CW carrier detection using WSJT-X, mode FT8

Using the new WSJT-X FT8 Mode waterfall, makes an effectieve detection tool for very weak cw carriers.

The picture represents the watewrfall of a beacon carrier with an average signal strength between 0 and approx 3 dB above the noise over a few minutes of recording.

FT8 refreshes measurement results each 15 seconds.