- Shareware dual channel audio spectrum analyzer
for Windows 2000/XP which can provide either a scrolling time-frequency display or a spectrum analyzer
scope display in real time for any sound source connected to your sound card. Can be used for MTHELL, QRSS and DFCW by R S Horne
- Zelscope is a Windows software that converts your PC into a dual-trace storage oscilloscope and spectrum analyzer
. It uses your computer's sound card as analog-to-digital converter, presenting a real-time waveform or spectrum of the signal - which can be music, speech, or output from an electronic circuit.