Miscellany
Icom 2SRA Discriminator Output Modification
The Icom 2SRA is a 144MHz FM transciever and wideband (50-905MHz) receiver HT, ideal for mobile communications and ham radio. With the increasing popularity in digital data monitoring, using protocols such as POCSAG, FLEX, and MDT4800, audio signals from the speaker output are noisy and not suitable for digital decoding. This brief document describes the modification of the radio to get a tap from the discriminator output, which will allow for an unfiltered and unamplified signal and is suited for interfacing to digital decoding hardware or software. [ continue ]
Joystick-Controlled Pneumatic Cannon
The Joystick-Controlled Pneumatic Cannon is what happens when engineers go bored. Created at Design Continuum in August 1996, this group project used an off-the-shelf PC flight simulator joystick to control the cannon barrel’s rotation and trigger a sprinkler valve, which dumped the compressed air from the storage chamber into the barrel. Many racquetballs and ceiling tiles were harmed during this project’s very short lifespan. [ continue ]
Bipolar PROM Reader
The Bipolar PROM Reader, created in September 1994, was designed specifically to read 82S123 256-bit Bipolar PROM (Programmable Read-Only Memory) devices. These devices were commonly used in first generation analog cellular telephones to store ESN/MIN pairs and this reader was used to acquire that information. A binary counter was manually triggered using a toggle switch to increment each address location. The data stored at the address location was displayed on eight red LEDs. [ continue ]
Universal Garage Door Opener
The Universal Garage Door Opener, created in July 1994, was designed to open many popular RF-based, non-rolling code garage door systems. Most garage door systems of that type use a series of DIP switches to set the transmit and receive addresses. If the address of the garage door receiver matches that of the garage door transmitter, the garage door will open. [ continue ]
Laser Listener
The Laser Listener, created in July 1994, was a low-cost experiment in reconstructing audio from window vibrations. Such systems are rumored to be used by the United States Government for surveillance purposes and this project was an attempt to prove the concept. A 5mW HeNe visible red laser was aimed onto the target window and the reflected laser light, now modulated by the vibrating window, was captured by a phototransistor and fed through a high-gain amplification system. [ continue ]