Category Archives: Propagation

Mini QRP to the field

On the evening of July 28th I took a short drive from Moscow, Idaho to Roundtop Park in Pullman, Washington where I set up my S9 vertical against a very tall pine tree, hooked up half a dozen radials across very dry weeds and ground, and then fired up my KX3 on 20m.

Here are a few photos from my setup on Roundtop at about 7pm local time.

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This is the sign at the entrance to the short trail leading to Roundtop.

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Here’s the KX3 with the S9 just beyond overlooking The Palouse on a beautiful Pacific Northwest evening.

Conditions at Gray Line time on 20m were very good. Lots of DX activity including Brazil, Russia and Sweden. I was able to work 2 Russian hams and another ham in Belarus. I was running about 3W on CW.

I was impressed considering the radials were, for the most part, not even touching the ground. Proving once again that it doesn’t always pay to get too hung up on all the technical details with antennas and radials.

The propagation gods were smiling down, no doubt!

Gray Line Propagation to Europe on 20m

June 9-10 have seen good 20m propagation to Europe around 0430Z.

June 9: worked F2GL and FG8NY and DF2PY. June 10: worked LY2BAW, and EW8O.

This evening heard, but did not work, LZ1534GWS, SM5COP, 9A2HF and OH4RF. Signal strength around 5 for those stations.

All these on the new home brew indoor 40 ft loop antenna mounted on the ceiling at about 25 feet above street level.

S9 v31 vs. a dipole at 20 feet

I set up the S9 for a nighttime test comparison with one of my dipoles mounted about 20 feet up and touching my house. I was running my NorCal 40a on battery power. Skies were clear at about 65 degrees F. There was a fair amount of activity on 40 meters, conditions were good for a test.

The result? The vertical was, at least this time out, a superior performer. There was no comparison. The ground-mounted S9 v31 was significantly quieter and heard more signals as well. The other thing about the S9 is that signals are so strong I typically have to reduce my RF gain by 25-50% so my eardrums don’t get blown out. It’s amazing how much louder many signals are on the vertical vs. the dipole.

While comparing the two antennas,I worked Kevin, K7KHC, in Aberdeen, Washington using the vertical. Had a nice QSO but discovered that trying to use my key mounted on a clipboard was a bit awkward. Still need to optimize that set-up.

After that experiment I moved my NorCal 40, power supply and cables up to my second floor outside porch to enjoy the night sky and see if I could catch any DX. Right around 0500Z I chanced on ZL2AGY, Tony in New Zealand! He was in a QSO so I waited till they finished, but was unable to contact him. Not sure if my signal was not getting out strongly enough or whether he had gone QRT. Anyway it was great to hear propagation working so well into Moscow, Idaho for my S9.

I hope to receive my new radial plate this coming week and am interested to learn whether it will improve the strength of my transmissions. My current radial plate is nothing more than a plumbing fixture with some paint scraped off so the screws and wires all make good contact. Not optimal.

It was great sitting out under the stars, tuning around just by feel. The NorCal 40a has no display so I was able to sit in total darkness, watch up at the sky and tune quietly around the CW portion of 40m. Any time I needed to write, I just clicked on my Petzl headlamp with the red filter on to minimize getting blinded. Worked great.

Looking forward to many more evening sessions like this.

40m opening today

1130Z: No 20m propagation this morning but there was light DX activity on 40m. Heard JA8BM and K2IX (NC).

Motorcycle battery is really inadequate for my station operation. Run time is just a couple hours, much less if transmitting, even at QRP. Time to upgrade to a power supply and keep a deep cycle battery for emergency.

Follow-on to 2005 paper on sunspots, solar wind and Propagation

New research finds that the number of sunspots provides an incomplete measure of changes in the Sun’s impact on Earth over the course of the 11-year solar cycle. The study, led by scientists at the High Altitude Observatory of the National Center for Atmospheric Research (NCAR) and the University of Michigan, finds that Earth was bombarded last year with high levels of solar energy at a time when the Sun was in an unusually quiet phase and sunspots had virtually disappeared.
Scientists previously thought that the streams largely disappeared as the solar cycle approached minimum. But when the study team compared measurements within the current solar minimum interval, taken in 2008, with measurements of the last solar minimum in 1996, they found that Earth in 2008 was continuing to resonate with the effects of the streams. Although the current solar minimum has fewer sunspots than any minimum in 75 years, the Sun’s effect on Earth’s outer radiation belt, as measured by electron fluxes, was more than three times greater last year than in 1996.

When the solar cycle was at a minimum level in 1996, the Sun sprayed Earth with relatively few, weak high-speed streams containing turbulent magnetic fields (left). In contrast, the Sun bombarded Earth with stronger and longer-lasting streams last year (right) even though the solar cycle was again at a minimum level. The streams affected Earth’s outer radiation belt, posing a threat to earth-orbiting satellites, and triggered space weather disturbances, lighting up auroras in the sky at higher latitudes. (Illustration by Janet Kozyra with images from NASA, courtesy Journal of Geophysical Research – Space Physics.)

If you want to really understand the interaction of solar activity and HF propagation read this very well written article by Paul Harden, NA5N. The 8-page PDF is a paper presented at the 2005 Dayton Hamfest FDIM Symposium and is entitled, “Solar Acitivty & HF Propagation“. Paul provides excellent diagrams, examples and explanations in a style that’s very accessible. He also offers valuable insights for QRP operators. This is a must read paper.