Jackson Labs FireFox, Руководство пользователя

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FireFox Synthesizer User Manual
6 © 2006 Jackson-Labs
After a certain time, the voltage on the battery will drop to a level at which the GPS real time clock
ceases to run. The GPS unit will continue to hold the data in its memory for several days after this
happens, but the time and date will not be updated anymore. This may cause the unit to turn on with
an internal time/date that is stale (old by several days), causing the GPS receiver to search for a
satellite constellation that presently does not exist. This may cause the GPS receiver to require a
significantly longer time to first fix (TTFF) than if the battery was completely discharged. It may take
up to 12 hours for the GPS receiver to start the Auto-Survey process under this fault condition.
To speed up the TTFF in this condition, the user may configure the unit to be remotely controlled
(
Communication->GPS->Remot e). To do this, connect a PC to the GPS-Serial connector on the back
of the unit, and use WinOncore12 to set the time and date of the GPS receiver. WinOncore12 has a
configuration wizard for this purpose (see the FAQ/GPS section on www.jackson-labs.com for
information on where to download WinOncore12).
1.4.3 Setting up the GPS
1.4.3.1 GPS Time Offset
The FireFox Signal Generator requires the user to set the political time offset to GMT time. Enter the
SETUP->GPS->GPS TIME OFFSET menu and select between -12 to +12 hours of time offset to
Greenwich Mean Time (GMT)
1.4.3.2 Selecting Metric/US Mode
The unit may display GPS height, time, and date in either Metric or US mode. Select the
SETUP->TIME->US/METRIC menu to change the setting of the relevant GPS data in the LCD
Display.
1.4.3.3 GPS Auto Survey
Enter the SETUP->GPS->AUTO SURVEY menu to start the GPS Auto Survey mode. This will
initiate the GPS receiver to build an average position using 10,000 position readings, and to store this
average position in its’ memory to improve the timing accuracy. Operating with the averaged
position is called Position Hold mode. Pressing the
enter key in this menu will re-initiate the Auto
Survey mode. The FireFox will indicate the Auto Survey mode by displaying “AS” in the main
frequency setting window above the “STAT” indicator. Operating in Position Hold mode is indicated
by an “OK” display above the “STAT” indicator.
1.4.4 Setting the Frequency
Figure 1.1 shows the front panel LCD and keys used to change the output frequency of the FireFox
Signal Generator. The LCD shows either the frequency setting mode, or the menu mode. The
frequency setting mode is the default mode after power up. Press the menu key until the unit shows
the frequency setting mode if the unit is in any of the sub-menus. The left and right keys now control
the cursor which can be moved onto any of the frequency triplets, or onto the RF output power
setting. The cursor will wrap-around the display automatically.