Paul,
Bottom line - looks like I got it.
Thanks for answering. I am using a Lenovo T60 laptop. I am running Ubuntu 14.04 LTS - a Linux distribution. Much
experience with computers, but not much with Linux and none downloading and expanding zip files.
Bizarro - I tried to open the latest download. Archive Manager listed 19 files. I chose the Extract option. It pulled out one file, "wheaton-permaculture-263-update-part1.mp3" with 15.7 MB. It is playing fine as I type. But, I can't get it to extract any other files. Then I went back and tried again and it worked. Looks like all 19 came through. The rocket-mass-heater-gob.zip file was 334.0 MB.
More bizarro - when I sent the Rhythmbox music player looking, it found hundreds of podcast and
permaculture files. Thank you for all the candy.
The typical download that didn't work had rocket-mass-heater-podcast-gob.zip with 0 bytes and rocket-mass-heater-gob.zip.part with 334.0 MB. That may be a clue - in Linux, if you download and get the filename you were looking for plus another one with ".part" added to the end, something went wrong with the download.
Bobby