Digital Modes in 2008: An Overview
by Andy K3UK
To arrange QSOs or see a list of activity from these varying modes,
you are encouraged to try
http://www.obriensweb.com/sked/ (click on digitalradio)
http://www.projectsandparts.com/30m/
http://psk.gladstonefamily.net/pskmap.html
and join http://groups.yahoo.com/group/digitalradio/ for on-line
email discussion of how to get started in digital modes.
Common Modes
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PSK31 , usually the easiest to get started. Works well under most
conditions, MANY users. Check 14070, 7035, 7070, 3580. 10140.
Available in DM780, Winwarbler, Multipsk, MMVARI, FLdigi, MixW
PSK63: Twice as fast (and wide in your waterfall)) as PSK31. Great
for contesting and nets. Not as good as PSK31 for weak signal
reception. Available in DM780, Winwarbler, Multipsk, MMVARI, FLdigi, MixW.
PSK125/250. Good for VHF/UHF nets, file transfers, emergency
communication. Available in DM780, Multipsk, FLdigi, MixW.
RTTY: Prone to the effects of propagation and occasional "gibberish"
is received. Very common during contest weekends, the de facto
digital mode for contests. Also used by many DXpeditions. Not a lot
of "rag chew" QSOs, these months. Check 14080-14100. Available in
DM780, Winwarbler, Multipsk, MMVARI, FLdigi, MMTTY. Hamscope, MixW,
and many more.
MFSK16: Performs "better" than PSK31 under weak conditions. Not a
lot of users, can go hours without hearing a MFSK16 signal. Can be
difficult to "lock" on to a signal at first. Some software
applications for this mode facilitate the sending of a small picture.
Check 14072-14085, 10141. Available in DM780, Multipsk, MMVARI,
FLdigi, MixW.
Olivia: Perhaps the "best" for weak signal QSO modes, Not a lot of
users, can go hours without hearing a Olivia signal. Varying
combinations of tones can make it hard for a ham to determine which
variety of Olivia it is. When conditions are really tough, this is
the one to try. Check 14077, 14105-14110. 10141, 7077. Available in
DM780, , Multipsk, MMVARI, FLdigi, MixW.
HELL: With the efforts of the Feld-Hell Club this "odd" mode is more
common that some of the aforementioned modes. 80 Meter Net 0300 Z
Saturday 3.574. NOTE NEW FREQUENCY Net Control is AC7XF Hugh
30 Meter Net 0000 Z Monday 10.138. Net Control is W8LEW Lew
10 Meter Net 1800 Z, Monday, 28.074. Net Control is N3LFC Larry*
40 Meter Net 0200 Z Thursday 7073 KHz. NOTE NEW FREQUENCY. Net
Control is W8LEW, Lew. This modes performs quite well bit not as good
as PSK31, Olivia, and MFSK under average conditions. Requires good
eyesight for weak conditions. Available in DM780, Multipsk, MMVARI,
FLdigi, Mixw.
DominoEX : Can be as good as it can get for weak signal detection and
QSOs. Not a lot of users, can go DAYS without hearing a DominoEx
signal. As with Olivia, several varying settings add to dificulty in
determining which setting to use for decode. Check 3581-4, 7077,
14077. Available in DM780, Multipsk, , FLdigi, MixW
THOR: Still an experimental variant of DominoEX, but may be more
common in the next few months. Currently Alpha testing in FLdigi and
may be release with NBEMS. Available in FL-Digi if an alpha tester.
ALE: Gathering steams as a "mode" to be used for emergency
communications. Can be very frustrating to set up, and even more
frustrating to get it to decode basic ALE digital formats. If used
correctly, for "automatically" establishing a link to another station
and then SWITCHING to a mode that matches conditions, there is
nothing better ! Check http://hflink.com/ for MANY active
frequencies. This one is not for the rookie, but can be a lot of fun.
ALE 400 within the software program Multipsk performs very well and
has LOTS of promise. Only two applications support SOFTware ALE,
PC-ALE and Multipsk. Several expensive radios support FIRMware
applications of ALE.
MT63: Used by some MARS stations, but you can go weeks without
hearing an MT63 stations on the hams bands. Very good weak signal
decode, takes up a LOT of bandwidth. Signal sounds like a low-toned
white noise. Available in DM780,,Multipsk, MixW.
SSTV: Used for sending pictures and text. Very active used among
some hams. Check 14230 for analogue SSTV and 14.233 for digital.
Check also 10.138 for narrow SSTV. Digital variants of SSTV in such
software as Easypal are very efficient . Analogue SSTV is available
in Multipsk, DM780, MixW, and MMSSTV.
Throb/ThrobX. Another one that does well under very weak conditions
but you can go weeks without hearing a station. It sounds just like
it's name, a steady throbbing tone. It can be mistaken for JT65A or
MFSK8 at times. Available in DM780, Multipsk, FLdigi. Several
different "throbbing " rates .
JT65A: The best of them all for weak signal detection with evry low
transmit power needed. Very active, many stations on the air with
this mode, worldwide. Google the K3UK Bozo's Guide to JT65A for more
details. This is NOT a frag chew mode, it is a SLOW digital
communication mode. An exchange of callsign , location, and signal
report takes at least three minutes. Check 7076, 10139, 14076 and
also http://jt65.w6cqz.org for a live list of active stations.
Available in Multipsk or WSJT.
WSPR: The newest very low power mode. It is NOT a two-way
communication mode..yet. You transmit and rely on places like
http://wsprnet.org/ to list reception of you stations. This mode is
amazing. Looks like a steady narrow vertical line in a waterfall that
lasts two minutes. Sounds like someone tuning up on the band.
Transmit power at 1 watt or less is the mist common. 30 Meters is the
most common band , 10140. Available only in WSPR by Joe Taylor, free
at http://physics.princeton.edu/pulsar/K1JT/ . A new version that
allows two-way communication is being tested.
FDMDV : Digital Voice. Talk in to your PC's mic and have your high
quality audio come out of the other ham's speakers after being
digitized! It works suprisingly well but unlike most other digital
modes it requires a fairly strong signal to work well. Get it from
http://n1su.com/fdmdv/download.html . Try 14236 on weekend afternoons
in North America. Should be great when 10 or 15 Meters opens up world
wide (low noise on those bands). Poor on 40 and below when QRN is high.
