Broadcast Electronics FX-50, Instruction Manual

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©2011 Broadcast Electronics
11 SYNCHRONOUS FM BOOSTER
This section provides general information and specifications relative to operation of the optional synchronous
FM booster system.
11.1 SYSTEM DESCRIPTION.
The synchronous FM booster system is designed to provide precise and reliable frequency locking of one or
more slave FX-50/E exciters to a master FX-50/E exciter. The system features a plug-in circuit board installed in
the master exciter which generates a reference signal. This signal is transmitted to a similar circuit board
installed in the slave exciter at the booster site to synchronize a 10 MHz voltage controlled crystal oscillator
(VCXO).
If transmission of the reference signal is interrupted or lost, a clamping circuit on the slave circuit board will
operate to stabilize the 10 MHz VCXO. The slave exciter will continue to operate reliably and well within the
assigned frequency range.
11.2 SYSTEM CONFIGURATIONS.
The optional synchronous FM booster circuit boards may be ordered in the following con figurations:
MODEL NO. PART NUMBER DESCRIPTION
FX-50/E 909-0131 Master synchronous FM booster circuit
board for the FX-50/E exciter, factory
installed.
FX-50/E 909-0132 Slave synchronous FM booster circuit board
for the FX-50/E exciter, factory installed.
11.3 ELECTRICAL SPECIFICATIONS.
Refer to Table 11-1 for synchronous FM booster system electrical specifications.
Table 11-1. FM BOOSTER ELECTRICAL SPECIFICATIONS
PARAMETER SPECIFICATION
POWER REQUIREMENTS -20V and +5V supplied by the FX-50 Power
Supply/Control Circuit Board.
REFERENCE FREQUENCIES
STANDARD 125 kHz, + 0.375 Hz, 0˚ to 50˚C, for STL
Subcarrier.
ALTERNATES 100 kHz for Omega International Synchronous
Repeater Systems or 90.909 kHz for Composite
Subcarrier.
REFERENCE SIGNALS
INPUT
LEVEL 500mV to 5V p-p.
IMPEDANCE 100k Ohms, Resistive.