ARRL The Doctor is In is a podcast based on the popular QST magazine column "The Doctor is In." Hosted by QST Editor in Chief Steve Ford, WB8IMY, and columnist Joel Hallas, W1ZR, the podcast is a lively 20-minute discussion of a wide range of technical topics. Sponsored by DX Engineering.
http://blubrry.com/arrl_the_doctor_is_in/
HF Propagation
The key to getting the most from Amateur Radio on the HF bands is to understand the concept of "propagation." HF propagation can be fickle at times, and often downright spooky!