Friday, February 26, 2016

A cycle within the solar cycle

Everyone knows the sunspot cycle. A cycle that is there with a timespan of about 11 years. The amount of sunspots gives you an idea of propagation on the 11m HF band. Anything around 100 or above is good.  At the moment we just had a peak of suncycle 24 and sunspots are going down.  With the decline of cycle 23 back in 2004/2005 I already noticed another cycle. It is the rotation of the sun in about 27 days. That could mean that "good" or actually better propagation is appearing every 27-28 days as well as any active sunspots will appear again within that time. This can especially be noticed when in the solarcycle minimum. I've been searching for this phenomenon on the internet but only little can be found. Though I noticed it several times through the low sunspot years and others probabely did as well. But it is not known by many 11m radio operators.

Find some excellent written info understanding HF propagation here:

A day by day International Sun Spot Number can be found here:

Last week around 15-16 Feb. I had several QSOs with 43 div. (Australia) and 153 div. (Thailand). The week before I managed to talk to 2 (USA) , 5 (Venezuela) and 347 (Curacao). At the moment propagation is low. But I expect some better propagation next week.

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