W2UC: Union College Amateur Radio Repeater

Union College, Schenectady, NYDepartment of Electrical Engineering

Senior Project Final PresentationRobin 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

Receiver Transmitter

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

What’s Next?

Improvements Data Communication

Acknowledgements

Professor Hedrick Jules Madey Elroy Tatem Gene Davison Paul Tompkins Mike Beatty Professor Williams

Final Results

.9µV receiver sensitivity at 12dB SINAD 15W Output Power FM Deviation ±5kHz Frequency Accuracy ±.5 PPM