I've got a similar set-up out in one of our sheds. Used an exercise bike, like in the video. However, the bike tire was removed, and in it's place there's a belt, which is connected to an old tape drive motor. I built a regulator for it too, and it terminates in a cord with an Anderson powerpole. It works well enough, I forget how many amps it puts out. It's a good device for kids that have too much energy. Have the kid pedal for 10-15 minutes, and it'll top off your batteries.
I had a Ten Tec 505 too, and a Power-Mite, and a 509, and a Century 21. The Century 21 was one of my favorites of the Ten-Tec radios, used it to get to 13 wpm for the General license, back in the day. Currently, the only Ten-Tec radio in the stable is an Omni D, which is the primary radio for CW here, so it doesn't get used much.