Operation and Maintenance Manual

Page 2 RF Technology T220
CONTENTS
Contents
1 Operating Instructions 5
1.1 Front Panel Controls and Indicators 5
1.1.1 PTT 5
1.1.2 Line 5
1.1.3 PWR LED 6
1.1.4 TX LED 6
1.1.5 ALARM LED 6
2 Transmitter Internal Jumper Options 7
2.1 JP2: EPROM type 7
2.2 JP3: Dc Loop PTT 7
2.3 JP4: Audio Input Source 7
2.4 JP6: Input Level Attenuation 7
2.5 JP7: Audio Response 8
2.6 JP8: Sub-audible Tone source 8
2.7 JP9/10/11: dc Loop Configuration 8
3 Transmitter I/O Connections 8
3.1 25 Pin Connector 8
4 Channel and Tone Frequency Programming 8
5 Circuit Description 9
5.1 VCO Section 9
5.2 PLL Section 10
5.3 Power Amplifier 10
5.4 600
Ω
line Input 11
5.5 Direct Coupled Audio Input 11
5.6 Local Microphone Input 11
5.7 CTCSS and Tone Filter 11
5.8 Audio Signal Processing 12
5.9 PTT and DC Remote Control 12
5.10 Microprocessor Controller 13
5.11 Voltage Regulator 13
6 Field Alignment Proceudre 13
6.1 Standard Test Conditions 14
6.2 VCO Alignment 14
6.3 TCXO Calibration 14
6.4 Modulation Balance 15
6.5 Tone Deviation 15
6.6 Deviation 16
6.7 Line Input Level 16
6.8 Output Power 16