Tektronix TG700, Руководство пользователя

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Operating Basics
The mainframe oscillator is calibrated by storing the current frequency of the
oscillator while it is locked to a GPS or a reference video signal. This stored
frequency value is used when the instrument boots up and when there is a loss of
signal lock and the instrument is con
fi gured to switch to internal timing.
The following fi gure shows the CAL OVEN submenu. You can fi nd a complete
internal frequency calibration procedure in the Oven Calibration Procedures
section. (See page 3-98.)
Figure 2-25: Internal frequency calibration menu
Press the ENTER button to execute the oscillator frequency calibration routine or
press the CANCEL button to exit the menu.
Gain calibration. Use this menu to characterize the oscillator frequency as a
function of voltage. This menu is only available when the mainframe is in factory
mode, has software version 5.1 or above installed, and has a GPS7 module
installed. Do not run this characterization if the unit is in service because this step
requires a temporary frequency shift.
You can fi nd a complete gain calibration procedure in the Oven Calibration
section. (See page 3-98.)
Figure 2-26: Gain calibration menu
Press the ENTER button to start the gain calibration routine or press the
CANCEL button to exit the menu.
CAUTION.
To prevent an incorrect oscillator frequency from being stored as the
calibrated value, be sure that the instrument is locked to one of the following
signal sources before you run the internal frequency calibration routine:
Rubidium clock, GPS antenna (GPS7 module only), or the master sync signal of
your video installation. To run the gain calibration, the instrument must be locked
to a GPS reference.
TG700 TV Signal Generator Platform User Manual 2–29