1. FLDigi for Narrow-Band Emergency Messaging System
FLDigi NBEMS Suite
FLDigi for
Narrow-Band Emergency Messaging System
11/28/2018

2. Why NBEMS Communications?
Voice communication is not always best
Data communications is needed too.
List of items
Roster of Personnel
Part Numbers
Images
11/28/2018

3. The FLDigi Suite fldigi flarq flwrap flmsg Digital sound card modem
ARQ file transfer
flwrap
Checksum verifier and (un)compressor
flmsg
Form-based Message Generator
11/28/2018

4. What do you need? Radio Laptop
Built-in speaker and microphone can be used
Wireless mouse is recommended
Touchpads are RF sensitive
11/28/2018

5. Useful Items External microphone is helpful Interface box
That isolates radio from computer
Generates PTT signal
Adjust audio Levels
11/28/2018

6.
11/28/2018

7. FLDigi -Digital Modem FLDigi uses a sound card as a modem
FLDigi can Record Audio
Capture incoming audio
Save outgoing audio
Playback saved audio
FLDigi can control some Radios
FLDigi also has Logging functions
11/28/2018

8. Setup Download and run install programs
Enter Operator and Station Data
Configure Interfaces
Rig Control
Sound Card
Adjust Audio Levels
Adjust for Sound Card sample rate
11/28/2018

9. Operator Information
Callsign, Name and Location
11/28/2018

10. Rig Config PTT can be control by: Serial Port Parallel port
Other Interfaces
11/28/2018

11. Select Audio Sources
Select Input and Output Audio Sources
11/28/2018

12. Sample Rate Adjustments
WWV mode to adjust sound card's sample rate
Use setting from MMSSTV
11/28/2018

13. “TUNE” Button
Generates a continuous single frequency audio signal at the exact frequency to which the waterfall cursor has been set.
Peak amplitude of this signal is the peak amplitude of every modem signal generated by fldigi.
Use a dummy load and adjust audio level to just below the radio's ALC indicator
11/28/2018

14. MMSSTV Soundcard Calibration
11/28/2018

15. FLMsg-forms management editor
11/28/2018

16. Flwrap-verifiy/compress messages
11/28/2018

17. “TUNE” Button
Generates a continuous single frequency audio signal at the exact frequency to which the waterfall cursor has been set.
Peak amplitude of this signal is the peak amplitude of every modem signal generated by fldigi.
11/28/2018

18. FLMsg-forms management editor
11/28/2018

19. Message automation
11/28/2018

20. MT63-2000 Orthogonal Frequency Division Multiplexed
64 parallel carriers
Differential BPSK modulated
Tolerant of tuning
This mode requires a very linear transmitter.
Over-driving leads to excessive bandwidth and poorer reception.
11/28/2018

21. Multi-frequency shift keyed (MFSK)
A single carrier of constant amplitude is stepped in a constant phase manner. As a result, no unwanted sidebands are generated, and no special amplifier linearity requirements are necessary.
The tones selected are set by the transmitted (4 or 5 bit) bit pattern and a gray-code table.
Forward Error Correction, so it is very robust
Tuning must be very accurate.
11/28/2018

22. MFSK-16 Pictures Grayscale(B/W) and 24-bit color
Double and Quadruple Speed is available
Time(sec) = W * H / 1000 for grayscale
320x240=77 seconds
Time(sec) = W * H * 3 / 1000 for color
240x180=130 seconds
11/28/2018

23. Interfaces Soundcard Interface Rig Control Acoustical mike to speaker
Rig Control
11/28/2018

24. Digi-Pup Live Linux CD
This Bootable CD runs an older version of fldigi in the computer memory
11/28/2018

25. Resources FLDigi home page WPA NBEMS page MT63 on Wikipedia MMSSTV
WPA NBEMS page
MT63 on Wikipedia
MMSSTV
11/28/2018