Here is the link to the episode, and the feed…
This, sort of, is just the beginning. The Indo-European, the Aryan, and the Indo-Iranian languages and terms are such thorny issues, and I cannot even pretend to have answered them all. Hopefully this will set the stage for future discussions, and some questions, comments, and discussions here.
Notice that I tend to spell the word Ariia in order to name the “Indo-Iranians” as they are, and to distinguish it from the Aryan, which is used in a modern, political sense.
Check out the Bibliography for some book and article suggestions…
Schematic map of major Indo-European language groups
Map showing the extent of the Andronovo and BMAC cultures
Iranologie.com 
The notion that the Aryan race idea was imported into Iran from Europe is ironic.
I’ve only discovered this show a few days ago but have already catched up. It’s a great resource already, I’m especially looking forward to the episode(s) about the religions of the time.