Tektronix CMD 80, User Manual

Page: 335 / 672

Audio Measurements
3–262
CMD 80 Digital Radiocommunication Tester User Manual
H
AUDIO ERROR RANGE. Press this softkey to set the variation that you
want to allow from the target audio level. If the input voltage at the AF
VOLTM connector deviates from the target audio level by more than the
audio error range while the test is running, the test will be suspended until
the input voltage returns to the acceptable range. While the test is suspended,
the AUDIO LEVEL field appears in inverse video and the HARMONIC
DISTORTION fields display dashes.
In the PARAMETERS section of the menu, you can make the following settings:
H
HARMONICS MEASURED. Press this softkey to toggle between 3RD
HARMONIC and ALL HARMONICS setting.
H
FILTER. Press this softkey to toggle between a C-MESSAGE or CCITT
filter.
In the AF GENERATOR section of the menu, you can make the following
settings:
H
FREQUENCY. Press this softkey to set the frequency of the sinusoidal test
tone generated by the AF Generator (300 Hz to 3300 Hz).
H
LEVEL. Press this softkey to adjust the RMS output voltage of the AF
Generator (0 to 5 V
RMS
).
H
DEFAULTS. Press this softkey to return the menu settings to the following
defaults:
DISTORTION LIMIT % 5.0%
DISTORTION LIMIT DB –26.0 dB
AUTO STOP OFF
TARGET AUDIO LEVEL 2500.0 mV
RMS
AUDIO ERROR RANGE 2500.0 mV
RMS
HARMONICS MEASURED ALL HARMONICS
FILTER C-MESSAGE
AF GENERATOR
FREQUENCY 1004 Hz
LEVEL 0.0 mV
RMS
Press the MENU UP front-panel key to return to the AUDIO MEASUREMENT
(HARMONIC DISTORTION) menu shown on page 3–260 or to the AUDIO
MEASUREMENT CONFIG menu shown on page 3–259, depending on which
menu you used to enter this menu.