[The Mike Stuff] has an interesting proposition. He asserts that ancient people like the Greeks could have built a form of radio that was purely mechanical. We aren’t sure we agree, but even if it were possible, we are sure it would have sounded awful. You can see the details in the video below.
The idea is that you can compress air with a waterwheel, blow it through a rotating disk with slots in it, and a valve to amplitude modulate the airflow through the disk. Horns like an old gramophone speaker would amplify the signal at both ends. The demodulation is straightforward and doesn’t even require power, like compressed air.
This is a fun idea, but even [Mike] notes it wouldn’t be very good. We suspect you’d just hear a 10 kHz buzz. On the other hand, this would be pretty easy to build if you wanted to test it. Use an electric motor to spin the disk — after all, we’ll stipulate that you could turn a disk with water power, even if speed control is a little challenging.
If you build it, we’d love to hear about it. Just don’t use it to send us an air-radio message. Try e-mail instead. What do you think? Would this work? We get that if it did, it wouldn’t work well, but would it work at all? Let us know what you think.
If you think about it, building regular receivers that are of low performance is easy enough. With a little work, simple receivers can actually work quite well.