Sunday, March 14, 2010

Well YES, actually, this IS rocket science...

OK, maybe not exactly rocket science but close enough. Ever since I started working satellites back in the early nineties I've dreamed of having a fully automated setup. A computer aims the antennas and tunes the radio to compensate for the doppler shift and all I have to do is sit back and make contacts. Doing everything manually during a pass and trying to log contacts at the same time can sometimes be reminiscent of the proverbial one-armed paper hanger, especially when it is a fast moving LEO bird like VO-52!

Learning the code...

No, not THAT code. I'm talking about the kind of code that computers understand. I taught myself to program in BASIC as a teenager back in the early 1980's. My Radio Shack TRS-80 Level II had a whopping 4K of RAM and, for it's time, could do amazing things. A decade later I decided to dust off my old programming skills and write a Windows program that would handle the doppler tuning for my satellite receiver, a Yaesu FRG-8800 with a built-in UHF converter. Much to my dismay, it was only AFTER I took the shrink wrap off my brand new copy of Visual Basic 3.0 that I found out only the much more expensive Visual Basic Professional version included the trivial ability to talk to a serial port! Dejected and thoroughly ticked off, I ended up doing the project in QuickBasic under MS-DOS by starting with a version of G3RUH's PLAN13 tracking software and adding in code to calculate the doppler shift and send the frequency data to the radio's CAT port. That worked pretty well and eventually, when the first version of ZL2TPO's WiSP came out I did finally find a way to use VB 3.0 with a serial port and wrote a little Windows application that tuned the radio based on tracking data passed from WiSP via the Windows DDE interface.

Garbage in, garbage out...

So automated doppler tuning was never that big of a deal but the real holy grail was automated antenna tracking. Back then there were a several options available (most notably the legendary Kansas City Tracker board) but they all had one thing in common. They all assumed that the operator was using a Yaesu G5500 az/el rotator setup. Pretty safe bet because I'll bet that 99% of stations were and still do use that rotator combo to this day. Now it was pretty easy to adapt the control boards to any rotators that used a 0-5V position feedback system and that was central to my problem. Expensive rotators (and for that matter, expensive computer control boards!) have always been a bit too pricey for my budget and I've always gotten by with cheap TV antenna rotators that have no positive feedback. Getting a $50 TV antenna rotator to turn a huge VHF/UHF antenna array is a tricky business and I've always figured that if it died on the job, at most I'd only be out fifty bucks to replace it. But unless I could find a way to get accurate position feedback I'd be out of luck for an automated tracking solution. In the wind and cold there was just no way to predict how far the antennas would actually turn and the indicator on the control box was almost always out of sync.

The light bulb comes on...

When I built my new satellite antenna setup last year, one of my stated goals was to find a way to automate the station. CX6DD's WiSPDDE software was quickly put to use to handle doppler tuning the TS-2000 but since I used yet another cheap TV antenna rotator I was still at square-one for automated antennas. Well, almost at square-one. One of the nifty devices I had come across in my travels was the LabJack U3. This dandy little device would plug into a USB port and provided a plethora of analog and digital inputs and outputs for interfacing to the real world. I knew the moment I saw it that this was the gizmo to solve my antenna interfacing problems. My new antennas were using an old TV dish actuator arm for elevation. This had a little slotted wheel inside between an LED and a photoresistor and when the jackscrew turned it would send pulses down the wire to the control box. Looking at it reminded me of the insides of a computer mouse and that's when I started to get an idea of how to make this all work together. If I took some parts from an old computer mouse and somehow hooked the wheel up to the antenna mast with a belt it would send pulses as it rotated in azimuth just like the elevation jackscrew. All I would need to do is brew up some software to talk to the LabJack, throw in a few relays and I'd have it made.


The LabJack unit and pieces of an old mouse sat in a little box near my desk for a long time waiting for the moment when I would figure out how to physically put it all together in a way that was mechanically sound and operational in all-weather. In the meantime, I made do with manual tracking and the unreliable position indicating. Things actually worked pretty well over the summer, hence the somewhat low priority on the project. Once winter came, however, the situation deteriored. The azimuth rotator would often stick and turn sluggishly in the cold. I missed most of the EME contest because I couldn't accurately point the antenna in overcast when I couldn't see the moon. Working satellites wasn't as much fun because I was always losing the bird at some point during the pass when the indicator got out of sync. In fact, for the two coldest months (December and January) I didn't even bother to put up the antennas. It wasn't until a 'warm' spell in early February that I finally put up the antennas again. I was thrilled to work the new HO-68 satellite. Finally we had an amateur satellite with an AO-7 sized footprint and a strong, multi-mode transponder. I worked the east coast of the USA and a UA0 on the same pass! Not exactly AO-13 but still pretty cool! It also had a digital BBS mode as well. I was a big fan of the pacsats back in the old days and couldn't wait to give the packet mode a try. Unfortunately, the warm spell ended and with the thirty-below weather came all the old problems again. I decided that I had to get moving on my automatic tracking project. It was time!

Back to BASIC...

After stuffing the mouse parts into a weatherproof electrical box and rigging up a little pulley and drive belt, the next step was software. Fortunately, Microsoft now has a freeware version of Visual Basic. Unfortunately, after downloading and installing it I found another 'gotcha': Visual Basic 2008 doesn't support DDE! According to Microsoft, DDE is an antiquated way of doing things and by now all applications that need to pass data back and forth should be using some sort of COM thingys. That's nice, Bill, but all the satellite tracking software out there still uses DDE! After some Google searching I found out that I wasn't alone in my quest for DDE and there were a couple of solutions out there. The one that worked for me was a standalone DDE library written a number of years ago as an improvement on the DDE built into VB. Now that DDE is written out of VB it is quite an improvement indeed! The author has since passed away and the support group seems to have dried up three years ago but it works! Within an hour of downloading it from the dormant web site I was pulling tracking data from Orbitron into the first draft of my program.

The Mad Scientist...

With the azimuth indicating lashup ready to go, the alpha version of the software written, and the LabJack mounted in a box with the relays and power supplies, the next step was to put it all together with the antennas. Surprisingly, the elevation part of the software worked right out of the gate. A few hours of tweaking the code and testing and it was good enough to move onto the azimuth part. This was where things started to go off the rails. The biggest problem was the belt driving the little pulley connected to the optical encoder. It was a good theory but the rubber O-ring I was using got very stiff in the cold and started to crack. Furthermore, I couldn't get the tension set properly. The belt would be almost too tight at one postion and then too loose and slipping at another. Turns out that the mast is not quite centered on the carrier plate. I spent many hours and hundreds of trips up and down the ladder trying to find a solution that would work reliably. No matter what I did the belt (now a toothed microdrive belt) would still slip. I finally determined that not only was the belt slipping, but the lashup with the old mouse board was also somehow skipping pulses. By the time I figured this out I had been going at it for several days in a row. I commented on my Facebook page that I was beginning to understand how a regular scientist turned into a mad scientist! The final straw came when I accidentally broke the mouse board trying to make adjustments to how it mounted in the box. I walked away from the whole thing and decided to just leave it alone for a couple of days while I decided what to do.

A New Approach...

After pondering the situation I decided to abandon the idea of using an optical encoder. It originally seemed like a good idea and, like all ideas, it would have been fine if it had worked. In situations like this you have to know when the time is right to cash in your perseverence, admit defeat, and start looking for a new plan. In this case, I didn't need to look too far. I decided the best course of action would be to replace the encoder with a potentiometer and just do it the same way the rotator manufacturers did. Not finding anything appropriate in my junk pile I pulled up the DigiKey catalog and ordered a nice 10-turn 1K ohm pot. It took less than two weeks to arrive (no UPS in this neighborhood!) and once it was installed in place of the optical encoder things came together quite rapidly. After a couple of hours of mental gymnastics working out the math in the program to deal with the fact that my antennas drive from 180 degrees to 179 degrees (instead of the more usual 0 to 360 degrees) I was ready to give it a try.

The Holy Grail...

When it comes to writing software, eventually the eureka! moment arrives and you find that last tweak did the trick and for the first time it actually works. I had the satisfaction of standing outside and watching the antennas moving incrementally in azimuth and elevation to follow a satellite across the sky. An hour later HO-68 came up and I made my first satellite contacts ever without having to manually adjust the antenna pointing. I still have a bit of calibration to do on the elevation drive and of course the software needs some polishing but for the moment I'm going to stand back and just bask in the glory of completing a complicated project. Once this island thing is wrapped up I might even find the time to do some more work on my KW VHF amplifier...

Thursday, March 11, 2010

CK8G - Greens Island NA-182

It's now official: I'll be on from Greens Island NA-182 from April 15-20, 2010.

Located at 69 22' 36" N 125 25' 35" W in the southwest corner of the Amundsen Gulf, Greens Island qualifies for the Inuvik Region (East) IOTA Group, as confirmed by IOTA Manager G3KMA. The community of Paulatuk, NWT is a scant 15 miles to the east and from there the island is easily accessible by boat in the summer or snowmobile in the winter. While a summer operation would be far easier, more comfortable, and (probably) cheaper, I wanted to go in April to take advantage of the better spring time propagation. The operating plan for the trip will be similar to my other operations. I'm expecting around-the-clock propagation on 20m so I will concentrate on Europe during their sunrise and sunset, North America during their sunset, and Asia right after their sunrise. This should allow me to work a good balance between all the areas and still get a few hours sleep every night. To insure strong signals in both directions I will again be bringing my TH3JRS yagi and FL2100B amplifier.

Luckily, I am very familiar with the area and do not anticipate any problems actually making the operation happen. In fact, I will likely have an opportunity to travel to Paulatuk on business sometime in the next few weeks which will allow me to make all the final arrangements and maybe even allow for a scouting trip out to the island.

I waited for quite a long time to make an announcement as I was still trying to come up with a plan that included bringing a CW operator along but in the end it was just too difficult and expensive. Air travel costs in the Arctic are astronomical and bringing a second op would have tripled or quadrupled the costs of the operation. Even though Greens Island is only 250 miles from my house, the cost of airfare and air freight for myself and my equipment to get to Paulatuk and back is more than flying economy class from Toronto to Paris! Once you add in the cost of renting a snowmobile, generator, and provisions, this whole operation rapidly turns into a very expensive proposition.

nyone wishing to contribute can click on the Donate button at the right side of the screen to make a donation via PayPal or credit card.

Thanks in advance for your support and I will post any new developments right here.

John - VE8EV

Monday, March 8, 2010

ARRL DX - Life is Like a Box of Chocolates...

Now that we have a grand total of 3 (three!) active amateurs here and (theoretically) some half decent propagation I was kind of planning on this to be our first true multi-multi operation. Unfortunately, VE8DW had to go out of town and VE8GER decided he wasn't quite ready for that yet so it ended up being another single-op effort by yours truly. I didn't have the slightest idea about what to expect going in. The dramatic increase in solar activity has also been stirring up the aurora a lot more and lately I've been starting to get the feeling that overall band conditions are actually slightly worse than they were at this time last year. The forecast was also calling for active geomagnetic conditions this weekend and, with that in mind, my plan was to be ready for anything. If conditions were really lousy I'd go single-band-20m and just take whatever I could get. I also decided to stay off the spotting network for the first day in case I wanted to go unassisted.

I took Friday off from work and spent the morning getting the shack trailer all squared away for moving. The truck and the trailer hadn't moved since Sweepstakes so there was a lot of shovelling to do and I had to buy two new batteries for the truck (grrr!). Fortunately, the weather was unseasonably mild and I spent the day working in bright sunshine and wearing a light jacket. By mid-afternoon I was all set up at the contest site and plugged into the big TH6DXX tribander at 100ft and the 33ft top-loaded low-band vertical. In between trips to the store for supplies I tuned the bands a bit to see how things were shaping up. I was surprised to find that I was hearing stations from any direction I pointed the antenna. Europe and Asia were both booming in on 20m and several JA's and KH6's were loud on 15m. Even 40m already had several Europeans making it over the pole. This was my first hint that this contest would definitely NOT be business as usual!

After the opening bell I spent the first couple of hours bouncing back and forth between 15m and 20m and alternating between S&P and trying to get a run started. Conditions seemed to be pretty good out to Asia and the Pacific. A couple of rare mults (VU and E51) called in and quite a few low-power JA's and VK's but no decent rates ever developed. With just over a hundred in the log at 0400z and the jury still out on whether conditions were good or bad I popped down to have a go at 40m. Surprisingly, I was able to work almost everyone I could hear and in a half hour I picked up a dozen new mults from Europe, Asia and the Caribbean. Things were starting to look up but it was soon time for the real test. European sunrise was coming up and if the 40m conditions were any indication we were going to get a huge opening on 20m. I pointed the beam north, found a frequency and did a 100/hour run of Europeans. I should have just stayed at it but the opening was so good that the DXer in me took over and I spent the next few hours hunting multipliers on the low-bands. 40m was still cooking and I even spent a bit of time on 80m. No mainland Europe was heard on that band but I did manage to work G, GM, EI, KH6 and KL7. Because of the auroral forecast I hadn't bothered to install the 160m coil on the vertical. As a result, my only 160m contact was KL7RA. I heard KH7XS both times we tried on 160m but couldn't make the contact. If that was the only mult I missed on 160m then it was probably worth it to not having had to wade through the waist-deep snow and monkey around in the cold for an hour. Eventually I decided to try to get my head back in the game and went back up to 20m to work more Europeans. After doing another 100/hour run to Europe I just couldn't help myself and had to go up and see if anything was happening on 15m. I love sneaking over the pole in the middle of the night on 15m and sure enough I worked a few Eastern European and Middle Eastern mults. After that it was back down to the low-bands for a bit more DXing. Several more mults went into the log on 40m (including JT1CO) and I even worked JA, UA0 and LU on 80m before turning in for a much needed 3-hour nap. I set the alarm (and the timer on the coffee pot!) for 5:30am and sacked out with a smile on my face and 400 Q's in the log. Even if the bands tanked over the next two days I already had enough points for a respectable showing so anything from this point on was just gravy. Little did I know that for the rest of the weekend the gravy would be flowing like Niagara Falls!

The bands were still kicking when I got up the next morning so first thing on the agenda was another run of Europeans. For the next three hours I kept the rate meter at 100/hr until the aurora flared up a bit and the run came to a screeching halt. While I was waiting for the aurora to subside I S&P'd a bit, had a nap and ran home to grab a shower. Around 2000z guys finally started answering me on the first call so I went down to my usual watering hole at the bottom of the band. I did another 100/hour to Europe and then after that took a quick spin around the globe and Worked-All-Continents. I left the beam pointed out west for Asian sunrise and did a 100/hour of JA's and Pacific stations. Band conditions were great and only getting better. By midnight zulu the DXer in me was screaming to be let off the chain so I made the call to go single-op-unlimited and pulled up the cluster on the internet. A flurry of Caribbean and South American mults followed and I even made a successful pass from 15m to 10m with LT1F for my only 10m contact. For two solid hours virtually every needed spot on 15 and 20m made it into the log and I even worked a handful of Europeans on 40m (early!). It was a very strange situation but by that point I didn't know what to do with myself anymore. In all my previous contesting experience I had always reacted to conditions. If conditions were good, I'd run. When they weren't then I'd search and pounce. When they got really bad, I'd take a nap. Having outstanding propagation, for so long, on so many different bands was a situation that I just wasn't prepared for. I sat back and was listening to a very loud JT1CO running stateside stations on 20m while I ate my supper and after some thought I decided not to worry about strategy and just enjoy it while it lasted. I always knew that if the sunspots and the aurora ever cooperated our unique geographic location could be huge advantage instead of a disadvantage. It seemed like this was that weekend and being a rare multiplier in the contest was just icing on the cake! By 0600z the greyline had finished tracking across Asia and now the Europeans were again booming in on 20m. I worked TL0A in Central Africa and then did yet another 100/hour running Europeans. Once the run slowed on 20m I spent the next couple of hours DXing on the low-bands. After that, even with all the excitement, I was getting pretty tired. With almost 1000 contacts in the log and closing in on 'weekend-DXCC' I decided to turn in and grab a few hours of sleep.

In the week leading up to a contest I always plan to get plenty of rest. I know that if I'm well rested I can do a 24-hour contest non-stop and a 48-hour contest on 3 hours sleep each night. Unfortunately, life always seems to conspire to prevent me from getting the rest I need before the contest and this time was no exception. Several busy days in a row at work (including a 12-hour day on Thursday) and several late nights meant I was running on empty even before the contest started. When I woke up Sunday morning at 1300z the bands seemed only marginal (aka: normal) so I decided to go back to sleep and try again in a half-hour. Two hours later when I finally got going, the bands had bounced back and I jumped right onto 20m and started running Europe. It's easy to calculate how many Q's I missed by sleeping in because my operating pattern was pretty much the same all day long: run for an hour then play DXer for an hour. 15m never really opened to anywhere except Japan (around their sunrise) but there was just enough weak African and South American stations to keep my attention on that band in between runs of Europeans on 20m. D4C (Cape Verde) was audible on 15m all afternoon and every so often someone else would pop up out of the noise. Despite all the time and knob spinning the end result of my Sunday afternoon efforts on 15m were less than a dozen multipliers. I was also religiously checking 10m every half-hour or so but never heard anything.

The last few hours of the contest were the most fun of all. After the final 100/hour run of Europeans on 20m I was up on 15m digging out a few more South American multipliers when I kept hearing (and easily working) loud JA's off the back of the beam. I decided a good strategy might be to try to run JA's on 15m with the beam on South America. I did that for a little while but with no takers from South America I eventually just turned the beam to Japan. In a half-hour I worked about 50 very loud JA's, most reporting power of 50 watts or lower, many with 10 watts and even a few QRP stations! With the time running out I turned the beam back to the southeast and spent the last 30 minutes picking up the remaining Caribbean and Central American multipliers on 20m. The band was wide open and everyone was incredibly loud. Every continent except Africa and Australia was booming in, even with the attenuator on and the gain turned down. Most of the stations had huge pileups going but one way or another I managed to get through to most of the ones I needed. The last one went into the log at 2358z and then it was all over.

As one might expect, there were LOTS of high points on this outing:
  • Setting up Friday afternoon in the unusually warm early spring sunshine.
  • Working a handful of stations on four bands. The exclusive club: D4C JA1ELY JA1YPA JA3YBK KH7X KL7RA RT0C
  • Working DXCC in a single weekend. Back in the day it took me three years to work 100 countries!
  • Working several all-time-new-ones for DXCC: New Caledonia (FK8IL), Central Africa (TL0A), India (VU3DJQ), Cambodia (XU7ACY).
  • Making the 10m contact with LT1F.
  • Eating supper on Saturday night while listening to JT1CO run a huge pileup of stateside stations on 20m when suddenly he announces that he's going to 15m and gives the QRG. I hit the bandswitch and was the first to work him for a new mult on 15m (I had worked him the night before on 20m and 40m).
  • Working Antarctica (again!). I caught VP8DMH Saturday night on 20m. I get a big kick out of making 'inter-polar' contacts and I've only ever done it twice before.
  • Having almost all the bands open to somewhere at the same time. In the middle of the night, during the 0800z hour on Saturday, my log has four contacts in a row that go 15m-20m-40m-80m (Africa, Europe, Hawaii, Japan)
  • Spending five futile minutes near the end of the contest shouting into a humongous pileup on YN2EA when a W2(?) gets through and after his contact tells the guy to 'listen up for the VE8 calling you'. I was so surprised I didn't have a chance to remember who it was but thanks for the multiplier!
  • Having the presence of mind right after the contest to take advantage of the excellent conditions and the big antenna to work Maine and Rhode Island on digital for my Triple Play Award. I still need 2 more on CW and 3 more on digital but propagation-wise they're all easy ones (ND, SD and NE).

The only low-points:

  • Spending almost an hour on Sunday morning calling V51YJ on 15m for an all-time-new-one. He never did hear me. Once again, that's for all the guys that spent time in the pileups unsuccessfully calling me this weekend. It usually goes both ways...
  • Demobilizing the station during a surprise blizzard on Sunday night.

From up here you never know what you're gonna get...

This will likely be the last 'serious' contest effort from here until Field Day and Canada Day this summer but we should be able to dabble in a few events between now and then. Also, listen for me in April as CK8G from NA-182.

John - VE8EV


ARRL DX Contest, SSB

Call: VE8EV
Operator(s): VE8EV
Station: VE8EV

Class: SO Unlimited HP
QTH: Inuvik, NT
Operating Time (hrs): 36

Band QSOs Mults
160: 1 1
80: 16 9
40: 68 39
20: 984 96
15: 149 27
10: 1 1
Total: 1219 173 Total Score = 631,661



The short version: Wow!

Long version at

John - VE8EV