This pattern is developed based on my Cabled Keyhole  Scarf pttern. A detailed written description of the cable is provided in the pattern, available at the link above. Each technique needed to knit the blanket is also demonstrated in a video. Links to the videos are also above. The main fabric of all panels is double stockinette.  The stitches to each side of the cable are modified to make the cable stand out.

Potential stitch gauges counting on ONE FACE of the fabric or ONE BOARD on the double knitting board 2, 2.5, 3, 3.5, 4, 4.5, 5 stitches/inch. Pegs & stitch counts are given in the same order in the information below.

Knit 2 cable panels 7" wide
At 2, 2.5, 3, 3.5, 4, 4.5, 5 stitches/inch
Use 15, 17, 21, 25, 29, 31, 35
If you adjust stitch count, choose an odd number of pegs/stitches.

Knit the first cable panel to the length desired, record the row count, them match the other panels to this one.

For a baby blanket, make the 14" center panel
29, 35, 42, 49, 56, 63, 70 pegs/stitches wide. For larger blankets, knit more panels or use more stitches per panel. Ex: A typical afghan size of 42x60" could be achieved with 4 cable panels 7" wide plus a plain center panel 14" wide. My row gauge for the sample is 3.7 rows/". At this gauge, 222 rows=the 60" length.