Homo ludens radiactivus

There are two classes of people in this world: Those who shudder when seeing such an ugly kludge of aluminum, iron, copper and plastic obscuring the sky, and... well... radio amateurs, lovingly called "hams"! I definitely belong to the second class of people. You may call me XQ2FOD instead of using my name. If you want we can talk in Morse code, for even if I don't like it at all, I had to learn it,  and, please, don't ever try to tell my that my antennas are ugly! By the way, these are not mine, they belong to Claudio Santander, CE5SG. My antennas include an azimuth-elevation rotator with a large satellite antenna too. Just a little bit more iron on the roof...

This is the most fascinating hobby I have, and it will be for life, so much is sure. There is just so much to explore. But before starting that, let me tell you about the history of my ham career. It may show you how much fun I have had, and above all, how many hours I have spent on this hobby! Be patient, this story is several dozen photos long, plus the text, so if you have a slow connection it will take some time to fully load. I hope it will be worth it.

How it started

I felt attracted towards technical things since I was very small. Let it suffice to say that I installed electrical lighting in my sister's doll house, electrified my mother with a coil and battery, built a steam turbine that soon had the condensation running down the walls, all before I was eight years old. By the time I was eleven, I had built electric signaling systems, several electric motors, an improved steam engine, coupled it to my bicycle's dynamo, and despite this self generated power I was increasing my battery consumption at an alarming rate. Oh yes, plus the candles used for the steam engine's boiler...

It was in this promising time when I reached my twelfth birthday. My parents had the marvelous idea of giving me a "KOSMOS Radiomann" set. That's a german educational game. It's just a box containing a few resistors, capacitors, a bulb, battery, a diode, two coils, some wire, and even a real transistor, mounted on a yellow plastic base! It also included all necessary connection material, a childproof protoboarding system, and an instruction booklet that described over one hundred experiments to be done with these parts, starting from the taste of electricity (put a 4.5V battery against your tongue, try it!), electricity out of a lemon, an AM radio, right through a spark transmitter with coherer receiver! I was in heaven. This game teached me more electronics than the entire university career did, several years later!

Shortly later, in an hobby exhibition, I discovered the booth of the Radio Club Concepcion. It was my first contact with ham radio. People there were very friendly, starting with whom would become my long-time tutor in ham radio, Emilio Troncoso, XQ5BIB. Shortly later my father and I were invited by Enrique Oelker, CE5DF, my father's friend, to come over and visit his radio station. I still remember that visit, how that very kind man switched on his radios, commented that the conditions on that saturday morning weren't so good, switched on a linear amplifier containing a radio tube larger than I had ever seen or even imagined, called a few times, and got answer from a ham in Germany. Wow! There he was sitting back in his chair, talking to a friendly guy 10.000 km away, across oceans and continents, as easy as that! You must keep in mind that this happened years before home computers and internet, even years before any affordable and reliable long-distance telephone service, at least in this part of the world.  My father seemed more interested in the huge collection of classical music that was in the same room, but I could hardly get my eyes away from that radio! My spark transmitter reached 10 meters, and this thing, not so much larger, covered a million times more!

The next day I biked to the Radio Club, and became a student member. Apparently the youngest member in its history. But they had bad news for me: Chilean regulations of that time set a minimum age of 15 years to get the simplest ham license! I fell short of that, by what seemed an eternity.

So, being to young to use radios, instead I learned to build them. First of all I built an adjustable, reasonably regulated power supply, that delivered 0-15 Volt at about 1 Ampere. It's the one on the upper left in this photo. I built the box from 1 mm aluminum sheet, and lacking any decent tools, made the holes with hammer and nails... The transformer, hand-wound of course, was glued in, as it lacked any screw holes. This power supply had to be kept in upright position at all times, otherwise the transformer could have fallen off and smashed the other parts... I remember how it took several days to convince my mother to let me plug it in.

Under Emilio's instructions I put together a low power direct conversion transceiver for the 40 meter band. It could run double sideband or continuous wave. That's the big thing under the other boxes. It featured a Hartley variable frequency oscillator. The receiver comprised a 2N2222 RF preamplifier, an MPF102 mixer, a 741 opamp audio amplifier and an LM380 power amplifier. It worked, but had lousy sensitivity. Anything below S9 got swamped by the noise. The transmitter was quite decent, having another 741 as a microphone amplifier, a two diode balanced mixer, and three RF stages ending in a class-A power amplifier built around two 2N3553 transistors. Note that these are UHF devices! At least they did RF...

This radio was built on a style of crude circuit board: I cut a piece of chipboard, glued small scraps of copper foil to it, and soldered the components to those copper spots. I must confess, I had not yet discovered that it was allowable to cut the leads of the parts, so every resistor and every capacitor was soldered with full lead length! The IC pins were soldered to wires, to make them long enough. It was a mess, but it worked! Unfortunately I have no photo of it...

As I had no license to actually put this radio on the air, I asked Emilio to test it for me. He did, it worked, but suddenly he was holding a knob in his hand. He teased me for several years with this! I could build a functional transceiver, but I could not fasten the screws of the knobs!

Bored by waiting for my 15th birthday, I temporarily turned my back to ham radio and built the third thing you can see in the photo: A citizen's band transceiver based on a surplus board. I basically put it into a homemade enclosure (this time I did fasten the screws!), cabled and adjusted it. It worked very well, putting out 4 Watt in AM, on all 40 channels.

I used this radio a lot! I made dozens of friends on CB. This was the time of the CB boom in Chile, and that band was boiling with activity. No license was really required, everyone just used the band. This photo shows my bed station in a summer cottage where I often went. The bed was a two-story affair, my brother slept below me, and I had to share my mattress space among the sleeping bag and the radio station. Note that the station is more complete already: A large 13.8 V, 15 A power supply has been added. The box in the middle is a battery case containing 10 NiCad cells. So I could put the line-fed power supply away from the bed before sleeping. And yes, I slept with my radio...

The toy walkie-talkie was used as a portable, to communicate to my "big" CB rig. It transmitted on channel 14, and received the entire band, with no selectivity at all, due to its regenerative receiver. Sometimes I was so generous that I even let my little brother use the portable!

The battery pack was also often put to good use during portable operation. I climbed every hill within a distance reachable by bike or on foot, searching for the sweet spot that would put my tiny signal across the oceans. I contacted Europe, North America, even a few asian stations, all with 4 Watt on AM and a vertical dipole strung in any convenient tree! Brazil and Venezuela were everyday contacts.
Did you notice the microphone? I had no money for fancy things. All was financed by a rather thin allowance. That microphone was the very cheapest I could find... It worked. Don't ask for more.

Very often I got help from classmates, neighbor kids, other friends. Here you can make the acquaintance of Antonio Diaz, who helped me carry the gear up some hills and was setting up the station here. He was into technical things too, being the first among my buddies to get a programmable calculator! I remember that Casio, I think it was an FX702, programmable in BASIC language. Wow! He was our computer genius, and I learned my first steps in BASIC on his machine.

But such mountaineering trips cost a lot of effort! He barely made it back... And I didn't feel like going out again either. We were 14 years old by that time, full of energy, full of desire to get out higher, farther, greater, longer, wider, but sometimes the desire was just a tad larger than the energy...

Note the multimeter and tools on the bench in the back, behind the Asterix&Obelix magazine.

I was getting confident enough in my skills to start repairing things for money. But it was not often that I got two TVs of the same model for repair, at the same time! These hybrid "Antu" TVs were still common in Chile. I took the opportunity to make a photo, showing the tools used for the task, like a hammer, and a hacksaw. I used this photo to shock my classmates...

The business soon flourished. I charged little money, and most often I could repair the equipment. If I couldn't, for whatever reason, of course there was no charge. This type of warrantee brought me lots of clients, and the income was very welcome to finance both the radio hobby, and photography, which was eating up lots of money by that time.

This photo shows my radio station a few months later. I was now 15 years old! I had registered for my ham exam that same day, and soon was the holder of my first real ham radio novice license! I got the callsign CE5FOD. This event caused an equipment building rush, as I noticed that my first radio was just too deaf for any decent work. And the long-legged parts often came loose. So, I finally disassembled that thing and started building a new, much improved radio, reusing the same parts. That's the metal thing you see on the left. It was ready, except for the cabinet. And it worked great! I photographed it after the first contact.

Note the new SWR meter. Behind it is a new 0 to 15 V, 3 A power supply, with full short circuit protection. On top sits a chipboard based antenna tuner, and the small knot of parts in front of the SWR meter is a 30 Watt power amplifier! The station was quite usable, despite the look!

Here is the inside of the new radio. The transmitter used much the same circuitry as the first model, but was assembled in a very much more compact way, on a real printed circuit board! Lots of shielding made it stable. The VFO was now a much more stable Colpitts type, and thanks to a reduction dial mechanism it didn't need a separate fine-tuning knob like its predecessor! The receiver was totally new, based on "An optimized QRP transceiver" by Roy Lewallen, W7EL, published in the August 1980 QST magazine, but modified for my purposes. I had four stages of active audio filtering for good selectivity! The TX-RX switching was fully electronic now, I just did not like relays.

This radio worked well and was my workhorse for several years. It traveled up countless hills and some mayor mountains. But on this photo the station is assembled on the lunch table in the summer cottage. The radio is complete now, box and all. Just the amplifier is still unboxed.

Note that now I even have a more decent microphone than in the old CB days! I had some more income now and could afford that luxury!

Yes, the station had to be dismantled and stored away before every meal...

My skills as a repair man were increasing. Don't you just love this electronic landscape? I do, I can't help it! This is the CPU section of a Betamax video recorder. I tracked down a bad solder joint on this board that was causing erratic operation. I spent two weeks on that. But video equipment was very expensive, so the owner paid me a tidy sum of money for the fix! To me, as a 15-year-old, it seemed like a fortune!

By the way, do you remember the Betamax format? I used it some time, in the school's "video academy", to make a movie about Concepcion's tourist attractions! I remember carrying around lamps that had a total power of almost 10.000 Watt, otherwise it was just impossible to light the scenes well enough for those insensitive picture sensor tubes. CCDs were not yet available. Of course, it was not easy to find enough power outlets for all those lamps. Today you just need a 30 Watt battery powered light...  Oh oh, I seem to be ooooold!!! :-)

Some months later. School is a secondary thing in my life, first is ham radio! The amplifier is now encased in a nice box, sitting on the transceiver and below the SWR meter. The bright smaller box is a half finished frequency counter, built from a kit, that has just four digits but counts well into the UHF range. I regularly used it as a digital dial. Many commercial rigs still didn't have that feature!

The large open chassis is a tube-type linear amplifier. It started out with two 2E26 valves, but they were just too small. I soon replaced them by a pair of 6146Ws. Powered by 1.2 kV, they ran nicely at the 300 Watt level, driven by the tiny 1 Watt output from my QRP rig!

The greenish gray box in the foreground is a Heathkit grid-dip meter. CE5DF gave it to me. It's a big help, even today.

Note that poverty had still not left my ham shack. The large power supply has a gaping hole instead of a meter. Holes are cheaper than meters. Meters can be added later. And coax connectors were absurdly expensive. I skipped them and plugged the wires directly into the sockets. See the left side of the SWR meter...

This is a very rare photo. Indeed it's the only one I have of myself operating my base station during that era! I always thought, and still think, that I prefer being the guy BEHIND the camera, not the one IN FRONT of it. It took quite some stalking efforts to shoot a photo of me! The headphones shielding off my peripheral hearing helped the sneaky photographer. I still remember the shock from the photo flash. I thought something in my radio setup had just exploded!

The bright thing up on the wall is a lamp screen made from aluminum foil. There is a 12 V car lamp in it. We had power outages several times a week, and I had a trusty car battery under the desk...

I was 16 years old, nearly 17.

Two years earlier I had developed a quick way for producing printed circuit boards. I designed the layout on paper, then taped the paper onto the copper clad board and drilled the holes through the entire sandwich. Then I removed the paper, and used fingernail polish to freehandedly draw the copper areas on the board. Then the board was tossed into acid, and all my shakings got etched, together with the design, into the copper. The nail polish was removed using acetone, and the board was ready. The whole process, including design for a simple board like this, could be done in just over an hour.

There was just one problem to this method: I can tell you, it is highly embarrassing for a 14 year old boy to go into a pharmacy and ask for brightly colored nail polish!

This is how such boards looked from the component side, after assembly and before being integrated into radios. These four boards are all the electronics inside my new creation: A new QRP transceiver! The small board is the VFO, using a CMOS chip as a buffer. To its right is the receiver board. The board in the upper right is the transmitter driver, and the upper left one is the 5 Watt power stage and TX-RX switching logic. Such few components are needed for a fully functional double side band radio! Just add a box, a speaker, some connectors, switches, potentiometers, a variable capacitor, and a few dozen wires.

For someone who likes mountain climbing, and likes radio, what can be better than joining both? Sebastian Oehrens was my willing helper on an exhausting trip up the Antuco volcano. We set up my station on the rim of the crater, about 2800 meters above sea level. There are no trees up there, so we had to carry a foldable mast up the volcano.

Sebastian was quite interested in ham radio, but as far as I know he never got his license. It seems that the stupid requirement for Morse code knowledge kept him out.

This is me again, but you cannot see much... I'm wrapped up like on a polar tour. It gets cold up there, when the sun is blocked and the wind howls. You can see part of the radio, my new 5 Watt 40 meter rig. It put S9+30dB signals into locations 800 km away, and nobody wanted to believe that I was running that low power! I can assure you that a good altitude helps on HF too, and the snowy reflector did the rest. It was truly enjoyable, despite the icicles growing on my nose.

Welcome to the full line! This was my home built equipment in september 1983, the year I finished school. I was 17 years old. This photo was shot on a hobby exhibition, which explains the signs... The entire setup was fully functional.

From left to right: The new antenna tuner, using a big roller coil. On top of it sits a small tunable field strength meter. Then comes the 300 Watt amplifier, now boxed too. Then the 15 A power supply, which now even has a meter closing the hole! On it an RF power meter with built-in dummy load. Then comes the variable 3 A power supply, and the frequency counter, now encased in a decent box too. On top of the two is the SWR meter, almost falling down. Then, the new QRP transceiver! Next to it, the old one. You can see the similarities. The receivers and oscillators are pretty much alike, but the new one has an improved transmitter, and the frequency offset in CW mode is now controllable. It has RIT, too. Then comes the 30 Watt amplifier, nicely cased, and the former CB transceiver, which had been converted to 10 meter FM!

Can you understand how I felt explaining all this to the crowds? Almost like I feel now, bragging about it...!

By the way, the newspaper that's in front of the power supplies features an article by me, describing the construction of a simple radio, plans and all, and encouraging kids to join this hobby. By that time I wrote a lot for magazines and other media.

One day CE5SG asked if I could build him a good power supply. He had burned out just too many of those flimsy commercial things. He wanted something that could deliver full current, as long as he needed it, to power large VHF amplifiers. I made him buy a huge heavy-duty battery charger, modified the transformer, used the same case, rectifier, meter, circuit breaker, but added a large filter and the regulating circuit, using six high-power transistors on a hefty heat sink. Full protection against both overcurrent and overvoltage was included.

The last time I asked him about it, he was still using this power supply. That was 10 years later.

This guy is the one. Claudio Santander, CE5SG. The owner of the antenna array at the top of this page. And the proud owner of the first large "FODelectronic" power supply, and of some more equipment... He is well known among DXers. 

But commercial production of equipment was just starting. These twins are multistandard radio modems. The Atari 800XL had become the most common home computer in Chile, and many hams were using the HAMSOFT program together with some lousy interfaces. I designed this modem for the Atari to cover the entire range of frequency pairs, splits and speeds that were used in that time on ham bands. It was a tiny but capable box. A matrix system programmed the tone generator, PLL and filter chips.

I started assembling these modems for sale, but very soon the requests overwhelmed my production capability. I was now an university student, and my free time was just too limited. Soon I offered only the kits, so everyone had to assemble his own modem. Some did, but others didn't. Finally I gave the business over to XQ5BIB. He cared for the kits, and paid a guy some money to assemble units for those people who preferred it that way. He sold the production, and paid me royalties for the design.

We sold these things right into the starting era of packet radio, when they became obsolete. We even exported them!

Have a good look at this picture. It's this radio's last one. The new transceiver was reliable, and was performing better than this one. I was in real need for components to put into my new projects, and very short of money. It almost broke my heart, but I had to disassemble this cute radio, to reuse the parts.

A last look into it, VFO shield cover removed. Considering my age when I built it, you will have to agree that it was well engineered... Of course, it had not been exempt from problems. The board hanging from those cables is an additional buffer stage, which proved necessary after the first few contacts, to keep the balanced mixer from frequency-pulling the VFO. It all was dismantled that very same day, after these photos were made.

And the bottom side, under the PCB. As you can see, I had already applied surface-mount technology! :-)

I always regretted having disassembled this radio. It was so nice, so compact... Everything was hand made, there was not a single right angle in it... I felt like a murderer after destroying it. But, I needed the parts...

I also shot an "after" photo, showing the heap of recovered components on one side, and the pile of box parts, shields, and the PCB on the other. But it broke my heart when I saw the photo today. I will not publish that one.

The king is dead. Long live the king! This was my next radio! It is shown here among some QSL cards worked with it. Note the special callsigns on the two left cards! This radio netted me a lot of great contacts! Note also my own QSL card in front of the radio: I had become XQ5FOD!  The change in callsign prefix is due to the change in license class: I had earned the Superior license, of which less than 30 existed in the country. It required a Morse test at 20 words per minute, and proving exceptional participation in ham radio, among other things. But the reason why I had to wait so long to apply for that license class was that it required being 21 years old. As with all previous licenses, I applied for it as soon as I reached the required age.

This photo was made for a magazine article, a considerable time after I built that radio. It shows the complete portable station. A small battery case, a mini solar panel for recharging it, and a coiled dipole antenna with 10 meters RG174 miniature cable. Some green nylon rope included, the entire communication package weighs in at less than 2kg! The radio measures 20 x 10 x 4.5 cm. Note the tiny microphone. You don't need a big case for an electret capsule and a microswitch! I took this station along on many mountaineering trips.

About the internals: I turned away from direct conversion radios. This transceiver is an up-converting superheterodyne, using a crystal lattice filter to produce real single sideband signals. It was designed for good performance, very low power consumption, and easy use. It features wide range automatic gain control, automatic TX level control, a speech processor, TX audio spectrum shaping (this increases the perceived signal strength at the other end by an impressive amount!),  a very stable VFO, signal, power and voltage metering, SWR protection, and a few other goodies. It is designed for a nominal power supply voltage of 12 V instead of the typical 13.8 V. This allows to use normal 12 V batteries until they are really empty. The radio works correctly from about 9.5 to 15 V. Current drain is only 28 mA during receive at moderate volume with the dial and meter lamps switched off, and on TX it takes an idle current of 70 mA with peaks of up to slightly below 1 A, while putting 5 W into the antenna. That's quite a good efficiency.

This radio uses a minimal amount of stages, and most of them operate at high impedance, to conserve power. There is a MOSFET mixer at the front of the receiver, then comes an IC IF amplifier, a MOSFET product detector, and an IC audio power amplifier. Add the AGC circuits, and that's the receiver. Not a single part could be deleted. The VFO runs at 2.5 to 2.8 MHz, and is a highly stable Colpitts with temperature compensation. A single FET is used as buffer. The beat oscillator uses a FET and a crystal. The signal from the electret microphone is passively coupled into an IC doubly balanced mixer,  the DSB output goes to the crystal filter and the IF amplifier, which are shared by the receiver. Then follows another IC mixer, and just two stages of RF amplification using rather hot transistors, together having a gain of almost 40 dB! The emitter current of the class-A driver is used to bias the class-B output stage, to conserve power. All control and switching is done by CMOS circuitry.

I designed this thing during a family summer trip into Chile's beautiful deep south. The VFO part was designed on Chiloe Island, the IF and receiver circuit took shape at Futaleufu, Rio Cisnes, Puerto Aysen and Coyhaique, while the difficult RF power amplifier work was done on the return trip via Bariloche in Argentina. So this is an international design!  Once back at home, for the first time in my life I did a thorough computer simulation of the whole thing. I hacked around the program for two weeks, and then my poor Atari had to spend another two weeks crunching numbers. It found some potential problems. I improved gain distribution, corrected mistakes, and then went straight to designing the printed circuit board, without doing any real-world test.

I had better technology now, using rub-on pads and self-adhesive tapes on transparent plastic film, then photographically transferring it onto the board. I made a double sided board, all signal connections on the bottom, while the top layer was left intact as a ground plane. All ground connections were soldered from the top side. A single PCB was used to mount everything, including connectors, switches, the meter, the volume control, even the dial reduction mechanism was integrated into the PCB design! Then I assembled the radio, switched it on and started using it. There was no single modification to do! This was the first time in my life that I designed something as complex, built it, and had absolutely no trouble with it!

When I applied for my present job, which also was my first "official" one, I took along this radio. There were two electronic engineers in the interview room. They asked for permission to open it. I gave them permission. They removed the screws, looked inside, asked some questions, I answered them. I got the job.

I still use this radio sometimes. Now it's about 13 years old. It never developed any problem.

Many times I have been offered heavy money for it. Sorry, it's not for sale...

But before I got that job, and while I was still a university student, my interest ranged widely into microprocessors. I wrote communication programs for the Atari and a complete stand-alone RTTY BBS program, both in pure assembler language. The Atari had no UART usable for these purposes, so each bit had to be generated in software. Not an easy task, considering that the main CPU in that computer was shut down 60 times a second, in order to let the graphic chip access the main memory! Of course, you could disable these interrupts, but then you got a black screen...

I also wrote several electronic design programs, for active filters, impedance matching networks, crystal filters, and so on. The circuits were presented on screen, in text mode, using a modified character set to draw electronic symbols.

The photo here shows something different. It's a repeater controller. Based on an 8035 microcontroller, it implements all the basic control, timers, CW ID, telemetry, and remote control using a proprietary highly secure code over a low speed subaudible FSK channel. The whole thing runs from 5 Volt and needs less than 30 mA.

This is the underside. This was one of the last printed circuit boards I made by rubbing symbols onto transparent laminate, applying self-adhesive strips, and then doing the photoetching process. All my later PCBs were done by computer layout, but the photographic part stays the same until today. I just have not found any really usable method that can replace it.

Note that this is a single-sided board, and it holds the entire circuit (lots of address and data lines) without needing even a single jumper! As a well known inventor liked to say, engineering is a combination of brains and material. The more brains you use, the less material you need. Even for rather simple projects, as this one.

When the time came for my thesis project at the university, I had so much to draw upon that I let the professors choose... At the end I wrote a book about this thing, including all paraphernalia around it: There was an Atari-based EPROM programmer, together with its control program written in 6502 assembler, the remote control code generator with its compiled BASIC program, and of course the controller proper, with its MCS-48 assembler firmware. Also included was the MCS-48 development platform, hardware and software including a cross-assembler, which I had made for the trusty Atari!

I remember the professors' puzzled looks when the controller sent its Morse telemetry. They just had to trust me, as they didn't know Morse code...! I got the maximum grade.

When I finished university, and took up my new (and first "official") job starting 1989, I had to leave my parent's home, as the job was more than 1000 km away... I rented a small two-room house in La Serena, and one of the first things I did there was setting up half of the house as a real radio shack. I built this large table, which at last could hold everything related to radio at one place. The music equipment was there too. Note the Atari computer, using one of those ubiquitous old hybrid (tubes/transistors) TVs as a monitor, displaying an assembler program. Above are the radios, including a Raytheon direction finder, music equipment, and to the right is the workshop section. Note the new equipment: A hi-fi tuner (the shiny thing on top of the music amplifier), a 60 Watt VHF brick amplifier (top unit just left of the red riser) which I used with my first factory made radio, a second-hand Kenwood TR2400! To the right you see an oscilloscope, which I bought cheaply, in bad condition, and repaired, and above it, believe it or not, is a homemade portable oscilloscope which I built just two months before I got the chance to buy the other one! It helps to have two of them... Oh, and the small thing with the green and red LEDs on top of the direction finder dial is the UPS used for the Atari computer! Small and effective, like most things I build! :-)

The new zone brought with it a change in my callsign: I was now XQ2FOD.

But the small size of my new house was a real shame. I just had not enough space to take with me all those things! Among the many beloved objects that had to be thrown away, or donated to a new loving home, was my battery collection. Since I was small, I kept all exhausted batteries that were of different brands or types. This is just a small sample of the treasure in zinc and carbon that had to be fed to the trash can! There were so many funny things, like the original and famous "BEREC" batteries, and their cheap and bad "BEREO" copies! The colors and shapes had all been copied! For several other brands I had look-alike copies too! For "Everready" batteries alone there were three different copy brands! And one of the greatest mysteries in my life is the gold-and-green "Superpila". It had no other markings, and was the most humble specimen you can imagine, just a zinc cell in a carton sleeve! Where was that thing made?

After the hi-fi tuner I devoted my free time to more serious projects, like this. It's a 13.8V switching power supply, that can deliver 20 A on an intermittent basis and 10 to 12 A continuously. It measures 16 x 18 x 4.5 cm, and weighs considerably less than 1 kg. I used this power supply for eight years, until I replaced it by a larger one.

While I had previously published most of my projects in the chilean RadioAficion magazine, this one was published in Mundo Electronico, which I hoped would find more readers, being a general electronic magazine. Previously I had published other things there too, but never got much feedback. I finally quit sending them articles. I still sometimes contribute to RadioAficion, though.

A great amount of time was devoted to the two local radio clubs. When I moved to La Serena, I became a member of both of them, the Radio Club La Serena, and the much older Radio Club Coquimbo. I'm still a member of the latter, but not of the former, because I stopped attending when that club devoted its sessions to fighting each other, until it broke in two. By the way, I also still am a member of the Radio Club Concepcion, as they named me honorary member for special merits...! I visit Concepcion once or twice a year, and the visit to the club is a pleasure.

This photo shows one of the two VHF repeaters the Radio Club Coquimbo had when I became a member (now it has three). It's installed at the very top of the Tamaya mountain, overlooking the land and the ocean from its 1280 meter altitude (plus 20 meter of tower!). It's not at all unusual to contact peruvian stations through this repeater, over a distance of close to 2000 km. The repeater sits right inside the duct that forms stably during most of summer!

This repeater was soon enhanced with one of my 8035 controllers, and shortly later a packet node was added, sharing the tower, cabinet and solar power system. Here you can see me installing one of the antennas for the node. It was mounted well below the Phelps-Dodge antenna at the top, to reduce chances for intermodulation problems. No, that's NOT a mexican hat! It's the somewhat smaller chilean version! Big enough to throw some shade, but not enough to get airborne in that mountaintop wind.

While the repeater is an old RPTelectronics transmitter with a modern Hamtronics receiver and my homemade controller, the packet node uses a very, very old General Electric "Royal Professional" transceiver. It's built SO solidly that we almost were unable to carry it up the mountain! I'm still in doubt if those copper moldings are lead-filled...!  The TNC is a PacComm Micropower-2, with THENET firmware. The node has worked well during the last 9 years, and links packet stations up to 300 km away.

Despite the often-cloudy weather, solar power provides great performance here, because the mountain top most often is above the clouds. But of course, there is no road up to this place! Access needs one hour highway driving from Coquimbo, followed by half an hour on a maze of dirt roads, then stone-hopping up the trail in the jeep as far as it will go, followed by a hike through the cloud cover that can take anywhere from one and a half to three hours, depending on physical condition and the amount of cargo. Any mission to this place takes a full day. We try to keep the things reliable enough so we don't have to come up more than once a year or so. A homemade solar charge regulator considerably increased battery life, so at least that most heavy work of all, hauling new batteries up to the summit, has to be done only every five to six years.

The other two repeaters of our Radio Club are reachable by car, so their maintenance requires much less effort.

Having a decent salary now, the era of factory-made radios was starting for me. I had gotten a tube-type Heatkit RX-TX combo from a work mate, but soon after that I bought a brand new Kenwood TS450. I later took the Heathkit to my dormitory at the job (it's remotely located), where I still have it. The TS450 was first used for a mix of fixed and mobile work. Shortly later I installed a packet BBS, and since then the radio works 24 hours a day in heavy-duty forwarding service, without mercy. It has never had a single failure. Well done, Kenwood!

As a long-time user of homemade radios, I would like to say that factory-made radios are better than what you can reasonably build at home. But home building has still a large appeal, for several reasons: It's fun, it's highly instructive, but above all, you can tailor the product to your own very specific need! There just is no factory-made portable 40 meter QRP transceiver that could outperform mine, in terms of size, weight, power consumption, and performance!

In January 1991 I bought my own apartment and gave up that tiny rented house. The radio desk was disassembled and reassembled in the new home. The station was growing fast: When this photo was taken, a PC had replaced the old Atari, complete with flight simulator yoke and pedals... I was flying just in theory back then! The most important addition to the station was a Yaesu FT736 satellite transceiver. I had to order it from the USA, because there was no way to get one locally. In an effort that spanned several years, I set up a fully automatic groundstation for the digital satellites, complete with a satellite node and a satgate, coupled to my packet BBS. At the time of writing this (1999), the satellites are still my primary operating activity in ham radio.

This is the typical display on my computer screen. The background window contains the F6FBB BBS software, the upper window runs SatSked and SatLink together with a lot of glue-and-fill programs, while the lower one runs FodTrack, my homemade satellite tracking system (software and hardware) that is now well known among satellite users worldwide. Several other complementary programs run in background, and pop up if needed. Thanks to a lot of effort invested in reliability, I can let this station run for long time without any attention. I have been away from home for six weeks at a stretch without the station developing any problem, while most other amateur satellite setups have a much shorter failure interval. Specially when using Windows, computer crashes and hangs seem unavoidable. This system, based on DOS and DESQview, is reliable.

Since this photo was made, in 1995, the versions of the programs have changed, but the basic setup is still the same.

I have been slowing down in equipment building, basically because of my increasing involvement in other hobbies, like making excessively long web pages. But I still enjoy building equipment from time to time. This is a switching power supply that delivers 13.8 Volt at 40 Ampere continuous duty. It has high efficiency, is very reliable, short-circuit protected, and generates absolutely no detectable radio noise from 100 kHz up. I designed and built it in 1997, and it was published by ARRL both in the Radio Amateur's Handbook, and in two parts in the QST magazine, in the december 1998 and january 1999 issues. Check it out in the homo ludens electronicus section.

How do I look now? Well, a little more hair in the face, less on top of my head, all the rest stays pretty much the same. As you can see, I keep the same working style, which is, fill up the desk and then work on the lap. The half ready project in this photo is an inter-repeater link. Completely remote-controlled, it can link its local host repeater to any, several or all of three neighboring repeaters. It plugs into a 25 pin repeater bus which I designed, that allows to daisy-chain several such boxes, adding links, telemetry, and lots of other options to any of the club's repeaters.

I will stop it here. Congratulations for having read up to the end! You are probably as tired from it, as I am from writing!

Back to the homo ludens homepage. And if you are interested in building equipment, be sure to check the homo ludens electronicus page.