HF Propagation Site
 

A fabulous site is the one provided by Australia - the URL is:
http://ips.gov.au A PDF file(25 pages) - "Introduction to HF Radio
Propagation" is included, click on "HF Comm. Problems" on
home page, then "PDF file Intro to HF radio Prop." at bottom of page.
Many other factors about HF prop. are included on this very, very
interesting and informative site. Some or many listeners may already
know of this site, but for those who haven't it's well worth a look-
see.
Good Listening to All from SW4ever...