Tektronix RFM150, Instruction Manual

Page: 81 / 278

Making Measurements
RFM 150 Instruction Manual 2–35
FM Deviation
The instrument measures both the visual carrier level and the peak
FM deviation of the aural carrier. The FM deviation is the peak
deviation of the aural carrier. Note that the FM deviation is
dependent on the content of the programming; its value reflects the
fluctuating volume of the signal.
Table 2–9 defines the key actions in this mode.
Table 2–9: Functions of active keys in FM deviation measurement mode
Key Action
Menu keys Enters selected menu. (Aborts a partial keypad entry.)
Function keys Tune instrument to preset frequencies. Override partial keypad entry.
Knob Tunes instrument according to entry mode. Overrides partial keypad
entry.
Numeric keypad Keying either channel or frequency, followed by CHAN, MHz, or ENTER,
tunes the instrument – if chan. or freq. is in the active channel table.
CHAN Terminates keypad entry as channel. Switches to channel entry mode.
MHz Terminates keypad entry as frequency. Switches to frequency entry
mode.
ENTER Terminates a keypad entry in the active entry mode (channel or
frequency, as outlined in the top line of the display).
Pressing backspace during a keypad entry erases the character
preceding the cursor. Backspacing 1 click after field is empty aborts
partial entry.
HELP Displays context-sensitive help screen; aborts a partial keypad entry.
ESC Exits the submenu or menu, one level at a time. Aborts a partial keypad
entry without changing the instrument setup.
Measuring FM deviation. Press MEAS. The function keys are
reassigned to HUM, C/N, and FM DEV. Select FM DEV. The FM
deviation measurement screen, illustrated in Figure 2–16, will be
displayed. The top line of the display shows the channel number and
frequency of the channel being measured, along with the instrument
Making Measurements
RFM 150 Instruction Manual 2–35
FM Deviation
The instrument measures both the visual carrier level and the peak
FM deviation of the aural carrier. The FM deviation is the peak
deviation of the aural carrier. Note that the FM deviation is
dependent on the content of the programming; its value reflects the
fluctuating volume of the signal.
Table 2–9 defines the key actions in this mode.
Table 2–9: Functions of active keys in FM deviation measurement mode
Key Action
Menu keys Enters selected menu. (Aborts a partial keypad entry.)
Function keys Tune instrument to preset frequencies. Override partial keypad entry.
Knob Tunes instrument according to entry mode. Overrides partial keypad
entry.
Numeric keypad Keying either channel or frequency, followed by CHAN, MHz, or ENTER,
tunes the instrument – if chan. or freq. is in the active channel table.
CHAN Terminates keypad entry as channel. Switches to channel entry mode.
MHz Terminates keypad entry as frequency. Switches to frequency entry
mode.
ENTER Terminates a keypad entry in the active entry mode (channel or
frequency, as outlined in the top line of the display).
Pressing backspace during a keypad entry erases the character
preceding the cursor. Backspacing 1 click after field is empty aborts
partial entry.
HELP Displays context-sensitive help screen; aborts a partial keypad entry.
ESC Exits the submenu or menu, one level at a time. Aborts a partial keypad
entry without changing the instrument setup.
Measuring FM deviation. Press MEAS. The function keys are
reassigned to HUM, C/N, and FM DEV. Select FM DEV. The FM
deviation measurement screen, illustrated in Figure 2–16, will be
displayed. The top line of the display shows the channel number and
frequency of the channel being measured, along with the instrument