The original gruephone 2 is an old (really old) phone from Holland.
I got this off ebay, and was feeling a little bad for gutting it, except, A) nobody else bid on it and B) it doesn’t actually work (I don’t know if this is because it’s old, broken, or incompatible with the US phone system, but I couldn’t hear much above some crackles and pops). Update on 2016-08-01: It plays audio fine.
I didn’t use this in GruePhone 1.0 because the handset is a little larger than the standard, and doesn’t quite fit into the modem cups in the TTY/TDD,
One of the interesting features of this phone is the little white button labeled PTT.
A reader, pointed out that the phone company in Holland had the initials of PTT, and that’s likely the meaning of the button. I used it as a “Push to Talk” button for a while, but since that’s no longer needed, It’s unused. Its original purpose was similar to the Flash buttons on more modern phones.
While attending the virtual “Bring-a-hack” session for Hackaday’s remoticon.2, one of the participants (whose name I didn’t catch, but went by Inne) pointed me at a few pages about old dutch (and other european) phones. There’s this one (in dutch) and this one (in dutch or english). Turns out my old dutch phone is a Heemaf type 1955, made from 1955 to 1957.
Read about the whole teardown here.
The additional worlking gruephones are both based on Deco-tel chest phones, which come enclosed (or concealed-which is why they’re sometimes called spy phones) in a decorative box that looks a little like a humidor. I have one touch-tone and one rotary version. I thought that he box would give me more room to embed things, but it turns out that the usable space is actually smaller than. the old phone that I used for the original. The raspberry pi (3B) computers I used just barely fit under the dial of each phone once I put on the battery management hat and a 2100 mah lipo battery. The original has a 6600 mah battery, and it can run for over a day disconected from power, but the deco-tel boxes only manage about an hour. (The pi is also more power hungry than the chip computer.)
I also have other phones that I plan to convert at some point in the indefinite future, including an pair of old multi-line rotary phones. Figuring out how to use the extra buttons and also the potential for lights is going to be interesting. One idea is to have multiple instances of the phone running, and the buttons allow you to switch between them. Another possibility is to use it as a voice selector or similar. Suggestions welcome.