Posts Tagged ‘Ionosphere’

Radio propagation and space weather course

As the propagation columnist for several amateur radio magazines, I hear from a diverse group of interested people that find space weather and the propagation of radio waves fascinating. I admit: I am a space weather and radio propagation nut, and it is always good to correspond or meet with other interested folks. This is an aspect of our hobby that never grows old, as there is so much that we don’t yet know–we communicators are in a perfect space to make discovery and to make improvements to our understanding of this science.  Over the years, I’ve heard a lot from readers of my columns, expressing their fascination with the science of radio and solar phenomenon.

Are you interested in learning about the Sun and the Sun-Earth connection (space weather), including topics of sunspots, solar flares, coronal mass ejections, and so on?  Do you want to delve deeper into topics including the ionosphere, the magnetosphere, and how radio waves propagate from transmitter to receiver?

foF2 Map for June 2014

The critical frequency (foF2) for mornings during June 2014.

You might consider a time-proven “course”–material that is very comprehensive–that you can self-study, to become well-versed in this information. The course (one that has been used in professional disciplines) is offered either stand-alone, or bundled with the ray-tracing PropLab PRO software. 

Some may say, “But, I like the magic of just getting on the air and trying my luck! If I learn all this stuff, then it becomes science, and not a hobby.” It is true that there’s a joy at being dazzled with the magic of radio; buy a super cool transceiver, and a factory-made antenna with coax already fitted with connectors, adding the necessary accessories to make it come alive, then begin exploring the shortwave frequencies. Magical, indeed! But, there are many in the hobby that wish to learn how all of that works. Some even begin learning how to build antennas, radio kits, and discover the joy of the “science” of radio. A few eventually take the step with gained “scientific” knowledge of electronics, and they design and build equipment for their hobby. The course is part of that mix: learning how the Sun affects getting a radio signal from point A to point B, and how to leverage their time and efforts, is a joy, indeed.

Interested?  Here’s the web page:


Ray Traced Radio Wave

PropLab PRO creates ray-traced radio wave analysis


If any disclosure is necessary, here you go: The proceeds from a purchase of this course go to the funds I use to keep,, and other resources at, plus up and running. There are monthly fees, yearly fees, and software licensing to cover, as well as the purchase of hardware from time to time. These operating and maintenance funds are mostly covered by me, Tomas, NW7US, out of my personal funds. Any donations and sales helps out. Haters and Hecklers can send their comments to the bit bucket.

73 de NW7US

An Amazing Moment in Space Weather – Massive Solar Eruption June 2011

While many are talking about how Solar Cycle 24 is the weakest since the Maunder Minimum (the period starting in about 1645 and continuing to about 1715 when sunspots became exceedingly rare, as noted by solar observers of the time — see this Wiki entry), there are moments when activity on the Sun strongly increases, providing brief moments of excitement.

Here is a case in point, witnessed by the Solar Dynamics Observatory (SDO; see SDO Mission) on June 7, 2011, when the Sun unleashed a magnitude M2 (a medium-sized) solar flare with a spectacular coronal mass ejection (CME). The large cloud of particles mushroomed up and fell back down looking as if it covered an area almost half the solar surface.

SDO observed the flare’s peak at 1:41 AM ET. SDO recorded these images in extreme ultraviolet light that show a very large eruption of cool gas. It is somewhat unique because at many places in the eruption there seems to be even cooler material — at temperatures less than 80,000 K.

This video uses the full-resolution 4096 x 4096 pixel images at a one minute time cadence to provide the highest quality, finest detail version possible.  The color is artificial, as the actual images are capturing Extreme Ultraviolet light.

It is interesting to compare the event in different wavelengths because they each see different temperatures of plasma.

Credit: NASA SDO / Goddard Space Flight Center

Video: – Massive Solar Eruption Close-up (2011-06-07 – NASA SDO)



Solar Plasma Filament Eruption – The Sun – November 6,7 2013

The Sun currently is active, with powerful, complex magnetic structures that have formed a healthy number of sunspots. We are seeing a fair number of x-ray flares, which push the 10.7-cm flux higher than we’ve seen in a while.

Sunspots and flares means better propagation in general, especially on the higher frequencies of the shortwave spectrum.  While a flare can cause a short period of “blackout” conditions (especially on the lower frequencies) on the sunlit side of the Earth, such activity is part of the positive activity that ionizes the F-region, providing for DX.

Here’s a movie of one such flare and the release of solar plasma, a release known as a coronal mass ejection (CME): At about midnight, UTC, on 6 November 2013, a moderately-strong M-class flare erupted, with a “beautiful” CME:


We will see continued flare activity over the weekend, so expect great conditions on the HF bands, with momentary blackouts.  Keep up to the minute on space weather at

73 – de NW7US
Propagation Columnist, CQ Communications Magazine, Popular Communications Magazine

My first 50-MHz QSOs with Japan from new Colorado QTH

I made contact with 19 Japanese stations yesterday afternoon (June 14, 2013) on the 50-MHz (6 meter) band between 2314 and 2356 UTC.  This was my first “JA opening” on 50-MHz in a LONG time; my last Japanese QSOs on 50-MHz were back in the ’90s when we lived in Tiffany, Colorado (grid square DM67), a bit south of our new home in Glade Park, Colorado (grid square DM59pa). During the years we lived in Vermont the furthest west I ever reached on 50-MHz was Guam, a bit short of Japan.

If I’m anywhere near my radio (and sometimes when I’m not – thank you, smartphone) I point a Web browser at the “ON4KST 50 MHz IARU Region 2″ chat page to read late breaking 50-MHz DX related news, spots, rumors and general chatter especially during during times of the year when 50 MHz propagation is known to be possible:

  • Around the spring and autumn equinoxes for Trans-Equatorial Propagation (TEP)
  • May through the first half of August for the northern hemisphere summer Sporadic-E (Es) season
  • A few weeks either side of New Year’s Day for the northern hemisphere winter Es season sometimes with propagation links to the southern hemisphere
  • And – if we had more sunspots than Cycle 24 has seen fit thus far to bequeath – the northern hemisphere autumn and winter for F2 propagation

(Of course 50-MHz can open at any time of day and year and much of what happens on “The Magic Band” is poorly understood.  But the periods above are the ‘prime time for six.’)

It all began yesterday afternoon at 2200 UTC (which was 4 pm Colorado time) when Han JE1BMJ, a noted 50-MHz enthusiast and propagation theorist, was reported on 50,090.5 kHz by Jay K0GU on the ‘KST chat which grabbed my attention.  Jay lives in Wellington, Colorado (grid square DN70mq) about 230 miles east of me and is a dedicated, experienced 50-MHz DXer.  Jay hears a lot of stations before any one else in the Rocky Mountain region and his ‘KST posts are always worth noting.  I turned my new 50-MHz antenna (thanks to K7JA for assistance in building and installing this last month and of course G0KSC for the design) towards Japan – 312 degrees azimuth – and started listening.  At 2226 UTC I started hearing Han’s CW (Morse Code) signal slowly fade and out.

Green Heron RT-20D controlling a Spid RAK rotator

Green Heron RT-20D controlling a Spid RAK rotator

When I first attempted to make contact with Han but he was unable to hear my complete callsign and was responding to me as “AA7X” (leaving off the final T, I am AA7XT).  I eventually stopped calling JE1BMJ – I didn’t want to ‘hog the DX’ as Han and other Japanese stations were being heard over much of the US.  For a two-way contact to be considered legitimate in ham radio circles each party must copy correctly the other parties callsign and preferably some other information such as a signal report. caught the action! caught the action!

At 2314 I noticed Han’s signal had gotten louder so I called him again and made a solid contact straight away.  Success!  I was amazed my ‘barefoot’ (no amplifier, only 80 Watts output) Elecraft K3 transceiver and InnovAntennas 8 element LFA Yagi (an awesome antenna but it was on a tower parked at only 3 meters [10 feet ]above ground due to recent high winds) were making the 9,000 kilometer journey!  At ten feet up towards Japan my antenna was looking into a hillside!  I listened to Han work other stations for a few few minutes and savored the moment.

InnovAntennas 8 element 50-MHz LFA Yagi

InnovAntennas 8 element 50-MHz LFA Yagi

Here’s a short YouTube video I made of JE1BMJ’s signal yesterday:

I would have likely made many more contacts if had started calling CQ earlier!  For a long time I was only hearing JE1BMJ so I didn’t bother calling CQ until around a full hour after opening started.  I had an ‘instant pileup’ after first my CQ call; clearly I should have started CQing much earlier – Doh!  I proceeded to work 18 more Japanese stations before the path closed:



Toshi ,JA0RUG, who I worked during this opening, sent me a MP3 recording of my signal as heard in Japan (click on link to listen to the audio):


Here are the grids I worked during yesterday’s opening:

The WG7J Gridmapper is a great post opening analysis tool

The WG7J Gridmapper is a great post opening analysis tool

The first hop was certainly Es as I was hearing loud stations in Oregon, Washington and British Columbia at reasonable Es single distance, but how about the rest of the way?  Han, JE1BMJ, the first station I worked in this opening, has developed a theory on these openings – which cluster around the summer solstice – and he has dubbed the mechanism “Short-path Summer Solstice Propagation” aka SSSP.  Articles on SSSP by JE1BMJ, W3ZZ, WB2AMU and KH6/K6MIO have been published in Dubus, CQ VHF, Six News and elsewhere.  Here are a few links:

So far, SSSP, if it in fact exists (such mysteries make 50-MHz DXing a fascinating avocation!) seems to be unique to the 50-MHz band.  I look forward to learning more about SSSP as more and more DXers become aware of the mode and watch for it.  Ham Radio is the exception to the ‘watched pot never boils’ rule of thumb.  In DXing, an unwatched band never opens!  One interesting note is that propagation like SSSP frequently repeats itself the next day so you can be sure I will be at my radio this afternoon!

73 and CU on the Magic Band!

Bill AA7XT


PS:  Some interesting recordings of 50-MHz DX signals heard in Japan by JE1BMJ can be found here (including yours truly):

Show Notes #104

Episode #104 Audio (Listen Now):


  • Pete is back on the show along with Russ


  • Hamvention 2013 is happening May 17-19, 2013 in Dayton, Ohio. LHS reached the donation goal and thus will be in the Hara Arena. Thanks to Sierra Radio Systems for their incredibly generous donation that put us over the top. We will be talking with George from Sierra and Nick from Pignology in Episode #105. It’s a show you DO NOT want to miss.
  • Bill, KA9WKA, has announced that he is also going to be on hiatus for a while. Therefore, we now have an opening for a show notes taker and keeper of all knowledge! If you’d like to be that person, please send us an e-mail or get in touch with Pete or I in the IRC channel.
  • Website that lists known Linux Events.



  • Topic for short discussion: How is Ham Radio Free and Open Source?
  • Due to the length of the interview with Steve Nichols, feedback will be moved to after the interview in Episode #105.

Contact Info:



LHS Episode #104: Propagation 101 with G0KYA

Steve_Nichols_220412_smallWe sometimes on this show attempt to bring you interesting interviews with people who are both computer literate and ham radio literate at the same time. In this case, we bring a scholar, physics buff, aerospace engineer and brilliant guy, Steve Nichols (G0KYA), to discuss the science of radio wave propagation. No need to turn the show off before it even begins. Steve makes understanding the Earth’s atmosphere, its magnetic field, and a ton of stuff about the sun simple and approachable. No mind-bending equations, no physics lectures, just some great information for anyone interested in learning how a radio signal gets from here to there. A bunch of follow-up information in the form of books and Web sites are provided as well, links to which will be in the show notes, for anyone who wants to further their education. Thank you as always to our loyal listeners. Make sure to tell a friend next time you’re out for a cold one. The more the merrier.

73 de The LHS Guys

Planning My New QTH (Ham Radio Station) Part I Of III: Taking Inventory Of My Evolving Interests

We moved to Glade Park, Colorado last November and, unusual for me, I’ve been planning my new QTH before commencing construction (QTH = ham radio ‘Q code’ for ‘location’ which hams use to as a catch all term for their home and ham station).  I’ve had pretty big ‘antenna farms’ over the years in Malibu, California, Tiffany, Colorado and East Topsham, Vermont.  Each time my enthusiasm to get back on air led me to ‘plan’ as I built.  Although each of these stations performed very well on the air, I eventually realized that each station could have been better.  So this time,  it’s different…

My inspiration to be patient and plan has been the detailed and thoughtful strategic planning that my friend Tom Taormina, K5RC, is employing in the updating of his potent ‘contest station’ (a ham radio station optimized for radio contesting a/k/a ‘radio sport’) near Reno NV.  Tom has a club callsign that he uses in contests, W7RN.  If you’re a radio contester you no doubt recognize this callsign.

Tom was a NASA executive during the Project Apollo glory days and today is an author and ‘Forensic Business Pathologist’ using his NASA expertise to advise corporations on employing rocket science – literally – to operate their businesses better.  Tom’s contest station planning is extraordinary in scope and detail.  (Tom’s business Website is and you can learn more about his contest station at

Since re-entering the amateur radio hobby in 1989 I have spent most of my ‘on air’ time operating radio contests on the HF bands (HF is technically ‘High Frequency’ 3 to 30-Mhz, but most hams consider the Medium Frequency 1.8-MHz ham band to also be part of the HF spectrum) and in between contests making contact with as many countries as I could on each different amateur radio band between 1-MHz (’16o meters’) and 50-Mhz (’6 meters’).

By 2003 I passed 2,800 total ‘band-countries’ (total number of countries contacted on each band added together).  2003 was the year my daughter was born and also when my professional responsibilities – then in the music business – multiplied.  Fatherhood and career conspired to soak up my ham radio time and my station, we were living in Vermont at the time, gathered dust for 8 years by which time I had changed careers and moved the family back west.

Most mornings I wake up and gaze at the sun rising east of our 35 high desert acres in Glade Park CO, where we moved late last year.  Glade Park is a small community perched on a high plateau west of Grand Junction.  Its rural, scenic, private, dry, sunny and as far as I can tell, a great place to ‘grow some aluminum’ and ‘work the world.’  Sipping my morning coffee I frequently wonder what signals are being refracted down all around me from the solar energized ionosphere and ponder what antennas I should build to find out.  I’ve also been taking careful of the moon as it traverses the sky above our property, especially moonrises (more on that later).  Gradually, day by day as the sun and moon rise and fall, a station plan has come into focus.

The first step in the planning process was taking inventory of my evolving ham radio interests.  This hobby is a big tent with close to a million licensees in the U.S.A. alone.  Some hams enjoy providing communications as a public service during natural (and man made) disasters – ‘when all else fails amateur radio gets through,’ others enjoy long, ‘rag chew’ conversations with friends old and new around the world, some enjoy building and tinkering with gear, some ‘chase DX’ (make contact with odd bits of geography, the further away and more obscure the better), and some focus their energy on radio contesting.

In the past radio contests and DXing motivated me to get on the air.  My years away from operating my station have given me time and space to meditate on exactly why I love this hobby.  I eventually realized that it wasn’t so much the contest scores or the growing list of countries contacted, although there was pleasure in these accomplishments, my core interest is my fascination with the physics of what makes a radio signal propagate around the world.  Take the energy used by a common household lightbulb, push it down a coax cable connected to a bit of aluminum and, voila! electromagnetic waves are launched into the ether coming back to earth thousands of miles away.  This has intrigued me since I was a teen age ham radio operator in the 1960s.

DXing and contesting activities tend to reveal the most extraordinary radiowave propagation; this I have come to realize is why I enjoy DXing and contesting and why I will continue to contest and chase DX but with changed focus – some of the most extraordinary propagation modes and paths are revealed during radio contests and while chasing DX.

My passion for antennas is direct by product of my passion for propagation.  Better antennas allow you to explore more exotic propagation modes and paths.  At this point perhaps you shouldn’t be surprised to learn that I became a partner in an antenna company last year – InnovAntennas, Ltd. of Canvey Island, England – after becoming enthralled by the groundbreaking antenna designs company founder Justin Johnson (also a ham, callsign G0KSC) was creating.  My passion now = my career.  (More info: for North America and for Europe and ROW.)

I’ll now steer this blog entry back to my station planning.  The ham radio band with the most exotic propagation is the 50-MHz (6 meter) band.  This is adjacent in the electromagnetic spectrum to TV Ch. 2.  Can you imagine tuning into 100+ countries and all continents on your living TV set via its rooftop antenna?  Well, that’s the challenge of 50-MHz.  Most of the time radio waves on this band propagate ground wave, maybe 100 miles, and not much further.  Whereas other ham allocations such at the 14-MHz (’20 meter’) band routinely offer up global contacts, long distance contacts on 50-MHz are always special and much of the propagation at this part of the spectrum is not well understood.

There have been midsummer 50-MHz contacts between Japan and the southern USA – nearly half-way around the globe – in recent years and the propagation mechanism for these contacts is not well explained by the known physics of the ionosphere, yet these contacts are real and happening.  My friend Dr. Lew Sayre, W7EW, made over a hundred contracts all across Europe on 50-Mhz from Oregon late last June.  This is a long, long way and traverses the northern polar regions – usually death for such high frequency radiowaves – how did those radiowaves take that trip?  Incredible!  Dr. Jim Kennedy, KH6/K6MIO, a physicist and a ham, has been presenting papers on ‘extreme’ 50-MHz propagation at ham radio conventions in recent years which are utterly fascinating due to both what is explained and what remains mysterious.

Thus, my new station will be well-equipped with antennas for 50-MHz.  I want to have the capability to access exotic propagation modes that a pedestrian system would never detect.  My friend Dennis Motschenbacher, K7BV is building a MASSIVE 50-MHz antenna system at his Turkey, NC home: a stack of six ’11 element LFA Yagi’ antennas (InnovAntennas models, thanks Dennis!) nearly 70-feet long apiece spread across a nearly 200-foot tall radio tower.  Dennis and I, it should be obvious, are lucky to married to women who in addition to being beautiful are tolerant of our hobbies.  I am thinking about building something similar.

I’m splitting this blog entry into three parts.  This first missive shows how I put a big 50-MHz antenna system on the top of my priority list.  The next two parts will cover (a) why the new Flex-Radio 6700 transceiver (a device that transmits and receives radio signals) has caused me to put all of my other ham radio transcievers – except for my beloved Elecrafts – for sale and motivated my business partner Justin Johnson to develop a new antenna design which will find a home at my station, and (b) why I have become so interested in the moon and why I will be building at least four antennas systems which will be aimed at our planet’s lone natural satellite.

Bill AA7XT


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