Propagation Forecast Bulletin 24 ARLP024 From Tad Cook, K7RA Seattle, WA June 13, 2014

To all radio amateurs

ARLP024 Propagation de K7RA

Last week’s bulletin opened with your author (me) moaning about a decline in solar activity, but this was short lived. The current week saw average daily sunspot numbers more than double, rising from
60.1 to 144.3, and average daily solar flux rise from 104.1 to 146.4. In addition, on June 12 the daily sunspot number was 196, and solar flux was 174.5. It actually was not long ago when sunspot numbers were last at that level. April 16-19, 2014 had numbers ranging from 245-296.

Predicted values are also up. The latest has solar flux at 170, 165 and 155 on June 13-15, 145 on June 16-18, 140 on June 19, 130 on June 20-21, then reaching down for a low of 110 on June 24-25, then peaking at 165 on July 8. The outlook for Field Day Weekend has brightened, with solar flux at 115 on June 27-28 and 120 on Sunday, June 29.

Predicted planetary A index is 18, 20, 10 and 8 on June 13-16, 5 on June 17, 8 on June 18, 5 on June 19-24, 8 on June 25-26, 5 on June
27 through July 5, 15 on July 6, 5 on July 7-9, 8 on July 10, 5 on July 11-14, and 8 on July 15-16.

OK1HH predicts mostly quiet geomagnetic conditions on June 13, quiet to active June 14, quiet to unsettled June 15, quiet June 16-18, quiet to active June 19, quiet to unsettled June 20, mostly quiet June 21, quiet June 22-24, mostly quiet June 25, quiet to active June 26, active to disturbed June 27, quiet to unsettled June 28, quiet on June 29, quiet to active June 30, mostly quiet July 1-2, quiet to unsettled July 3-4, quiet July 5, quiet to unsettled July 6, active to disturbed July 7, quiet to active July 8, and mostly quiet July 9.

Again this week there was an interruption in data from the middle latitude geomagnetic observatory in Fredericksburg, Virginia, so the middle latitude A index numbers at the end of this bulletin for June
8-9 are my own guesses.

We saw a lot of geomagnetic activity over last weekend, June 8-9, when the planetary K index reached 6 in two 3-hour periods, and the planetary A index was 13 on Saturday, then 39 on Sunday. This geomagnetic storm was from a CME which hit Earth at 1630 UTC on June 7, but left the Sun on June 4.

A significant solar flare on June 10 could cause polar geomagnetic storms today, Friday June 13. It will probably deliver a glancing blow to Earth’s magnetic field. See for an article about the June 10 flare, and for a UPI story on possible effects today, see

Ted Leaf, K8HI sent a fascinating video and article about renewed activity at the peak of the current solar cycle. See .

Max White, M0VNG sent two relevant articles. See

David Moore sent a review of “Nearest Star; the surprising science of our Sun” which you can read at .

An excellent book I’ve been reading is “Tesla: Inventor of the Electrical Age” by W. Bernard Carlson. This may be the best biography yet on Tesla, as other articles and books I’ve seen accepted uncritically some of his later work, which included transmitting electrical power via wireless. I think copper wire works better for this.

NASA has a new and slightly revised prediction for Cycle 24.  View it at . The changes from a month ago are:

May 2, 2014 forecast: “The current prediction for Sunspot Cycle 24 gives a smoothed sunspot number maximum of about 70 in the Fall of 2013. The smoothed sunspot number reached 75.0 in October 2013.”


June 12, 2014 forecast: “The current prediction for Sunspot Cycle 24 gives a smoothed sunspot number maximum of about 70 in late 2013.
The smoothed sunspot number reached 75.4 in November 2013.”

These are smoothed numbers, averaged with real and predicted values over a year, so when we have higher and extended activity this year, that changed the maximum from fall of 2013 to late 2013, and 75.0 in October 2013 to 75.4 in November 2013.

Astrophysicists at Trinity College in Dublin are using crowdsourcing for classifying sunspots. They want people to visit to rank pairs of sunspot images based on complexity. As you are presented with each pair, use your gut feelings and vote for the image that seems the most complex. Or if you want examples, go to .

We learned of this from the Irish internet news site, and you can read their article “Trinity College astrophysicists want you to play ‘Hot or Not’ with sunspots” at .

Another interesting project to use crowdsourcing is “Seafloor Explorer,” where they want help classifying real images of the ocean floor. Check it out at . People who believe they see a face on Mars or pyramids on the moon should find a lot to like here.

Find other projects and educational info at Click on “Study explosions on the Sun” to enter their Solar Stormwatch project.

This weekend is the ARRL June VHF Contest. The multiplier is number of grid squares worked. The contest begins at 1800 UTC Saturday. See for details.

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 the 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 5 through 11 were 102, 132, 155, 144, 152, 149, and 176, with a mean of 144.3. 10.7 cm flux was 110.5, 133, 136.7, 148.6, 161.2, 166.2, and 168.4, with a mean of 146.4.
Estimated planetary A indices were 7, 6, 13, 39, 5, 7, and 7, with a mean of 12. Estimated mid-latitude A indices were 7, 5, 14, 40, 6, 7, and 8, with a mean of 12.4.

Massachusetts to Host USA ARDF Championships June 5-8

The USA ARDF (Amateur Radio Direction Finding) Championships return to the Northeast this year. ARRL ARDF Coordinator Joe Moell, K0OV, said on-foot foxhunting fans of all skill levels will gather near Boston in early June for 4 days of intense competition. Registration to participate in the event has been extended to June 1.

Activities begin on Thursday, June 5 with a 10-transmitter short-course sprint competition on 80 meters. The following day is the foxoring event, a combination of RDF and classic orienteering on 80 meters in which participants navigate to marked locations on their maps where very low-power transmitters can be found nearby. Saturday morning will be the classic full-course 2 meter main event, with five transmitters in a very large forest. The banquet and awards presentation follow that evening. A similar full-course 80 meter main event takes place Sunday morning, with awards presented afterward.
ARDF champ Vadim Afonkin, KB1RLI, is this year’s lead organizer, event host, and course-planner.

National ARDF championships typically take place in late summer or early fall. This year, though, the ARDF World Championships will take place during early September, however. To provide plenty of time for selecting Team USA members and planning overseas travel, the 2014 USA ARDF Championships must take place 3 months before.

ARDF championship rules are set by the International Amateur Radio Union (IARU). For scoring and awards, participants are divided into 11 age/gender categories. In classic ARDF championships, competitors start in small groups comprised of different categories.

The USA ARDF Championships are open to anyone who can safely navigate the woods solo. A ham radio license is not required. Each participant competes as an individual.

Stateside winners will be considered for membership in ARDF Team USA, which will travel to Kazakhstan for the 17th ARDF World Championships.

An online entry form and more information are available on the Boston ARDF website. Read more. — Thanks to Joe Moell, K0OV, ARRL Amateur Radio Direction Finding Coordinator


Building a portable 12 Volt DC power source

If you’re like me, you not only enjoy your radios in the comfort of your shack, but like to go outside to “play radio” in events such as the upcoming 2013 ARRL January VHF Contest. This is a contest where I enjoy being a rover station. I also take part in spontaneous DX parties, public service events such as road races and providing Amateur Radio communications in times of need to such organizations as the American Red Cross. All of these activities at one time or another may require that battery power be used, as commercial power may simply not be available.

In this article, I’m going to discuss how I made my 12 Volt DC portable power source. I urge you to make, and have an auxiliary power available for yourself in the event you find yourself without commercial power. Fortunately for me, except for the battery box, everything else I needed was found around my shack and home.

The components of my 12 Volt DC portable power source include:
1. Four Anderson Powerpoles – Two red, two black and all with 45AMP barrel connectors.
2. 10 gage red/black zip-cord power wire (It’s best if you not use speaker wire).
3. Heat-shrink tubing of various sizes.
4. Two battery post terminals, for the AGM 12 Volt battery.
5. One 4-pole snap-in panel mount for 2 sets of Anderson Powerpoles.
6. Two Velcro Velstraps – 3ft X 2in
7. One 12 Volt (AGM) vehicle battery. As your power needs may vary, and there are any numbers of detailed articles about battery selection, I’m not going to cover that here.
8. One full-sized battery box.

Go-Kit Components

Go-Kit Components

Once the components were laid out, the first thing I did was to turn over the battery box. Then with my trusty Dremel Tool and multipurpose cutting bit, I cut out two thin rectangle holes just big enough to pass one of the Velstraps through [Picture A.]. Once the holes were made, starting from inside the box; I simply passed the Velstrap out one of the holes, across the underside of the box, then back into the box via the other hole [Picture B]. This Velstrap will later be used to hold the battery in place, once it’s inside the battery box.

Dremel Tool, Battery Box Bottom

Dremel Tool, Battery Box Bottom

I next took the top of the battery box, and again using the Dremel Tool and multipurpose cutting bit, I cut a square hole measuring 1.00 inch by 1.25 inches. This hole will later be used as a place to insert the 4-pole snap-in panel mount to hold the Anderson Powerpoles [Picture I].

The wiring came next. Following proper techniques, I crimped a 45 AMP barrel connector onto each of the four wire leads of a 10 gauge red/black zip-cord power wire. Then, keeping with ARES/RACES standard orientation, I assembled the red and black connectors (tongue down, hood up, red on the left, black on the right as viewed opposite the wire side). With each pair assembled, I then joined the two pairs together, one set over the other. NOTE: When using large gauge wire, it’s easier to put the connector housings together before putting the barrel connectors in.

Once the four connector housings were together, I inserted the wire lead’s barrel connectors into their corresponding connector housings. Red into red, black into black. Using the proper sized heat-shrink tubing, I fed both sets of zip-cords through it, then brought the heat-shrink tubing all the way up until it met the base of the Powerpole connectors. I applied heat and shrunk the tubing in place.

Using a sharp knife, I then split the ends of the zip-cords and separated the red side from the black side all the way up till it reached the heat-shrink tubing near the Powerpole connectors. I then fed both red wire leads into one length of heat-shrink tubing, then both black wire leads into a separate length of heat-shrink tubing. On both sets of wire leads, I left a generous amount of wire extending beyond the heat-shrink tubing. I applied heat and shrunk each of the tubes around their respective wire lead sets.

Powerpole connectors on, power-leads separated then heat-shrunk together by polarity, it was time to insert the four-gang of Powerpole connectors into the 4-pole snap-in panel. The Powerpole connectors simply slide in to the 4-pole snap-in panel and are held in place by inserting a retaining pin [Picture II].

Were almost home, just a few more steps: Holding the lid at the distance I wanted it to be from the bottom of the box, I measured out the length the wire leads from the 4-pole snap-in panel to the battery posts needed to be, then cut off the excess wire. Now cut to length, I inserted both red and black sets of wire leads into a single heat-shrink tubing. I remembered to leave enough of the wire leads exposed in order for me to later attach these wire leads to the battery terminals. I then applied heat and shrunk the tubing. Once the heat-shrink tubing cooled, to minimize movement of the wiring harness I secured it to the top of the box. After striping away enough of the outer coating, I attached each set of wire leads to their respective battery terminals and attached the battery terminals to the battery posts [Picture III].

Assembled Components

Assembled Components

The above having been completed, I placed the top onto the bottom of the battery box and secured it using the last Velstrap…Done! I now had a safe, secure and ARES/RACES standard orientation compliant source of 12 Volt DC power.

Completed 12 Volt DC portable power source

Completed 12 Volt DC portable power source

It’s my hope that this article, by showing you how with readily available components and it’s quick and easy assembly, you’ll be motivated to create your own portable 12 Volt DC power source.  After all, the bottom line is this: You never know when that next event will cause the lose of power to your shack, and there’s no guarantee there’ll be commercial power available at the places you go to, or get called to. A piece of equipment like this will give you one more way to be ready to get on, and stay on the air.


Rich – N1KXR

KX3 from PEI

Yesterday I has the chance to set up the KX3 while vacationing on Prince Edward Island. Unfortunately the weather was not great but I managed to get an end fed wirestrung between two small pines and down to the deck. I heard a few summits but they couldn’t hear the little KX3 on the EFW.

Much better luck was to be had in the evening. There was a QRP contest starting at 0100z, the Run For The Bacon (RFTB). Dialing down the KX3 to 5 watts I managed eight contacts, one a far as Germany! I took a break in the middle of the test and even managed to check into the reddit net on 75 meters.

Off to do some bike riding and tourist stuff today, probably get back on 40cw later this evening.

Don’t forget about the club meeting on the 7th, hope to see you there.