QRSS is a term used in ham radio to mean “very slow speed morse code”. QRPp means “using a very low power radio transmitter”. What happens when you combine these concepts? Small, simple, radios that can communicate over thousands of miles using about the same amount of power as a TV remote control.

The radio shown above is based on a kit by Hans Summers, G0UPL, that I picked up at the Four Days in May QRP convention. It uses a single-sided circuit board, with three transistors, one crystal, five toroids, a basic microcontroller, and a handful of resistors and capacitors. I added a 5v regulator, an LED to show the keying activity, and put it in an Altoids tin. The whole thing probably cost about $25 in parts, and took one evening to assemble.

After building it and tweaking it to get it on exactly the right frequency, I hooked it up to the dipole on the roof of NYC Resistor, and flipped on the power switch. My 100 milliwatt signal went up into the sky, bounced around between the ionosphere and the ocean a bit, and was picked up by a radio operated by Johan, ON5EX, in Belgium. He runs what is known as a “grabber” — a radio and computer combination that monitors the QRSS portion of the 30m band, converts the signals into digital spectrographic images, and publishes them on the internet.

Here is a screen capture from Johan’s website shortly after I powered on my transmitter. It shows about 100Hz of spectrum (frequency is on the vertical axis) over 11 minutes (horizontal axis). My signal is in the center of the graph. It’s my call sign, W2VV, sent repeatedly in morse code (·–– ··––– ···– ···–) at about 10.140015 MHz. If you listened to this signal as audio, you would mostly hear static. The horizontal lines you see in the graph would come out as tones. The higher the line, the higher the pitch of the tone. My signal would sound like a tone that changes pitch ever so slightly up and down as the dots and dashes are sent. However my signal would probably be so weak as to be inaudible through the static. It is only discernible when converted to visual form and then compressed over a long period of time.

Belgium is about 3600 miles away from New York, which means this transmission achieved an amazing power efficiency of 36,000 miles per watt. Also, it occupied just a tiny sliver of bandwidth — only 5Hz, meaning many other people could share the same range of frequencies without interfering with each other. However you don’t get something for nothing in life, and the tradeoff in this situation is that very little information was sent. It took six minutes just to send my four-character callsign. Still, that’s not a bad deal for a $25 radio that fits in your pocket.

Visit my Flickr page for more photos of the build. Better yet, come to our Ham Party on Saturday and see it for yourself! And if you can’t make it to our place, visit one of the hundreds of other ham radio clubs across the country hosting public events this weekend in honor of ARRL Field Day.

72/73, Dave W2VV

Inspired by the upcoming 2010 ARRL Field Day event, we finally got off our duffs and set up a real amateur radio station at the resistor clubhouse. We now have a 60 foot long dipole on the roof, an antenna tuner, a couple of transcievers (one 100W and one QRP), a CW key, and a TNC for using digital modes with a laptop. With a few hours of operating under our belt, our logbook shows contacts with stations in the US, Canada, Europe, and South America, using phone (voice), CW (morse code), and PSK31 (digital).

The best part of our station is how little QRM (man-made noise) our antenna picks up. When we first put the station on the air, I thought something wasn’t hooked up right. Being in the middle of a densely-populated area, I expected to hear horrendous noise from power lines, AC motors, etc., but heard almost none. This makes tuning the bands a real pleasure.

Our club callsign is N2YCR. If you hear us calling CQ, give us a call back. We’d love to talk to you!

How do you keep an iPhone running for long periods of time when you are off the grid? You can’t change the battery in the phone, so carrying a spare isn’t an option. Devices like LadyAda’s excellent MintyBoost use AA batteries and can keep you going indefinitely, but unfortunately the MintyBoost and several other similar products don’t work with the iPhone 3GS. And anyway what I really wanted was a device that would take power from the high capacity 12V NiMH rechargeable pack that I use to power my portable ham radio gear. I could have re-purposed a charger meant for use with cars, but many of them use linear regulators and are therefore very inefficient, or aren’t compatible with the 3GS; plus they are overpriced. So instead I built a charger to suit my needs: the MintyBuck.

The circuit is a simple step-down DC to DC converter, based on the National Semiconductor LM2674-5.0 switching regulator. The PCB is one of the little square perfboards from RadioShack. The USB connector was cut from a USB extension cable. The red and black power inputs are 30 amp Anderson PowerPole connectors. These are neat genderless connectors widely used in the ham radio community. The case is a random mint tin I had lying around. There’s not much to it, really, but it’s still quite handy.

I haven’t measured the output current, but it draws about 200ma when charging, and holds a steady 5v on the output. Supposedly the iPhone draws 500ma when charging, which would put the efficiency at around 95%. I bet it’s actually less efficient than that, but I’m sure it is still much better than an LM7805 would have been.

If you want to make one yourself, you can follow this schematic. If you make a cigarette lighter plug adapter, you can use it in your car too. Note that the input capacitor I used for C1 is technically only rated for 10V, which is not enough for this application. I’m going to swap it out for a higher-rated part at some point. So don’t follow my example on that part. A few more photos are available on my Flickr page.

73, Dave, W2VV

This weekend is the Adventure Radio Society‘s annual Flight of the Bumblebees event. Amateur radio operators will be using portable low power stations from mountaintops, beaches, trails, parks, picnic tables, and backyards across North America. Many participants build their own equipment, either from kits or from scratch. Most stations are lightweight — a few pounds or even fractions of a pound — and yet many are capable of being heard thousands of miles away. All communication is CW (morse code) using no more than 5 watts.

This event was my excuse to learn morse code. I have some iPhone apps (Dah Dit and HamMorse) that I use to kill time on the subway, and after a few weeks of practice I can now send and receive at a beginner’s level of 5 words per minute. Experienced CW ops go a lot faster than this, but most will gladly slow down to accommodate a novice like myself. I’ve already made a couple of contacts on the air and I’m looking forward to making many more on Sunday.

73, W2VV/BB

Last weekend I threw my ham radio gear into a backpack and carried it to the top of South Beacon Mountain in upstate New York, along with with my friend Tom Tumino, N2YTF, and we spent several hours at the summit making contacts with other hams around the globe. Tom is a SOTA enthusiast who has introduced me to this great new aspect of amateur radio. The SOTA program (short for Summits On The Air) encourages hams to get out of the house and operate “mountaintop portable”. Peaks are ranked and assigned point values according to their prominence, with the idea that you want to collect as many points as possible by operating from as many high peaks as you can. The points aren’t good for anything except bragging rights, but it’s a nice incentive to get you out of bed at 7:00 am and on the road.

SOTA is most popular in Europe where they have thousands of peaks cataloged. Here in the US, the program is just gaining momentum, and the administrators are still building the databases of eligible peaks. However there are many portable operators in the states and several other clubs that are active in mountaintopping independent of SOTA. Steve Galchutt wG0AT has created a great series of videos documenting his hikes on Mount Herman in Colorado with his two mountain goats Rooster and Peanut. HFPack is an active organization that focuses on portable and “pedestrian mobile” operations (i.e. backpack radios). Slightly more eccentric is the Polar Bear Club which encourages portable ops in the winter months.

The photo above is of a 70 foot fire tower at the summit of South Beacon that we used as an operating base (you can see our antennas and a SOTA flag at the top if you squint). More photos after the break.

Me (W2VV) sitting in the fire tower making contacts on 20M with a Yaesu FT-857d, NiMH battery, and Buddipole antenna.

Tom rotates his portable 2M Yagi while holding a Yaesu FT-817.

A plot of our APRS traffic, showing our real-time GPS position as we made our way up the mountain, from aprs.fi.

Many more photos from this and other activations can be found on my flickr page or Tom’s page.

Recently, Dave (W2VV) and I (KC2UHB) went to Turks and Caicos to operate ham radio and get a little winter time sun. We were given a temporary prefix VP5 to operate under making us VP5/W2VV and VP5/KC2UHB. We did some DXing and worked the satellites. To our pleasant surprise, VP5 turned out to be a more desirable location than we thought, and many hams tried to make contact with us as we called CQ on 20 and 40 meters. We had a few pile-ups.

We operated an FT-857d transceiver with a 13.2V 10AH NiMH battery pack and a Buddistick vertical antenna which we brought as a carry on through airport security (no problems). It was a lot of fun operating on the beach and the ocean really improved the signal. We made many contacts in Europe and one as far as Kazakhstan. Propagation was best in the morning and evening so we amused ourselves during the day snorkeling. Now I am spoiled and have become a total beach ham. I wonder if Yaesu has free promotional orange bikinis and beach towels to go with their free promotional Yaesu hats.

APRS Display: W4AEJ, 992 miles away

Friday Nights are typically “Satellite Night” for a few of the Resistors.  We get together and aim for the stars (literally) and generally try to communicate with other intrepid radio operators.  Last Friday night, atop an ivory tower in the frigid winter wind, we set out to communicate with the International Space Station.

Diana, Dave and I met early in the evening with our homebrew dual-band Yagi antennas, a myriad of handheld radios, and a few satellite pass predictions. Manmade Satellites travel in predictable orbits around the Earth, and sites such as www.heavens-above.com provide pass predictions that make it easy to plan for  an evening of satellite chasing.

Typically we try to communicate with other ham radio operators via FM voice using a combination of 2 meter (144-148MHz) and 70 centimeter (420-450MHz) frequencies.  We transmit to the satellite on the 2m frequency, and the satellite responds on the 70cm frequency as a repeater – something akin to a mirror which reflects back to you what you’re sending.  While the astronauts periodically participate, most of the time the ISS acts as a repeater for ground stations, allowing hams from all over the ISS’s “footprint” of coverage to communicate with one another.

This night was different, however, in that the ISS was also operating a digital radio modem, which permitted amateurs to reflect short messages and GPS position data off the Station.  This technique, known as the Automatic Packet Reporting System (APRS) is very popular within the ham community and enables vehicle tracking, sensor data from automated weather stations (and other types of sensors,) and short messages with guaranteed delivery.  I happened to have a radio equipped with a 1200/9600 bps modem and an APRS software implementation built into the firmware.

Up on the roof, we struggled to reach the satellite via voice, but the ISS’ modem was clear.  I flipped the radio to APRS mode and transmitted 5 watts of RF on the 2 meter band into the copper arrow we made months ago.  The satellite was crowded with other operators trying to make contact, but persistence paid off and an echo of my APRS packet flashed on the radio’s tiny screen.

Later, after we’d had enough of the cold wind, we checked the Internet and found the position report.  Sure enough, RS0ISS-3, the APRS node on the Station, had received and re-transmitted our position to the Internet gateway.  Afterward, we attempted another contact with the SaudiSat SO-50, carrying a voice payload – but were unable to reach it.  Perhaps next Friday will bring more successful contacts for the intrepid trio.

The road to ham radio is paved with free stuff...

Four of the Resistors made it out to the Ham Radio University 2009 in Bethpage, NY last Sunday.

HRU is a day long convention of amateur radio operators holding forums on various topics of interest to radio operators, including digital modes, best practices, long distance (DX) communications strategies, emergency services developments, and ham radio license exams.

Diana and Bill successfully passed the General Class license upgrade, giving them access to frequencies below 30 MHz on the amateur bands.  30MHz represents the common denominator between the shorter range bands open to the basic class amateur, and the lower frequency bands that typically traverse continents and oceans.

We came away with an appreciation for tiny world-capable antennas, new digital voice gear from Icom, and piqued interest in DX contesting – the art of individuals to wrangle radio waves to reach out to specific parts of the world and communicate with others without relying on anything more than the ether to carry their signal.

… oh, and free hats.

Check out this little gem: a ham radio store in the heart of New York City! It’s called Barry Electronics, and you’ll be forgiven if you’ve never heard of it, since they don’t have a website, or a sign, and as far as I know they don’t advertise anywhere. What they do have is an ample stock of Yaesu and Icom radios, various aftermarket antennas, several shelves of radio books, and a bunch of other ham equipment. According to the proprietor (appropriately named Jonathan), most of their business is in commercial Motorola VHF/UHF radios, but most of their showroom is dedicated to ham equipment because the corporate customers aren’t interested in window shopping. If you want to visit, they’re at 224 W. 35th St. (between 7th and 8th Avenues), Suite 408.

Bill (KD4ISF), Diana (KC2UHB), and I (W2VV) spent a couple of hours at the shop this afternoon building a dual-band Yagi antenna for working ham satellites. Yes, believe it or not, there are multiple satellites orbiting the earth right now that are dedicated to amateur radio. All you need is a license, an inexpensive portable radio, and a weird looking antenna to use them. As of 3:00 pm today, we only had two out of the three, but by 7:00 we were on the roof listening to two different “birds”, SO-50 and AO-51.

We’re just getting our feet wet with this, so stay tuned for future updates as we improve our equipment and skills. In the meantime, why not get your license so you can join in on the fun? All you have to do is read this book (or visit one of the free online study guides) and then take a test given by your local club.