APPENDIX A
TECHNICAL CHARACTERISTICS
Item
Specifications
Electrical
Power Requirements: CELP assembly
+ 5 V dc ±5%, .70 A, typical, 1.0 A maximum, 3.50 W, typical
+ 12 V dc ±10%, 7 mA, typical, 10 mA, maximum, 0.084 W, typical
– 12 V dc ±10%, 30 mA, typical, 40 mA, maximum, 0.36 W, typical
Telephone Interface (4-wire/E&M)
Impedance
600-ohms resistive
Return Loss
18 dB minimum, (300-3400 Hz)
Longitudinal Balance
56 dB minimum, (300-3400 Hz)
Usable Audio Bandwidth
300-3400 Hz
Idle Channel Noise
Less than –65 dBm0p at 6.4 and 4.8 kHz.
Transmission Levels
Transmit Section:
Nominal Input Level
–16 dBm or 0 dBm (switch selectable)
Input Adjustments (around nominal
in put level)
–6 dB to +1.5 dB in 0.5-dB steps. Adjustments made by DIP switch.
Receive Section
Nominal Output Level
0 dBm or +7 dBm (switch selectable)
Output Adjustments
– 6 dB to +1.5 dB in 0.5-dB steps. Adjustments made in software.
Data Rates
Multiplexer
9.6, 6.4 or 4.8 kHz
M-Lead Input Characteristics
U.S. E&M (Types I-V)
M-Lead Input Resistance
2.4 kilohms (approximately)
Threshold Currents
Idle
1 mA or less (M-lead to station ground)
Busy
2.0 mA or greater (M-lead to station ground)
U.K. SSDC5A
An earth via resistance of up to 1500 ohms in parallel with a capacitor of 1 micro-
farad ±10% applied to the M-lead draws a minimum of 5 mA and is recognized as a
Busy condition.
An earth via resistance of greater than 400-kilohms in parallel with a capacitor of
1 microfarad ±10% applied to the M-Lead is recognized as an Idle condition.
E-Lead Output Characteristics
Idle leakage Current
500 microamps maximum at 64 V
Max “on” voltage
2.0 V at 5 mA
2.5 V at 50 mA
A-1
