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The K7RA Solar Update


Recent sunspot activity -- which ended on November 22 -- pushed up the moving average we've been tracking for several years. Because we have all the data for November, we now have the most recent 3-month average of daily sunspot numbers, which centers on October. For 2009, the 3 month moving average centered on January through October was 2.19, 2.02, 1.49, 2.01, 4.23, 5.2, 4.0, 4.0, 4.64 and 7.1. The latest value is the highest since April 2008, when it was 8.89. The monthly averages of daily sunspot numbers are also rising, although not as smoothly as the three month average. The monthly averages for March through November 2009 are 0.77, 1.27, 3.97, 6.6, 5.07, 0.39, 6.6, 7 and 7.7. The November average is the highest since March, 2008 when it was 15.87.

Sunspot numbers for November 26-December 2 were 0, 0, 0, 0, 0, 0 and 0 with a mean of 0. The 10.7 cm flux was 74.7, 73.7, 72.9, 72.1, 72.4, 72.2 and 71.4 with a mean of 72.8. The estimated planetary A indices were 6, 2, 3, 1, 2, 0 and 1 with a mean of 2.1, while the estimated mid-latitude A indices were 3, 0, 2, 1, 1, 0 and 0 with a mean of 1. Current projections show a steady quiet planetary A index of 5 for December 4, then 8 for December 5-6 and back to 5 through the end of the month. Solar flux predictions show December 4-6 at 72, 73 on December 7-10 then 75 on December 11-23. The predicted solar flux value of 75 seems to correspond to the return of an active region that we can see emerging from the dark spot on STEREO. An area that looked promising a few days ago has moved over the horizon and not produced any sunspots. Geophysical Institute Prague predicts quiet to unsettled conditions December 4, unsettled December 5 and quiet December 6-10.

The same 45 day forecast from NOAA and US Air Force referenced above also predicted a planetary A index of 5 for December 3, but in fact all indices that day were 0. The last time the planetary A index was five or above was November 24-26. This directory has links to the daily forecast for the past few weeks. By sampling the forecasts, you can see that the forecasters seem to prefer a planetary A index of 5 for their minimum value. Five is an indicator of very stable and quiet conditions, but in fact conditions have been even quieter. Low geomagnetic activity should be good for the ARRL 160 Meter Contest this weekend, and perhaps we will see some sunspots return for the ARRL 10 Meter Contest the following weekend.

Over the past few years, we've received reports from Dave Greer, N4KZ, of Frankfort, Kentucky, usually about 6 meters. This time N4KZ wrote about 40 meters: "I've been operating 40 meters for a little more than 40 years now and the band has impressed me with its daylight DX numerous times during the past few years. The most recent examples occurred during the recent CQWW CW DX contest. On Sunday, November 29 at 1931 UTC, I worked 4O3A in Montenegro on the low end of 40 meter CW. That was 2:31 PM EST, a good 2.5 hours before my local sunset. That might not be a big deal for East Coast stations, but I don't often hear Europe here that early. But just a minute later, I tuned lower and heard an A71 station in Qatar, in Zone 21, working a pile-up of Europeans in the contest. I didn't hear a single European on frequency, but the A71 had a decent signal into my Central Kentucky QTH. Two or three US stations were calling the A71, but I don't think any of them ever made it through the European wall. But I've heard Europe even earlier in the day on 40 meters. A couple years ago, a station from the Netherlands was a S5 on SSB into Kentucky at high noon in the dead of winter. I never heard anything like that on 40 meters during high sunspot years. I've also been quite pleased at my ability to work DX from my 100 W 40 meter SSB mobile station since the broadcast stations signed off between 7.1 and 7.2 MHz. I have worked numerous Europeans, Russians, three VK stations and some Africans from my car." Thanks, Dave!

Bob Elek, W3HKK, of Johnstown, Ohio, also commented on 40 meters this week, but first had a lot to say about stealth antennas and experiences with wire antennas on the low bands. Bob was a serious DXer and contester from 1976-1995, but then moved to a home with deed restrictions. Check out what's below, all from Bob.

I began experimenting with stealth antennas hidden in a small wooded area behind my last home, adjacent to a golf course. I spent years trying assorted homemade loops, verticals, bob-tail curtains and inverted Ls (all mired deep in the trees to keep them hidden from prying eyes) that would fit in my situation using nothing more than existing trees for support. I also gravitated to the WARC bands and 160-80-40 meters.

A few observations:

  • Upper corner, direct fed bobtail curtains only a few feet off the ground work very well. I worked worldwide (such as India, Afghanistan, Kazakhstan, Japan and Mongolia) on 12 and 17 meters with them, and highly recommend them to anyone who has two properly spaced supports to hang them from.
  • While the trees clearly muted performance, delta loops and quarter wave inverted Ls (however crudely erected) are also fine performers on 40-80-160 meters. I was fortunate to have one 80 foot oak tree which served as the support for many of my experimental, less than ideal antennas.
  • I began putting up homemade ground planes for 30 and 20 meters, from cheap fiberglass telescoping fishing poles taped to a short length of PVC piping, with #14 wire serving as the radiator (taped of course) and radials/guy wires. These performed well, despite being surrounded by trees.


This past summer, I moved to three rural acres in central Ohio. Due to the almost complete absence of trees on my property, I decided to go with homemade ground planes for 20, 30 and 40meters, plus a single feed two band inverted L for 80 and 160 supported by a 15 foot (!) tree in the back yard. Yes, a mere 15 feet high inverted L, at the apex! I run 100 W, mostly on CW, but some SSB as well.

The new QTH differs from the last one in that it is on open rolling hills with cornfields to the east, is sloping slightly downhill for 1000'+ to the east, north and west and slightly uphill to the south. My antennas are lined up E-W about 50 feet apart, with 4-16 radials, both on ground and 3-4 feet above ground. SWR runs 2 to 4:1, with direct fed 52 ohm coax (cobbled together from left over scraps that are 20-40 years old. My antenna analyzer shows losses are acceptable for the appropriate frequencies. Those where it was excessive, I threw out).

Point #1: On 160 meters, even a single coax direct fed pair of 15 foot vertical inverted Ls, with the remainder of their quarter wavelength sloping down to 7 feet above ground at the ends, perform pretty well. Cobbled coax of 150 feet (soldered at the joints, then taped) matched through a tuner in the shack allow me to work all over the US, and as far as the West Coast on the 3905 Net on 1.892 MHz on a regular basis. In November's CQWW CW Contest, I worked three Caribbean and two South American stations, in limited operating. This with 100 W and the 15 foot vertical portion on my inverted L, plus 8 ground laid radials, four for each band. On 80 meters, I've done less operating, but one would expect similar if not slightly better performance there. I have worked all over the US, plus a couple of Europeans, North Africans and Caribbean/Latin American stations on SSB around 3.798 MHz. By comparison, at my last QTH -- with the top of the vertical portion of my 160 meter L at 80 feet, and 4 radials -- I worked into Europe, Africa and the Caribbean/South America about 100 times with 100 W with the antenna buried in trees. In one 160 meter SSB contest, I made 553 contacts with it in one weekend. Not bad for an antenna in the woods with a handful of radials.

Point #2: And my main point. With my new 40 meter quarter wave ground plane with 8 radials, in the open, 100 feet from the house, direct fed by 52 ohm coax, my SWR is below 1.5:1, and I work nearly all that I hear, even DX, even on SSB. And in recent weeks I have heard KL7, VK6, ZL, KH6, ZS, 9L5, CE, CN2, EA9, HC8, OH0, P33, TX3A (Chesterfield Is), TF, JA and a myriad of the more common countries, all on 40 meters, and I worked them all. In addition, I heard several Chinese, Indonesian, and KH2 stations multiple times for long periods of time, and as late as 10 AM!

Point #3: What is going on with 40 meter propagation? While the short skip is less frequent, about half the US is coming through during the daytime with 59+ signals. And at night time, tuning around 7.125-7.2 MHz SSB, the world is at our finger tips. With the increasing wealth of third world countries, kilowatts and 3-4 element Yagis are everywhere now and these guys come through like gang-busters most any night. Look especially around their sunset and sunrise times. Or look between 5-10 AM local time to Asia and the Pacific. You'll find VK6, JA, China, Hong Kong, Malaysia, often in our portion of the phone band. A few recent examples: Last week around 6 PM, I heard a guy in New York City working a JA who was then working the Caribbean. Then a couple of ZSs broke in to say they were copying Japan, the US and the Caribbean, all 59+. Amazing! Another example, around 9 PM I heard a KL7 calling CQ through S-9 QRM, and I worked him, armchair copy both ways. I have heard VK6s (the antipodal point on the globe from central Ohio) coming through on 40 SSB, both in the morning hours and in the late afternoon routinely during the past month. As I recall, November conditions were usually well down from September and October, but not this year.

Point #4: I have often tuned 7.125-7.200 MHz and heard nothing, just noise. Of course, the shortwave broadcast stations have vacated this spectrum, but with the long skip, we have large segments of unused frequencies in the evening hours. As I continue tuning the silent frequencies, all of a sudden I will hear a 5-7 to 5-9+ station from Brazil, Argentina or Europe call CQ, and I usually work them on my first call.

So there is plenty of DX out there to be had. And vertical/ground plane antennas that are far short of the optimum 120 radials, will get you through far better than most dipoles or inverted Vs. So grab a fishing pole, a rebar, some duct tape and #14 wire and go see for yourself! Go get your share of the DX. They're listening for you.

Whew! Thanks, Bob. Believe it or not, that was edited down for brevity. To read more of Bob's writing, check out his narrative on his trip to Brazil in the July-August 2005 issue of the NODXA Rag.

Amateur solar observer Tad Cook, K7RA, of Seattle, Washington, provides this weekly report on solar conditions and propagation. This report also is available via W1AW every Friday, and an abbreviated version appears each Thursday in The ARRL Letter. Check here for a detailed explanation of the numbers used in this bulletin. An archive of past propagation bulletins can be found here. You can find monthly propagation charts between four USA regions and 12 overseas locations here. Readers may contact the author via e-mail.




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