Table of Contents
Using A Captn Crunch Secret Decoder Ring
| Field | Phone Freaking |
| Went Obsolete | With out-of-band signaling phone systems. |
| Made Obsolete By | Blueboxes, blackboxes, or other tone generators. |
| Knowledge Assumed | The ability to blow a whistle. |
| When useful |
A blind friend of John “Captain Crunch” Draper's named Joe Engressia (later known as Joybubbles) informed him that a toy whistle that was, at the time, packaged in boxes of Cap'n Crunch cereal could be easily modified to emit a tone at precisely 2600 hertz�the same frequency that was used by AT&T long lines to indicate that a trunk line was ready and available to route a new call. This would effectively disconnect one end of the trunk, allowing the still connected side to enter an operator mode.
