Orban OPTIMOD-FM 5518, Руководство по эксплуатации

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5518-FM DIGITAL TECHNICAL DATA
6-15
ROM read-only memory
SC subcarrier
SCA
subsidiary communications authorization

a non program-related subcarrier in the FM
baseband above 23 kHz (monophonic) or 57 kHz (stereophonic)
SMT surface-mount
S/PDIF
Sony/Philips digital interface (standardized as IEC958)
TRS tip-ring-sleeve (2-circuit phone jack)
THD total harmonic distortion
TX transmitter

s Microseconds. For FM preemphasis, the +3 dB frequency is 1 / (2
 
), where

is the pre-
emphasis time constant, measured in seconds.
VCA voltage-controlled amplifier
VU volume unit (meter)
XLR a common style of 3-conductor audio connector
XTAL crystal
Parts List
Many parts used in the 5518 are surface-mount devices (“SMT”) and are not in-
tended for field replacement because specialized equipment and skills are necessary
to remove and replace them without damage to the circuit boards. The list below
includes substantially all of the parts used in the 5518 (including surface-mount de-
vices), and inclusion of a part in this list does not imply that the part is field-
replaceable.
See the following assembly drawings for locations of components.
Obtaining Spare Parts
Special or subtle characteristics of certain components are exploited to produce an
elegant design at a reasonable cost. It is therefore unwise to make substitutions for
listed parts. Consult the factory if the listing of a part includes the note “selected” or
“realignment required.”
Orban normally maintains an inventory of tested, exact replacement parts that can
be supplied quickly at nominal cost. Standardized spare parts kits are also available.
When ordering parts from the factory, please have available the following informa-
tion about the parts you want:
Orban part number
Reference designator (e.g., C3, R78, IC14)
Brief description of part
Model, serial, and “M” (if any) number of unit

see rear-panel label
To facilitate future maintenance, parts for this unit have been chosen from the cata-
logs of well-known manufacturers whenever possible. Most of these manufacturers
have extensive worldwide distribution and may be contacted through their web
sites.