[CTSARA] Announcing Digital Mode Boot Camp

[Jon Perelstein]

As announced at the Sept 2nd club meeting, Tony O'Connor and I are starting a 
SARA digital communications bootcamp. 

We are going to be teaching the use of the so-called "soundcard" digital modes 
-- digital modes that can be used with pretty much any computer that has a 
half-way decent soundcard.  Some of the modes are PSK, DominoEX, MFSK, MTS, 
Olivia, and Throb.  There are other soundcard modes such as RTTY (yes, that 
RTTY), CW (yes, that CW), and Hellschreiber, but we're going to focus on those 
modes that are most used for emergency communications as well as great DX.  

For example, as I write this at 11:30 at night, using nothing but a Carolina 
Windom that's only 30' off the ground, I'm hearing 12 different European 
stations on 40 meters (including stations from Western, Central and Eastern 
Europe) as well as statoins from Central and South America.  A little later 
tonight, I expect to hear Australia and the rest of the Pacific Rim on 20 
meters.  I expect to be able to work each of those stations with only 25 watts. 
 Tony is only two states away from WAS and only 10 countries away from DXCC -- 
all in about four month's time.

Soundcard modes take the characters that you type on your computer and translate 
them into tones that are used to modulate SSB or FM.  There are all sorts of 
different ways of generating the tones -- some modes use one tone with phase 
shift to represent binary 0s and 1s, some use two tones, some use as many as 16 
tones to represent the 0s and 1s, and some use even more than 16 tones (plus 
phase shift and other interesting rocket science.  The more complex the 
representation, the more error detection and error correction that is built in. 
 For example, some modes such as Olivia are essentially sending each character 
many different times on the hope that at least one good copy of each character 
will be received on the other end.

There are a number of different software programs that can be used to generate 
and receive the data.  Some are specific to only one mode, such as Digipan (for 
PSK) and MMTTY (for RTTY).  Others are multi-mode software that can do a number 
of different modes, such as MixW, HRD with DM780, and FLDIGI.  We are going to 
focus on FLDIGI, for two reasons:

1.  FLDIGI is available in Windows, Linux, and Macintosh versions.

2.  FLDIGI is the base software for the Narrow Band Emergency Management System 
(NBEMS) which is a set of protocols that provide additional error correction for 
various digital modes, as well as making it possible to send binary files via 
radio (files that do not contain ASCII characters, such as spreadsheets and Word 
documents).


We are going to start the bootcamp on Sunday Sept 5 at 9pm, right after the 
regular SARA weekly 2 meter FM net.  As announced, we are going to meet up on 
the New Canaan repeater using voice.  For the 5th, we are going to focus on 
sending different modes so that people can get used to tuning in the signals on 
FLDIGI.  We may send the data over the New Canaan repeater itself, or we may use 
a simplex frequency -- we'll have to play that by ear.


To download FLDIGI, go to http://www.w1hkj.com/download.html and download the 
appropriate version of FLDIGI.  Another program called FLARQ will come with it 
-- don't worry about it for now.  It's a straightforward install -- just follow 
the instructions.  

If you have any problems between now and then, please send a message to the 
mailman reflector and one of us will help you.