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NBEMS (Narrow-Band Emergency Message System) is perhaps the best solution available for moving messages, data and other text-based information over amateur radio frequencies, to handle emergency communications. We will be discussing this and demonstrating it at our upcoming ARES meeting.

The use of the NBEMS software requires nothing more than a laptop or desktop computer and an amateur radio transceiver (even an HT) to send and receive data/text using the NBEMS soundcard-based digital software.

For pure email WinLink 2000 works fine if you're near an RMS node (and can access it) and don't need to handle a lot of traffic. But when it comes to handling local traffic in ICS-205, ICS-206, ICS-213, ICS-214, and ICS-216 forms in addition to ARRL Radiograms the NBEMS/FLDIGI software holds the answer.

NBEMS was developed as a collaborative effort between Dave Freese W1HKJ and Skip Teller KH6TY, the developer of the popular DIGIPAN PSK31.

The main programs, FLDIGI, FLMSG and FLWRAP are designed to run under Linux, Free-BSD, Windows XP, Win2000, Vista and Windows7.

The NBEMS system is designed to operate on all amateur bands, but is optimized for short to medium range communications such as SSB VHF, or HF with an NVIS antenna can provide. It can however be utilized on VHF FM, and even operated through a FM voice repeater if needed.

MT63 and Olivia

Each mode has it's advantages and disadvantages and our recommendations are based on extensive field testing under varying situations and conditions.

MT63 2k Long - Local FM Comms

For local portable, mobile and fixed station operations on 2m and 70cm FM (repeater or simplex), MT63 2K long is our primary mode for detailed situation reports and database transmission and has been chosen for the following reasons:

- Can be used very effectively without a sound card interface (audio coupling)
- Extremely effective under poor RF conditions
- Extremely accurate decoding (major duplication of data and forward error corrected)
- Very forgiving on sound card tuning and calibration when used on FM
- Excellent for sending larger situation reports or databases

MT63 1k Long - Regional/Local HF Comms

For regional and local portable, mobile and fixed station operations on HF USB under moderate to good condition, MT63 1K long is our primary mode for detailed situation reports and database transmissions and has been chosen for the following reasons:

- Very effective under moderate to good RF conditions
- Extremely accurate decoding (major duplication of data and forward error corrected)
- Works well under QRM and QRN conditions - Excellent for sending larger situation reports or databases

Disadvantages:

- Requires fairly accurate tuning
- Does not work well under very poor RF weak signal conditions
- Long decoding FEC delay not well suited for short keyboard to keyboard communications
- 1k audio bandwidth is very wide as compared to other digital modes

MT63 500hz Long - Regional/Local HF Comms

For regional and local portable, mobile and fixed station operations on HF USB under poor to moderate conditions, especially heavy static resulting from lightening. MT63 500hz, long interleave is our primary mode for detailed situation reports and database transmissions under adverse band conditions and has been chosen for the following reasons:

- Very effective under moderate to poor RF conditions (especially heavy static crashes)
- Extremely accurate decoding (major duplication of data and forward error corrected)
- Works extremely well under QRM and QRN conditions - Excellent for sending larger situation reports or databases

Disadvantages:

- Requires fairly accurate tuning
- Very long decoding FEC delay not well suited for short keyboard to keyboard communications
- If a standard 1000 hz center waterfall frequency is being used, when changing to MT63 500hz long interleave, the waterfall center is shifted to 750hz. Those not already set to 1000hz on the waterfall must retune to the MT63 500hz signal with their transceiver VFO in fine tune mode.

Olivia 8 Tone/500 Hz and 16 Tone/500 Hz - Regional/Local HF Comms

For regional and local portable, mobile and fixed station operations on HF USB under good to poor conditions, Olivia 8/500 is our primary mode for short messages and situation reports and has been chosen for the following reasons:

- EXTREMELY accurate decode, even under poor conditions (major duplication of data and forward error corrected)
- Very resiliant to QRM and QRN
- Best suited for short messages and situation reports
- 16 Tone/500 Hz is slower but better under poor conditions

Disadvantages:

- Slow data rate (slightly faster than writing speed)
- 500 Hz audio bandwidth is wider than several other modes

The FLMSG software provides the ARQ feature for NBEMS which gives you 100% accurate transmissions of the messages and images you transmit. In addition to email, you can send comma delimited spread sheets/data bases, text, and many ICS form-based messages.

The FLWRAP add-on program allows you to transmit a bulletin to an unlimited number of stations simultaneously. Each recipient can confirm individually whether they have received the data with 100% accuracy, as FLWRAP generates a checksum for each message.

NBEMS Features:

• Inexpensive ( free soundcard software )
• Simple to use, reducing training requirements
• Effective, perfectly tailored to the EMS mission
• Narrowband modes conserve spectrum
• A live operator on each end, eliminating interference potential
• Flexible enough for use with most equipment under most conditions
• The software is great for everyday use, again reducing training requirements
• Specialized add-on software for net control, rig control, callbook data, logging etc. are available

To learn more about NBEMS and to download the software:

Basic information and software download:
http://www.w1hkj.com/ Download FLDIGI & FLMSG for Windows and watch the videos on the links above.

NBEMS information on setup and configuration:
http://www.panbems.org/
ARRL articles about NBEMS:
http://www.wpaares.org/ecom.html
http://www.arrl.org/nbems