If North America were a toroid, one could pass the windings through the Dakotas.
Having recently put up the G5RV, I gave the ARRL DX CW contest a shot this past weekend. The antenna is up only about 10m and is not resonant on 15m, but it has performed well on 10 and 20m in the past. On the first night, 10m was very quiet, but activity on 20m was brisk, particularly in the early morning hours when I was working two calls per minute.
In principle, 10m should have been open starting the in mid-afternoon on Sunday, but it was slow until around dinner time. Again, 20m was my main band, despite having mostly mined it out the previous day. I managed to get a few contacts on 15m, and even fewer on 40m, where local noise was a problem.
I didn’t stay in the chair the full time, even when I had favorable North American windows. I had to disconnect the antenna for some time due to thunderstorms on Saturday afternoon and on Sunday evening I had a guest in town and went out for dinner. Still, I am happy with the number of contacts I made given my conditions.
I worked a few states that I hadn’t such as Vermont, Rhode Island, Delaware, West Virginia, Nevada and Wyoming — hopefully, those stations will QSL via LOTW. I heard a North Dakota station, but barely, and he was drowning in a pile up. Maybe I’ll take another shot when Sweepstakes or some other convenient contest rolls around and I have the hexbeam up.
My final tally:
Sunset in Nice.
Living in Madagascar, I have enjoyed operating from a sought after DXCC entity; little did I suspect the same would be true on my recent trip to Europe. I packed along the FT817 on a trip to Nice, France, where I attended a business meeting. I had picked a hotel with an open 8th floor deck and hoped to string up the end-fed to operate in the evening. On the way out the door, my wife asked me, “so I don’t suppose you’ll have any time to visit Monaco, while you’re there?” I have to admit that I hadn’t really thought about it, but as soon as she mentioned it, the gears began turning. I had meetings in Nice and Lyon, but some free time on Saturday before flying out. On the way to the airport, I double checked that Monaco was a signatory to the CEPT convention.
Continue reading 3A/AI4SV Reverse Dxpedition
I envision having a few antennas: the hexbeam, the G5RV, lindenblads for 70cm and 2 satellite work, perhaps a vertical of some sort if I can figure out where to place it, and maybe some kind of beam antenna for six meters. To make all that work, I’ll need some sort of way to bring the lines in the shack and to switch among them. I brought four alpha-delta four position switches, which should be enough to both perform this function and switch the lines to the available rigs. With that intention, I laid the switches on the bench and drew out the wiring diagram.
However, I never got there; not yet, at least. After piling up some connectors and coax and wood, I realized that what I really needed in the garage in order to do this sort of work was some kind of background noise to keep me entertained. So, I pushed the very useful antenna switching project to the side and turned back to the computer that I had fried a few weeks ago by plugging it into the 230V while its power supply was set to 110V.
Continue reading How my antenna switch became a loudspeaker
The antenna situation has improved. There is progress on the hex beam, but in the meantime I’ve put up a G5RV. It is almost exactly the size of the largest run possible on my property. I had some difficulty getting enough angle on the trees to shoot the line and I am frankly surprised it all worked. The line is tied down to the tree trunk on one end, and the other loops over a tree, then through a metal loop screwed into the property wall, and that end suspends a brick, which maintains tension on the line but has enough give to allow tree motion. The center twin lead is centered over my house and I was not able to get the two arms of the antenna high enough to allow the feed line to hang down straight; this is not ideal as it will change the plane of radiation since the feed line is active in this design. I was also concerned about the feed line coming down too close to the metal roof, so I have arranged another support for the feed line, which pulls it close to horizontal. It also keeps it away from the high power security lights that rim the roof and which put out some RF.
I swept the antenna with an MFJ analyzer in the shack and the SWR is less than 3:1 on 80, 40, 20, 17 and 10m. I have had some good runs on 10, 17, and 20 meters, and a few contacts on 40m. Even on bands where it it not resonant, I’ve had reasonable success using a tuner; being able to run 100W gives me some margin for inefficiency. I worked one EU station after another one afternoon on 30m, and finally had a contact with Alain, 5R8AL, also in Madagascar on 12m. The additional power has allowed me to run a frequency on voice. I’ve now set up the TS450 for digital communications and have had a few PSK31 contacts as well. I’ve getting some RF back, which is affecting the external USB sound card, so a near term project will be fixing station grounding.
As for the hex beam, I finally have all materials. I visited a local lumber yard and had a 4m x 15cm x 15cm post milled. It arrived at my house on a cart and is now sitting across two chairs on my porch. I’ve given the post a coat of wood treatment (permethrin + cobalt salts) and will paint it for more protection. Meanwhile, an almost 2m deep hole has been dug in the backyard, and I’ve purchased about 200 kg of cement, which with some aggregate will become the base for the wooden support beam.
The plan is to get the base in place and set up a shelf using angle iron to support the G450 rotor. Further up the post, I will install a universal thrust bearing to handle the lateral load. A 10m spiderbeam telescoping mast will support the hex beam, and will itself be guyed at two levels. Finishing this project will await some good weather and enough time to see it through.
Voici ma première critique d’une IF française en français (ou, j’espère en une langue qui se ressemble un peu au français)…
Comédie par “Edgar Havre” est composée des scènes liées par les courtes conversations. Grace au module “Simple Chat” par Mark Tilford, les conversations se déroule comme une série de choix. Pour commencer une conversation il faut “parler à qqn”. Les conversations se modifie un peu en fonction des événements observés. En cette manière, les conversations sont limitées, mais elles servent pour introduire les puzzles.
J’emploie encore les meme critères qu’auparavant, sur une échelle de 1 à 10 dans chaque catégorie:
C’était un bon histoire. Au commencement du jeu ce n’est pas évident pourquoi le PC veut entrer dans un théâtre se faire passer pour l’assistant metteur-en-scène. En parlant avec les ouvriers, le joueur a l’opportunité d’explorer ses propres motivations et celles des autres personnages. Le seul négatif: l’histoire se termine trop rapidement et enfin on apprend que tous les efforts du joueur ont été réduits à zéro. Après avoir terminé le jeu, je crois que les joueurs trouveront cette conclusion un peu decevante.
C’était un plaisir de jouer, mais il y a quelques instances ou le joueur a besoin de choses qui ne sont pas décrits dans le texte. Par exemple, dans le première scène, j’ai trouvé le badge par hasard:
(-> le badge)
Vous ne pouvez pas parler au badge !
Oh? Un badge se trouve ici? D’accord, je le prends.
Dans une autre scène, il faut récupérer un objet dissimulé dans une pièce sombre. Comme d’habitude, j’ai cherché un feu pour illuminer la pièce mais la solution exige que le joueur prenne un objet invisible de la pièce. Une conversation donne une astuce, mais c’est au joueur de deviner le mot attendu.
J’ai trouvé le dernier puzzle difficile. Le mécanisme du puzzle marchait bien, mais j’ai eu du mal à “penser autrement”.
Tous les personnages ont des personnalités bien caractérisés.
En tant qu’un anglophone jouant au jeu francophone (merci, wordreference.com), le jeu m’est semblé bien écrit. J’ai remarqués quelques petites fautes de frappe qui peut être corriger après le concours.
Pas de problèmes de programmation. Le système de conversation était performant et bien utilisé.
<Avertissement: les spoilers apparaissent après la ligne>
Continue reading Concours IF 2015: Comédie
The original fuse (white tube, bottom left) after cutting away black heatshrink tubing.
As a public service message, I feel obliged to share the following nugget of wisdom: before plugging a tower computer into a 220V outlet, reach around to the back of the computer and make sure the input voltage select is 220. Sounds simple, right? This isn’t something you have to think about for most laptops, which have dual voltage power supplies. They are happy plugged into either voltage and the power supply brick just works.
I’m not [arguably, perhaps] an idiot – I was aware of the switch. I just thought that the power outlet was off, but also I didn’t expect to encounter an issue until the computer itself was turned on. Wrong — ATX switching power supplies are always on. When I plugged the computer in 220V, there was a popping sound followed by smoke from the back of the unit. Never a good sign.
I pulled the power supply out, opened it up, and looked around. Nothing was obviously charred. My nose has lousy spatial resolution — it confirmed that something wasn’t right, but couldn’t help me localize the problem. I followed the wiring from the outlet inward. For a cheap supply, I was glad to see some decent capacitors on both live and return wires to ground, and across them. Also, some inductors to quell EMI. Next in line: the fuse. It had blended in because as a safety precaution, it was wrapped in heat-shrink. I cut away the heat shrink to reveal a white tube. I couldn’t see into the fuse, but my continuity tester showed it had blown. There was no fuse holder; the fuse was just soldered in by its leads, so I dutifully unsoldered it.
I looked through the rest of the supply, and it looked fine. The next component in line was an NTC thermistor, and it seemed okay, then the primary transformer, and onward towards the voltage doubler circuits (since the switch was in the 110V configuration at the time it blew). It seemed to good to be true, but I thought I might get away with just replacing the fuse. Having ransacked some other switching power supplies in the past, I did have a 250V 6.3A fuse on hand (which is good, because it would have taken at least a month to order one).
Scorch marks at the location of the former MOV, to the left of the bridge rectifier, also removed.
After encasing the fuse in heat-shrink tubing, I stuck the new fuse in, closed up the power supply, wired it back into the computer, and made sure the switch was on the 220 setting this time. I put on my safety goggles and plugged it in. Puff! Another impressive pop and some smoke.
Again, I yanked the supply. Obviously, the problem ran deeper than the fuse. I couldn’t see any failed components, but between various wires and component density, plus copious amounts of sticky glue used to pot the components, it was difficult to get a good look at the whole board. I like to find and fix problems, but I’m also not crazy. I ordered a replacement power supply from New Egg and got to work on a postmortem. At the very least, I figured that I could harvest the inductors and toroids.
When I dug down, I did find some scorch marks near MOVs that had given their lives for the cause. These charred little guys failed short, so no wonder the fuse kept blowing. They were also cloaked in heat-shrink tubing, which made the failure harder to spot.
As I dug through the board, I wondered if the bridge rectifier had also been damaged. So far as I can tell, no — it tested fine. In principle, I think I could have replaced the failed MOVs and fuse and had a working supply. However, given the layout of the board, I’m not sure I could have gotten easily to the MOVs. Oh well, at least some more parts for the parts bin. I’ll shelf the computer until the new supply comes and see where we go from there.
Two bad fuses, two bad MOVs, and one good rectifier.
Friday afternoon, a “moderate tropical cyclone” swept west-to-east across the Island. It was a big enough storm to get a name, Chezda, and I’d been watching it on satellite pictures for a couple days. In the last afternoon, it hit the west coast, bringing rain and wind. This is what it looked like. It’s the swirly cotton thing on the left. The more ominous looking storm on the right is another one, Bansi, that wasn’t a problem for Madagascar, but did affect Ile Rodriques. It is headed southeast, so not so much of a concern.
Since the picture was taken, the center of Chezda has moved off the east coast of Madagascar, but not before dumping a lot of water yesterday and blowing fiercely overnight. Many low-lying areas were flooded. We’re a couple weeks into the rice harvesting season, and in this area, it looked like only about half the rice had been harvested, so I would guess some crops might have been lost to inundation.
There were a lot of power fluctuations yesterday, but as far as I can tell, no major damage in the local area. The wind died down the the sun came out around ten this morning. I’m pleased to report that aside from a bit of water around the garage door, no water entered the garage. The improvements to drainage happened just in time.
The storm is predicted to continue to move south-east and should miss the populated islands in our region.
Water in the garage. This is a problem.
In the previous post, I mentioned that our shipment from the US came in several large wood crates, just as the rainy season started. I had a lot of boxes of radio gear, tools, and other items that needed sorting and I wanted to work in the garage, but since the garage is built below ground at the end of a down-sloping driveway, I was worried that the garage floor could not be trusted to remain dry. As the rainy season picked up, I soon found that this concern was justified, as the french drain in front of the garage could not cope with the run-off.
I had a few of the bottom pallets from the shipping crate; each sits about 8 cm above the floor on wood blocks. I moved these to the back of the garage (since the floor slopes towards the front where the drain is) and piled everything on top of them, while I considered my options.
Although it is rainy season, most of the time it is not actually raining. Most of the water in the front of the garage would run out almost immediately, and the floor would often be dry a half hour later. Unfortunately, the receding water would always leave behind a fine red mud, or after drying, dust.
Making some sort of raised flooring seemed like a good idea. Unfortunately, the plywood used in shipping crates is of very poor quality and only about a cm thick. I could walk on it, but it would groan and sag. However, I had a lot of it.
Fine, government-quality plywood.
I spent the next couple weeks disassembling all of the crates, pulling out the useful two-by lumber. I must have pulled out thousands of nails — most of which I was able to straighten and use again. I remember the day I packed out in Virginia: it was also raining. The moving guys covered the crates in copious amounts of plastic wrap. The corollary is that both the framing lumber and the plywood were chock full of staples. I painstakingly yanked them all because I was paranoid that I might hit them with an electric saw later in this process.
I piled up the lumber, trimmed off bits that were too damaged to be useful, and played a constant game of shifting around unpacked boxes, lumber and tools, to get at the materials I needed while still keeping everything high and dry.
Since the plywood was so thin, I added some reinforcing cross members to the lumber framing and then tossed another layer of plywood on top, laminating it to the existing plywood with some locally purchased wood glue. Between the wood glue and additional nails, the double-thickness plywood made a solid floor. Still a little creaky, but no real give.
Two of the pallets support a table on the left and a pile of bricks on the right. Note the red stain on the floor, where water had accumulated transiently.
The water never got more than a centimeter or so high in the garage, but I didn’t like the idea of wood blocks sitting in water. This set up has to last four years or so. I needed some kind of solid, water-resistant material to serve as supports for the wooden feet below the platforms. Not surprisingly, I obtained locally produced bricks. Bricks are very common here — they are produced from rice paddy mud between crops. They are not the best quality bricks as they lack binding materials and fiber; they are just baked mud. They are relatively fragile to shocks, but resilient to compressive force. For my application, they worked fine, and the price is right: 80 ariary each (about three cents a piece).
So, in boosted the existing flooring up, with two bricks under each supporting wood block, and then fabricated some additional flooring so I had covered the rectangular middle portion of the garage. The back of the garage is strangely trapezoidal, so I put that off for a bit.
A view from the back of the garage looking towards the door (which is down).
I needed a place to work and also some storage, so I made some work benches. I more or less followed a design from a YouTube video for a bench that looked very solid. I already had an Ikea table, which works best at a sitting height, so I made the benches to be used while standing. Like the floors, the benches are made out of wood recovered from the packing crates (although I did top one with some nicer, sanded plywood that I had shipped for that purpose).
Going back to the source of the problem, drainage, I had some workers clean out the drain area at the left end of the grill, above. I hadn’t realized how much silt had collected. They reamed out the pipe downstream as well. I watched the drain during the next heavy storm and was pleased that it had no problem diverting the water as fast as it came.
With less worry about moisture, I decided to install a short carpet in the central area of the garage. The addition of the carpet made it feel much more comfortable. Next came the rolling office chair.
Finally – some storage. All those tiny parts!
Finally, I set up the Ikea shelfing and was able to unpack the many boxes of hoarded electronic bits and pieces. I still have some unpacking to do, but I am now able to get to everything: patch cords, adapters, tools, etc., which will let me get going on station and antenna set up.
The first project for the new workspace: construction of an antenna panel to bring coax into the shack through lightning arrestors and antenna switches. Other projects on a near infinite list include finishing the back portion of the garage and installing some storage shelves for larger items, working on the mount for the hex beam antenna, and fabricating some additional antennas.
So far, the most difficult part of setting up an amateur radio station in Madagascar has been not being in Madagascar. Since I cover cancer programs through subsaharan Africa (and sometimes other places), I knew I’d be in for significant amounts of travel, but in the last two months, I feel like I’ve spent more time in the air than on the ground. Unfortunately, I haven’t had much time to arrange licensing or to set up portable stations while on the road, but as I get more familiar with some of the locations, particularly CEPT signatories like South Africa, I’m hoping to combine travel and operating. A longer term goal, though, is to make Madagascar my base of operations.
My major shipment from the US finally arrived in mid-November, after three months in transit, but I didn’t have a chance to dive into boxes until the third week of the month, just before the Thanksgiving holiday. As usual, not everything got sent to the right place: I ended up with some vintage Collins gear that I would much rather have sitting high and dry in a storage warehouse in the US versus transiting the Atlantic in crate and now sitting in tropical Madagascar. Conversely, my old tektronix analogue oscilloscope is in that warehouse, rather than with me. I suppose that just gives me leave to order a Rigol digital scope some time in the next year. Most of the other items that I had meant to ship did arrive, although it took me a while to locate them in boxes inside boxes.
The many boxes of radios, components, antenna bits, etc., piled up in the dining room had to be cleared to make way for the Thanksgiving dinner that we hosted for some other expat families and kids from the American School. The logical place to put the boxes was the garage, which I have had my eye on for a while as a potential workshop. The entrance to the garage is too low to accommodate our car, particularly with the car’s roof rack in place, so I think I am safe in laying claim to the garage, which provides a sizable workspace, has fluorescent lighting, and even has a couple power outlets.
This is after clean-up; initially, the wood was jumbled in a big pile and the blue tool box was hidden underneath in a corner.
The only drawback to the garage is that it is located at the lower end of our driveway. Gutters draining the driveway and the adjoining garden all run towards the garage. There is a drain grate right in front of the garage, so in principle, all the water runs into the drain. In practice, however, the first half meter beyond the garage door is wet after a rain. Not just wet, but sort of muddy, with fine red silt. I can imagine that this will only get worse as we get further into the rainy season. Some small amount of water also comes in through the ventilation holes at the side and rear, but these holes slope down and outward, and are not really a problem.
When I opened up the garage after getting back to Madagascar, the first thing I saw was piles of wood — the crates left over from the shipping process. I had asked my wife to hang onto the wood because I figured it would be useful for something. It looks like that use will be as flooring, to keep materials high and dry despite the rain. The crates consist about 1.2m x 2.4m x about 1 cm thick panels framed with two-by-fours. The sides that formed the bottom also have about 10 cm risers. I have laid these out of the floor along the sides of the room and that was good enough to keep the boxes off the floor while I figured out what to do next.
The plywood is not really thick enough to be a floor. When I walk on areas that are not directly supported, it sags and creaks ominously. However, I have many more 1.2m x 2.4m and 1.2m square panels, so I think I can fix that by doubling it up. My currently plan is to frame out the whole floor, and nail the whole thing together with double-thickness plywood. I’ll nail on the upper layer in a different direction that the lower layer, which should make it stronger and will also allow me to avoid cracks. It would be nice to have something to put over the plywood — indoor/outdoor carpet? Linoleum? I’ll have to see what is available locally, but for now, I’ll just be sure to wear shoes in there.
This project is going to require at least one tool that I don’t have — a circular saw to cut up the plywood. There is no difficulty in finding brand name commercial grade circular saws in Madagascar: Maketa, Bosch, and others. I had my eye on a Bosch GKS 190, but the price tag at Mr. Bricolage was high: 793,500 Ariary (at about 2600 Ariary/USD, that’s $305). However, I just found one in South Africa for 1822 Rand (at 10.9 ZAR/USD, about $167). Now…let’s hope I can get this saw back from Cape Town to Mada. I guess I’ll have to check the bag since it has a saw blade in it. Hope the saw does not disappear as the bag transits OR Tambo International Airport in Jberg. I never have felt like I needed to cling wrap a bag before, but I think I’ll make an exception for JNB given its reputation for baggage pilfering. [Note added in proof: I did cling-wrap the suitcase and can report that the saw made it safely back to Madagascar. 60 rand well spent, I think.]
So, the garage floor is project number one, but project number zero will have to be making some saw horses so I have something to saw on top of. That sounds like circular [saw] logic, but it does make sense to me. Some, some of the two-by-fours from the crates will become a pair of saw horses. If I have wood left, I suppose it may go into shelving of some form. I have an Ikea table (shown in the picture, above) that I have used as a soldering station, but I may also opt to add some bench space. If so, I probably won’t use the low grade paneling, but would go for something sturdier and more finished from one of the local brico stores.
Now, as for the station itself, it will be located in the house proper. I’ve had roughly the same station layout in Vienna VA, Brussels, and Fairfax VA. The radios are laid out on a two Ikea desks and a short storage unit, all of which are made from pine, are of the same height, and look well together. I’ve disassembled and reassembled them so many times, I can almost do it in my sleep, which proved useful this time, as the moving folks helped me by consolidating all the bits and pieces of pine furniture into one big pile. Desks, storage unit, shelving, chairs, etc., one nice big pile of pine and hardware. That was fun.
The windows in the room are hinged, and I had planned to remove one entire window and substitute a wood sheet that would be hung on the same hinges. However, in tapping on the wall, I noticed that there is a panel that leads to what used to be an air duct right under the window. I’ve now revised my plan to put a painted wood panel outside that duct with a stainless steel feedthrough plate. Conveniently, the house’s electrical ground is right next to that duct, so I can ground the plate with a very short run of ribbon cable. Incoming antennas will feed through the plate, with patch cords running interiorly up to an inside panel. Inside the shack, another wood panel will support three antenna switches, which will allow me to switch the hex-beam to one of several radios in the shack. When I’m not operating (and weather is not threatening), I’d like to route it to an SDR receiver for CW skimming.
The long term plan for mounting the hexbeam on a telescoping mast anchored in the back yard.
Another switch will select between a few different antennas, none of which are in place yet. Antennas that are a possibility in the future: a G5RV, an 80m dipole, the 80m backyard vertical that I had up in Fairfax, and possibly a dedicated 6m antenna. These feeds would go to the antenna #2 input on rigs that have that feature. Finally, I’d like to feed through 2m and 70cm Lindenblad antennas directly to the TS2000 for satellite work. I have to make those antennas first, though. The TS2000 has independent antenna inputs for those two bands.
I’m not sure which antenna will go up first. The easiest would probably be the G5RV. My only concern about dipoles is that I would need to shoot a line through a supporting tree from my neighbor’s back yard – and I don’t know my neighbor yet. Thanks to high walls around everyone’s property, it’s not easy to meet your neighbors. Knocking on the door and asking to shoot something from their backyard seems like a tall order for our first conversation.
The hex beam is still packed up. I don’t have the telescoping mast from spider beam because it took them so long to ship it that I wasn’t able to carry it back as luggage after my most recent visit to the US. For now, I am considering mounting the antenna temporarily on a support that extends from the house’s chimney. With one guy ring near the top, I think it would have good stability until I manage to get the telescoping mast to Madagascar. For now, I’ll omit the rotor and just aim it generally in the direction of Europe. If I get tired of Europe, I can manually rotate it around towards Asia at some point.
Unless I can find someone else who wants to lug the meter-and-a-half antenna to Madagascar, I probably won’t have a chance to carry it back here until June. When it is time to install the telescoping mast, I anticipate installing a supporting four-by-four beam in concrete behind the house. That beam will support shelves for the rotor and a thrust bearing. The antenna will also be supported by two tiers of guy ropes. At least that’s the plan.
The Madagascar equivalent of the FCC or OFCOM — this is where radio licenses are issued. The office is about a km from my house.
I am still operating when I can from my porch, using the FT817 and wire antennas; it is a modest operation, but I’ve managed over 200 contacts. By my reckoning, I’ve worked 45 DXCC entities, almost all on 10 and 20 meters. My prime times for operation are in the early morning before I go to work and in the evening around dinner time. In the morning, 20m is usually open to North America, whereas the evening favors Europe on 10m. I’ve had only a few contacts to the East including Japan and New Zealand, so I have yet to find the optimal times and band to work those areas. Continue reading Two additional bands: 6m and 15m