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The exact setting of this control will depend on the input sensi-
tivity of your exciter (or STL transmitter) and the desired peak
carrier modulation you wish to achieve. Use your mod-monitor
to check the off-air signal when making this adjustment, and be
sure that audio processing setup has been completed to your
satisfaction before fine-tuning the output level.
Multiplex
Output
Servo
The DAVID IV employs an open-loop servo system to maintain
the multiplex output at the precise level set by the user. As ei-
ther the 19kHz stereo pilot level or the RDS injection level is
adjusted (or even turned off), the composite/MPX output re-
mains constant so that no back-and-forth tweaking is required.
RDS SETUP
The Radio Data System, or RDS (called the Radio
Broadcast
Data
System, or RBDS in the US) enables the FM broadcaster to
transmit certain digital data along with his program audio. The
transmitted information includes ‘housekeeping’ functions that
identify the station format, keep track of rebroadcast transla-
tors, send time information, etc., and it can also display adver-
tising or music artist and title info on the faceplate of RDS ra-
dios.
An external encoder is required to generate the RDS subcarrier.
When RDS is enabled, the DAVID IV supplies a synchronizing
signal to lock the encoder to the stereo pilot, and a self-
metering combining network to add the RDS subcarrier to the
composite/MPX output signal. Additional details may be found
in Section II (Page 14).
Navigate to:
Setup / Stereo Generator / RDS Input
:
Before connecting your RDS encoder, be sure first to back the
RDS Injection slider all the way down.
Turn
the jog wheel to
bracket the slider,
push
the knob to select it, and then
turn
the
knob counterclockwise until the lighted portion of the slider is
off the bottom of the scale. Note that the numbers below the
slider do not change during this operation.
Next, connect your encoder. If it is programmed and ready to
go,
turn
the jog wheel to bracket:
Enable
, and
push
the knob
to set this function.
Next
turn
the jog wheel to again bracket the slider and
push
the
knob to select it. Watching the numbers beneath the slider,
carefully advance
RDS Injection
by turning the knob clockwise.
The lighted portion of the slider will creep up from the bottom
of the box, and at some point you should begin to see the injec-
Summary of Contents for David IV
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