Fldigi 4.2

Create a radio station for amateur operations. Perform frequency measurement tests or calibrate a sound card to receive a signal. Access a standard HF SSB radio transceiver and control the radio using serial port connections. Work with popular models like FM, AMS, LSB, RTTY, MFSK16, DominoEX, MFSK, Throb, Hell, Olivia, CW, and PSK.

Fldigi is a solution that provides users the means to transform their computer into a radio station. Equipped with digital modes, such as CW, PSK, MFSK, Hell, or Throb, it helps technology enthusiasts to calibrate a sound card to a time signal and do measurements of frequencies.

Aesthetically, it doesn't have a modern UI, with its menus and buttons having a poorly shaped design. Also, the main screen has poor delimited sections that increase the program learning curve. The CPU and memory are low and that is a big plus for users.

Apart from the supported digital modes mentioned in the beginning, Fldigi lets users manage signal, either by Waterfall, or FFT method, and view the spectrogram display of signal strength as well as an oscilloscope representation of the captured raw radio.
More, it has a built-in signal browser, text capturing options, customization options for data logging, and rig controlling capabilities.

To sum things up, Fldigi is a useful program for individuals who are passionate and have a strong knowledge base of managing radio signals.