Tilt is transmission loss in a coaxial cable. Transmission loss increases
in proportion to the square root of frequency, thus affecting the tilt.
As displayed by the DSAM 2500 unit, Tilt mode displays levels across a
band of channels. Tilt appears as the slope between lowest to highest
channel. Levels for each intermediate channel should reach the line.
Upon entering the Tilt measurement screen, gray dashes will appear in place
of numeric values until a valid measurement is complete for that value.
Marker Channel Area (above the bar graph)
This area shall display information about the channel currently selected
by the marker as follows:
- Channel label
- Channel type (Single, TV, Dual, Digital, or DOCSIS)
- Channel Number
To fully understand Tilt measurement results, you should be familiar with
the widths of the bar graph and the viewing options available in Tilt
mode.
Tilt Graph Bar Widths
The Tilt graph is comprised of up to twelve gray vertical bars. Depending
on the channel type a narrow or wide vertical bar will appear above each
channel number and the height of the bar represents the signal level of
that channel.
Narrow
A narrow bar width is used to represent a Single, TV, or Dual channel type.
Wide
A wide bar width is used to represent a Digital or DOCSIS channel type.
Pilot Information Area (below the bar graph)
This area consists of the following:
- Channel type icon (Single, TV, TV (scrambled), Dual, Digital, or DOCSIS)
- Channel number
- Carrier frequency (in MHz)
- Measured carrier signal level for the low and high pilot channels
- Tilt value (in dB)