Instruction manual

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14
COMPOSITE
PROCESSING
PEAK VALUE OF
CLIPPING PRODUCTS
OUT >60dB below 100%
1dB 50dB below 100%
2dB 45dB below 100%
3dB 40dB below 100%
Composite clipping is performed prior to injection of
the 19kHz stereo pilot and any subcarriers. This
averts pilot clipping or other pilot amplitude
modulation. Nevertheless, crosstalk of the program
audio into RDS or SCA subcarriers is exacerbated by
composite clipping and its inevitable intermodulation
and harmonic generation. Use this feature sparingly!
“MULTIMETER”
An up/down momentary toggle switch cycles the front-
panel metering among the various display options;
LEDs identify the function monitored. The metered
values are:
L Left program input channel.
R Right program input channel.
L+R The sum of the left and right channels.
L–R The difference of the left and right
channels.
MPX The composite multiplex output.
PILOT The 19kHz stereo pilot.
SUB 1 Subcarrier #1
SUB 2 Subcarrier #2
POWER
(Sorry, the function of this switch is classified.)
BARGRAPH METERING
The front-panel bargraph meter is useful in initial level-setting and to
verify proper operation of the 708 Stereo Generator. The up/down
switch to the right of the display cycles the meter through its various
measurement functions.
The meter is peak-responding, and is scaled both in percent-modulation
and in dB, with 0dB corresponding to 100% modulation. When switched
to show measurements of PILOT, SUB 1 or SUB 2, an additional 20dB