
You could probably making a bundle of cash making updated ones for cell phones, hehe - Popular Mechanics 1941 - Link.
Voice Silencer on telephone lets you talk in secret
Recent Entries
- 3D renderings of the Mandelbrot set
- New in the Maker Shed: Microbe Motel kit
- Science through graphic novels
- Tiny solar-powered brass engine in a wineglass
- Maker Shed kiosks at Fry's
- New hackerspace in Chicagoland: Workshop 88
- Mint tin electronics dev kit packs the essentials
- Olympus BioScapes competition winners
- Mac mailbox
- LHC tweets its first circulating beam of 2009
Comments
Oldest comments listed first.
Leave a comment
Subscribe to MAKE Magazine!
Subscribe today, save 42% and get web access to MAKE free. MAKE Digital Edition is available only to subscribers.
$34.95 / 1 year
(4 Quarterly Issues)




































This is actually a historically important device: it's called a Hush-A-Phone. Back in the bad old days when you got all your phone equipment from The Phone Company, it wasn't quite clear whether this sort of thing (attaching a third-party device to a telephone) was legal. An AT&T lawyer saw an ad for it in a window and decided to sue. They lost on appeal, clearing the way for Makers to hook up whatever they wanted to their phones.
Reply to this comment