Sunday, January 1, 2023

Auroral Zone Case Study

I haven't had much time for radio these days.  At this latitude, the return of the sunspots put the kibosh on my 160m dxing and with 322 (mixed, current) DXCC entities confirmed there haven't been any workable new ones available for me.  My Station 2021 project has been languishing and even my existing station has fallen into disrepair.  My rotator quit working in 2021 and this spring I accidentally overdrove my amp and blew something.  Life was busy but sooner or later something would come along that motivated me to get back on the air.  I still followed the DX news and was keeping an eye out for any new ones coming along.  I followed (and donated to) the 3Y0J expedition to Bouvet Island, still on track for the end of January 2023, and also took note of the one-man operation heading for Crozet Island.  When Thierry F6CUK arrived on Crozet and began operating as FT8WW over the Christmas holidays I knew that it was time to get it together.

When swapping out a couple of boards in the amplifier didn't solve the problem I determined it had to be an issue with my homebrew T/R switch and attenuator.  After removing it and putting it on the bench I found that a 50 ohm resistor in the attenuator had failed.  Stands to reason that accidentally pumping 100 watts into a 30 watt resistor too often would eventually lead to problems!  I was already planning to replace one resistor in there to adjust for my new 10-watt IC-705 but I didn't have any spare non-inductive 50 ohm resistors.  Nothing in the junk box either but I did find an old splitter/combiner set that each had a 25 ohm resistor so I put them in series and voila- problem solved.  Fortunately, the antenna with the broken rotator is pointed North over the pole so I didn't have to climb the tower in the dark and 40 below, at least not until the Bouvet activation later this month. 

Once all that and all the other minor repairs and software upgrades were done it was time make a contact!  Well, that part was not going to be so easy.  FT8WW was
so far only using a low wire antenna .  The active solar conditions would make signals very weak as the path between here (at 68 degrees North) and Crozet (nearly antipodal from here) travels straight over the North pole (which means passing through the aurora TWICE) and then all the way down the other side of the world.  At least we marginally shared a grey line between midnight zulu and 0200z.  That would be the best time to try.

The entire eastern hemisphere is straight over the pole from here and Crozet is no exception.

Conditions were lousy all week.  The elevated X-ray Flux attenuates signals like crazy up here!

I was in the shack every evening watching for him.  He was operating mostly FT8 digital mode and alternating between the 30m band and the 20m band.  FT8 is great for making contact with weak signals but it is strongly affected by the multipathing and phase shifting from the aurora.  The sun was spitting out B and C-class solar flares every few hours.  The aurora was blazing overhead and the absorption was extremely high.  Most of the time I could only decode a few of the hundreds of other stations calling FT8WW.  You could even see on the waterfall display how the geomagnetic activity messed with the signals.  Instead of straight lines on the scope they would often "bend" in the middle like digital macaroni.  Occasionally I would see a weak trace on the scope that I assumed was FT8WW but the horrible conditions prevented successful decoding.  I could see the KL7 stations in Alaska calling and giving him good signal reports but even stations only a few hundred miles south of here have a path to Crozet that manages to skirt the edge of the auroral oval and follows the grey line perfectly.

Nevertheless, I persevered. Finally, on New Year's Eve, FT8WW was on 30m around 0100z and as I watched the signals all started to get a bit stronger.  Then I finally got ONE decode of FT8WW, only -18dB.  Three minutes later I got another decode, this time -15dB.  I started calling him.  4 periods (2 minutes) later he decoded again, this time I got both of his streams (he was using MSHV and running two carriers).  Then nothing again for another 5 minutes.  I could SEE his transmissions on the display but they just weren't decoding.  Finally, I got another decode and it was the one I wanted to see. He was answering me!  I acknowledged my report (sent RR73) and right away received an RR73 from him.  Done and done.  And that was it!  I didn't get any more decodes after that.  I only received a total of 7 transmissions from him and between calling and answering I transmitted 13 times over six minutes.  

So what actually happened in that very short time span?  Here is what I think was going on.  The first thing was the auroral oval.  Here is the NOAA Ovation forecast for that period around 0100z:

You can see that there is a gap in the oval around solar noon.  I was just inside the gap which probably helped to get his signal down to me.  The path between us (marked in red) also crossed a slightly narrower auroral band on the other side of the pole.

Shooting through the gap helped but the real answer was the solar wind.  Like earthly wind, it "blows" fast or slow depending on the level of solar activity.  The stronger the solar wind the worse the space weather is for HF radio in the polar regions.  And again like the earthly wind, it also has "gusts" but these variations aren't changes in the speed.  They are changes in the magnetic polarity.  In the Northern auroral zone, the more negative the magnetic polarity the stronger the geomagnetic badness is.  Here is the NOAA real-time solar wind plot for the time of my contact:

You can see right at the time I started getting a few decodes from FT8WW, the magnetic polarity (Bz) of the solar wind peaked in the positive direction which momentarily eased the distortion from the electromagnetism.  This effect is especially pronounced on the lower HF bands.  Our contact was on the 30m band which tends to share characteristics of both the lower and higher bands.

#323 finally in the log!

As an aside, for those radio Luddites out there, CW transmissions are also affected by the geomagnetic field here in the same way.  For anything faster than about 15 words-per-minute, the multipath distortion makes CW sound like a weak RTTY signal.  The differences between dots and dashes is virtually indistinguishable.  Think about that the next time you're in the ARRL CW Sweepstakes looking for that NT multiplier but blasting away with the keyer set at 30wpm!

Next up at the end of January is a two-fer: Bouvet Island and Burundi, both of which I have been waiting for a chance at for a long time!  The last attempt at both of those did not end well but I have a feeling that 2023 is going to be the year they finally make it into the log.  Fingers crossed!

Monday, May 24, 2021

Station 2021

Looking only at the content of this blog you might think there was not much going on here recently.  That is true to a degree.  I was working 160m pretty regularly late last year and recently I've managed to get on the 17m and 30m bands enough to confirm DXCC on both.  That just leaves 12m and 160m to complete 9-Band DXCC.  I still need 9 more all-time-new-ones on any band to make DXCC Honor Roll but that's just a waiting game.  Only the much-cursed Burundi is not at the top of the most-wanted list but still not confirmed in my log.  It will likely be years before the rest of the rarest-of-the-rare are ever on the air at all.  The time has come, however, to make some big changes.

Somewhat by design and some by coincidence, I have always changed things up along with the progress of the 11-year solar cycle.  I built my first high-performance HF station for contesting and DXing back in 2013 at the beginning of Cycle 24.  As the cycle began to wane in 2017 I optimized the station for working the lower HF bands and I cruised through the sunspot minimum over the past few years without skipping a beat, earning the 5-Band DXCC award and DXCC Challenge.  Now that the sun is starting to awaken again it is time to make changes.

I've been dreaming of building a 2m EME station for 25 years now.  I've built huge imaginary antenna arrays in my head and even started building a tube-type VHF kilowatt amplifier once (it was a fail).  Back in 2015 I started to get more serious about the whole idea.  I completed the hardware and software for the azimuth/elevation tracking equipment.  I found W6PQL's web page and started planning for a solid-state LDMOS amplifier.  Most importantly, I started collecting all the little bits and pieces that I would need to put everything together.  I found a 2000W 50V power supply on eBay for $30.  I scavenged coaxial relays, hardline cable and connectors, aluminum tubing and rod for antennas, and a huge assortment of other odds-and-ends that will all have their place in the final product.  I'm even planning to repurpose the 50W UHF amplifier module that I build a few years ago.

For HF I had wanted to put up my DMX tower and the TH6DXX again but concluded that a more sensible option would be a smaller tower with a 10/12m duoband yagi (built from old TH3JRS parts) and a re-worked 6m yagi.  I really hadn't given too much thought to six meters but then I had a good idea for a small linear amplifier to use on that band and with the optimized yagi it should be good for making EME contacts on the horizon (at least with the "big guns") and working the infrequent band openings, possibly even over the north pole.

In the past my plans had always included my venerable Kenwood TS-2000.  It was the only radio I owned with VHF/UHF capabilities but it had long ago succumbed to the endemic TS-2000 filters failure, ostensibly caused by overheating the ceramic filters when production first changed to lead-free solder.  A couple of years ago however, I was considering a new radio to put in my boat and came across the first information about the then-unreleased Icom IC-705.  It was only a 10 watt QRP radio but I thought that maybe with some outboard amplifiers it might be okay for marine use.  The more I thought about that the more I realized that I'd rather have the IC-705 in the shack and just fix the old Kenwood to use in the boat.  I already had an HF amplifier that only required 50mW drive power and a VHF LDMOS amplifier would likewise require only a few watts of drive.  The 705 also boasted an astonishing array of features like a direct-sampling DSP receiver, touch screen, bluetooth, GPS, DStar, and on and on and on.  The only thing it lacked was full-duplex cross-band receive which I required for working satellites.  That was easily fixed by including a dedicated SDR receiver in my plans.  The FunCube Dongle Pro+ that I already had would work perfectly for this.

Over the past few months I got more serious about getting this all done THIS YEAR.  I relentlessly completed all the detailed design drawings for the controls, feedlines, and antennas.  The concept is a simplified design that will make everything happen with the flexibility to work HF and 6m, satellite, and 2m EME, provide high performance and low-loss, while also protecting the expensive amplifier components.  After innumerable iterations and revisions, all the details have now been finalized and I have almost completed obtaining all the remaining parts required to make everything happen.  Only the IC-705 is waiting to join the party.

This is how it will all go together.  Blue is RF and red is control lines.  I'm very excited to finally get on with the new build and look forward to blogging about all the individual elements as they come together.  Stay tuned!

Sunday, January 3, 2021

DX Year in Review

Shortly after I wrote my last annual 'DX Year' post in early 2020, things changed pretty fast once all the travel restrictions came into effect from the global pandemic.  Nevertheless, despite the lack of DXpeditions, in November I finally managed to break my two year dry spell and worked JX2US on Jan Mayen Island for an all-time new one #322.

Despite its relative proximity to me, there has not been much activity from Jan Mayen in the last 10 years and I somehow managed to miss every dxpedition and the occasional operator at the Norwegian weather station there.  Ken LA7GIA put in a brief appearance (only a couple of hours) from there in 2019 but was planning a much larger operation for 2021.  Then Eric, LA2US, was posted to the island around the same time the dxpedition was announced, and eventually it was cancelled when Eric announced his intention to make an effort to fulfill the needs of DXers such as myself (which he did admirably!).  I never did catch him on 160m as I had hoped but I did manage a few contacts on 40m and 60m during his time there.

In early February I started to notice that I had amassed almost 1000 DXCC Challenge points and a little push was all it took to confirm enough on LoTW to qualify for the award.  A couple of years ago I had passed on the new plastic 5-Band DXCC Plaque (I ended up just getting the certificate and making my own 'old-school' plaque) but the new plastic DXCC Challenge plaque looks pretty nice hanging on the wall of the shack here.


I spent a lot of time on 160m this season (September through December) and picked up a dozen new ones there to bring my total up to 70 confirmed on that band.  Those four months are really the only productive ones for DXing on 160m from here.  I'm not sure why but long-distance 160m propagation always tanks right after the new year even though we still have lots of dark hours left.  It will be interesting to see what happens next season with the increasing solar activity.  I'm not expecting conditions to be very good on Top Band from under a mostly disturbed auroral oval. 

That said, in keeping with the start of the new solar cycle I'm already making plans for higher bands and some other interesting activities.  Stay tuned!


Monday, November 30, 2020

Here It Comes!

On November 16th, 2020 the reported sunspot number was zero.  Since then it has rocketed up to an astonishing 83 as of November 29th.  The sunspot number wasn't forecast to hit that level until 2023 but, ready or not, here it comes: solar cycle 25.  The starting date of a solar cycle is actually determined retroactively and a few months ago it was determined that cycle 25 really began a year ago in December 2019.  For hams, though, the real beginning of a new cycle is when the solar flux starts getting high enough for the upper HF bands to open up and starts generating stronger signals than we are used to on the middle bands.  I had noticed quite a few times recently that the 12m band was open, mostly to the US west coast and Asia.  Last Friday, however, even 10m was open and I made my first new contacts on that band since 2015.  Just for fun, I even made a series of QSOs that started on 10m and progressed through each band all the way down to 160m (I didn't have any luck on 60m, even though I was hearing a few weak European stations).  A couple of days before that I had worked a guy in Washington state on 40m FT8, off the back of my beam, only running driver power (15 watts) and I got a report from him of +23dB.  I was seeing him at +31!!  I can see how the effectiveness of the FT8 mode may soon become somewhat degraded as more and more powerful signals are crammed into such a tiny sliver of spectrum on each band.  Some expansion of the FT8 sub bands seems very likely in the coming years.

Ol' Sol has unexpectedly become quite active!

Its not all fun and games, though.  The more active the sun becomes, the more it tends to disrupt propagation for high-latitude stations like mine.  The more active part of the cycle is marked with lots of minor disturbances that stir up the aurora and generally degrade propagation.  Now the increased solar flux is making for stronger signals that can more easily break through the disturbed conditions.  On days when the absorption is low and the flux is high (like last Friday) radio conditions here can be outstanding.  There is also an increase in major disturbances like the little M-class solar flare that we saw this past weekend. I saw icons and colors on my propagation monitoring software that I haven't seen for years as the D-layer absorption spiked here and both the x-ray flux and proton flux climbed off the bottom of the scales where they've generally been sitting for the past few years.  I blogged about how this tends to degrade the signals here back at the beginning of the last cycle and the details haven't changed at all.  See here and here.  An active sun makes for some very interesting effects up here in the polar region.

Colorful, isn't it?  :(
When the last solar cycle was winding down in 2015 I put a lot of effort into getting my station ready for the sunspot minimum and it was well worth it. I received my 5-Band DXCC award by finally working the necessary number on 80m and I'm even up to 72 countries worked to date on the 160m band.  Now, with the changing of the radio seasons upon us, I'm thinking about putting up antennas for the high bands again.  I don't know yet how the coming of the new maximum will change my operating habits but it always has before.  I don't expect that this time will be any different...

Monday, August 24, 2020

Marine Mobile

Some of my fondest childhood memories are of camping out on the water in our family's big cabin cruiser.  My dad would bring along a Heathkit receiver that he built and while we relaxed and fished he would listen to interesting stuff like hams and marine HF-SSB ship-to-shore traffic.  I would marvel at the fact that we were on a boat out in the middle-of-nowhere in the Arctic and listening to cruise ship passengers phoning home from the Caribbean.

After languishing under a tarp at my dad's place for 20-odd years, the old boat eventually followed me home and in 2015 I did a complete restoration on it.  Ham radio was in the plan from day-one.  During the refit I made sure to install all of the antennas and cabling that would be required.  The HF antenna is a 19-foot long two-piece fiberglass vertical mounted on the gunwale with a counterpoise of 2-inch aluminum foil tape run along the inside of the hull right at the waterline.  On the roof I installed an MFJ-1436 tri-band whip for VHF/UHF and 6m.  I used the aluminum tape again under the fiberglass to form a suitable ground plane for the whip which I intended to use mostly for working satellites.  Summers up here are quite short and it was already August that year before the boat was finally ready to go in the water.  The installation of the radios had to wait until the next season.

Back on the water after all those years.

My plan for the radios got somewhat complicated.  What I really wanted was an SDR version of my venerable old Kenwood TS-2000.  My Kenwood was gathering dust, having fallen victim to the dreaded "ceramic filters failure", and there was nothing available in my price range that did 100-watt HF, full-duplex all-mode VHF/UHF for satellites, and was SDR-based.  The closest I could come up with back then was a Flex-1500 QRP radio with an HF amplifier and transverters and amplifiers for VHF/UHF.  I'd mount all the gear in a portable travel case and bring along my laptop to operate with.  To make it all work the way I wanted would take a lot of homebrewing.  The HF part was easy, or so I thought.  In the junk pile I had an old commercial HF transceiver.  I pulled the 100-watt amplifier off of it and added connectors and a T/R relay.  Since I planned to operate into a non-resonant antenna, I bought a cheap manual antenna tuner which would also take care of harmonic filtering.

The VHF/UHF part was even more complicated.  The little Flex radio had a separate transverter output so I built a pair of switchable transverters and brick amplifiers for each band.  Since I needed full duplex for satellites, I opted for a separate receiver using an RTL USB dongle built into the transverter box.  With everything bench tested in the shop and mounted on a plastic board in a carrying case I was ready to go.  Or at least I thought I was.  I took all the gear and put the VHF/UHF whip on my truck to see how it worked.  It didn't.  I couldn't seem to hear anything.  I pulled out my Arrow dual-band yagi and that seemed to receive ok but, despite my best efforts at shielding when I built the transverters, there was significant desense when I was transmitting on the opposite band.  I had a FunCube Pro SDR dongle which I pressed into service to replace the RTL stick (thereby bypassing the 10m IF chain) and it worked but obviously
some re-engineering was needed.  With the 2017 boating season fast approaching I decided to just focus on getting the HF setup going.

As I mentioned before, the summers here are short.  If time and weather cooperates I can
maybe get the boat in the water a dozen times between mid-June and Labour Day.  Over the next couple of summers I'd bring the radio case and the laptop out with me every once in a while but getting it to work on HF proved surprisingly frustrating.  The manual antenna tuner was very finicky and the laptop running the PowerSDR software would frequently lock up from RF on the USB cables before I could get the tuner adjusted.  I'd spend a half-hour or so and then give up until next time.  More ferrites.  Different cables.  Oops, the amp blew up, need another one.  Maybe an auto tuner?  Nope, won't tune with so many unattenuated harmonics.  Oops, blew up another amp. After the summer 2019 season I officially gave up.  That winter, I sold off the Flex radio and the auto tuner and decided to just fix up the old TS-2000 and use that.  A handful of new ceramic filters and a couple hours of delicate solder surgery was all it took.

With the repaired TS-2000 in the boat this summer, I got the HF working right away in June.  I had initially assumed that the auto tuner in the radio would be able to load the big fiberglass vertical but alas it would only tune up on 30m.  Before the next trip I put the old manual tuner from the previous iteration in and was then able to operate across the HF bands.  I also gave up on the big laptop and opted to use the Pipo X8 that was already mounted on the dash.  The little nav computer was a bit slow but would run WSJT-X without much difficulty.  I still wasn't having much luck with VHF/UHF though.  The MFJ antenna didn't seem to work at all.  After checking all the cables I started to think that there might be something wrong with the antenna itself.  Since by this time it was long out of warranty, I decided to just buy a new one.  At the same time, I also opted for another automatic antenna tuner.  The manual tuner did work but was still finicky and the longer this project dragged on the less patient I was becoming.  After scouring the marketplace I found that HRO in Anaheim had stock on both an MFJ-939 auto-tuner with the Kenwood cable AND a replacement antenna.  Being so close to everything finally getting sorted out, I also opted for express shipping.  Even here in the far north, Priority Express mail from the USA gets here in about a week.  HRO shipped them out the same day and I followed the tracking as the package passed through LAX and landed in Vancouver two days later.  Then, nothing.  No more tracking updates.  USPS said it arrived in Vancouver, Canada and Canada Post said it was waiting to receive it.  I thought maybe it fell off a truck or something!  After 21 agonizing days (yes, THREE WEEKS!) Canada Post finally received the package and sent it to clear customs.  It was out of customs the same day and arrived here a week later.  I have no idea what it was doing all that time at the airport in Vancouver but I did see anecdotal reports of mail backed up at the border for weeks on end so I was just happy to have it eventually arrive here intact.

The HF station mounted at the helm.  The radio on the left is a marine VHF.

I installed the new tuner right away (works great!) and a couple of weeks ago I got around to replacing the VHF/UHF antenna.  Unlike the HF (which only works on the water), I could do this part in the driveway.  Armed with my SWR meter, antenna analyzer, cables, and the HF/VHF/UHF triplexer, I pulled the boat out from under the carport and put up the new antenna.  After checking everything and hooking up all the cables and the triplexer, I made a satellite contact on AO-91.  After four years of monkeying around I finally had it all working!  I gathered up all of my tools and test gear, closed up the boat, and put it back under the carport awning, eagerly anticipating the next boat trip. 
I paused as I walked into the house and a sinking feeling came over me.  I went back outside to look and, sure enough, I forgot to fold over the antenna after I was done and broke it off backing under the carport. $@#%!^@#$!!!

Actually, this story does have a happy ending.  All that broke was the brass NMO mount and I was able to quickly rustle up a replacement and install it.  I loaded fresh Keplerian elements into Orbitron and set up WiSPDDE to handle the radio tuning.  In between fishing and relaxing last weekend I made over a dozen satellite contacts as we swung on the hook in a beautiful local lake.  Life is good!

Saturday, February 8, 2020

DX Year in Review

I suppose I could have just left the rest of this post blank.  For the first time since I was licensed (and active) there were no new DXCC entities worked in a calendar year.  Ducie Island in 2018 was the last one.  Things are looking up for 2020, however.  Preparations for the expedition to Swains Island in March are proceeding apace and has now been joined by a surprise announcement of a trip to St. Peter and St. Paul Rocks, also in March.  And maybe, just maybe, this will also be the year that the Rebel DX Group makes it all the way to Bouvet Island.  Time will tell...

In the meantime I've been chipping away at 160m and picking up the odd one here and there on 80m.  I just noticed recently that I'm only about 50 away from the DXCC Challenge award for working 1000 band/country slots.  Not quite sure how I managed that but I guess they do add up over time.  To that end, when nothing else interesting is going on I'll watch 40m and pick up new ones there if they pop up.

Hopefully I'll have more to write about in next year's review!

73 and good DX

Update: Since I wrote this less than two weeks ago BOTH Swains Island and St. Peter St. Paul Rocks expeditions have been postponed or cancelled!  I will surely be stuck at 321 forever :(