OK... I'm a fairly new ham... but I get it that the higher the SSN number the better the "conditions" should be - esp in the higher HF bands. Except that the other numbers in a Propagation Report are less clear to me; the A Index, for example... when I see it drop from 14 to 4, does that mean anything, immediately, to me? Are band conditions going to suddenly change for the better? Someone told me that a high A Index number usually means noisy bands... is that true?

Where can I find a meaningful, not-too math-heavy explanation of all the factors of a typical Propagation Report.

Right now, for instance: SF:113 A:4 K:2 SSN:90 What is the meaning and releationship of these numbers in terms of band conditions as I would experience them?

I have the N0HR add-on on my Foxfire browser... http://www.n0hr.com/phpBB/

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N6RLS Robin Spalding

Robin,
I suggest you Google 'HF Propagation Tutorial' this should give you a start in understanding HF propagation. After that, try Googling 'HF Propagation Report Tutorial'. There are many sites on the web that will provide info for you.
Good Luck and 73
Andy - n1ork

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N1ORK Orest 'Andy' Zajac

Lots of things are going on. If one has many xray flares and no heavy particle impacts, then the F2 layer heats-up and long haul communications gets better on the higher frequencies, i.e. MUF rises. If one gets heavy particles (CME, auroras, etc), they cause geomagnetic storms and disturbances, so the lower frequencies will absorb more RF - less useful, and MUF drops. So you want xray flares w/o CMEs for higher MUF and if your A index drops from 14-4, that is good for better low freq paths (i.e. 80m, 40m). Ideal situations for good long haul F2 layer propagation would be a lot of xray flares and very low A and K indicies. And as Andy said, check out some of the good on-line references. Cheers, Joe, K1YOW

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K1YOW Joe Dzekevich

As Joe say above, but it is a very involved study, and I have to say, an enjoyable one.

What I would like to add, is that mother nature and science have a habit of throwing things unexpected. I have, on numerous occasions calculated propagation paths and concluded the circuit to be closed, in practice, the circuit has been very much open. Some of the best QSOs have been gained this way. I do the Math, then switch on the rig and confirm. Often you will get surprises. Don't let the calculator get in the way of practical operating, because propagation is an element of science still not fully understood. It's an area where anyone can make a discovery, fill in another jigsaw piece.

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2M0CDD John D'Hunt

Maybe a bit off topic... I just re-joined eQSL after a lengthy absence. I paid $50 which should qualify me as a "silver member" and should allow me access to the Propagation Forecaster tool. I have just tried it 3 times and I keep getting a pop up that says I have to be a "silver member" (I am) or a "gold member" to use this feature. Am I doing something wrong to get at that tool?

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N8EB KEITH MCKENZIE

Hi Keith,

After making changes like that you need to log out and then back in again to refresh the cookie, from the error message it sounds like that was the problem.

Is it working for you now?

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73, Dave - VA3KAB

Dave - Thanks, that must have been it. Signing on today and working fine!

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N8EB KEITH MCKENZIE