Instruction Manual
Table Of Contents
Specifications
9-3
● CH70 Watch Keeping Receiver
Receiving frequency 156.525MHz (CH70)
Receiving system Double superheterodyne
1st IF 58.1MHz
2nd IF 455kHz
Local oscillation frequency Receiving frequency + 58.1MHz
Local oscillation method Frequency synthesizer
Local oscillation frequency variance ±10 x 10
-6
or less
Sensitivity 1% or lower symbol error rate at 0dB V
Selectivity 6dB bandwidth: 12kHz or more, 70dB selectivity: 25kHz or less
De-emphasis characteristics 6dB/oct, within +1dB, -3dB
Co-channel selectivity
Symbol error rate of 1% or better at a wanted signal level of 3dB V
and an unwanted signal level of -5dB V
Adjacent channel selectivity
Symbol error rate of 1% or better at a wanted signal level of 3dB V
and an unwanted signal level of 73dB V
Desensitization effect
Symbol error rate of 1% or better at a wanted signal level of 3dB V
and an unwanted signal level of 73dB V
Spurious response
Symbol error rate of 1% or better at a wanted signal level of 3dB V
and an unwanted signal level of 73dB V
Intermodulation characteristics
Symbol error rate of 1% or better at a wanted signal level of 3dB V
and an unwanted signal level of 68dB V
Blocking characteristics
Symbol error rate of 1% or better at a wanted signal level of 3dB V
and an unwanted signal level of 93dB V
Radiation 9kHz - 2GHz: 2nW or less
● DSC/ATIS Modem
Modulation rate
1200baud ±30ｘ10
-6
or less
Modulation method FSK
Modulation index
DSC: 2.0 ±10% or less
ATIS: 1.0 ±10% or less
Mark frequency (Y) 1300Hz ±10Hz or less
Space frequency (B) 2100Hz ±10Hz or less
DSC protocol ITU-R Recommendation M.493-11 (Class A)
DSC operation standards ITU-R Recommendation M.541-9, M.689-2, M.821-1, M.1080-0
ATIS protocol, operation standards EN 300 698-1 V1.3.1
● Controller
Communication speed 9600bps or 57.6kbps
Communication interface RS-485 and RS-232C
Microphone input impedance 150 balanced
Standard modulation input -54dBm
Rated audio output
Internal speaker (4): 2W or more
Handset phone (150): 1mW or more
LCD display 3.8 inch FSTN monochrome, 320 x 240 dot, LED backlight