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NGR SJ325991
53° 29' 3" N
3° 1' 2" W
Locator = IO83LL
Node = 364553

Propagation data

Charts by kind permission of Paul L Herrman. Visit http://www.hamqsl.com/solar.html

SFI [High is good]
>70 Bad
80-90 Low
90-100 Average
100- 150 Good
>150 Ideal

SN (sunspots) [High is good]
<50 Bad
50-75 conditiona attenuated
75-100 Good
100 - 150 ideal
>150 exceptional

The A Index [Low is good]
1 - 6 is Best
7 - 9 is OK
11+ is BAD

The K Index [Low is good]
0 or 1 is BEST
2 is OK
3 or more is BAD

XRay [Low is good]
B: Very Low
C: Moderate
M: Moderate to high
X: High to extreme

The reference below is reproduced by kind permission of Edwin C. Jones, MD, PhD (AE4TM)
Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996-1200

A- and K-index:
Geomagnetic activity indices, high indices (K:>5 or A:>20) means stormy conditions with an active geomagnetic field. The more active, the more unstable propagation with possible periods of total propagation fade-out. Especially around the higher latitudes and especially at the polar regions, where the geomagnetic field is weak, propagation may disappear completely. Extreme high indices may result in aurora propagation, with strongly degraded long distance propagation at all latitudes. Sporadic-E is strongest during low indices. Low indices result in relative good propagation, especially noticeable around the higher latitudes, when transpolar paths may open up. Maximum K-index is 9, and the A-index can exceed well over 100 during very severe storm conditions, with no maximum. The ARRL often reports the K-index from the Alaskian station where this index is known as the College K-index. Other stations reporting K-indices include Planetary and Boulder. In contrast, the A-indices are usually reported for the Planetary station only.

The higher the K-index, the more unstable propagation becomes, the effect is stronger at high latitudes, but weaker near low latitudes.
When storm level is reached, propagation strongly degrades, possibly fade out at high latitudes.
Classification of K-indices are as follows:

K1=Very quiet
K5=Minor storm
K6=Major storm
K7=Severe storm
K8=Very severe storm
K9=Extremely severe storm

As with the K-index, the higher the A-index, the more unstable propagation becomes.
Classification of A-indices are as follows:

A0 - A7 = quiet
A8 - A15 = unsettled
A16 - A29 = active
A30 - A49 = minor storm
A50 - A99 = major storm
A100 - A400 = severe storm

Background X-ray level: This may vary from B (very low), C (low to moderate), M (moderate to high) to X (high to extremely high), the higher the number after the letter, the stronger the X-ray radiation. So an X0.1 is stronger than an M9.9. High amounts of X-ray radiation causes intense ionization of the D-layer, resulting in strong absorption of HF-signals. Solar flares are commonly measured in the amount of X-ray radiation.

Solar Flux: This flux number is measured from the amount of radiation on the 10.7cm band (2800MHz). It is closely related to the amount of ultraviolet radiation, which is needed to create an ionosphere. The lowest possible number for this solar flux is 63.75. Single hop propagation already starts at 70 in lower latitude areas. Worldwide long distance propagation (DX) may turn up already with a solar flux at 120. From experience, an average solar flux of 170 seems to be ideal for 10m-20m bands QRP DX with good possibilities during these conditions to reach every possible part of the globe with a simple dipole running as low as 5 Watts!

The reference above is reproduced by kind permission of Edwin C. Jones, MD, PhD (AE4TM)

Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996-1200

VE3EN's Website www.solarham.com is an excellent resource for upto date solar and propagation data.
The definitions page (www.solarham.com/help.htm) is particularly useful for interpreting results.

© Copyright Ken Dumbill 2008 - 2015