In 1959, the RCAF – Royal Canadian Air Force – made a serie of interesting training video clips on Antenna Fundamentals, with the help from the Canadian National Film Board. I love these old training documents, they hold a gold mine of useful information about useful Amateur Radio theories. Sometimes, you need to have something explained differently to get it. Theses ones are about Propagation|Directivity|Bandwidth.
Make some popcorn, turn off the lights and switch on the movie projector! Let the military teach you a thing or two …
I hope you enjoyed these clips. Although “old school”, they explain the properties of waves with unprecedent accuracy.
As a bonus, here is a 1947 USAF equivalent.