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©2011 Broadcast Electronics
9.3
REMOVAL AND INSTALLATION
This section provides removal and installation procedures for the AFC/PLL circuit board assembly.
9.3.1
REMOVAL PROCEDURE.
REQUIRED EQUIPMENT. A number 2 Phillips screwdriver with a 4 inch (10.16 cm) shaft is required to remove
the AFC/PLL circuit board assembly from the exciter chassis.
PROCEDURE. The removal of the AFC/PLL circuit board assembly requires the unit be placed on a suitable work
surface. To remove the circuit board, proceed as follows:
WARNING
DISCONNECT EXCITER PRIMARY POWER BEFORE
PROCEEDING.
WARNING
A. Disconnect the primary power to the exciter.
B. Remove the exciter top-cover. Disconnect J1, J2, and J8 from the AFC/PLL circuit board.
C. Disconnect RF sample BNC connector P6 from the output of the modulated oscillator assembly.
D. Remove the four screws securing the AFC/PLL cover to the circuit board. Remove the cover and the
ground straps.
E. Remove the four screws securing the AFC/PLL circuit board to the exciter chassis and remove the circuit
board.
9.3.2
INSTALLATION PROCEDURE.
To install the AFC/PLL circuit board assembly after repairs have been completed, proceed as follows:
WARNING
DISCONNECT EXCITER PRIMARY POWER BEFORE
PROCEEDING.
WARNING
A. Disconnect the primary power to the exciter.
B. Follow the REMOVAL PROCEDURE in reverse order.
9.4
THEORY OF OPERATION
This section presents the theory of operation for the exciter AFC/PLL circuit board.
9.5
FUNCTIONAL DESCRIPTION.
The AFC/PLL circuit board contains nine circuits. Figure 9-1 presents a simplified schematic of the AFC/PLL circuit
board. Refer to Figure 9-1 as required for a description of the following circuits.
A. Reference Divider Circuit
B. Reference Oscillator Activity Monitor
C. RF Sample Divider Circuit
D. Comparator Circuit
E. Loop Filter Control Circuit
Summary of Contents for FX-50
Page 12: ...x 2011 Broadcast Electronics This page intentionally left blank ...
Page 20: ...8 2011 Broadcast Electronics Figure 2 1 FX 50 E REAR PANEL CONNECTIONS SHEET 1 OR 2 ...
Page 21: ...9 2011 Broadcast Electronics Figure 2 1 FX 50 E REAR PANEL CONNECTIONS SHEET 2 OR 2 ...
Page 32: ...20 2011 Broadcast Electronics Figure 3 1 FX 50 E CONTROLS AND INDICATORS ...
Page 35: ...23 2011 Broadcast Electronics Figure 4 1 FX 50 E OVERALL SIMPLIFIED SCHEMATIC ...
Page 40: ...28 2011 Broadcast Electronics Figure 5 1 FX 50 E ASSEMBLY ...
Page 46: ...34 2011 Broadcast Electronics Figure 6 1 CONTROL CIRCUITRY SIMPLIFIED SCHEMATIC ...
Page 49: ...37 2011 Broadcast Electronics Figure 6 2 POWER SUPPLY SIMPLIFIED SCHEMATIC DIAGRAM ...
Page 53: ...41 2011 Broadcast Electronics Figure 6 4 PARALLEL LOAD CONNECTION ...
Page 56: ...44 2011 Broadcast Electronics Figure 6 5 NO PA VOLTAGE TO THE RF AMPLIFIER ...
Page 58: ...46 2011 Broadcast Electronics Figure 7 1 METERING CIRCUIT REMOVAL AND INSTALLATION DIAGRAM ...
Page 60: ...48 2011 Broadcast Electronics Figure 7 2 METTERING BOARD SIMPLIFIED SCHEMATIC ...
Page 68: ...56 2011 Broadcast Electronics Figure 8 1 MODULATED OSCILLATOR SIMPLIFIED SCHEMATIC DIAGRAM ...
Page 74: ...62 2011 Broadcast Electronics Figure 9 1 AFC PLL CIRCUIT BOARD SIMPLIFIED SCHEMATIC ...
Page 81: ...69 2011 Broadcast Electronics Table 9 2 FREQUENCY SYNTHESIZER PROGRAMMING ...
Page 84: ...72 2011 Broadcast Electronics Figure 9 4 NO RF OUTPUT LOCK IS EXTINGUISHED ...
Page 85: ...73 2011 Broadcast Electronics Figure 9 5 NO MODULATION LOCK INDICATOR ILLUMINATED ...
Page 89: ...77 2011 Broadcast Electronics Figure 10 1 RF AMPLIFIER SIMPLIFIED SCHEMATIC ...
Page 92: ...80 2011 Broadcast Electronics Figure 10 2 RF AMPLIFIER CIRCUIT BOARD CONTROLS ...
Page 95: ...83 2011 Broadcast Electronics Figure 10 3 RF AMPLIFIER TROUBLESHOOTING INFORMATION ...
Page 100: ...88 2011 Broadcast Electronics Figure 11 1 SLAVE FM BOOSTER SIMPLIIFED SCHEMATIC ...
Page 101: ...89 2011 Broadcast Electronics Figure 11 2 MASTER FM BOOSTER SIMPLIFIED SCHEMATIC ...
Page 161: ...149 2011 Broadcast Electronics Figure 14 1 OPTIONAL LOW PASS FILTER ASSEMBLY ...
Page 162: ...150 2011 Broadcast Electronics Figure 14 2 EXCITER FRONT RAIL MOUNTING APPLICATIONS ...
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