio is about setting personal challenges, and then working to achieve them. I’ve called it “going boldly where others have gone before”, and if that seems odd to you, consider that you might want to see the Louvre, or Westminster Abbey, or Chitzen Itza with your own eyes even though you could just buy books and read about them. It’s about learning and growing and sharing with people of similar interests, and I see technology as only enabling more of that.

G4ILO maintains a webpage and a blog. If you surf over to his page, you can see a picture of his shack, which has at least nine radios which contain microprocessors. (In fact, I don’t see a single one which doesn’t.) I suspect you’ll find a couple more microprocessors in the visible power supplies and tuners. If technology is bad for amateur radio, I wonder why Julian seems to possess so much of it? If technology is such an anathema, a threat to the magic of amateur radio, then shouldn’t we all just go back to alternators, audions and spark gaps?

Technologies like cell phones and the Internet are incredible tools to bring the world closer together, and to allow us to communicate and share our part of the human experience. When we talk in hushed tones about the good old days when amateur radio was king, we just look foolish.

I do agree with Julian about a few things: I’m not a fan of D-Star, not because it uses the Internet (the Internet significantly extends its utility for hams) but because it relies on a patented technology which must remain forever (well, until the patent runs out) beyond the realm of experimentation and deployment. But the problem isn’t one of technology: it’s one of ownership. I also think that the ARRL (which does do a great many good things) doesn’t serve amateur radios best interest by promoting it mostly as an emergency radio service. As other communication technologies become more pervasive, it seems clear that amateur radio’s role is shrinking over time, and even if we were to reverse that trend, we’d basically be simply duplicated a radio network that could be provided by the government or by private industry.

Technology can be scary, but it also can be exciting and empowering. Let’s embrace technology, rather than drag our heels and complain that we can’t understand it. Let’s rise to the challenges that we have inside us to learn, to experiment and to embrace.

I always like reading G3XBM’s blog: he’s been interested in all kinds of cool QRP and LF stuff that I find really intriguing. What makes it even more great is that he’s decided to apply his significant talents toward designing a very simple sideband rig for 10m. It looks like he’s aiming toward a dual sideband rig with a simple direct conversion receiver, with a target price of around $32 US. Very intriguing! I’ll be monitoring this closely. As the sunspots heat up, a little rig like this could be an awesome amount of fun.

A Simple Sideband 10m Transceiver – G3XBM.

I haven’t even got this on the air yet, and I’m already imagining all sorts of interesting possibilities to improve and change the basic beacon design. (This is a credit to Hans for creating something simple enough to build, and yet interesting enough to inspire.) I’ve been brainstorming a bit this morning, and thought that I’d just write down some of the ideas I’ve had.

• First, there is the question of output power. I think that with the 3v supply (probably more like 2.8v) the maximum output power is somewhere around 14mw. This might suffice for reports for other DX entities in Europe, but to reach other countries from the U.S., a few additional milliwatts (say between 100 and 250mw) would be better. I suspect that I’ll have to go to a 6v supply to make that happen, but in any case, it’ll be an interesting thing to work out.
• Even without additional power, the addition of an output buffer amp is probably good. I noticed that even changing the configuration of the short wire that i was using as an antenna changed the loading of the oscillator to shift the output frequency a few hertz.
• Temperature control would probably be a good thing. Stu Phillips had some nice ideas in his own QRPp transmitter, which is probably worth emulating.
• It seems silly not to make more use of the Arduino. If I had a thermister or some other temperature sensor, I could log temperature. I could also use it to monitor battery voltage. I am also pondering using one of the cheaper processor boards: perhaps a LaunchPad ($6 is a lot cheaper than $30 or so for an Arduino).
• Using the PWM outputs of the Arduino as analog control voltages means constructing a discrete a low pass filter, or a resistor ladder. This is fine for mucking around, but using a proper DAC might also be good. Microchips makes a nice little I2C 14-bit DAC that you can get from Sparkfun on a little breakout board for $5. I suspect that if you monitored the temperature using the processor, you could calibrate the output frequency to stabilize the output with respect to temperature digitally.
  Breakout Board for MCP4725 I2C DAC – SparkFun Electronics.
• Oh, and put it in a proper metal box. With perhaps a variety of inputs and outputs. Including maybe a tap that I could use with my Norcal frequency counter.

Okay, that’s a pretty good list. Should keep me busy for quite some time.

So, today I drove down to HSC in Sunnyvale and got (among other things) some trimmer capacitors so I could tune my beacon, and when I got back, I set to work. I pulled the 22pF capacitor and put in my trimmer, and then hooked up my SDR-IQ receiver to the laptop so I could see where the radio was tuning. A few tweaks with a screwdriver (wish I had a non-metallic one for this) and I got it centered in the band between 10.140Mhz and 10.140100Mhz. It seemed to stay there pretty well. I had previously made a simple input filter on the board (consisting of a 10K resistor, and a 22uF capacitor (too high, but it was what I had on hand). I wired it up through a 1M ohm resistor (as per Hans’ schematic) and then took the voltage from the two AA supply (let’s call it 3v, even if it is really somewhat less) and tapped it into the input. Sure enough, the radio tuned up about 40Hz. When I removed it though, the filter drained really slowly, returning to its original value only after twenty seconds or so. I thought this was going to be a problem, but then I realized that the filter capacitor had to discharge through the 1M ohm resistor, because the input was floating, but when hooked to my Arduino, it would would discharge back to the ground inside the Arduino through the 10K resistor, which would mean that it would discharge 100x faster. That seemed to work out in practice as well.

But my first test was simply an unfiltered test: sending either the high or low value to an output pin, and sending it into the modulation input of the beacon. To generate the keying waveform, I just modified my earlier Arduino Morse Beacon to send at 1 second dits, and then used Spectravue on my SDR-IQ to scan a relatively small (500hz) bandwidth. A few seconds later:

I then tried sending the input through the smoothing filter. As you can see, the waveforms now look fairly rounded:

But the Morse is still clearly legible. I decided to leave the input filter as it was, since in QRSS3 mode, the dits would be 3x longer. Measuring the overall frequency deviation, it seemed like it was about 50 or 60 hertz. Rather than setting up a pot as a voltage divider, I instead programmed the Arduino to vary its voltage between 4 and 5 volts, which I figured would give me 1/5th the total deviation, or about 10 hertz. And… it works! Witness the absurd and poorly lit video, demonstrating reception via my FT-817 and Spectran, but still transmitting into the same 50 ohm resistor at the lowest power setting (I suspect right around 2 or 3 mw).

Bill, N2CQR will probably appreciate that initially, I seemed to be generating upside down Morse as well. I modified the program to flip the Morse around, and all was well. But then I moved this radio to hook it up again, and the Morse code seemed upside down again. So, I flipped it back. All is well. For now.

I was concerned about the stability, but it seems pretty good, considering that I just used the crappy stuff from my junkbox. Eventually, I’ll get it in a box to keep the temperature more stable, I’ll make some software improvements (perhaps sending Hellschreiber) and then get it on the air.

73 de K6HX

Addendum: Here’s the link to Hans’ design. Thanks Kenneth, for reminding me that I had forgot to link to the schematic. Click on “Construction”.

My evening’s hacking will probably be in coercing an Arduino to do DFCW (at least) and may SMT Hellschrieber. Of course, as soon as you say something like that, you find that others have been there ahead of you. Witness AA6DY’s nice description of his QRSS operations:

QRSS operations from AA6DY.

My regenerative receiver was annoying me, and I wanted to do some soldering tonight anyway, so I thought I’d tack together a really simple transmitter project. I wound a coil, and spent about 45 minutes tacking a simple QRSS transmitter (really just a Colpitts oscillator) which should dump about 14mw of power into a 50 ohm load. I also created an LTSpice model for it, which I should put up in the next few days.

YouTube – QRSS beacon, ala Hans Summers, G0UPL.

More writeup later.

Addendum: Before crashing last night, I moved it out to my dining room table where my FT-817 was sitting, and verified that it does indeed seem to emit radio waves.

I’ve listened to the SolderSmoke podcast for quite a while, and you’d think I would have availed myself of Bill’s sage wisdom. He’s previously made mention of the endless fun and rapture he’s had tinkering with crystal radios, carried away to the sounds of heavenly lutes (okay, I’m extrapolating here). But he’s also mentioned that he’s had considerably less fun with regeneratives: indeed, proclaiming that they must come from the place where all the solder smells like brimstone.

SolderSmoke Daily News: Crystal Radios from Heaven, Regens from ?

You think I would have listened. But no: I had to try to tinker together N1TEV’s Ultra Simple W1AW Receiver. I’ve now got the all the worst features of regeneratives:

• Hand capacitance: the oscillator wavers and even halts when I touch the regenerative control.
• The oscillator starts and stops unpredictably. If you adjust the regeneration control until the oscillator starts, you can back up and it will stay running until it suddenly clicks off.
• Gain is pretty low. I can just barely hear W1AW, along with some of the digital signals within the band. I installed the optional volume control to boost the level, which helps some, but it’s not brilliant.
• Antenna loading seems to do odd things to the antenna too.
• Touching anything in the circuit seems to quench oscillation.

I did gain a few bits of knowledge in doing this project, but frankly, it’s annoying. Perhaps in the light of day, when the clerics of electronics have said their prayers for my salvation, this thing will seem worth investing time in debugging. I have no doubt that if I lived only a hundred miles from W1AW, this would work, but it’s not inspiring me to greater investment of time.

I think I’ll convert to the Direct Conversion faith for my next project.

G4ILO has a post on his blog grumbling about the increasing use of USB technology in amateur radio:

G4ILO’s Blog: USB technology du jour.

As seems typical with many things he talks about, I disagree with virtually all of his points.

My position: I absolutely hate special purpose cables. My FT-817 has some wacky DIN-6 or something on the back. My TH-D7A (and I think the VX-8GR) use a 2.5mm plug to carry data. Every time I have to buy a special purpose cable, I grimace, mostly because I know that they are shafting me out of $30 or whatever for a cable that provides about $2 worth of manufactured value. USB has three (or is it four) plug types, but at least they are commodity items: you can get them inexpensively if you hunt around, and chances are you probably have a couple of the right type from a phone, or a disk drive, or whatever.

It’s nice that G4ILO’s shack has four different serial ports. I have one machine in my office that has a DB-9 in it, but I have six other machines which combine to provide probably two dozen USB ports. If I want to add a couple of ports to something, I have a $7 powered hub that I keep around (it was useful a couple of times with a laptop that provided only one USB port). G4ILO tries to portray USB as being the side with limited expandability, when precisely the reverse is true: USB has much greater expandability.

There is one criticism which I think is valid: I despise manufacturers who require the use of proprietary drivers to access functionality. Luckily, the USB standards folks have figured this out: USB defines class codes. This means that you can create devices which comply with certain USB specifications, and the USB devices simply work. You plug in a device, and it is recognized as a serial port, or an audio card, or a modem, or an ethernet controller. I love the idea of the TH-D72a: you simply plug in a USB cable and plug it into your computer, it recognizes it as a serial device and creates the necessary device entries. Windows/Mac/Linux, it all just works.

Yes, if you wanted to hook it to a microcontroller, it isn’t that helpful. So in exchange for making it work better for 99.9% of the people, it doesn’t automatically fufill the needs of of the .1%. I’ll take that tradeoff any day.

Sending analog audio down cables sounds great, and of course we find that radios like the TH-D72a of course still have audio inputs and outputs. But having digital ones via USB opens up lots of possibilities: like sending data noiselessly, and being able to control levels with actual program controls.

Do we need plug and play controls on our radios? ABSOLUTELY. There is nothing about ham radio that implies that we have to be masochists and invent the kludgy solutions that everyone else in the universe is well beyond.

USB is hardly a technology du jour. It’s perhaps the single most widely supported standard in computing, is supported on every major operating system, and has created a huge industry of peripherals that are simply expected to work.

As for longevity: who can tell, but I’ll simply say that I’ve had USB peripherals since the Windows 95 days. It was rocky back then, but fifteen years later, they are still going strong.

As consumers (and most of us are consumers of ham radio stuff) we should expect better from the manufacturers. Radios should use well-developed USB technology.

David Rowan of Wired.co.uk has an article over on their website:

Why ham radio endures in a world of tweets (Wired UK)

He waxes philosophically about the thrill of establishing long distance radio communication, about receiving QSL cards, and gives mention to the role that ham radio plays in time of emergency.

I hear these things repeated a lot. They aren’t false, but neither are they entirely enough of the real picture to paint a realistic view of amateur radio.

It’s wrong to think of amateur radio as a single hobby: it’s a bunch of different hobbies all united by the need for a radio license. There are radio contests. There are people who chase awards. There are people who just want QSL cards to decorate their shack. There are people who setup FM repeaters to serve their communities. There are people who operate only low power transmitters (“QRPers”) often that they construct themselves. There are people interested in space communications such as satellite or EME operation (moonbounce).

Amateur radio continues to exist because radio amateurs continue to find their own areas of interest, do the necessary work to become licensed, and then pursue those interests. Whether it is contesting, construction, serving your community in times of emergency, or just plain old talking to your neighbors, people are still finding reasons to get licensed and get on the air.

I pursue amateur radio because I’m interested in the complexity of physics that allows radio to propagate. I’m interested in construction, and experimentation. And I’m interested in finding other people with similar interests. No advances in cell phone or computer technology will really blunt that. I suspect that each ham finds his own reason to pursue it, often beyond the point where any practical economic argument.

It’s what we do for fun.

I like using my SDR-IQ software defined receiver for listening to short wave and ham bands. It’s a great way to look at a bunch of frequencies all at once, and to isolate the signals you are interested in. I had heard that there were new versions of the SDR-Radio application and Spectravue which I hadn’t tried out yet, so last night and this morning I tried them both out.

I’ll defer SDR-Radio to a later time (I think I screwed up something in the configuration, and my tired brain couldn’t figure it out), but Spectravue has a nice new AGC control that really works well. In any case, that’s what I used for this morning’s mucking around.

Here is what the main screen looks like. You can see that I’m scanning a segment of spectrum 10khz wide, centered on 7.0392Mhz. That corresponds to the frequency of the Russian “F” beacon. You can see the trace of its signal in the waterfall down the display. Just to the right of it you can see another dashed line. That’s at about 7.0394Mhz, and is the Russian “M” beacon. And you can see a bit of blobbiness all around them: that’s a voice signal which is overlapping them. I can’t make out what they are saying or doing. But here’s my recording anyway.

It’s a .wav file, but only 8khz sampling and 60 seconds long.

I decoded this with a typical CW filter with 500hz, which isn’t wide enough to decode the signal, but it isn’t strong enough to really work out. Perhaps some more knowledgeable types could tell me who operates voice down this low.

Addendum: A few minutes later, the voices were much stronger. Spanish speaking, it would appear. Here’s a bit of it, recorded with a more appropriate filter setting of 2.7khz LSB:

Spanish voices, on 7.040Mhz LSB

Addendum²: Upon listening to it some more, I’m actually not 100% sure it is Spanish.