IV3PRK Pierluigi "Luis" Mansutti (ex HC1PF)

  160 meters Band: DXing on the Edge


In this section I put the monthly graphs showing my observed daily DX conditions, and the daily solar and geomagnetic data, from which all the previous graphs are built. Each month I will update the following pages:

- The “Last three months” with the last month graph on top of the previous two or more months

- The same months “four years before” (before leaving for Ecuador) and the next two to see which conditions could be expected

- The same months “one cycle before”  to see what happened at the same phase of the previous solar cycle

- The same months “two cycles before” to get a comparative situation during the same period of two cycles before.

On these graphs we can generally see some 27 days recurrence in the Dx conditions mainly in the years of high solar activity. It does not happen in the years of low solar cycle as there are no sunspot active areas turning with the 27 days rotation of the Sun, and thus no 27 days recurring geomagnetic disturbances on the Earth.



The blocks on these graphs represent the quality level of that particular path (quantity of stations ­signal levels - duration of openings), but consistently with the time of my hobby activity, so low values or no value do not mean necessarily lack of conditions…. may be I was not at the radio to get the best opening.

The values are in the  10 to 60 range in order to get meaningful heights on a scale compared with the A Index and Solar Flux numbers, and take into consideration the distance and the difficulty of the path from my QTH (Lat. 46.1 N Long. 13.1 E – JN66ne - near Slovenian border) as follows:

NA = North America

10 =  short and weak opening with the East Coast, usually the Big Ones with low signals (like VE1ZZ, K3UL, W4ZV, etc.)

20 = stronger signals and more stations from the East Coast or the first row from in 4 with the best equipped stns (W8UVZ, VE3NE, etc.)

30 = even better signals (over S9) from East Coast and W/8/9 area and the first row of W5 and W0 (W5UN, W0FLS, etc.)

40 = opening with Colorado and strong signals from Middle West or South Eastern areas

50 = short West Coast opening, just a single W7 in zone 3 (N7JW, N7DD, N6TR, N7UA, etc.)

60 = more consistent West Coast opening with good signals and the toughest path to California

70 = EXCEPTIONAL LONG opening into W6, W7 and VE7 …never happened again since December 1997

CA = Caribbean / Central America

20 = modest signals from resident well equipped stations (NP4A, FM5BH, etc.) and Florida

30 = some more stations from Caribbean with good signals ( and NP4A at 599)

40 = strong Caribbean signals also on SSB and XE opening (distance 10.000 Km.)

50 = EXCEPTIONAL all night long opening with over S9 signals (or TI9, XE4, FO/C)

SA = South America

20 = modest signals from YV and Caribbean islands of SA (P4, PJ, 9Y4)

30 = better signals from northern part of the continent and HK, HC and PY openings

40 = more southern openings (OA, CP, LU, CX, VP8, Antarctica: 10.000 to 13.000 Km. distance)

50 = CE, CE0, or LU, CP, CX with good signals also on SSB

60 = EXCEPTIONAL long opening with many strong signals, or 3Y0PI (15.000 km)

AF = Africa

10 = only stations in zone 33 or 34

20 = West Africa stations with weak signals

30 = Indian Ocean and Central and South Africa stations with weak signals

40 = good signals from East, Central and South Africa

50 = strong signals and long openings, or farther paths (ZS8, VK0H, FT5X)

AS = Asia (without Japan)

10 = average stations in zone 17 (UA9, UN) or Middle East

20 = strong UA9's or UA0 m zone 18 and other stations in zone 21

30 = UA0’s in zone 19, China or South East Asia (zone 22, 26, 28) with best equipped stations like 9M2AX

40 = other Far East stations (BV, XV, HS, 9V1, etc.) with good signals

50 = EXCEPTIONAL long openings with 599 signals on 10.000 Km. paths

JA = Japan

20 = just a path opening with some weak signals in the noise (JA7NI 449)

30 = usual best equipped stations (JA7NI, JA7OEM, JA3FYC, JH3PRR, JA6BZI, etc.)

40 = JA pile-up's with many stations and good signals

50 = long duration openings with 599 signals and new stations of the 2nd and 3rd layer

OC = Oceania

20 = just a very difficult copy on VK6HD, not enough for a QSO

30 = DU, YB or VK6 opening with fair signals

40 = strong signals from VK6, other VK call-areas (16.000 Km.), or weak ZL opening

50 = KH6, ZL stations (18.000 Km.) with fair signals and all other Pacific area, or VK's very strong also on SSB

60 = ducting conditions to ZL with 599 signals

70 = Good opening with South/Central Pacific or long path to VK/ZL: never occurred here

The LINES represent the historical SOLAR and GEOMAGNETIC data:

SF = the daily Solar Flux : corresponds with the left scale numbers

A Ind. = the planetary 24-hours geomagnetic Ap index: corresponds also with values on the left scale (but for the monthly graphs it is magnified on the right scale).

GCRd = Galactic Cosmic Radiation decrease: his line shows the Galactic Cosmic radiation and has been arbitrarily put so high in order to not clutter the graph. Each point represents the percent GCR decrease data as published on the Moscow Neutron Monitor  (multiplied by 10 and subtracted from the 300 top line reference).

During the years of low sunspot activity the GCRd is minimum and the cosmic radiation is maximum. During the years of high solar activity the cosmic rays are shifted away by the solar wind and thus GCRd is high and the cosmic radiation reaching the Earth is very low.

Prof. Brown, NM7M, says that very long DX haul, under ducting conditions, are enhanced by high GCR decrease numbers, and thus with low cosmic radiation, which happens during the high solar cycle.

I have been trying to find a better correlation between GCRd and my log data  ( see these pages: New Zealand and Australia ), but K9LA, one of the authors of the theory, wrote me:

“… Luis, I don't think you'll ever find a good short-term correlation between 160m openings and CGRd.
The reason for saying that is Bob and I agree that there's still another variable (or two) out there that we simply don't understand. More than likely it is tied to events in the troposphere coupling up to the ionosphere. Unfortunately I don't think we'll figure this out in our lifetimes - there simply are very few specific scientific investigations and measurements going on in this area. Carl, K9LA”


This comment matches with the title of another great article on CQ Magazine, March and April 1998:

The 160-Meter Band: An Enigma Shrouded in Mystery



So a long way to go … and I am really engaged on it!