The following 2D spectra show the various stages in the Colour Recovery process, with the input file consisting of white noise. In all cases DC is in the centre of the plot, the horizontal frequency range is -18 MHz to +18 MHz and the vertical frequency range is -540 c/aph to +540 c/aph.
1. Horizontal chrominance bandpass filter (centered on 4.43361875 MHz):
2. Isolate 72 c/aph and 216 c/aph components:
3. Derive 288 c/aph vertical signal with zero horizontal frequency:
4. Separate 72 c/aph into U and V components:
5. Separate 216 c/aph into U and V components:
6. Derive 8.866 MHz horizontal signals with 144 c/aph vertical frequency (72 c/aph X mode):
7. Derive 8.866 MHz horizontal signals with 144 c/aph vertical frequency (216 c/aph X mode):