FOBB 2013

sidepluslighthouse_smWhile on vacation on the beach in Montauk, New York, I took part in this year’s Flight of the Bumblebees, a QRP event in which portable stations receive a bumblebee number in advance of the event, and work home stations and each other during a four hour period.  I wasn’t sure that I’d have time to play radio this weekend, as this was a family outing, but by the Sunday of the event, the family had enough sun and sand, and I was able to drive to Camp Hero to set up my station.

This is about the best location that I could ask for: the very tip of Long Island: surrounded on three sides by salt water, no neighbors or noisy interference (except occasional low-flying planes and helicopters), and a flat plane in all directions. Camp Hero is a former US Air Force Base, but is now a New York State Park. It is a little less traveled than the rest of Montauk as there is a small cover fee to enter the park, and there is no beach. The park is surrounded by cliffs with warnings that the edges may be undermined and that people should keep back from them.

birdWhen I got to the parking lot on the Atlantic side of the park, I took it as a good sign that a giant (now inactive) radar dish was keeping watch over my site. I struck on foot to the NE along a path that parallels the cliffs. It was tempting to set up on what must have been a missile placement, but I kept going, past various bushes until I came to an area that had a conveniently placed wood fence. In the distance, the Montauk lighthouse alternately faded and resolidified in the mist.

I managed to carry in everything in one trip: a push up mast, antenna, radios, chair, operating table, batteries, water, etc. Earlier this year, when W7SUA moved to Arizona, I had purchased a push-up mast from him, and that mast was used to support the center of the “untangleable folded dipole” that I had made earlier this year for the W5O operation at the QRPTTF event.  I attached the mast about six feed down because the top gets pretty thin and I wasn’t keen to guy the pole. In fact, I got away with duct taping the pole to the fence at two points and called it a day. I tied down the two ends of the folded dipole to form an inverted V. The antenna had given me about 1:1 swr when flat topped at QRPTTF, and it did likewise in this configuration — which is good, since I didn’t bring a tuner.

I set up the FT817nd using a 2Ah battery as a support and a 7Ah battery as a back-stop. As usual, the palm paddle key mounted magnetically on the 817. Since the 817 is wide as a barn, with no roof filter, I ran the speaker output through my recently built switched capacitor audio filter based on the New England QRP Club’s NESCAF design. I cranked the filter over to “narrow” and peaked it on my side tone. After that, the filter made all the difference in the world in pulling out close-in signals. Thankfully, there were no other major contests that weekend except the NJQP, which was inside the skip zone, so front-end overload was not an issue.

equippileI slathered myself in sun block, downed a liter of water and settled in about half an hour before the event. I had a test QSO with with Mark, K4NC, who said that he was also getting ready to try QRP in the FOBB. I wished him luck and was glad to work him again a few hours later during the contest proper.

In four hours, I logged 69 contacts, although three were duplicates. It may be that those stations didn’t copy all my info on the first pass or that like me they were logging by hand in a notebook, so I happily worked them a second time.  Of the 66 stations worked, 40 were fellow bumblebees. I noted that a couple stations were on the event listing as bumblebees, but gave their power in the exchange, so I assume that they were folks that had planned to get into the field, but had to work as a home station on the day of the event, likely due to weather.  Contacts included 27 US States, including all three continental west coast states. In Canada, I had two contacts to Ontario, and my best DX was with France grâce à F6BZG.  Most of the non-bumblebee stations sent 5W, and the lowest power in my log was 2W K4MU and 3W AA7EQ.

20 meters yielded a fairly steady rate, and having carried in 9Ah worth of battery, I was not adverse to calling CQ all afternoon. I had a couple lulls, but was happy enough with 20 meters that I didn’t feel compelled to dig into my bag for the 15 meter end-fed that I had also brought along. Twenty seemed to be in good shape all afternoon.

I worked W7CNL‘s 4W station from Idaho just under the wire at the conclusion of the contest – this was a 339/339 exchange, and we were both struggling as the clock counted down.  Thanks, W7CNL for hanging in there!  FOBB was a FB event.

Guitar Center

Quarter Inch PlugsAn observation: when it comes to audio connectors, people who need their connectors to work when they are running back and forth on a stage under hot lights and yanking their equipment around by the wiring — these are the people most likely to have evolved sturdy connectors.

The photo at right shows three quarter-inch stereo plugs. The first, I bought in bulk via mouser. They are pretty cheap: thin metal tables, tight spacing in side the connector, and the strain relief is molded plastic that is part of the barrel itself. The middle ground is from Radio Shack, probably a few years back. The barrel is phenolic plastic and there is no strain relief.

At bottom, a much sturdier metal shell that screws together and compresses the connections. This connector is from Guitar Center, and has some heft. I think it was a couple dollars more than the Radio Shack connector, but there is no question in my mind that it will last decades longer. While I was at Guitar Center, I also bought a few shorter mono-cables as patch cords and about thirty feet of two and three-conductor shielded audio cable.

FD 2013

meatonforkOnce again, the Vienna Wireless Society participated in ARRL Field Day from Burke Lake Park in Northern Virginia. For the last three years, I have captained the non-40m CW tent. The plan this year was slightly updated to move the stations closer together, while maintaining adequate antenna spacing.

sunnySpiderI had a few secret weapons this year. First, with the move up the hill, I was close to the spider beam mount that I was able to use it to work 20 meters, and for a bit of the contest, 10 meters. The 40m station typically runs 15 meters, so I did not use the beam on that band. When the spider beam went up, I also tacked on an AO-50 omnidirectional 6 meter antenna, so we picked up a few contacts on that band as well, but far fewer than I had hoped. The other trick I had up my sleeve was to roll out a newly minted K3 rig. I had put it together about two weeks back, just in time to test it out in the NAQCC sprint for May. In addition to the stock 2.7 kHz roofing filter, the K3 has 200 and 400 Hz roofing filters for CW.

As for weather, we enjoyed both heat and humidity on Saturday and were surprised by chilling, drenching thunderstorm on Sunday. Good times.

I’ve stopped hearing CW in my car creaks and the howling of my home’s air ducts, but my brain is still not entirely recovered from the continuous operation of the station over that 24 hour period. Thanks to Leon, NT8B, I did catch some sleep during the event, otherwise I would be even more posty-toasty.

Some preliminary results (some contacts logged separately, e.g., our VHF activity, also all of the added point categories like GOTA, solar power, etc., are not included):

Band Mode QSOs Pts
1.8 LSB 3 3
3.5 CW 185 370
3.5 LSB 66 66
7 CW 424 848
7 LSB 477 477
14 CW 376 752
14 USB 45 45
21 CW 34 68
21 USB 121 121
28 CW 38 76
28 USB 27 27
50 CW 3 6
TL Both 1799 2859

Things that were planned and worked out well:

  • Rain gear: Packed a poncho and umbrella despite a clear forecast. Similarly, packed long sleeve shirts and a sweater despite heat and humidity in the 90s.
  • Trash bags: Plastic bags enabled us to keep the station up, even when sideways rain was splashing through the mesh sides of our operating tent
  • Plastic sheeting stashed in the club’s field day bucket, someone years back had thought to buy some large plastic sheets. Not long after rain started, John Righi realized that he could drape our tent with the sheets to keep water out.
  • The spider beam: It is a pain to put up, but works well.
  • N1MM: Prior planning and testing with N1MM lead to a smooth operation
  • Poison Ivy on the main antenna support tree: Recognized, avoided.
  • Food: Yummy, and plenty of it.

groundrodThings that did not go entirely according to plan:

  • The deep-dwelling ground rod: An 8-foot ground rod, hammered in 4 feet deep proved difficult to extract. With many helpers, a hydraulic jack, a vise grip to provide purchase on the rod, and a thick wood log to increase surface area under the jack, the rod was recovered, averting plan B, which involved a hack saw.
  • The tree-loving guy line: one of the supports for the 80m dipole was particularly long, and an overlooked knot in the end became fouled on a high tree branch. Pulling only lead to comical moonbouncing around on the lawn. The solution: tying the line to a pick up truck and running for cover. The 3/8″ line held, a tree branch came down, and the problem was considered solved.
  • The logging computer, an old Panasonic Toughbook, decided that its track pad would no longer function when we set it up at the station. The touch screen still worked, so we weren’t entirely out of luck, but we had to scramble a bit to find an external mouse. I’m still not sure what happened, as the pad had worked right through the WVQP a week ago, and up to the previous evening when I was setting up the database for field day.
  • It turned out that we did not have a satellite station for field day, so between HF stints, Ben Gelb and I monitored satelite passes and attempted to jury rig a station from my car, which is outfitted with a computer controlled TS-2000. Ben was at least familiar with the software, whereas I was reading the TS2000 manual right up to the first pass. We had a 70cm yagi, the car’s 70cm/2m vertical, and a small 70cm magmount antenna. We ran HRD’s satellite tracking program, and set up a waterfall using Ben’s digicube dongle, while the TS2000 provided duplex audio for both up and downlink. We did manage to find the satellites each time, but had some difficulty setting the T/R offset and tuning around in real time during the pass. We heard both CW and SSB transmissions on the birds, and even succeeded in hearing our own CW signal, so at least we knew that we were making it in. This set up may have worked on a quieter day, and I think it needs only a bit of tweaking to get it right…maybe next year, with some practice in between.

Things to consider for next year:

  • We worked absolutely everyone that we heard and were often the first station through pile-ups. Maybe we could go entirely QRP next year? Bigger score multiplier, less inter-station interference
  • Check that we have plastic sheeting for every operating position.
  • Check wireless routers for RF emission. I’m not sure this was a problem, but something blanked out our satellite receive capability on one pass, and having eliminated other sources, we suspect a wifi router may have been the culprit.

k3

The Laptop That Time Forgot. Almost.

Encouraged by my recent repair of the TS450 that had languished without computer control for a couple of years, I decided to reach back even further in the time stream and to pull my trusty Compaq nc6000 out of the vault. That laptop was my main computer for several years, starting in Sri Lanka right after the tsunami, then back to Bangladesh, a year in Virginia, and in Belgium up to 2008. In that year, it developed an annoyingly intermittent failure that slowly increased in frequency until the machine was unusable — it would just power itself off. It got to the point that it would turn off in only a few seconds, so my initial thought that it was heat-related didn’t hold up for long.

max1987I noticed that if I pushed on a specific place on the upper edge of the keyboard, just to the left of the fan, I could convince the computer to remain powered up for as long as I held pressure. I though it might be a bad motherboard edge connector or perhaps something to do with the fan itself, so I tightened down the fan. At the time, HP (which had recently acquired Compaq) was of no help, but over time, users consistently reported the same failure mode and kludgy solution. Finally, someone must have looked at the computer under a microscope and diagnosed that these failures related to microfractures in a single chip: the maxim 1987, a 48pin QFN chip that controls CPU power. If you google that chip, you’ll find scores of reports of its failure, either intrinsically or due to poor soldering connections. For my model, most of the speculation is that stiff hinges flexed the motherboard and caused mechanical failure, but I wonder if the failure is more related to repeated heating and cooling of the chip in operation.

The fix for this sort of thing is to resolder the chip, so that’s what I did. Unfortunately, the chip is on the underside of the motherboard, which is buried deep in the laptop. There’s nothing to do (aside from dremeling through the case) but to disassemble every module in the computer, completely remove the main board, flip it over, solder, and put it all back together. Torx screw drivers are not optional — there are a lot of torx screws of varying sizes, plus a few tiny philips head screws.

nc6000_splayed

I used a sparkfun hot air rework station 303D set to 385C and toasted the chip for 5-10 seconds per side. I could see that the solder melted as I did so, but had to take it on faith that the chip was sitting correctly and that all the connections were good (direct visualization is not possible).

In disassembling the laptop, when I removed the heat sink fins near the exhaust port, I found a cat-like fuzzy creature composed of many years of hair, link, fur, dust, and whatever else has been in the air that I breathe. I looked much worse than the air filter that they force you to inspect every time you take the car to JiffyLube. I did a general cleaning as I went through the computer, dusting out cooked ants, moth wings, and other animal life remnants. Since I didn’t want to cook the CPU, which is not far from the max1987, but on the other side of the board, I removed the heat sink and the chip itself while I was soldering. I cleaned off the chip, removing dry and questionably effective heat sink grease, and reapplying some of my own industrial grade heat sink compound.

I was surprised as anyone when the machine went back together with nary a left over screw. After five years out of action the LiON battery was dead flat, but I put in back in position anyhow. When I powered up, I got the bios splash screen followed by the Windows XP/SP2 screen. Windows did not fully load, but got to the point where the screen turned light blue and I got a usable mouse cursor. Program manager and task manager weren’t working, so I couldn’t get much further.

I suspected that the drive had been corrupted by erratic shutdowns, so I ran SpinRite from CD-ROM at level 2 and it detected and repaired some flawed sectors. On the next boot: success, 2008-style. I was staring at the same screen that I had used in 2008, now oddly dated looking. I fired up a few programs, and everything ran correctly. I was not, however, able to get the computer on my home network despite being able to physically activate the wifi module and to detect local networks.

IMG_20130620_002752I plugged the machine directly into my router and spent the next couple hours watching netflix (on my other computer), while windows update did its thing. Many were the times that I heard the windows boot sound. I enjoyed watching the patches of yesteryear strut their time across the stage: NET framework, Windows “Genuine Advantage”, and finally, the 800 pound gorilla: service pack three.

At the end of all this, I found that my home wifi didn’t work, but I could connect to an open network, so it was a problem with encryption. I realized that WPA2 wasn’t out when the machine was manufactured, and that my home router would not roll to a lower standard. I was pleased that the Intel wifi card was supported by an update that came out in 2009, and which enabled it to connect to modern wireless access points with good security.

So, the nc6000 seems to have made a full recovery. I’ve promoted it to “back up logging computer” for the station, which is great timing, since I now have two computer-controllable radios. A new battery (a bit less than $40) has been ordered, and will complete the update.

West Virginia QSO Party 2013

I hadn’t planned on entering the WV QSO Party this year because I thought that I had another event on Saturday. Then, scheduling shifted around and the weekend opened up. Having recently participated as a rover in the Indiana QSO Party, the car was still set up for mobile operation. Further, I had a hideous showing in last year’s WVQSOP, so I was hoping to redeem myself this year.

wvqso2013countiesI did the planning late on Friday afternoon. After grabbing the current rules and a list of WV counties from the event website, I headed over to an online county mapping tool. Between that and google maps, I plotted a loop through the northeastern part of the state, concentrating on reasonably large roads that crossed county borders, but not over a river. I didn’t have much time, so rather than obsess about the route as I usually would, I just took the first candidates, without optimizing for elevation, signs of power lines, and so on. The route is saved as a google map. On that map, if you select a way point and hit “directions”, the map provides the long/lat for the way point.  I programmed those coordinates into a dedicated GPS, having learned last year that my android phone does not do well as a GPS once I’m a few miles into West Virginia, and out range for my (and sometimes any) cellular network.

For the record, here are the waypoints, each of which turned out to be a reasonable operating location:

County Line Latitude Longitude Range to next
Jefferson-Berkeley 39.319575 -77.98796 19 mi
Berkeley-Morgan 39.445992 -78.198828 44.4 mi
Mineral-Hampshire 39.465354 -78.714981 38.5 mi
Grant-Hardy 39.13016 79.037683 124 mi

The weather looked great on the morning of the event. Even the space weather looked not half bad. Solar flux had been drifting down, but it was around 100 and most importantly, quiet. I left around ten in the morning, hit the bagel shops on main street in Fairfax, and made it to the first way point at noon.  It took  a few minutes to set up the antenna and get sorted out, and the first contact was recorded at 12:15 local, fifteen minutes into the contest. From then, I operated non-stop until the closing bell at 10 pm local.

My main antenna was the 40m hamstick, but I also adjusted the screw driver to 20m and used it from time to time to test the waters on that band. I alternated between CW and phone throughout the day. I hovered on each location for at least an hour, and spent the last three hours at Grant-Hardy.  I was surprised that I got so few contacts at the Berkeley-Morgan stop. It seemed ideal — the top of a mountain, a nice place to pull over, and no obvious sources of electrical interference. Maybe it was propagation or time of day, but as soon as I started driving again through Morgan County, I started picking up more contacts.

Here are the statistics for the day:

Band Mode QSOs
3.5 CW 26
7 CW 181
7 LSB 71
14 CW 16
14 USB 10
TL ALL 304

So…what’s my score? I’m not sure. The contest rule do not fully describe scoring, but refer to a summary sheet. QSO points are weighted, CW counts more than Phone and contacts with mobile stations are also more valuable. There are bonuses to work the official event stations (I worked them ten times), plus bonuses for number of counties activated (11 — see the map). Speaking as a mobile operator, these incentives to work rover stations are very appreciated. Looking over the logs from past WV QSO parties, I’m surprised that more stations don’t enter in the mobile category given the scoring algorithm.  Anyhow, part of the scoring method seemed ambiguous for me, so before I do any totaling, I’m waiting for some clarification from the contest organizers by email. At least I am sure that I did better than last year.

From the perspective of fixed stations there is a bonus for working the same mobile station in five counties. By my reckoning, I provided this credit to:

Call Contacts Counties
K4BAI 11 7
W8POF 10 7
K8JQ 7 5
KB3AAG 6 5
KQ3F 6 5
W2CVW 5 5

Looking through the log, I worked 27 US states, plus Ontario in Canada, and one station each in Germany and  the Slovak Republic.  As in the INQP, I think I would have done better had I been able to get a 20m antenna into the trees, but operating this contest single-handed, I didn’t want to take the time to wade into the brush and grapple with ropes, wire and coax.

wvqso2013statesIt was a great day for a contest, and while I was driving frantically around West Virginia, I was also enjoying the scenery. My final location was on a mountain top, where I watched the sun set. Around dusk, a family of deer walked through the clover and grass next to the car. By the end of the event, the stars were out in full force and I started at the constellations for a bit…

…which was helpful, because for the last mile of the trip, my GPS stopped functioning normally. The road that I was on was a shiny new highway, and evidently not in the memory of the Tom Tom GPS, that I had purchased in 2009 in Belgium. The GPS constantly tried to recalculate where I was, as it could not accept that I had driven the car off a farm and up into the woods on the side of  a mountain. Taking bearing from Polaris, I headed east until I found a road that my mildly brain dead GPS recognized, and made it home about two hours later.

County and state maps were generated using the Do-It-Yourself Maps tool.

TS450: Life after lightning

In August 2010, one of the Mid-Atlantic summer lightning storms did some damage — the strike was nearby and not direct, but it fried my Astron power supply, a Panasonic tough book, and my Kenwood TS-450SAT radio. The radio would power up and the display looked normal, but I had no audio and suspected that the front end and perhaps switching diode had been zapped.  At the time, I didn’t feel up to tackling the radio repairs, so based on eham reviews, I contacted KI4NR at LPC Wireless and mailed the rig off to Florida.

Lightning damage at the antenna port on the rear of the radio. The protecting diode has been more or less vaporized.
Lightning damage at the antenna port on the rear of the radio. The protecting diode has been more or less vaporized.

 

Damage on the underside of the low-pass board.
Damage on the underside of the low-pass board.

Meanwhile, I checked out the Astron and concluded that the voltage regulator IC was dead. After replacing the chip, the supply was as good as new.  Next, the computer: it had been interfaced to the radio via a G4ZLP cable, a work-alike to the original IF232 from Kenwood. As mentioned previously, I had modified the cable to also serve for CW keying of the rig. The computer powered up from battery okay, but did not work on wall power. A small board with the voltage regulator and battery charging circuits had been fried. I found the same model Toughbook on Ebay for a good price — broken screen, no hard drive or battery, and was able to combine the two into a functional unit.

LPC had sent me pictures of both the damage and repair, which are displayed in this posting.  When received by LPC, the lightning protection diode had vaporized and the PC board was charred. They repaired the lightning damage, but also performed factory calibration, enabled transmission on the 60m band, and replaced the backup battery, which was close to the end of its life.

Repaired RF board, with intact protective diode, and replacement relay.
Repaired RF board, with intact protective diode, and replacement relay.
Low pass board, with repaired traces.
Low pass board, with repaired traces.

The only item that didn’t work right was CAT control of the rig, but at first it wasn’t clear where the problem was: in the computer port, the interface cable or the rig itself. Swapping computers didn’t seem to matter, so the next step was to order another G4ZLP cable. Even with a pristine new cable, I was not able to establish serial communications to the rig.

Not having CAT control was a minor inconvenience. For normal operation, it wasn’t a big deal to type in the frequency, but for contests, it slowed me down a bit to not have the band map automatically populated. Similarly, for digital modes, it made operating awkward.

cat_schemaLooking at the schematic for the digital board within the TS450/690 service manual, there is an inverting buffer right after the physical connector to the cat cable. This chip is all there is between the outside world and the microprocessor that runs the radio. I reasoned that if the microprocessor had been cooked, nothing would work, so it was very likely that the 7404 chip had been cooked by the electrostatic discharge.  The chip is designated SN74AS04NS, so an “advanced schottky” version of the chip.

I couldn’t find that exact version of the chip, so I ordered the “next best” version: SN74ASO4D.  According to the data sheet, the two are electrically equivalent and have the same pin out. Both have 0.05″ pin spacing, but the dimensions of the ICs are slightly different: the D model is 1.75 mm shorter, 1.6mm narrower, and from side to side the “arm span” of pins is about 2mm less. I was hoping, though, that this would be close enough.

I removed the old 7404 by cutting the pins near to the chip body and then removed the remaining leads with a soldering iron. This left behind some clean, well-tinned pads. When I aligned the new chip, it was apparent that the replacement chip was not wide enough to span from pans on one side to the other. Since the new chip had the same pin spacing, I taped it in place and soldered one side of the chip, leaving a gap of 1-2 mm to the free pads.

A size comparison. On the left, the old chip, minus its pins, which were cut off. On the right, the smaller replacement chip.
A size comparison. On the left, the old chip, minus its pins, which were cut off. On the right, the smaller replacement chip.

After experimenting for a while, I settled on using a very fine tipped soldering iron and  made the connections using individual strands from stranded copper hookup wire. I did my best to check continuity, closed the radio up, and connected the newer interface from G4ZLP. I fired up Ham Radio Deluxe and defined a new radio, with communications set to the correct COM port, and serial parameters of 8 data bits, no parity and 2 stop bits. The radio synched up immediately and displayed the correct frequency. After brief testing, it appears that the CAT control is operating correctly.

IMG_20130613_222517
The before picture – the 74AS04N on the left, microprocessor on the right.
The repaired hex buffer. The blue area is some insulating tape. The left side is soldered to original pads; the right side is jumped to the board with thin wires.
The repaired hex buffer. The blue area is some insulating tape. The left side is soldered to original pads; the right side is jumped to the board with thin wires.

I then went back and tested the original CAT cable from G4ZLP, and it appears that it had also died in the electrostatic discharge. Opening up the serial cable end connector, there is a small circuit board, covered by white rubber or silicone. I peeled a bit of it back to reveal a small circuit board with surface mount components. I didn’t consider it worth fixing, since I do have another cable that works fine.

workingAlthough it was something of a pain to replace the cable and the 7404 chip in the radio, the sacrifice of these two components was far preferable to having the damage go one chip further and take out the radio’s microprocessor.

 

 

Washington Times Marketing Scam?

[We interrupt this stream of usually relevant material, for a gripe about a local service. Please bear with me, after this vent, back to the usual topics]

so-called renewal notice from the Washington Times newspaper - redacted for personal identifying informationA few weeks ago, plastic-wrapped issues of the Washington Times started arriving sporadically on or near our door. For those not familiar with the paper, it’s a far second in the DC market to the respectable Washington Post, and the editorial slant of the paper is strongly to the right. Add in that it was founded by the Unification Church cult.

For the first couple weeks, I’d just throw them away if they ended up near my door — then a bill came, asking me to pay for my subscription.  What? There’s no way I’d ever subscribe to this rag.  From past experience, I know that I don’t have time to read even a good newspaper, so from an environmental perspective, I would not want one delivered (much less piling up on my door step, my neighbor’s lawn, and in the storm sewer in their plastic wrap).

I phoned the Times, had a bit of a wait, and talked with a representative who suggested that college kids may have gone around selling subscriptions. I don’t recall any students selling anything, and certainly not the Times. This seems like a very lame excuse for what appears to be a marketing scam. After shoving newspapers at people, how many feel obligated to pay when they receive a bill? This seems like a  particularly scummy business practice, so I’m sharing it here in the hope that other people in the region will read it and be forewarned, and also that similar stories can be aggregated.

According to the representative in the call center, the subscription is cancelled (how can you cancel something I never had… oh, never mind) and the account is zeroed out. If bills continue to arrive or this shows up on my credit report, I will be showing up physically in their offices, not in a good mood.

Operation Rolling Pork

P5042730

In 2011, I got together with Ben (NN9S) and Tymme (K9TYM), and we participated in the Indiana QSO Party from Tymme’s house, just outside Bloomington, Indiana. None of us were experienced contest operators, but we managed to set up a multi-multi station in short order and kept it on the air for the duration of the event, giving out QSOs for Monroe County.

We couldn’t pull the team together last year because of jobs and travel schedules, but we entered this year as a Rover team. My 2009 Hyundai Sonata is outfitted with a Kenwood B2000, similar to the TS-2000, but without  a front panel. The main radio unit is housed in the trunk, with a remote head mounted on the dash.

Over the last year, I’ve gradually modified the car for this operation, with power connectors running down the left electrical channel to the trunk, and audio, keying, RS-232 and antenna control cables running along the right electrical channel. One of the radio’s antenna ports is dedicated to a 2m/70cm antenna, while the other is used for HF: either a screw driver antenna or MFJ hamsticks.

IMG_20130502_192123I took a few days off of work for the event and camped on the way out and back to Indiana from Virginia. Before leaving, I lightened up the car a bit by removing the passenger side seat. The seat is held down by four bolts, easily removable with a socket wrench, plus some electrical cables that had to be disconnected.  In place of the seat, I screwed in a RAM Mount for my panasonic toughbook laptop, with power from the car’s accessory power port and rig control via RS-232. This allowed the computer to be operated from either the driver position or the rear seat. Similarly, the microphone reached to the rear seat.

Either passenger in the back could operate the microphone, and the passenger behind the driver typically also fulfilled the role of navigator. The other passenger in the rear seat operated the computer, and the driver either drove, or while parked, operated CW using paddles mounted on the center console behind the shift lever. An autokeyer with rate adjustment was installed into the front dash.

We followed a counter-clockwise loop, starting near Tymme’s house in Monroe county. Our plan was to aim for county borders that were along an efficient route. In the weeks before the event, we roughed out a plan using Google Maps and Street View to try to find places that would be safe to pull over and operate and ideally far from sources of electrical interference. We also tried to find locations with some elevation and good prospects for pitching an antenna into a tree or setting up a support pole.

Our signboard reminds us that we are parked at the Monroe/Lawrence county border.
Our signboard reminds us that we are parked at the Monroe/Lawrence county border.

We got off to a wobbly start because we did not make good time from Chicago to Bloomington, and we got a little turned around in Bloomington. Consequently, when the contest started, we were still on the way to Tymme’s house. This wasn’t a major set back, as we just started operating mobile on voice until we got there. As soon as we pulled it, storm clouds were gathering, and the decision was made to shoot the 80m antenna for the evening’s operations before the sky let loose. While Ben and Tymme disappeared into the woods to shoot strings into trees, I operated CW from Tymme’s driveway.

Before long, we were underway, first way point: the Monroe/Lawrence border. Our circuit continued with operations in Orange, Dubois, Martin, Washington, Scott, and Jackson counties.  We had surprisingly few contacts in Martin country, which I thought would be a highly sought location, and I’m not sure why — we had a remote, high location; maybe propagation was just off at that point in the day.

As the first person to operate phone when we got to the Orange/Dubois border, I learned that “Dubois” isn’t pronounced the way I thought I was. In Indiana, it rhymes with “noise” rather than “quoi”.

P5042727
Ben and Jack pose with the Porkmobile and the trunk-mounted screw driver antenna in front of a genre-appropriate restaurant

We continued operating the entire duration of the contest, driving through pouring rain for the last few hours. The rate began to drop off in the evening, a reflection of the poor efficiency of mobile antennas on the lower bands. Looking at the clock and the map, we reckoned that we would need to get back to Monroe country quickly if we wanted to have a chance to use the 80m full-length dipole that we had spent some time setting up earlier in the day.  We nicked Brown county on the way back to Tymme’s, but unfortunately didn’t land any QSOs.  In retrospect, I think we should have written off getting back and tried to get a couple contacts in Brown country, but we were also constrained by our over all travel plans — we had to be back in Chicago by 6 am the next morning, so we were keen to get back to Tymme’s by midnight and catch a few hours of sleep.

Tymme took the wheel for the last hour or two of the contest, flying through Indiana back roads like Luke Skywalker in the trenches of the version 1.0 deathstar. I’m pretty sure Tymme turned off the targeting computer and just followed his instincts home. Surprisingly (to me), when we got to Tymme’s house, he didn’t stop driving, even though the driveway had run out. Tymme continued to sail over lawn and into the forest behind his house, with the car slicing through waist-high grass. He stopped when he got to the tree supporting the 80m dipole and we hooked up the feed line to the radio in the car’s trunk.

Tymme operating phone from the back seat
Tymme operating phone from the back seat

Aside from some boozy yokels on 75m, we didn’t hear much activity, but once we started calling CQ, we had a pile up of responses. When we had wrung out sideband, we switched down to CW and a similar hot run. In the last half hour of the contest, I was pleased to work many calls that I recognized as QRP stations.

During the 12 hour event, we reckon that we worked 30 states/provinces and 48 sections. This is actually fewer states than we had worked in 2011. I believe that this could be improved in future efforts if we used higher antennas and paid more attention to the 7Q contest. Here is the breakdown by band and mode:

band  mode   qsos   pts  mults
3.5   cw     33     66   8
3.5   lsb    24     24   6
7     cw     135    270  47
7     lsb    127    127  44
14    cw     12     24   5
14    usb    13     13   8
21    cw     2      4    0
total        346    528  118
score: 62,304

Doing some quick calculations after the contest, it appears that Ben has now achieved the first rank of “worked all Indiana” between Operations Sizzling Pork and Rolling Pork.

On the way home, I attached the 10m MFJ hamstick to the trunk mount and worked CW. Conditions were great, with solar flux up around 150. I logged QSOs to the following countries: Honduras, Nicaragua, Argentina, Cuba, Guadeloupe, Brazil, Canary Islands, Mexico, Paraguay, Puerto Rico, the Balearic Islands, and South Africa.

This year, we had some nice mini-pileups, which made it an exciting event. After getting back to Virginia, I called up records from dxsummit to see if and when we were spotted (thanks, by the way, to everyone who did spot us). I would have guessed that we had been spotted at some additional times, so maybe this records isn’t all-inclusive of spots, or perhaps people are just good at finding fresh stations to work:

N9IO  3530.0 NN9S inqp      0347 05 May   United States
K3CT  7225.0 NN9S QSO Party 0012 05 May   United States
KB9NW 7244.9 NN9S           2244 04 May   United States

I hope we are able to build on our effort in INQP 2014. The first item on the plan for INQP 2014 will be operation from Brown County.

SCAF audio filter build

Completed FilterI have a few CW rigs that have lousy filtering. Rockmites and other low part count direct conversion rigs naturally don’t have much in the way of selectivity, but this is also (unfortunately) true of my unmodified Yaesu FT-817nd.  I should probably invest in the an IF filter for the 817, but for other rigs, it makes sense to have an external audio filter that I can use across projects. A natural choice would be the New England QRP Club’s NESCAF filter.

The NESCAF filter is designed around a family of versatile switched capacitor filter chips. The grand-daddy of the family is the MF10, but more modern versions exist (e.g., the pin-compatible LMF100 or the LTC1060) and have better performance. Each of these chips has two 2nd order filter stages, which can be configured as low pass, high pass, all pass , notch, or band pass depending on how it is wired up and what external components are used. One stage can serve as input to the other to create 4th order filters.

IMG_20130525_232918In the case of the NESCAF, the chip is configured as a Butterworth filter — maybe not the sharpest band edges, but minimal ripple in the pass band. Referring to the MF10 datasheet, it looks like the NESCAF implements this through two sequential mode 1 filters with a Q of 10. The filter bandwidth is controlled by two ganged 50k ohm potentiometers, with a section devoted to each filter stage. The center frequency is driven by dividing a time base by 100. A 555 timer outputing 70 kHz will result in a 700Hz center frequency. The 555 rate is controlled by a panel-mounted potentiometer. The center point of that potentiometer is set an onboard trimmer potentiometer. Output from the filter is amplified by an LM386. Some builders make this an onboard trimmer set to yield a gain of 1 relative to the input signal, but I made it panel mount to allow adjustment of volume.

Power input is nominal 12V and the LM386 uses this level directly, with only a couple of capacitors for smoothing. The rest of the circuit operates at 9V regulated by an 78L09. The MF10 chip is used in single-supply mode via a resistive voltage divider.

IMG_20130526_221504This design is sold as a kit through the New England QRP club, but schematics are openly available.  To try it out,  I decided to build my version on vector board, which was great in terms of character building, but next time I would certainly save a boat load of time and get their PC board.

The dual-ganged bandwidth pot takes up a lot of room in a case, so ideally the project would be housed in a deep enclosure. I had a bud box on hand, so I used that. The project schematics call for a 4.7k resistor on the power indicator LED, but that value results in such a dim LED that it would only be useful in a dark room. I knocked the value down to 1k in one build and 1.5k in another, and both worked fine. The marginal power cost is insignificant to me — I’d rather have a reasonably bright LED to let me know that the unit is powered.

scafback04I had no difficulty machining the cast aluminum case with titanium coated bits, but a stepped drill bit made it a pleasure to bore out the holes for pots and switches, leaving a burr-free hole with minimal effort. The rectangular hole for the power pole connector is still something of a pain. I drill a few holes, enlarge them, and then refine it with some tedious file work. It amazes me that there is no elegant way to panel  a single power pole pair. There are snap-fit panel mounts for 2×2 and larger arrays, but I would think the most common requirement would be a simple pair. The only solution I have found so far is to order very overpriced metal retention brackets that clamp on both sides of the socket. With a single screw in each bracket, they have a tendency to tilt, which gives the project an unprofessional look.

For once, I remembered to drill first and paint later. In this case, two layers of white spray paint. I made the lettering by printing text on water gilde decal paper using my laser printer. I filled the sheet with words, numbers, abbreviations, etc., that I thought I might need in future projects, since the paper is somewhat costly. After applying the decals and letting the cure for half a day, I went over everything with two coats of clear matte acrylic spray and then assembled the project.

WaterfallAs a functional test, I played back a recorded session of PSK31 signals and output to a computer running MixW. I made a video of this session and also took the photo at left. In that photo, events at the bottom of the waterfall are the oldest. So, proceeding upward, I had the filter off with audio bypassing it entirely. When the filter was turned on, signal was lost until I turned the AF gain up to the point where the level was similar to the source volume. The filter was already set to narrow bandwidth and the curvy line resulted from me dialing down the center frequency. Towards the top of the waterfall, I had opened up the bandwidth and then dialed up the AF gain to greater than unity, oversaturating the waterfall.

 

QRP TTF 2013

For the 50th anniversary of the Vienna Wireless Society, the club operated under a special event call sign: W5O. As usual, there was a good turn out of club members for both the picnic and on-air activities. We put a couple rockmites, FT817s, and a KX3 on the air, and accumulated 62 contacts in our log in total running predominantly CW, but some phone as well. We had multiple contacts with other operators also participating in the QRP TTF, but also the Florida QSO Party, and one SOTA station. In the next couple weeks, we should send out our QSL cards to confirm the contacts.

untangleable1In the days before the event, I put together  an “untangleable folded dipole” antenna made from 300 ohm twinlead, plus a matching box comprised of two toroids and two capacitors. The antenna was based on a design found on the blog of KI6SN, and I summarized the construction details for my effort on a Google-plus post.

After spudgunning two trees, we hoisted the folded dipole to a flat 40-foot deployment. The feed line is about 25 feet, so a short BNC-terminated coax extension was used. The antenna worked great and allowed us to work a Swiss station, and to score reverse beacon hits throughout Europe on 20m.  I swept the antenna with a MFJ analyzer at the end of the event, and noted that SWR was below 1.2 for the entire CW portion of the band, and less than 2 from below 20m to above the voice portion of the band. So, quite impressed with the folded dipole design. As advertised, it packed up easily and without tangling.

untangle3