Phonopaper (and questions - maybe to Volhout???)

Author	Message
Volhout Guru Joined: 05/03/2018 Location: Netherlands Posts: 5994	Posted: 11:50am 05 Jan 2023       Hi Frank, In the world of "lots of processing power" this is pretty straightforward. In the MPEG compression (i.e. MP3) one of the first steps is to convert the audio signal into frequency bins. The compression happens on these bins. Afterward the bins are reconstructed to audio. If you look at the raw MP3 data over time, that could very well translate directly into this phonopaper.... How they did that in 1950. Well, that is not to difficult. Early electronics did filter tones based on "tone relays". This is like a normal mechanical relay, with adjustable contact arm. The contact arm would be tuned for a certain frequency (resonance). You would only need a single coil, with many different arms, each with their own switch contact. The arm that resonates at that particular frequency would make a contact. This is an article on a 1950's 6 channel RC system that used similar "tuned" reed relay contacts And THIS you probably have seen before.... Volhout Edited 2023-01-05 22:07 by Volhout