There is no strict standardization for the signals coming from analog signal sources. Certain
adjustments are therefore necessary, depending on the graphics adaptors and used cables. When
the Raptor SQ2801 is connected to an analog signal source for the first time, an integrated “automatic
adjustment” function performs this adjustment. It uses the H and V frequencies of the input signal to
adjust the frequency, phase and picture position of the image. Depending on the quality of the
displayed image, it may be necessary to tweak the image manually.
3.3.1 Adjustment Phase and Frequency
The two most important parameters of an analog signal are frequency and phase adjustments.
Frequency adjustment precisely indicates the total number of pixels per line.
With phase adjustment, the capture point of a pixel is determined. See the illustration below.
For adjustment of frequency and phase, pictures with plenty of vertical stripes (ideally alternating
black and white columns) are very useful. A test pattern like this allows simple adjustment of
frequency and phase.
Pixel 1 Pixel 2 Pixel 3 Pixel 4
Pixel clock
Video signal
Phase adjustment Capture
3 Operation and Adjustment 41