Digital modes of local interest?

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    Bob, W6RES

    Hi, all-


    Jeneen’s note brings a question to mind for me… if we’re inclined to wander off and tinker with the various digital modes, what modes (RTTY and variants, PSK31 and variants, MFSK, the various fax modes, SITOR-B, all with a bit of learning associated) should we prioritize, both for anticipated activities in our context and as well for outreach and cooperation with other groups?




    A really good question that, unfortunately, doesn’t have a solid answer. We seem to be on the leading edge around here so we may be setting the standard for at least the near term.


    Narrow Band Emergency Messaging Software (NBEMS) seems to have gained acceptance for several good reasons including the ability to transmit commonly used ICS forms and Radiograms without error and automatically. The actual modulation scheme is MT63 which includes forward error correction (that is;  enough redundant information to be able to recover the message even with a lot of noise.) The software is FLDigi which supports many other commonly used digital modes, runs under Windows, OS X and Linux and is available for free from The companion software in the NBEMS suite include FLArq which controls automatic retransmission of garbled messages without operator input, FLMsg which sends and receives standard ICS forms by stripping out the data and populating a printable form at the receiving end, and FLWrap which lets you send jpg, jpeg, png, gif, bmp, ico, zip, gz, tgz, and bz2 files (slowly) by HF radio. A complete installation includes automatic rig control with FLRig and a hardware interface so that radio settings are always applied consistently: This eases the stress of quickly setting up a working station by presetting the operating frequencies, modes and levels as well as keying the transmitter as needed. The most basic station could simply be a radio and computer running some form of MT63 software as the mode is so robust that it will work by simply holding the microphone near the computer speaker and keying manually.


    The other digital mode which will be coming on line very soon is VHF Packet. Kings Mountain has a packet system operating on 6m which should be available in many areas, as well as Coastside Amateur Radio Club’s system on 145.050 MHz up in Pacifica. We’d like to get a Winlink packet system operating on Skyline near Portola Heights by this spring. Winlink works as a packet system but also lets you send email to anyone, anywhere from a ham radio. As you can imagine this is tremendously useful during an emergency. These systems operate on frequencies available to anyone with a Technician class license or higher. The NBEMS system requires a General class or higher license to operate on the HF bands.

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