spectrum 2000

Spectrogram  ^pop - 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

GSpec - Spectrum Analyser for Win9x/2000 and NT, that will display audio input to your sound card in the Frequency and Time domains