Tektronix ECO422D Technical Reference page 65

GPS7 module antenna
requirements
GPS7 module oven
calibration
Video Sync Pulse Generator and ECO422D SD/HD Changeover Unit System Integration
5. If this empty slot will not be used, you must attach a blank panel to the
mainframe to control instrument cooling and EMI emissions.
a. Align the blank panel with the open slot of the mainframe.
b. Tighten the two screws to secure the blank panel to the mainframe.
A blank panel is available as an optional accessory for the
generator mainframe.
6. If you want to install another module into the slot from which the module is
removed, perform the installation procedure starting at step 4. (See page 36,
Installing a module.)
The GPS7 module requires an external antenna to receive signals from satellites.
You must set up an antenna system to provide the GPS signal as an input to the
module. (See page 55, TG700 and TG8000 connections.)
When you install a GPS7 module into a TG8000 mainframe, it is suggested
that you calibrate the mainframe oscillator oven as part of the installation and
qualification process to optimize the system under the actual operating conditions.
This calibration is optional for the TG8000 mainframe but is required for
the TG700 mainframe. In addition, for the TG700 mainframe you must also
characterize the oscillator frequency as a function of voltage.
The oven calibration is performed using the CAL OVEN submenu, which is
located in the UTILITY submenu of the generator main menu. The CAL OVEN
submenu can be accessed in regular or factory mode. When the instrument is in
regular mode or factory mode, you can access the internal frequency calibration,
which can be performed while the instrument is in service.
For the TG700 only, you must also characterize the oscillator frequency as a
function of voltage. This characterization is only available only when the GPS7
module is installed in a TG700 mainframe and should only be performed when
the instrument is out of service.
Internal frequency calibration. Use this menu to set the internal frequency of the
mainframe internal oscillator. This may be done without removing the instrument
from service, allowing you to compensate for oven drift while the instrument
is in its operating environment. For the TG700, this menu only appears when
the mainframe has software version 5.1 or greater installed and when there is a
GPS7 module installed.
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 configured to switch to internal timing.
Installation
41