DIGTRX is a simple to use piece of software that radio amateurs can make use of. You can use it to record different types of transmissions.
Written by Roland Zurmely Py4ZBZ, this program evolved from a suite of programs (known as RDFT software by Barry Sanderson KB9VAK) designed
to send binary data (files) over an audio bandwidth channel using a computer sound
card. DIGTRX controls this original suite of programs and automates their functions.
Computer files can be transferred via amateur radio using DIGTRX.
How does this happen? Take the file to be transferred and convert it to a sound file in
WAV format (codify for TX). Play the sound file over the audio path (which may be a
radio link). Record the received sound file. Process the received sound file to recover
the original binary data (file) without errors (decoding).
The received sound file will contain noise, distortion, frequency response effects and
may be recorded at a slightly higher or lower level so how can this convey error free
data? The codify process adds an amount of redundancy to the file such that missing
or errors can be detected and even corrected in the decode process