Topcon GR-3 User Manual

Specifications
GR-3 Operator’s Manual
A-10
Digital UHF Modem General
Specifications
Table A-5 lists the Digital UHF modem’s general specifications.
Receiver (RX)
Sensitivity -105 dBm at 10-4 BER
Dynamic range 105 dBm
Data communications
Serial interface RS232
Serial data rate 9600, 19200, 38400, 57600 bps, user selectable
Effective radio link
rate
9600, 10200, 17000, 51000 bps
User selectable for FH915; automatic selection for
FH915+
Error correction FEC (15.7), majority decoding
Antenna Type
Type 1/2 wave articulating whip
Connector Reverse polarity TNC
Gain 2.5 dBi
Table A-5. GR-3 Digital UHF Modem General Specifications
Parameter Specification
Operating frequency range
country/region/purpose dependent
410-470 MHz
Modulation techniques GMSK, DBPSK, and DQPSK
Channel spacing 12.5 kHz/25 kHz
Transmission rates at 25 kHz spacing • GMSK/DBPSK – 9600 bps
• DQPSK – 19200 bps
Transmission rates at 12.5 kHz spacing • GMSK/DBPSK – 4800 bps
• DBPSK – 9600 bps
Table A-4. Internal TPS Spread Spectrum Specifications (Continued)

Topcon GR-3 Specifications

General

Brand	Topcon
Model	GR-3
Category	Receiver
Language	English