FWIW, more about sound-powered phones, intercoms, etc can be found at
https://www.navy-radio.com/manuals/ic.htm


On Tue, Sep 26, 2023 at 2:29 PM Nick England <navy.radio@gmail.com> wrote:
Thanks to Hue W7HUE, I have posted a document covering shipboard damage control communications (probably WW2). In case you've wondered how sound-powered phones are used, this makes interesting reading. Even if if you haven't wondered that, it makes interesting reading. 15 pages, typewritten.
https://www.navy-radio.com/manuals/ic-damage-control.pdf

Nick England K4NYW
www.navy-radio.com