SGLS Satellite Modems & Ranging Systems – RF IF & Sub-Carrier

Model 405 IF SGLS Satellite Modem

The Model 405 SGLS Modem comprises a configured set of modulation and demodulation functions housed in a 5.25-inch rack-mounted Modular Subcarrier Subsystem chassis. A functional block diagram of the Model 405 is shown below.

The Modulator section of the unit consists of the SUM005 Signal Summer and the PMM004 Phase Modulator. Optional PSK subcarrier modulation (B/Q/U/A PSK) and FSK003 AM/FSK (SGLS) Modulator functions are also available.

The Optional Demodulator section consists of the RDM021 IF Receiver/Demodulator, which includes a Linear Phase Demodulator and PSK Demodulator with dual Bit Synchronizer(s). The demodulation functions are firmware configured to meet specific customer needs. SGLS AM/ FSK demodulation for Echo Check is also available as an option.

The CPU010 Control Processor provides control of the unit via either the local front panel VF Display and keypad or the Remote Control Interface.

  1. LINEAR PHASE MODULATON
  2.      • IF/RF (Specify)
         • 10 MHz EXT REF
  3. LINEAR SIGNAL SUMMATION
  4.      • ANALOG / DIGITAL INPUTS
  5. MODULATION
  6.      • SGLS 1,2 kbps
         • Other Data Rates Available
         • FSK Tones :
             • (95 kHz, 76 kHz, 65 kHz)
         • PSK (Optional)
             • BPSK, QPSK, UQPSK
  7. DEMODULATION (Optional)
  8.      • SGLS AM/FSK
         • PM
         • BPSK
         • PM/PSK
         • U/A/QPSK
         • AM/FSK
             • SGLS 1,2 kbps
             • Other Data Rates Available
         • Ternary Echo Check (Optional)
  9. REMOTE CONTROL AND MONITORING
  10.      • RS-232 (Standard)
         • IEEE-488 (Option)
         • Ethernet (Option)

PHASE MODULATOR (PMM004)
INPUT
Input Level:
2 Vpp centered around ground
Input Impedance:
50 Ohms
Modulation Index:
0.00 to 3.14 radians
Frequency Reference:
10 MHz
Signal level: Sinusoidal
2.8 ± 1.5 Vpp; 50 Ohm

OUTPUT
IF:
70 / 75 MHz
Phase locked to the Ref Freq
RF:
Tunable L/S-Band (Optional)
Output Levels: (Factory Set)
0 to 2 Vpp, nominal, 50 Ohm load.
1 Vpp, nominal, 50 Ohm load.
Output Impedance:
50 Ohm, back terminated
VSWR:
< 1.5:1
Modulation Frequency:
0 to 5 MHz
Discrete spurs:
Less than -60 dBc

SIGNAL SUMMER (SUM005)
INPUT
Up to 3 inputs with Adjustable Levels

OUTPUT
Composite Signal, Linearly Summed

AM/FSK SGLS MODULATOR (FSK003)
INPUT
"1", "0", "S" and clock (RS-422)
Data Rates:
Selectable-1, 2, kbps

OUTPUT
Signal Level:
Fixed 2 ± 0.2 Vpp

PSK SC MODULATOR (OPTIONAL)
INPUT
Data/Clock:
TTL
Tunable SC:
DC to 5MHz (Extended SC Available)

PHASE DEMODULATOR (RDM021) (OPTION)
INPUT
IF:
70 / 75 MHz (Factory Set)
RF:
Tunable L/S-Band (Optional)
Input Level:
+10 dBm to -25 dBm
Bandwidth (3 dB):
8 MHz
VSWR: < 1.5:1
Modulation:
PM, PSK
Dual Bit Synchronizers (Optional)

OUTPUT
Demodulated:
PM, PSK

SGLS FSK/AM DEMODULATOR (FDM001) (OPTION)
INPUT
0.07 Vpp to 2.0 Vpp into 75 Ohms
FSK/AM per SGLS (TOR-0059(6110-01)-3)
FSK Tones:
(95 kHz, 76 kHz, 65 kHz)
Amplitude Modulation:
500 Hz (1 kbps commands)
1000 Hz (2 kbps commands)
Modulation Factor: 50% nominal
Synchronization Delay: 60% nominal

OUTPUT
Ternary 1, 0, S Data and Clock (RS-422)

LOCAL FRONT PANEL CONTROL
Power:
Circuit Breaker/Indicator switch
Key Pad:
Twenty (20) position keypad
VF Display:
Six (6) line-by-forty (40) character
Status Display LEDs

REMOTE CONTROL
RS-232 Interface (Standard)
IEEE-488 (Optional)
Ethernet (Optional)