venerdì 1 novembre 2019

The K7RA Solar Update

There are still no sunspots, but average daily solar flux rose this week from 65.3 to 68.5. Yet there have been surprising reports of HF stations heard and worked over long distances. However, the second-hand report in last week’s bulletin about a local station in my area working Belarus and Lithuania on 10 meters in the middle of the night turned out to be a misunderstanding, and I am sorry I reported it.

On Friday and Saturday, a coronal hole let loose a solar wind stream causing geomagnetic instability, and the average daily planetary A index for the week rose from 4.7 last week to 16.4.

Predicted solar flux has increased recently, with values of 70 on November 1-8, 66 on November 9-23, 70 on November 24 through December 6, and 69 on December 7-15.

Predicted planetary A index is 8 on November 1, 5 on November 2-4, 8, 10 and 8 on November 5-7, 5 on November 8-16, then 15, 8 and 5 on November 17-19, then 20 and 24 on November 20-21, 15 on November 22-23, 12 on November 24, 5 and 15 on November 25-26, 12 on November 27-28, and 5 on November 29 through December 15.

This weekend is the ARRL CW Sweepstakes contest, and conditions look favorable with a rising solar flux (it was 71.2 on Thursday) and moderate geomagnetic conditions.

OK1HH sent us his geomagnetic activity forecast for the period November 1-26, 2019.
Geomagnetic field will be
Quiet on: November 9, 13, 18-19
Quiet to unsettled on: November 1-2, 4-5, 10-11, 15
Quiet to active on: November 3, 8, 12, 14, 16, 25
Unsettled to active on: November 6 (-7), 17, 20, 24, 26
Active to disturbed: November 21-23

Solar wind will intensify on November (6-9,) 13, 21-26, (27-29)

Parenthesis means lower probability of activity enhancement.

Jeff, N8II, in West Virginia reported: “Tuesday through Thursday this week, October 22 through 24, was pretty amazing on 15 meters, especially considering the extremely low solar flux. I think Thursday that was the best when on 15-meter SSB I worked several European Russian stations including R1DA/M and stations in Ukraine, Finland, Norway, and several UK stations including a mobile running 5 watts who was peaking S9! The contacts were between 1345Z and 1420Z.

“On Thursday afternoon around 1800Z, I waited for VP6R on Pitcairn Island to build in strength above the noise on 12-meter CW and heard an OH3 and OH5KW in Finland, both well above the noise off the back of my 2-element Yagi as they worked VP6R! Later, at about 2200Z, there was a huge pile up on VP6R on 10-meter CW. I made it through after about 7-8 minutes.

“The CQ Worldwide SSB contest conditions were not nearly so good, but 15-meters was open all over Africa and to southern Europe with some very loud signals. I worked Crete, Greece, Cyprus, Slovenia, Serbia, Bulgaria, Croatia, Italy, Switzerland, Germany (only one), France, Spain, and Portugal and in Africa, Reunion Island, Canary Island, Madeira Island, Morocco, South Africa, Senegal, Gabon, Namibia, and Cape Verde Island. All South American mainland countries were worked except Guyana, and VP6R was in for hours on end.”

N0JK reported on October 27: "The VP6R DXpedition has been audible a couple of days in Kansas on 10 meters, usually at or just above the noise floor. But on October 27 VP6R was very strong, over S-9 at 2050z.

“Starting around 2030Z on October 27, VP6R had a strong opening across much of North America on 10 meters. VP6R was much louder than the scattered South America and Central America stations popping in on afternoon TEP. Signals seemed to peak in Kansas between 2045 – 2110Z. VP6R was running the table, a golden opportunity for anyone who needed Pitcairn on 10 meters.

“Then VP6R started dropped into the noise around 2110Z. KF0M in Wichita worked them near the end of the opening. During the peak, I worked a loud KY7M in Arizona on Es, and heard W2HZ Tucson, Arizona (both sides of contact) work VP6R.  Sporadic E was present on 10 meters. While Arizona is a little west of the Great Circle path to Pitcairn Island, I suspect that the strong October 27 opening was an Es link to TEP. That can explain the loud signals and how the opening turned on and off "like a switch." Was 6 meters open to Pitcairn from North America? Maybe. Es links to TEP took place on 6 meters October 17 from the Central US to South America. The only spot I noted during this period on 6 meters was a FT8 local contact between AC2PB and a N3."

Mike May, WB8VLC, of Salem, Oregon wrote: "There were weird conditions on the HF bands. The solar flux was so low, yet DX was still present.

“I am rethinking my HF operation vs low solar numbers after this month’s 10 meter and other from my ‘black hole’ location in Northwest Oregon with low-height small antennas and low to moderate power. None of this was a hindrance!

“Most signals have been very readable with minimal fading, low noise and no real struggle to make contacts. On 10 meters I use a short-boom 4-element homebrew Yagi antenna at 30 feet and 300 watts.

On 12, 15, 17 and 20 meters I am using homebrew antennas at just 22 feet on a single push-up mast and running 300-400 watts.

“I put up a Moxon beam antenna for 12-20 meters, so there are no fancy multiband Yagis used here in my postage stamp city lot.

“On the lower HF  bands, I use vertical antennas for 30-40 meters and inverted Ls for 60 and 80 meters with just 16 radials and just 50 watts on these four bands, but I still make plenty of contacts.

“Here is just a sample of the HF DX operation from September to October and I'm mainly a weekend operator. (Long lists of stations were edited out here—Ed.)

On 12 to 60 meters I have worked Tokelau on CW, SSB, and FT8 on 10 through 30 meters, Pitcairn Island on CW and SSB, Liberia on 17-meter SSB and FT8, Nauru on 20- and 17-meter CW, SSB, and FT8, and many others.

“The 60- and 80-meter contacts I’ve made were the first time since I was licensed in 1975 that I was ever on those bands.

“On 10-meter SSB, on every weekend, there are a good deal of SSB contacts to be made from my location to South America.

“So, despite the low solar indices, it is still contacts galore. I don't know what to think about the correlation, but I'm not complaining.”

Griff, NE3I, reported on October 26: "Conditions on 75 and 40 at the beginning of the CQ World Wide SSB Contest are the worst I have experienced in over 50 years as a radio amateur. With the exception of some Canadians on 75 meters, all signals received here in Eastern Pennsylvania, even US stations, are weak and difficult to intelligibly discern with fading and S9 noise levels across the entire 75 and 40-meter bands."

This is from John Boudreau, VE8EV, in Inuvik, Northwest Territories. Inuvik is way up there, north of 68 degrees north latitude. “When I read about the record-setting low solar flux in last week's report I recalled that the last time I checked in with you was March 2014 at the peak of Cycle 24.

“Back then, from our high-latitude location directly under the auroral oval, we were experiencing amazing propagation on the upper bands. Now, exactly 5-1/2 years later and with a (mostly) quiet sun, it is the lower band's turn.

“Last winter I took advantage of the quieter conditions to finish off 80meters for my 5-Band DXCC award and just recently I've managed to work 14 new countries on 160 meters, mostly on the extremely difficult polar path which, from here, includes everywhere in the eastern hemisphere.

“Whichever part of the solar cycle we are at, though, there is no escaping the effects of a disturbed geomagnetic field right over our heads. Last weekend during the G2-Level geomagnetic storm caused by a recurring solar coronal hole, I turned on my radio around 0400Z on Saturday night. Even with the CQ Worldwide contest going on, I could hear only two stations (a KH6 and a KL7) coming through on any of the bands. This can sure be a tough place to play radio!”

Here is the latest from Dr. Skov: https://youtu.be/p1OHijuoZO8

If you would like to make a comment or have a tip for our readers, email the author at k7ra@arrl.net.

For more information concerning radio propagation, see the ARRL Technical Information Service at http://arrl.org/propagation-of-rf-signals. For an explanation of numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere.

An archive of past propagation bulletins is at http://arrl.org/w1aw-bulletins-archive-propagation. More good information and tutorials on propagation are at http://k9la.us/.

Monthly propagation charts between four USA regions and twelve overseas locations are at http://arrl.org/propagation.

Instructions for starting or ending email distribution of ARRL bulletins are at http://arrl.org/bulletins.


Sunspot numbers for October 24 through 30, 2019 were 0, 0, 0, 0, 0, 0, and 0, with a mean of 0. 10.7 cm flux was 65, 68.6, 68.6, 68.8, 69.4, 69.2, and 69.7, with a mean of 68.5. Estimated planetary A indices were 18, 29, 25, 15, 11, 8, and 9, with a mean of 16.4. Middle latitude A index was 12, 29, 17, 11, 8, 8, and 6, with a mean of 13.


http://www.arrl.org/news/the-k7ra-solar-update-601