Orban OPTIMOD-FM 8600Si, Руководство по эксплуатации

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2-12
INSTALLATION ORBAN MODEL
Power Ground
•
Ground the 8600Si chassis through the third wire in the power cord. Proper
grounding techniques never leave equipment chassis unconnected to pow-
er/earth ground. A proper power ground is essential for safe operation. Lifting a
chassis from power ground creates a potential safety hazard.
Circuit Ground
To maintain the same potential in all equipment, the circuit (audio) grounds must be
connected together:
•
When the 8600Si’s stereo encoder is driving an unbalanced exciter input , you
may encounter a ground loop. (Some older exciters have unbalanced inputs.)
Unlike some older Orban FM processors, the 8600Si does not have a ground lift
switch. If you cannot reconfigure your grounding scheme to eliminate such a
loop, you can balance and float the exciter input with a Jensen JT-123-BMCF
transformer (see page 2-15).
•
In high RF fields, the system is usually grounded through the equipment rack in
which the 8600Si is mounted. The rack should be connected to a solid earth
ground by a wide copper strap — wire is completely ineffective at VHF because
of the wire’s self-inductance.
Studio Level Controller Installation (optional)
[Skip this section if you are not using a studio level controller ahead of the 8600Si.
Continue with “Quick Setup” on page 2-15.]
•
If you are using an Orban 6300 as a studio level controller, refer to its Operating
Manual.
If you are using Orban 8200ST external AGC
If the STL uses pre-emphasis, its input pre-emphasis network will probably introduce
overshoots that will increase peak modulation without any increase in average mod-
ulation. We therefore strongly recommend that the STL transmitter’s pre-emphasis
be defeated (freeing the STL from such potential overshoot), and that the 8200ST be
used to provide the necessary pre-emphasis.
If the STL transmitter’s pre-emphasis cannot be defeated, then configure the 8200ST
for flat output. In this case average modulation levels of the STL may have to be re-
duced to accommodate the overshoots.