User's Manual

Table Of Contents
APEX Exciter Incorporating FLO Technology
Details of the Exciter Status Screens Navigating the LCD Display Screens
2604s300.fm
03/08/07 888-2604-001 Page: 3-23
WARNING: Disconnect primary power prior to servicing.
TuneB: (range 0 to 4095) The number in the TuneB window represents the dc voltage
applied to the UHF tunable bandpass filter in the up converter. This voltage places the
selected transmitting channel in the center of the bandpass of the filter. The initial val-
ues for all channels are stored in the exciter. Adjustment is not required.
Using the up or down arrows, this voltage can be changed to change the filter tuning.
Increasing the number increases the filter center frequency. This test is performed,
while observing the exciter RF output on a spectrum analyzer, to check filter tuning.
If the filter is tuned slightly off the center of the channel, the RF response will tilt and
the signal errors will increase.
Reset Tuning: When pressed, this soft key will restore the default values to tune A
and tune B. When tune A and/or tune B values are changed, they are automatically
saved and will not revert to the default values after the exciter is momentarily pow-
ered down.
3.4.5.4 Down Converter Board Status Screen
DownConverterStatus.bmp
Figure 3-22 Down Converter Board Status Screen
For the PA and HPF samples, the RF level for each sample should be within a range of -30
to 0 dBm average power.
The following ia a list of entries on the External I/O Status Screen, refer to Figure 3-22.
EEPROM: (Ok or FAULT) The EEPROM is the local board memory. It stores board
specific information such as board revision, CPLD revision, and other local data.
RF Level: This is the RF level (taken after the AGC circuit) of the current sample. It
typically ranges between 0.6 to 1.0 Vdc when samples of proper power range are
present at the inputs.
+15 Vdc: Input power from UDC interface board via connector J8.
-15 Vdc: Input power from UDC interface board via connector J8.
8 Vdc: Input power from UDC interface board via connector J8.
RF Sample: This displays the name of the RF sample source (Exciter, Amplifier, and
HPF).