The K7RA Solar Update


We still have had no hint of sunspots or sunspots to come, though there was some geomagnetic activity on February 4 from a possible coronal mass ejection, raising the planetary A index to 16 that day. Sunspot numbers for January 29-February 4 were 0, 0, 0, 0, 0, 0 and 0 with a mean of 0. The 10.7 cm flux was 69.3, 69.1, 69.4, 69.5, 69.1, 69.3 and 69.5 with a mean of 69.3. The estimated planetary A indices were 4, 4, 7, 3, 2, 4 and 16 with a mean of 5.7. The estimated mid-latitude A indices were 3, 3, 4, 1, 0, 2 and 10 with a mean of 3.3.

Currently, predictions are calling for quiet conditions. Geophysical Institute Prague predicts quiet conditions for February 6-12. NOAA and USAF predict quiet geomagnetic conditions with planetary A index at 5, but it jumps to 8 on February 15. On February 22-22, it jumps back to 5 with a predicted planetary A index of 10, 8 and 8. While we don't see much excitement at the high end of the HF spectrum, the quiet conditions and winter nights are great for the lower frequencies.

There were many comments on the fascinating, several decades-old letter from Ed Tilton, W1HDQ, the editor of this bulletin until 1991 (see last week's bulletin). I've never learned when this bulletin began, and if Ed always wrote it. I remember copying it on CW from W1AW as a boy in the mid-1960s, and it was written by W1HDQ then. No one currently at ARRL HQ seems to know, either. Starting out as a 12 year old ham in the 1960s, I was always accustomed to having some source for info from an older ham. For instance, if I wanted to know how experimenters set up spark stations in the early 20th century, there were plenty of people still around in the late 20th century who had done it themselves when they were younger and could lend me their first-hand knowledge. But now after 44 years as a ham, there aren't that many people older than me of whom I can ask these sorts of questions.

Jim Muiter, N6TP, of San Mateo, California, commented on the W1HDQ letter: "Ed's letter pointed out there are many layers to 10 meter propagation, and that the selection of the date for the ARRL 10 Meter Contest was no accident. The 300 mile path makes good sense. I believe the British Chain Home Radar system of Battle of Britain fame used frequencies in that range, perhaps 30-50 MHz. In effect, it was partially an over-the-horizon radar and may have inadvertently relied on tropo."

Just after last week's bulletin, Jeff Hartley, N8II, of Shepherdstown, West Virginia, wrote that "The highlight of the week was Monday (January 26), working FW8DX on 75 meters at sunrise. Seventeen meters was barely open to Europe all week long, except on Monday, conditions were good enough for a brief opening on 15 meters to F/EA/sw DL from 1510-1545 UTC. I heard double hop E-skip on 10 meters Sunday evening (January 25) into New Mexico and Arizona, but no QSOs, as they were fairly weak here and they had a good opening going with the SE USA with S9 reports. By all accounts, the CQ 160 Meter Contest had the best conditions ever; I was too tired to operate past my normal bedtime, but did manage to work more than 1000 QSOs and 51 DXCC countries with 6W/DL2MDU being a new one. Conditions were so good that many East Coast stations worked UA9 and several caught EY8MM."

Mike Schaffer, KA3JAW, of Tampa, Florida, likes to hunt commercial broadcast television DX. He reported that last winter he didn't see any, but on January 25 he said, "I just snagged my initial 2009 winter season television DX on Channel 2 coming from HIJB Tele Antillas, Santo Domingo, Dominican Republic. I saw the station logo (TA) several minutes before 1700 UTC. The audio level was about equal to the video quality in this case, but normally the audio is loud compared to the video level. The distance from Tampa to Santo Domingo is 1045 miles. Half this distance, 523 miles, would place the E-skip plasma cloud near the southwest of George Town, Bahamas." Mike copied the signal for fewer than 3 minutes. Later that same day, he copied WKAQ on Channel 2 at 2313 UTC from San Juan, Puerto Rico, 1232 miles away. He said the sporadic-E opening that day ran from 1530-2320 UTC. The next day -- also on Channel 2 -- he copied a TV station in Managua, Nicaragua.

A new month began since the last bulletin, so we can calculate another 3-month average of daily sunspot numbers. This new one will be centered on December 2008, and includes data from November 1 2008-January 31 2009. We were, of course, hoping for an uptick, but the new average is 3.7, lower than the previous average of 4.4:

Jan 07 22.7
Feb 07 18.5
Mar 07 11.2
Apr 07 12.2
May 07 15.8
Jun 07 18.7
Jul 07 15.4
Aug 07 10.2
Sep 07 5.4
Oct 07 3.0
Nov 07 6.9
Dec 07 8.1
Jan 08 8.5
Feb 08 8.4
Mar 08 8.4
Apr 08 8.9
May 08 5.0
Jun 08 3.7
Jul 08 2.0
Aug 08 1.1
Sep 08 2.5
Oct 08 4.5
Nov 08 4.4
Dec 08 3.7

Bill Van Alstyne, W5WVO, of Rio Rancho, New Mexico, had some information and comments after this bulletin mentioned some weak signal methods for VHF. Bill said the Web site we mentioned deals with some European practice in Region 1. Stations in North America -- Region 2 -- use different protocols: "The Region 2 protocols are the default settings in the WSJT software, as it is downloaded from Joe Taylor's, K1JT, Web site. Please, download the manual as well as the software."

Bill continued: "JT6M is only one of the transmission modes contained within the WSJT suite intended for meteor scatter work. The original MS mode, FSK441, remains the primary mode used for MS in North America. Of course, JT6M will often work, but as stated in the Web page, you need a decodable burst of at least 1 second duration. While it is much more likely to get pings this long on 6 meters than on higher frequency bands, it is likewise true that most 6 meter meteor pings are shorter than that, and hence won't contain a full message. Using FSK441, a full message can be transmitted and decoded in as little as 150 ms.

"The trade-off between these two MS modes is sensitivity versus time. FSK441 is faster because it takes up more bandwidth and is therefore less sensitive; a signal at least 1 dB above the noise floor is necessary. JT6M, on the other hand, can decode a message as much as 12 dB or more below the noise floor! But the signal must be present for at least 1 second, and more reliable decodes are obtained when the signal is present for an even greater length of time. The best use of JT6M, in the opinion of many, is not actually 6 meter meteor scatter, but rather very-weak-signal tropo, ionoscatter or sporadic-E." Bill recommends the WSJT Yahoo Group for newcomers. The group has a Web site.

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 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.