SB PROP @ ARL $ARLP004

ARLP004 Propagation de K7RA

ZCZC AP04

QST de W1AW 

Propagation Forecast Bulletin 4  ARLP004

From Tad Cook, K7RA

Seattle, WA  January 23, 2015

To all radio amateurs

SB PROP ARL ARLP004

ARLP004 Propagation de K7RA

Average daily sunspot numbers for January 15-21 dropped 50.7 points

relative to the previous seven days, to 61.9. Average daily solar

flux declined from 151.3 to 126.2. For the past ten days sunspot

numbers have remained below 100. This benchmark has no special

significance, but the last time there were this many consecutive

days with double-digit sunspot numbers was October 5-20, 2014.

Geomagnetic numbers indicated more stable conditions, with average

daily planetary A index declining from 9.6 to 6.4, and average daily

mid-latitude A index dropping from 8 to 4.7.

The latest prediction from USAF/NOAA has solar flux at 130 and 135

on January 23-24, 130 on January 25-26, 135, 140 and 145 on January

27-29, 135 on January 30 through February 1, 130 on February 2-3,

125 on February 4-6, 130 on February 7-9, 125 on February 10-11 and

120 on February 12-13. Solar flux reaches a low of 115 on February

18, and peaks again at 135 on February 26-28.

Predicted planetary A index is 15 on January 23-24, 18 on January

25-26, 8 on January 27-28, 12 on January 29-30, 15 on January 31

through February 1, then 12, 15, 12 and 5 on February 2-5, 10 on

February 6-7, 8 on February 8-9, 5 on February 10-12, then 8, 5 and

12 on February 13-15, 10 on February 16-18, and 8 on February 19-20.

F.K. Janda, OK1HH predicts geomagnetic activity will be active to

disturbed on January 23, quiet on January 24, mostly quiet January

25, active to disturbed January 26-28, quiet January 29, active to

disturbed January 30, mostly quiet January 31, disturbed February

1-2, quiet to unsettled January 3, quiet to active January 4, active

to disturbed February 5, quiet to active February 6-8, mostly quiet

February 9-13, quiet to active February 14, and quiet to unsettled

February 15-17.

Randy Crews, W7TJ of Spokane, Washington posted these observations:

"Thanks for the link and update from NASA in your last bulletin. A

couple things I wanted to add to amplify on the trend and outline a

unique historical perspective.

"Cycle 24's peak is past and will fall into the ranks of the lower

Sunspot Cycles 10, 12, 13, 14, and 16. NASA's article pointed out

Cycle 24 being the smallest since Cycle 14 in 1906. It will probably

mirror Cycle 12 or 13 finishing with a smoothed sunspot number in

the high 70s low 80s plus or minus. A few additional points make

this cycle unique in addition to the second peak being higher than

the first: In past strong sunspot cycles (21, 22, and 23) we have

had what I would call the 'top 3' being 3 outstanding years of high

solar activity (the year prior to the peak, the year of the peak,

and the year after where Solar flux values have averaged between 150

and 225).

"Tying this observation to Cycle 23 (a lower but normal cycle in

2000, 2001, and 2002) during these peak years propagation on 10, 12,

and 15 meters was outstanding almost ALL the time. Cycle 24 has

bestowed just a little over one year of this type of propagation -

late 2013 to present. Graphically seen from the Solar activity

report from this Web link:

"http://www.solen.info/solar/images/comparison_recent_cycles.png

"Things become more interesting with the fact Cycle 24 will

obviously finish with a smoothed sunspot number of less than 100.

"This is the first time this has occurred since Cycle 16 finished in

1933 (over 80 years ago!).

"Link with the corresponding data:

"http://en.wikipedia.org/wiki/List_of_solar_cycles.png

"Graphically, Cycle 24 will fit into the BIG picture as follows,

accurately done by K9LA:

"http://k9la.us/A_Look_at_All_Twenty_Three_Solar_Cycles.pdf

"Connecting the dots from the graphs, historically there have been

decades of high and low solar activity spanning several sunspot

cycles. As one source has pointed out, got most of our radio amateur

lifetimes we have experienced some of the highest solar activity

periods in history, 1950 to 2009. The Graph from NASA of the current

trend pretty well sums up the overall direction:

"http://en.wikipedia.org/wiki/Solar_cycle_24#mediaviewer/File:Hathaway_Cycle_24_Prediction.png

"Summarizing:

"Cycle 24 will be a low cycle very likely to be followed by several

other low or even lower cycles - supported by the current and

historical data.  Make the most of the current band conditions and

upcoming DXpeditions - it certainly looks as if we are heading

toward a 'Propagation Winter.'"

Thanks, Randy.

I do not know if we are headed toward a "propagation winter" and

quiet Sun or not, although plenty of experts much smarter than me

might think so. I like to remember when some of the best minds made

a case for the upcoming Cycle 24 to be the biggest ever, and of

course it did not turn out that way.

I hope to be around for the next cycle, might even see the one after

that, but I doubt I will see three cycles out. When I started as a

Novice it was Cycle 20, right after the big one, and it sure seemed

weak!

We heard from Rich Zwirko, K1HTV of Amissville, Virginia. He wrote:

"Other than a few Es openings, 6 meters has been pretty quiet the

past few weeks. I think that we have seen the last of any 50 MHz E-W

F2 skip for this solar cycle and possibly future cycles. Magic

Banders will have to rely on summer multi-hop E-skip and SSSP

chordal openings for the next long haul 6 Meter DX contacts."

He also mentioned that his son, Andy, K1RA of Warrenton, Virginia is

operating a RaspberryPi as a multi-band HF WSPR beacon running only

10 milliwatts. (RaspberryPi is a tiny and inexpensive computer that

is popular as a microcontroller. See http://www.raspberrypi.org/ )

This not only changes bands automatically according to a timing

cycle, but the microprocessor actually generates the RF and connects

directly to the antenna feedline, via some simple filtering. The

signal is output as a square wave, but the harmonics are easy to

filter out and at 10 mw are simple to control. The beacon callsign

is KW4VA and the grid locator is FM18cr.

Andy wrote:

"I've been running a Raspberry Pi and the JamesP6000 WSPRryPi code

under my club call KW4VA recently, which you can read about at the

following URL for info, links and DX spot maps:

"http://www.k1ra.us/2015/01/03/kw4va-wspr-beacon

"In short the RPi CPU can natively generate about 10 milliwatts of

RF from 0-250 MHz off one of its GPIO pins. The WSPR code is based

off some earlier code developed in the UK to allow generation of FM

signal at 100 MHz:

"http://www.icrobotics.co.uk/wiki/index.php/Turning_the_Raspberry_Pi_Into_an_FM_Transmitter

"I'm running one of the IO pins to external wire antennas.  I was

stuck at about 7500 km for a few years until this past week when I

was spotted by ZS6AF on 17m at 13322 km, then in the last two days

by ZL1RS on 20m at 13811 km and finally VK2DDI on 30m at 15729 km.

Here are the spots from the WSPR propagation database:

"Timestamp       MHz        SNR Reporter RGrid  km

2015-01-19 08:22 10.140240  -27 VK2DDI  QF55hf  15729

2015-01-15 10:18 14.097116  -24 ZL1RS   RF64vs  13811

2015-01-08 21:14 18.106032  -22 ZS6AF   KG54mk  13322

"I've been playing with very low power WSPR for a while now.  In the

past I'd been using a PIC controller by AA0ZZ and a 0-60 MHz DDS

board by N2APB that also put out about 10 mw and was using a 30m

dipole in the attic at 30'. Then I was stuck on one band at a time,

usually 10m.  I'm sure the outside dipoles and wires at 45' help a

bit. With the use of the RPi though I've have been able to

automatically band hop. I think this too has helped to increase my

DX spots by other WSPR stations. I run 80, 40, 30, 20m every 2 mins

at night and 20, 17, 15, 12 10m every 2 mins during the day."

This weekend are the ARRL January VHF Contest (see

http://www.arrl.org/news/the-arrl-january-vhf-contest-offers-a-break-from-winter-s-doldrums

and http://www.arrl.org/january-vhf) and the CQ World Wide 160 meter

CW Contest (http://www.cq160.com/rules.htm).

For the 160 meter CW contest we would like to see very quiet

geomagnetic conditions. OK1HH predicts disturbed conditions on

Friday, then quiet on Saturday and mostly quiet Sunday. Quiet is a

good outlook, although I don't know what the effect of Friday's

conditions might be on the rest of the weekend if they are

disturbed.

NOAA/USAF predicts an A index of 15 on Friday and Saturday and 18 on

Sunday. This is neither quiet nor disturbed, but I would

characterize it as unsettled conditions.

Let's hope for dead quiet geomagnetic conditions over the entire

weekend. Have fun!

Following up on last week's link to an article about the National

Radio Quiet Zone and the people who flock there, N7SO sent another

article:

http://www.slate.com/articles/technology/future_tense/2013/04/green_bank_w_v_where_the_electrosensitive_can_escape_the_modern_world.single.html

We also heard from a ham who used to work there, Rob Welsh, N3RW,

who wrote:

"I was previously employed at NRAO Green Bank (see

http://www.nrao.edu/) on a Milky Way mapping project. Given that

NRAO GB is in the National Radio Quiet Zone, I was given permission

to put my QRP rig on the air on 17 meters using the HF Bruce array

at the observatory entrance. Few stations I worked believed that I

was running just 5 W. With about 100 feet of RG-58 between the dorm

and the antenna, I bet I was radiating more like 3 W at best."

Info on a Bruce Arrays:

http://rudys.typepad.com/ant/files/antenna_array_80160m.pdf

Rob also wrote in a subsequent email:

"The Bruce Array at the entrance to the Green Bank site is a rebuild

of the antenna used by physicist Karl Jansky who in the 1930s

studied radio noise for the Bell System's HF radio circuits.

"Jansky eliminated all noise sources except one which occurred 4

minutes earlier each day. In conversations with others, he was told

that the stars rise 4 minutes earlier than solar time.

"Jansky may have been the first to discover galactic radio noise as

he was recording the radio noise emitted by the Milky Way.

"One of my tasks while employed at GB was to perform a VSWR vs.

frequency plot of the Bruce Array. The center frequency, as I

remember, was about 20 MHz, so with a QRP antenna tuner I was able

to find a match for the 17 meter band.

"Radio astronomers consider the HF bands as 'low frequency' for

astronomical observations. There has been an increase in HF

observations at HF with the purpose of identifying galactic sources

at lower energy levels.

"Also at the entrance to the site is a rebuild of Grote Reber's

(W9GFZ, SK) 30 foot parabolic antenna. Reber read Jansky's published

work and went about measuring galactic radio noise at VHF.

"See my article in the December 2009 issue of QST titled 'How the

Ionosphere Was Discovered.'

"The callsign, W9GFZ, has been issued to NRAO and used at both the

Green Bank site and at the Very Large Array in New Mexico. I've

observed at both sites.

"You may see the antenna systems at GB by using:  www.gb.nrao.edu

and on the left side of the main page, surf to 'telescopes.'  My QSL

card has the 45 foot antenna on the front. That is the system I used

to map a quadrant of our galaxy at wavelengths of 3.5 and 2.1 cm.

Big antennas sure are interesting!"

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 web page at

http://arrl.org/propagation-of-rf-signals. For an explanation of the

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 January 15 through 21 were 62, 75, 49, 78, 62,

57, and 50, with a mean of 61.9. 10.7 cm flux was 131.4, 124.7,

121.9, 125.8, 130, 125.6, and 123.9, with a mean of 126.2. Estimated

planetary A indices were 6, 7, 7, 5, 5, 4, and 11, with a mean of

6.4. Estimated mid-latitude A indices were 5, 6, 5, 3, 2, 5, and 7,

with a mean of 4.7.

NNNN

/EX