W2UC: Union College Amateur Radio Repeater Union College, Schenectady, NY Department of Electrical and Computer Engineering Steinmetz Symposium Presentation Robin Stevenson (KC2OVQ) Project Advisor: Prof. James Hedrick
What is a Repeater? ARRL
W2UC Coverage
Project Goals Design and construct an RF repeater to extend the range of mobile radios in the area surrounding the campus Ballston Lake Provide a platform for future student projects involving radio frequency technology
Amateur Radio
Repeater Block Diagram Duplexer Controller ReceiverTransmitter Power Supply Control Line Power Line Signal Antenna Incoming FM Signal 447 MHz Transmitted FM Signal 442 MHz 12.5 V DC Baseband Signal Push to Talk control Baseband Signal
Components – Radio Frequency Motorola D1017A Transceiver Sinclair Technology MR354 Duplexer
Components - Antenna
Components – Control System Communications Specialists TS-64ds Cygnal 8051 microcontroller
Control System - Detail Audio and Tone From Discriminator Output HPF TS-64ds LPF Tone Detect 8051 Microcontroller To Microphone Input To Microphone Push to Talk From Tone Detect To 8051 Audio Mute Circuit Audio Tone
Requirements 1µV receiver sensitivity at 12dB SINAD 10W Output Power FM Deviation ±5kHz Frequency Accuracy ±.5 PPM Meet all FCC requirements
Measurement Devices Wattmeter RF Signal Generator SINAD meter Spectrum Analyzer Frequency Meter
Final Results.9µV receiver sensitivity at 12dB SINAD 15W Output Power FM Deviation ±5kHz Frequency Accuracy ±.5 PPM
What’s Next? Improvements RF Preamplifier Auto-Identification Feature Data Communication
Acknowledgements Professor Hedrick Jules Madey Elroy Tatem Gene Davison Paul Tompkins Mike Beatty Professor Williams
Questions?