RADIOACTIVITIES Newsletter of the Argonne Amateur Radio Club
Volume XLV, Number 8	October, 2004

We wish to thank Tony Levand, AA9CC, for his very interesting presentation about direction finding at the September meeting.

Club Volunteer Examiners please contact Jim Jorgensen; at the above address.

01		W9MKJ		Bill		Darien, IL
01		WB7NHS		Doug		Idaho Falls, ID
02		K9FAT		Jim		Crest Hill, IL
03		K9VIX		Vicki		Downers Grove, IL
06		W9KJA		Clem		LaGrange Park, IL
06		N7NHF		Robin		Idaho Falls, ID
07		WA9TLT		Clarence		Villa Park, IL
07		KB9SDJ		Joseph		Chicago, IL
08		K9JON		Ronald		Glenwood, IL
11		WB9IRH		Howard		Western Springs, IL
11		W9GBL		Jim		Yorkville, IL
13		KB9CYL		Jim		Orland Park, IL
22		N9TEB		Jim		Lombard, IL
26		KA9ZXN		Tom		Evergreen Park, IL
31		WA9FVP		Jack		New Lenox, IL
31		N9JTV		James		Wilmington, IL

The X was plastic 3" tubing to be raised onto a tree limb 36' high. The ends of the top wires go through a drilled hole according to the end fire spacing. The tubing lengths are 15' for 20 meters and 8' for 15 meters and tie a rope at the center of the boom for raising up 36'.

Try to keep the antenna 6' away from trees as the impedance goes up to 75 ohms instead of 35 ohms. I used RG58U throughout.

The four 20-meter elements are 17' 8" and the four 15-meter elements are 11' 8". Put insulators so they re in the center of the dipoles and the 15-meter phase line is 7' 8". Now remember to twist the RG58U for phasing by soldering the ground wire to the opposite side of the insulator on the second element of the dipole than you did on the first dipole. Do the same with the 17' 8" phase line of the 20-meter dipoles. I excited both dipoles from one length of coax to the front two 20/15 meter elements the spacing was whatever that distance may be. In my case they were 8' apart. Now for each four bottom dipole tie rope to brick to tighten it. I moved bricks when twisting system for another asmith direction one brick at a time. On 15 in contests, I worked Senegal, Rwanda, South Orkney, Annobon, Guinea, Ravilla Gigedo, Cuba, Abuail and on 20 meters, South Shetlands, Barbados, Campbellise Australia Mellish Reef, Mali, and others. It came down in a heavy windy storm and the tree limb fell and I found a dead sparrow in a mess of wires. A sad ending. My next project came Oct 1989; a 3 band full wave vertical.

DXers noticing a band opening will mark their calendar four weeks into the future. The period between full moons is a little over twenty-nine and a half days, and from time to time the dates of maximum sunspot number as observed will coincide with the day on which a full moon occurs because the syndic month is close to the suns average period of rotation and can persist for several months. These ancient hams were mislead.

The best times for DXing can be sunrise and sunset and about an hour before and after because of enhanced propagation at those times. Look the times up in the newspaper. Solar data given out by WWV is most helpful. The solar flux from 2800 Mhz is directly related to sunspot numbers and it varies from 66, which means zero to several hundred. Even a small change can have a profound effect. An increase of only 3 to 4 points, from 66 to 70 can mean longer 20 meter openings until way past sunset, even some 15 meter band openings during the day. An increase to 80 will open 15 meters and ten meters should be open when the flux hits 90. A decrease in solar flux means bad conditions.

The A index is a measure of geomagnetic activity or absorption of ionosphere. The higher the number, the weaker the radio signals. This index ranges from near zero to several hundred. Readings below 10 to 15 signify good conditions; over thirty, bad conditions.

The K index, like the A index, measures absorption on a three hour period and reflects now band conditions. Values vary from zero to nine. Zero to two is good; higher values mean disturbed conditions. The twenty-seven day and fifty-five day cycle into the future should be noted on a calendar. DXpeditions do it this way: The north-south path is little affected on higher readings. Consider turning your vertical to the south on high absorption days. Days of class X flares hide away or the radiation may burn your skin.

The long path is a great circle path around the earth rather than the short path. It opens on the dark side of the earth with the short path completely in sunlight. Conditions an hour or two past dawn at the eastern end of the path with the western end in the afternoon or early evening. The long path is largely over seawater with large number of hops. The bands favored for all this are 20, 17, 15, 12, and 10 meters. Conditions for north and south hemispheres are optimum during the spring and fall equinoctial periods; summer mornings NW-SE, nights NE-SW; winter mornings NE-SW, nights are NW-SE. The long path is 180 degrees away from the usual short path.

It all starts with refraction of the radio waves off various ionized layers, mainly the F layer, 150 to 300 miles up and a single bounce may return 1500 to 2000 miles in one hop and it must pass through the lower D layer of atmosphere twice; on the way up and on the way down. Daylight D layer is at maximum intensity, it absorbs the wave decreasing signal strength and also long haul DX.

Now at local sunrise and sunset the D layer is weak and absorption low. The F layer won't disperse at night when long path opens. The D layer is gone and maybe multi-hops are in order. The long path on 6000-mile hops is no better than the short path. The long path must be on almost in darkness. Solar activity must be high to keep the F layer alive. The geomagnetic field must be quiet, A index below 20, with K index below 3, below minor storm levels.

On ten meters look anywhere from 150 to 270 degrees over South Pole. Once in a while the North Pole brings a surprise. I worked YB Indonesia over North Pole at 10 AM. I told AF9J and the next day he did too. On 15 meters, for me, an hour or so after darkness, China Northeast, Southeast Africa. 20 meters at 6 AM due West Asibhtuan and Jim Smith for a weeks dxpedition worked VKs and wife Christy was only time I heard him half hour then gone never worked but I worked another group a few years later. Working the polar path signals have a watery sound called polar artic flutter, caused by signal passing through the polar auroral zone causes a lot of short term fading and reflections. Short and long path can be open at the same time and there can be a tremendous echo caused by delays over multiple paths. A 20db over S9 signal will be unreadable due to echo. Forty meters I've been told periods of lower sunspots in winter months is the place to be. Long paths shoots from light through dark to the light and grayline propagation. Mornings look southwest. Eighty meters can be a early morning DX hangout. 1AM I heard NAPAL but my long wire and 300 watts weren't enough. I gave up on 80DX from here hi-voltage power lines ruin everything.

Grayline long path is based on sunrise and sunset time of year angles. Openings between two points on the earth signals travel along the edge of the ring or band of twilight encircling the earth. The grayline is complicated and there are people selling a program on computer to do the work. I don't know who does it. They used to advertise in 73, Hamradio, CQ, & QST magazines a few years ago. Anyway, happy DXing.

SE of Manhattan, IL