QRP Club

QRP Station => Other => Topic started by: M0ggk on December 15, 2013, 16:57:52 UTC

Title: Solar flux index etc
Post by: M0ggk on December 15, 2013, 16:57:52 UTC
Hi all
        Ok this may seem a daft question but I will ask it and please forgive me?

When you look at the band condx when would be best to operate ? What am I looking for?

Any gurus out there that can answer ?

Dave M0GGK
Title: Re: Solar flux index etc
Post by: IZ5ZCO on December 18, 2013, 23:33:03 UTC
I use VOACAP Online HFBC:
http://www.voacap.com/hfbc/ (http://www.voacap.com/hfbc/)
Title: Re: Solar flux index etc
Post by: GM0LVI on December 23, 2013, 21:34:25 UTC
No such thing as a daft question Dave!
However the answer to yours is full of ifs and buts.
Propagation varies day to day as the SFI and A & K indices change, there are also seasonal variations and of course the sunspot cycle to take into account. For "Good propagation" you want a high SFI and low A&K.
And as you'll no doubt know time of day influences the maximum usable frequency.

If you download W6ELProp (just do a web search for it) it allows you to enter current SFI and K values and then will calculate signal levels for any chosen band between your QTH and any other and will show on screen or print out tables and/or graphs.
I've been using it for around 20 years and have found it to be a good guide when planning skeds and contest strategy.
Back in the early 1990s I was QSL manager for an Antarctic station and we used W6ELProp to plan our weekly skeds and it was pretty reliable.