Digital Television Signal Analyzer Measurement Guide : ISDB‑T Signal Analyzer : Frequency/Level Menus (Custom Mode)
 
Frequency/Level Menus (Custom Mode)
These menus describe the Custom mode Frequency/Level menus for the Channel Map options: UHF, UHF (Brazil), IF, or None.
Frequency/Level Menu for UHF Channel Map
Custom
Key Sequence: Frequency/Level > Channel Map > UHF or UHF (Brazil)
Frequency/Level Menus for UHF or UHF (Brazil) Channel Map
Channel Map
Press this submenu key to open the Select Channel Map list box to choose one of four options: UHF, UHF (Brazil), IF, or None. Selecting UHF or UHF (Brazil) displays the Channel submenu key to select a channel and its corresponding frequency.
Channel
This submenu key is displayed only when Channel Map is set to UHF. Press this submenu key to open the Channel Editor dialog box. For UHF, the channel range is 13 to 62. For UHF (Brazil), the channel range is 14 to 69. Selection of a channel automatically sets the corresponding frequency.
Bandwidth
Press this submenu key to open the Select Bandwidth list box and manually select a bandwidth: 6 MHz or 8 MHz.
Auto Reference Level
Press this submenu key to automatically set the reference level at an optimal value. Refer to Auto Reference Level.
Reference Level
Press this submenu key to open the Reference Level Editor dialog box to manually select a signal reference value. If the Pre Amp submenu key is On, then the reference level range is from – 10 dBm to – 50 dBm in increments of 10 dB. If the Pre Amp submenu key is Off, then the reference level range is from – 25 dBm to + 20 dBm in increments of 5 dB.
Pre Amp
On Off
Press this submenu key to toggle the Pre Amp setting to On and Off. The current state is underlined. When the preamplifier is switched On, the reference level is automatically set to – 30 dBm. When the preamplifier is switched Off, the reference level is set to – 25 dBm. Refer to the Pre Amp Warning.
One‑Seg
Press this submenu key to toggle the one‑segment view On or Off. You can view the One‑Seg Frequency Response measurement in Delay Profile or in Constellation and Sub-Carrier MER charts when the One-Seq submenu key is On. Refer to Figure: Modulation Analysis of Delay Profile, One‑Segment.
Warning
The upper limit level, up to which the instrument is not damaged, depends on the preamplifier state.
Preamplifier On: – 10 dBm
Preamplifier Off: + 20 dBm
Switching the preamplifier On, while applying greater than – 10 dBm with preamplifier Off, may damage the internal electronic circuit. Pay attention to the input level when switching the preamplifier On or Off while applying a signal.
Preamplifier Reference Level, Range, and Setting Resolution
Preamplifier
State
Reference Level Range
Reference Level Setting Resolution
On
– 50 dBm to – 10 dBm
10 dB
Off
– 25 dBm to 20 dBm
5 dB
 
Frequency/Level Menu for IF Channel Map
Custom
Key Sequence: Frequency/Level > Channel Map > IF
Frequency/Level Menu for IF Channel Map
Channel Map
Press this submenu key to open the Select Channel Map list box to choose one of four options: UHF, UHF (Brazil), IF, or None. Selecting IF sets the frequency to 37.15 MHz, and Spectrum Reverse is automatically turned on.
Bandwidth
Press this submenu key to open the Select Bandwidth list box and manually select a bandwidth: 6 MHz or 8 MHz.
Auto Reference Level
Press this submenu key to automatically set the reference level at an optimal value. Refer to Auto Reference Level.
Reference Level
Press this submenu key to open the Reference Level Editor dialog box to manually select a signal reference value. If the Pre Amp submenu key is On, then the reference level range is from – 10 dBm to – 50 dBm in increments of 10 dB. If the Pre Amp submenu key is Off, then the reference level range is from – 25 dBm to + 20 dBm in increments of 5 dB.
Pre Amp
On Off
Press this submenu key to toggle the Pre Amp setting to On and Off. The current state is underlined. When the preamplifier is switched on, the reference level is automatically set to – 30 dBm. When the preamplifier is switched off, the reference level is set to – 25 dBm. Refer to the Pre Amp Warning.
One‑Seg
Press this submenu key to toggle the one‑segment view On or Off. You can view the One‑Seg Frequency Response measurement in Delay Profile or in Constellation and Sub-Carrier MER charts when the One-Seq submenu key is On. Refer to Figure: Modulation Analysis of Delay Profile, One‑Segment.
 
Frequency/Level Menu for Channel Map Setting of None
Custom
Key Sequence: Frequency/Level > Channel Map > None
Frequency/Level Menus for Channel Map Setting of None
Channel Map
Press this submenu key to open the Select Channel Map list box to choose one of four options: UHF, UHF (Brazil), IF, or None. Selecting None displays the Frequency submenu key to allow manually configuring frequency.
Frequency
This submenu key is displayed only when Channel Map is set to None. Press this submenu key to open the Frequency Edit Dialog box and manually set a frequency within a specified range that is displayed in the window. The submenu key menu displays Units: GHz, MHz, kHz, and Hz.
Bandwidth
Press this submenu key to open the Select Bandwidth list box and manually select a bandwidth: 6 MHz or 8 MHz.
Auto Reference Level
Press this submenu key to automatically set the reference level at an optimal value. Refer to Auto Reference Level.
Reference Level
Press this submenu key to open the Reference Level Editor dialog box to manually select a signal reference value. If the Pre Amp submenu key is On, then the reference level range is from – 10 dBm to – 50 dBm in increments of 10 dB. If the Pre Amp submenu key is Off, then the reference level range is from – 25 dBm to + 20 dBm in increments of 5 dB.
Pre Amp
On Off
Press this submenu key to toggle the Pre Amp setting to On and Off. The current state is underlined. When the preamplifier is switched on, the reference level is automatically set to – 30 dBm. When the preamplifier is switched off, the reference level is set to – 25 dBm. Refer to the Pre Amp Warning.
One‑Seg
Press this submenu key to toggle the one‑segment view On or Off. You can view the One‑Seg Frequency Response measurement in Delay Profile or in Constellation and Sub-Carrier MER charts when the One-Seq submenu key is On. Refer to Figure: Modulation Analysis of Delay Profile, One‑Segment.
 
Auto Reference Level
The reference level indicates the signal level that is supplied to the instrument.
The reference level range for input to the instrument is determined by the reference level setting. Immediately after a signal is applied to the instrument, the input attenuator is automatically set according to the reference level. The relationship between the reference level and the input attenuator is fixed.
Raising the reference level increases attenuation of the input attenuator, enabling you to measure signals with higher input levels. Note that the noise floor rises in proportion to the attenuation of the input attenuator.
When applying a signal to the instrument, input a signal level that does not exceed the reference level value. If the signal level exceeds the reference level, raise the reference level. For example, if the signal level is 0.5 dBm with preamplifier off, then set the reference level to 5 dBm, not to 0 dBm.
If an interfering wave other than the intended signal exists, and if the power within the frequency range of approximately 100 kHz to 7.1 GHz is 15 dB or more higher than the measurement signal level, then set the reference level to take the large signal into account.