4.3 Digital Modes
PSK31, short for "phase shift keying" is just one digital mode which is fairly easy to set up. In most cases, all one needs is an interface between the transceiver and computer, and some software such as "digipan" or "Ham Radio Deluxe". PSK31 works by permitting the user to type on his keyboard, much like RTTY, and the software converts the typing to code, sending via the transceiver.
Most users view PSK31 on their computer screens via a "waterfall", where they can visibly detect transmissions. Simply by positioning a marker over the visible trace, the software and radio can decode the transmission.
Here is an introduction with more info on PSK31 using the free "digipan" software:
Here is another, more detailed introduction to PSK31:
Here is a page with many software applications for PSK31:
last modified: 2007-11-08 23:33:17
RTTY is short for Radio Teletype.
Originally associated with a large, floor-standing machine that was a cousin to a typewriter, and which clacked incessantly as it received and printed messages, RTTY has evolved to another computer-based mode of communications. As in other modes, there is software readily available on the internet and little equipment needed beyond a standard transmitter, a computer and an interface.
Much more info here:
last modified: 2007-11-09 00:31:23
Slow-scan television (SSTV) is a picture transmission method used by amateur radio operators to transmit and receive static pictures via radio in either color or monochrome. When originally explored, SSTV required some extensive equipment but, since the early 1990s, a personal computer and special software has replaced much of the custom equipment. The PC's sound card with special processing software acts as a modem. The computer screen provides the output. A small digital camera or digital photos provide the input.
A good site for more info:
These are the frequencies generally used within each band for digital communications. Each band has specific allocations based upon mode and license class, so consulting the band plan is a must.
10 Meter Band: 28.110 - 28.125 Mhz
12 Meter Band: 24.920 - 24.930 Mhz
15 Meter Band: 21.060 - 21.080 Mhz
17 Meter Band: 18.100 - 18.110 Mhz
20 Meter Band: 14.060 - 14.080 Mhz
30 Meter Band: 10.130 - 10.145 Mhz
40 Meter Band: 7.060 - 7.080 Mhz
80 Meter Band: 3.620 - 3.640 Mhz