24
Spectrum Operation (TV )
When the Combolook Color
HD
is first turned on in TV mode, the spectrum is displayed.
Upon connection of an aerial or CATV source, it will show a display similar to that above.
This portion of a spectrum shows a digital TV signal and an analog TV signal at the
marker frequency. The spectrum is displayed with the Start frequency at the top of the
screen and the Stop frequency at the bottom. The Span is the total frequency coverage
or the difference between Stop frequency and Start frequency. The current signal level
(53.3 dBuV in this example) is displayed for the frequency at the Marker. The knob is
used to change this to the frequency of interest.
The span of the Spectrum can be changed in two ways. Pressing the keypad ‘3Span’ will
toggle the spectrum to the minimum span of 13MHz and the maximum span of 900MHz.
For this minimum span, each division is 50 kHz. An alternate method is to use the
adjustable span. Pressing the knob allows the span to be adjusted from a minimum of
13Mhz to the maximum of 900MHz. At the maximum span, the entire IF band from
2MHz to900MHz is displayed.
When span is adjusted by pressing the knob, a second press of the knob allows the knob
to control the insertion of attenuation from 0dB to 45dB as indicated on the display. “DC
Offset” of the spectrum to be adjusted for best display. A further press of the knob
restores the operation to frequency adjustment. The span setting from the knob remains
as the current setting. The “DC Offset” is restored to 0.
The current video bandwidth (VBW) and Resolution Bandwidth (RBW) are shown. These
can automatically or manually set in the Setup Menu.
In the LCD display, the knob function (FREQ, SPAN, ATTEN) is shown and also shown is
the status of the Power Inserter to use with amplified antennas.
Picture)
Picture)
Picture)
Picture) Displays an analog PAL/NTSC/SECAM picture at the marker position frequency.
See Analog Picture Mode (TV) page 25.
