|
|
|
1200-SMSK-PMAFE DGPS Beacon Signal Generator
The 1200-SMSK-PMAFE is the signal generation module of the MR-101 enhanced DGPS medium frequency data modulator. This module accepts signals from a DSP card PMAFE interface and generates a Shaped MSK modulated data at user selectable data rates and carrier frequency. The 1200-SMSK-PMAFE timing is based on either an internal or an external 10 MHz frequency reference that may be both time and frequency synchronized to an external One-PPS pulse from GPS. The 1200-SMSK-PMAFE is designed to operate with a companion DSP-100 card hosted on a PC PCI bus. This combination permits control of the modulation process and the generation of the desired data message. An integrated peripheral comprised of the 1200-SMSK-PMAFE and the DSP-100 is available as the Mansfield Research Model MR-101.
To permit immediate testing of the 1200-SMSK-PMAFE, the cards are shipped with SMSK modulator test software. This Windows® based program generates a phase modulated carrier using standard RTCM SC104 formatted 6-of-8 formatted messages or fixed internally generated test messages. A screen shot of the control screen is shown below. Advanced data encoding and modulation Software is available please contact us. |
 |
The 1200-SMSK-PMAFE specifications are shown in Table 1 and the specification when integrated with a companion DSP card are shown in Table 2.
TABLE 1 ::
1200-SMSK-PMAFE specification |
| |
Item |
Specification |
|
|
|
| |
Mechanical Interface |
Momentum Data Systems PCI Bus MAFE Specification |
|
|
|
| |
DSP Bus Interface |
Momentum Data Systems PCI Bus MAFE Specification |
|
|
|
| |
Internal Frequency Reference |
10 MHz, ±2.5 ppm, –30 to +70 ºC Rear Panel Frequency Trim |
|
|
|
| |
External Frequency Reference Input |
> 0.25 Volts peak-to-peak Jumper Selectable 50 Ω termination |
|
|
|
| |
External One-PPS Input |
> 0.25 Volts peak-to-peak Jumper Selectable 50 Ω termination |
|
|
|
| |
Carrier Output Impedance |
50 Ω |
|
|
|
| |
Carrier Output Frequency Range |
105 to 535 kHz |
|
|
|
| |
Carrier Amplitude |
+10 dBm ±1dB into 50 Ω load |
|
|
|
| |
Out-of-Band Spurious |
-58 dBc |
|
|
|
TABLE 2 ::
1200-SMSK-PMAFE specifications when interfaced with the DSP-100 card (MRD-101) and CEI control software |
| |
Item |
Specification |
|
|
|
| |
Data Source |
User Supplied |
|
|
|
| |
Interface |
RS-232, RS-422 or TCP-IP |
|
|
|
| |
Data Output |
Transmitted 6-of-8 characters echoed out COM1, 9600,
n, 8,1 |
|
|
|
| |
Data Rates |
100, 200, 300, 400, 500, 600, 800, 900, 1000, 1200, 1500 and 1800 bps |
|
|
|
| |
Modulation |
GMSK, MSK, RCMSK and CW |
|
|
|
| |
GMSK Filtering |
User selectable β = 0.2, 0.3, 0.45, 0.5, 0.6 filters |
|
|
|
| |
RCMSK |
Type-A, ρ= 1.0, B=0.675, T1 = 1.4, T2 = 0.6 Type-B, ρ= 2.05, B=0.65, T1 = 1.4, T2 = 0.6 |
|
|
|
| |
Frequency Band |
150 to 535 kHz |
|
|
|
| |
Tuning Steps |
1 Hz Steps by data entry, 500Hz with Up-Down Buttons |
|
|
|
| |
Time Synchronization |
Offset from GPS time from -1000 to 1000 µsec in 1-µsec steps.
Accuracy ±300 n sec of specified offset from GPS time, ±500 n sec quantization error.
|
|
|
|
| |
Time Reference |
The leading edge of the One Pulse-per-second output from the Z-12/R GPS receiver |
|
|
|
| |
RF Output Level |
10 dBm ±1 dB into 50 Ohm load |
|
|
|
| |
Carrier Stability |
±0.005 ppm, long term locked to GPS One-PPS |
|
|
|
| |
External Reference |
Software selection of external 10 MHz reference. |
|
|
|
| |
Out-of-Band Spurious |
-58 dBc (dB below Carrier) |
|
|
|
| |
Fill Character |
User selectable ASCII Fill Character |
|
|
|
| |
Lost Data Flag |
User selectable: “All” or “Loss > One Second” |
|
|
|
|
