APEX
™
Exciter Incorporating FLO
™
Technology
Navigating the LCD Display Screens
Details of the Exciter Status Screens
Page: 3-22
888-2604-001
03/08/07
WARNING: Disconnect primary power prior to servicing.
• 15 Vdc: Input power from UDC interface board via connector J3.
• -15 Vdc: Input power from UDC interface board via connector J3.
• 8 Vdc: Input power from UDC interface board via connector J3.
• RF Detector: Rectified RF output voltage sample from exciter output amplifier.
• AGC Unlock. (OF or Fault) Note: AGC Unlock fault indicates an AGC problem, not
that the Output Power AGC is disabled, see Up Converter Diagnosis screen?
• Board Rev: This is the board revision for the Up Converter board.
3.4.5.3.1 Up Converter Diagnostics
UpConverterDiagnostics.bmp
Figure 3-21 Up Converter Diagnostics
The Up Converter Diagnostics screen is shown in Figure 3-21, with screen entries listed
below.
• Output Power AGC. When enabled, the exciter output power level is set from the ex-
citer main screen or the extended control. This is the normal setting.
When disabled, for test purposes, the exciter output power is locked in the previous
(enabled) AGC setting. This is a good mode for testing the analog tray RF circuits,
because the RF level will remain constant when an RF cable is disconnected.
• TuneA: (range 0 to 4095) The number in the TuneA window represents the dc voltage
applied to the UHF tunable notch filter in the up converter. This voltage places the
notch at the local oscillator frequency to improve local oscillator rejection in the ex-
citer RF output signal. The initial values for all channels are stored in the exciter. Ad-
justment is not required. In the UHF band, the local oscillator is 140 MHz below the
center of the channel and in the VHF band, the local oscillator is 140 MHz above the
center of the channel.
Using the up or down arrows, this voltage can be changed to change the notch filter
tuning. Increasing the number increases the notch frequency. This test is performed,
while observing the exciter RF output on a spectrum analyzer.