sabato 16 giugno 2018

Propagation de K7RA


ARLP024 Propagation de K7RA



Propagation Forecast Bulletin 24  ARLP024

From Tad Cook, K7RA

Seattle, WA  June 15, 2018

To all radio amateurs


ARLP024 Propagation de K7RA

Sunspots returned a few days ago after a 7-day absence. Average

daily sunspot number dropped from 12.9 in last week's report to 4

this week. Average daily solar flux dropped from 73.2 to 69.4.

Geomagnetic conditions were quieter with average daily planetary A

index declining from 11.7 to 4.4 and mid-latitude A index from 10.4

to 5.1.

Predicted solar flux is 72 on June 15-21, 75 on June 22-23, 74 on

June 24-25, 73 on June 26, 72 on June 27-28, 71 on June 29-30, 70 on

July 1-3, 69 on July 4-6, 70 on July 7, 72 on July 8-14, 73 on July

15, 74 on July 16-17, 75 on July 18-20, 74 on July 21-22, 73 on July

23, 72 on July 24-25, 71 on July 26-27 and 70 on July 28-29.

Predicted planetary A index is 5 on June 15-26, then 15, 28, 18 and

10 on June 27-30, 5 on July 1-8, 8 on July 9-11, 5 on July 12-15, 8

on July 16, 5 on July 17-23, then 15, 25, 15, 8 on July 24-27 and 5

on July 28-29.

Next weekend is ARRL Field Day, June 23-24. Predicted planetary A

index of 5 on both days is a welcome indicator of undisturbed

conditions, as are the predicted solar flux values of 75 and 74.

The latest from Dr. Tamitha Skov:

"Dear Tad,

"Have I ever mentioned forecasting Space Weather is hard? One would

think that with all the spacecraft and instruments we have trained

on the Sun, we would be able to do so much better than we do.  This

week is a perfect example of that. Just eight and a half days ahead

of us (in terms of weather that is) sits the STEREO-A spacecraft. It

sees solar features before we do at Earth and gets to sample the

solar wind created by these features on the Sun a little more than a

week before we do. Watching data from STEREO-A is a great way to

know what is coming. Except when it doesn't.

"This is of those times. Though STEREO-A gives us a great look into

the future, I must constantly remind myself how quickly things

change on the Sun. The coronal hole that was open just 8 days ago,

likely closed up a bit as it rotated to the Earth-strike zone. Not

only that, but right now, STEREO-A is about six degrees further

south in solar latitude than is Earth. Obviously, in this case that

makes a huge difference.

"So this week, we are only being brushed by a fast wind stream that

is flowing mostly south of Earth. I had hoped for a mini-solarstorm

that would bring us aurora, both in pictures and in propagation

modes, but it looks like we will need to wait for a change in the

weather. As STEREO-A creeps ever closer to us in its slow approach

to Earth, it can give us great insights into what things will be

like tomorrow.  But nothing is ever a guarantee. It's a good lesson

to remember.

"Cheers, Tamitha."

Her report from a few days earlier:

Gert Carlsson, AA7G sends along this information on the IY4M

interactive beacon robot:

Mark Lunday, WD4ELG of Greensboro, North Carolina reported on June


"I am here in my shack in central NC, truly amazed.  41 years in the

hobby; that does not happen too often these days.  Surprises, yes.

Pure amazement, infrequent.

"But here I sit.  It's 2300 LOCAL time (0300 UTC), I called CQ on 17

meters FT8 with 25 watts and a 160 meter inverted L with a remote

coupler at the base.  I got a reply from JH7VHZ.  This is a

non-directional wire, no gain, 90 feet vertical and 42 feet angled

down 45 degrees, with 20 radials, in a forest of pine trees, fed

with 300 feet of coax from my shack.  At 11 PM local!  And HE called

ME.  Sure it was FT8, but that's not the point.

"Last time I worked JA from east coast on the higher bands (it's not

that common for me here, with my antenna setup) was two years ago on

15 meters in the ARRL DX SSB contest.  Sure I can occasionally hear

them, very weak, but it's not easy to get through.  (Of course it's

much easier on 40 meters than 20/17/15)

"The last time I worked JA at that late an hour when it was NOT on

40 meters, was September 2012, on SSB on 20.  Before that, it was 21

years ago when I was closer to the ocean in Florida, so I had better


"And before that time in 1997, it was 1979, I was in W6 land, the

bands were ON FIRE, I had a dipole at 20 feet on a hill about a mile

from the Pacific ocean, and 15 meters was open well past sunset to

JA and UA0 out west.  I used to run CW pileups in DX contests at

high speed until 10 PM local on 10 meters, then switch to 15 meters

until midnight, then work them on 20 until I fell asleep at my desk

around 0200 (oh how I wish I had that energy of a 14 year old


"But I digress.

"We complain (well, I COMPLAIN) about the poor band conditions, but

maybe it's also factor of not having more activity during sunspot

cycle lows.  FT8 is a game changer, and it seems like activity has

really increased, especially DX.

"On 17 meters FT8, I am also copying E5 and UA9.  VERY strong.  On

FT8 on 20 meters, I am copying VK/ZL, EU, 9K.  All very workable,

very strong.  20 seems to be what it was at sunspot peak, always

open, frequently capable of worldwide DX especially at night.  Now

THAT is how I remember 1979.  20 was ALWAYS open.  Like it is


Bob Lombardi, W4ATM of Melbourne, Florida on June 11 wrote:

"I had been starting to refer to the sporadic-E propagation we had

from about June 1st and well into last week as 'The Great Sporadic-E

Opening of June 2018.'  Morning checks on DXMaps would show the

density of transatlantic propagation to/from Europe at densities

I've never seen.  For the first time in my life, I saw DX contacts

reported from Japan into the SE US one evening, including one into

my grid square.  (I was having dinner and missed the brief chance).

'I've been operating on 6m since about '03, and the June contest has

always been the most productive weekend of the year for me.  Last

year, after hearing about this new thing called FT8 while following

DX spots, I started experimenting with that mode and have played

with it a bit.  Not expert level, but I know my way around it.

"Last Monday, my country total in Europe went from 1 to 4.

"I suppose the attack of Murphy's Law for the contest was

predictable, but Saturday was the worst day I've seen since late

May.  Sunday was better, but new grids were hard to find, and my

ultimate hope of completing my 6-meter WAS never had a chance.  Not

one KH6 or KL7 to the mainland was seen all weekend.  The vast

majority of the grid locators I heard were among the first I ever

worked: FN, FM, EM and the eastern half of EN.  I did manage to work

a few Canadian grid squares I've never gotten before, into

Saskatchewan and Alberta, and a couple in the lower 48.

"Of course, there's a reason it's called 'sporadic,' and what little

we had this weekend was better than nothing, but what a contest it

would have been if the propagation hadn't peaked a week before the


"I'm left to wonder if this really was a June sporadic-E season for

the record books or if it's some combination of more people online

and reporting, more activity on 6, or the influence of FT8.  The few

times I looked at the modes being reported, it seemed 80 of the

reports were FT8."

Jeff, N8II reported:

"I worked CT1ESV, Portugal today June 14 at 2230Z, S8 on 10M phone. showed NA stations working S01WS Western Sahara on 6M FT8

and there were NA to EU QSOs too."

F.K. Janda, OK1HH reports.

"Geomagnetic activity forecast for the period June 15 to July 10,


"Geomagnetic field will be:

Quiet on June 20-24, July 2-3

Quiet to unsettled on June 16-19

Quiet to active on June 15, 25, July 1

Unsettled to active on June (26, 30)

Active to disturbed on June (27,) 28, (29)

"Solar wind will intensify on June (15,) 16-17, (18-19,

22-24, 26,) 27-29, (30,) July 1, (9-10)


- Parenthesis means lower probability of activity enhancement.

- Due to planned trips, this forecast will not be compiled from June

  21st (or 28th) to July 5th."

If you would like to make a comment or have a tip for our readers,

email the author at, .

For more information concerning radio propagation, see the ARRL

Technical Information Service web page at, For an explanation of

numbers used in this bulletin, see

An archive of past propagation bulletins is at More good

information and tutorials on propagation are at

Monthly propagation charts between four USA regions and twelve

overseas locations are at

Instructions for starting or ending email distribution of ARRL

bulletins are at

Sunspot numbers for June 7-13, 2018 were 0, 0, 0, 0, 0, 12, and 16,

with a mean of 4. 10.7 cm flux was 69.3, 68.2, 66.8, 70.2, 69.9,

70.3, and 70.8, with a mean of 69.4. Estimated planetary A indices

were 6, 4, 4, 4, 4, 4, and 5, with a mean of 4.4. Estimated

mid-latitude A indices were 6, 5, 5, 4, 4, 5, and 7, with a mean of