BJ-851 is globally the only mini duplex and single-mode antenna units which consists of duplexer, receiver, transmitter, CPU controller ect. CTCSS and DCS are built in.Aluminium diecasting outer cover of vehicular was adopted. Full duplex communication can be achieved between two duplexers and single set can be used as repeater also. It can be increase the communication distance. DCS/CTCSS are built in.

General
Frequency Range:	406-512 MHZ
Frequency Spacing:	10MHZ
Duplex Band Width:	1MHZ
Modulation Type:	FM 16F3
Operating Voltage:	12-14V
Current:	standby current  :  0.3A       Rx current : 0.8A      Tx current :3.0A
Frequency Stability:	≥2.5 PPM
Channel Spacing:	25KHZ
Weight:	Approx 3kg
Specification of Duplexer
Frequency Range (MHZ):	RX:453.5---456.5MHZ   TX:463.5---466.5MHZ
Frequency Spacing (MHZ):	10MHZ
Max Output Power (W):	10W
Receiving End Insertion loss (dB):	≤2dB
Transmitting End Insertion loss (dB):	<1.5dB
Transmitting-Receiving End Isolation (dB)	≥60dB
Max VSWR:	1.5
Operating Temperature Range:	-30-----+60°C
Frequency Stability:	Approx 2.5ppm/°C
Matched Impedance:	50Ω
Receiver
Simplex Sensitivity:	≥0.3uv(12dB SINAD)
Duplex Sensitivity:	<3dB
Squelch Sensitivity	≥0.2uv
Selectivity:	-70dB
Spurious Radiation:	-75dB
Intermodulation Rejection:	-75dB
Residual Noise:	-45dB
DEMP FO:	6±3dB
Audio Output Power:	4.0W
Audio Distortion:	<5%
Working Mode:	receiving mode
Transmitter
Output Power:	5-10W
Spurious Radiation:	≤80dB
Residual Modulation:	-45dB
Audio Distortion:	<5%
Max Modulation:	5KHZ
Pre-emphasis Frequencies:	6±3dB
Working Mode:	Transmitting Mode
CPU Controller
Receiving-Transmitting Frequency Setting
Automatic Repeater Setting
MIC and PTT control
PC Programming
CTCSS and DCS