[South Florida DX Association] ARLP041 Propagation de K7RA

[Bill Marx]

  ZCZC AP41
> QST de W1AW  
> Propagation Forecast Bulletin 41  ARLP041
> From Tad Cook, K7RA
> Seattle, WA  October 8, 2004
> To all radio amateurs 
> 
> SB PROP ARL ARLP041
> ARLP041 Propagation de K7RA
> 
> More mail this week about 10-meters and using beacons to detect band
> openings, but first let's look at the numbers.
> 
> Average daily sunspot numbers rose this week from last, jumping over
> 17 points to 38.1. Average daily solar flux was about the same.
> Solar activity has been very low, and fortunately geomagnetic
> indices are also low as well. Don't expect a change over the next
> few days, but a slight increase in solar flux is predicted for
> October 15-16, when it may rise to around 105. Otherwise, until then
> expect low sunspot numbers, and solar flux around 90-95.
> 
> Geomagnetic activity should continue to be quiet, but there is a
> chance of some unsettled to active conditions around October 12-15.
> Currently the visible sun is nearly spotless, but helioseismic
> holography reveals a sunspot group on the sun's far side. The sun
> rotates relative to earth about every 27.5 days, so it will face us
> later this month.
> 
> Now that the third quarter of 2004 has passed we can review
> quarterly averages for sunspot numbers and solar flux.
> 
> From the third quarter of 2002 through the third quarter of 2004,
> the average daily sunspot numbers were 193.5, 152.7, 120.3, 107.3,
> 110.2, 99.2, 72.9, 71.3 and 69.3. The average daily solar flux for
> the same period was 178.1, 164.2, 134.3, 124.2, 120.8, 137.4, 111.1,
> 99.5 and 111. Yet more evidence of cycle 23's slide toward solar
> minimum, currently forecast to occur a little over two years from
> now.
> 
> Geoff, GM4ESD wrote with more comments about copying African beacon
> stations on 10-meters from Scotland. Geoff wrote, "I am not at all
> certain that the summertime propagation mode is 'classic' multi-hop
> F2 during the 1100-1400z slot. Unless there is sporadic E about the
> same time, none of the beacons at [an] estimated one hop F2 distance
> from here toward ZS6DN are heard. When there is sporadic E about,
> ZS6DN tends to be much weaker, if heard at all, regardless of the
> location of the E 'cloud'. Only in the evening does sporadic E
> appear to help. Very often during this 1100-1400z slot ZS6DN's
> signal has a slight watery sound, but not as severe as on a 6-metre
> transcontinental signal."
> 
> Geoff goes on to say, "I have never heard an echo. I would have
> thought that I am a bit too far north for direct Trans-Equatorial
> Propagation, as we understand it to be involved so frequently during
> this time of day. If there is a 'classic' F2 opening between South
> Africa and here, most times I hear the ZS1J beacon as well, or ZS1J
> without ZS6DN. ZS6DN is not appearing so often after the equinox,
> either at 1100-1400z or at 1600-1700z. I suspect the 'rules' of
> solar flux/sunspot numbers are taking over, and now he only appears
> if there is a 'classic' multi-hop F2 path open to him."
> 
> Junji Saito, JA7SSB sent an email pointing out a typo in last week's
> bulletin, where I wrote that the solar flux was expected to reach
> 200 by October 7. He guessed correctly when he said 100. (KK4TA
> noticed as well, and also guessed the valid number correctly). In
> fact, the three daily readings at the Penticton observatory in
> British Columbia for October 7 were a bit lower at 91.4, 93.8 and
> 94.9. Those readings are taken daily at 1700, 2000 and 2300z, but
> the local noon reading at 2000z is always the official solar flux
> for the day.
> 
> Junji had other comments, in addition to politely correcting the
> predicted solar flux number. He said this Autumn he experiences good
> daily 20 meter propagation to North America around 0200-0600z, and
> he uses both SSB and RTTY. I expect he gets great propagation to the
> West Coast.
> 
> Here in the Pacific Northwest, Japan is often loud, and depending on
> conditions, sometimes pileups of JA calls respond when calling CQ
> with a good signal toward that direction. A reminder of this was
> when Henry Platt, W3UI visited Seattle last week. The bed and
> breakfast he stayed at was only a few blocks from Dan Eskenazi,
> K7SS. Dan has a great shot to the Pacific from his house on a high
> spot in West Seattle, with a commanding view of Puget Sound. His
> back yard ends at a cliff which drops off toward the west, a quarter
> mile from salt water. Henry loves CW, and couldn't resist getting on
> the air. He was amazed at the multitude of JA signals and how many
> other Pacific stations he could work from Dan's station.  Of course
> at home in Eastern Pennsylvania, Henry easily works Europe, but the
> path toward Japan is much further and polar as well.  A polar path
> has the disadvantage of being poor for HF propagation when
> geomagnetic indices are high. Dan works Japan easily, but Europe is
> a polar path for him.
> 
> Thomas Giella, KN4LF wants to remind us of the propagation email
> reflector mentioned in this bulletin eight weeks ago. You can sign
> up at, http://lists.contesting.com/mailman/listinfo/propagation.
> 
> Finally, Joe Pontek, K8JP in Indiana writes about working 6-meters
> from Central America in Belize. When he is there and signing V3, he
> often listens in the evening for South America. When he hears U.S.
> stations on backscatter, he calls them, but when they turn their
> beams toward him the signals are gone. He said this is particularly
> true with Florida stations. For an interesting web article on
> backscatter, see http://ecjones.org/backscatter.html.
> 
> If you would like to comment or have a tip, email the author at,
> k7ra at arrl.net.
> 
> For more information concerning propagation and an explanation of
> the numbers used in this bulletin see the ARRL Technical Information
> Service propagation page at,
> http://www.arrl.org/tis/info/propagation.html.
> 
> Sunspot numbers for September 30 through October 6 were 36, 37, 35,
> 39, 41, 40 and 39 with a mean of 38.1. 10.7 cm flux was 88.2, 88,
> 88, 89, 90.7, 90.8 and 92.1, with a mean of 89.5. Estimated
> planetary A indices were 4, 4, 12, 15, 10, 5 and 5, with a mean of
> 7.9. Estimated mid-latitude A indices were 2, 2, 8, 7, 8, 3 and 2,
> with a mean of 4.6.
> NNNN
> /EX
>