R&S SMB Troubleshooting
1407.0806.82 3.35 E-6
Stereo/RDS Coder adjustment
Error Error correction
RF carrier frequency is shifted by
more than 2 kHz when activating
Stereo modulation mode.
The RF carrier frequency offset in Stereo mode can be
internally adjusted. Perform
SETUP - Internal Adjustments
- Adjust All.
Deviation of pilot tone differs from
setting value by more than 4 % or
270 Hz, whichever is greater.
The pilot tone deviation can be internally adjusted. Perform
SETUP - Internal Adjustments - Adjust All.
Deviation of analog audio signal
using internal LF Generator or
analog external input differs from
setting value by more than 4 % or
1.6 kHz, whichever is greater.
The audio signal FM deviation can be internally adjusted.
Perform
SETUP - Internal Adjustments - Adjust All. If
error persists, check correct input signal on the external
Stereo audio analog input.
Deviation of audio signal using
external S/P DIF source differs from
setting value by more than 4 % or
1.6 kHz, whichever is greater.
The audio signal FM deviation using the S/P DIF input can
be internally adjusted. Unlock Protection Level 2: 147946.
Perform SETUP - Internal Adjustments - Adjust S/P DIF. If
error persists, check correct input signal on the external
Stereo audio S/P DIF input.
Stereo/RDS Coder Faults
Fault Test Action if test fails
External analog
Stereo input
faulty
Check the Stereo modulation with internal LF
Generator.
Check the Stereo mode signal path
(see page 3.36).
Otherwise, check the connection of
STEREO L, R cables to the Stereo
Coder module.
If connected correct, most probably
the Stereo Coder module is
defective. Check the Stereo Coder
being supplied correct (see
page 3.32).
External digital
Stereo input
faulty
Measure the input resistance of the STEREO
S/P DIF input on the rear panel with a
multimeter. The input resistance should be
75 K ± 20 %.
Check the connection of the
STEREO S/P DIF cable to the
Stereo Coder module. If connected
correct, most probably the Stereo
Coder module is defective.
Stereo
Modulation
faulty
The FM Stereo multiplex signal is generated
in the Stereo coder module and transferred to
the RF Board modulation input. Run Internal
Adjustments to ensure the VCOs generating
the RF signal working in their optimum and for
adjustment of the Stereo coder module.
The FM Stereo performance has to match the
values given in the datasheet. Measure with a
suitable demodulating receiver.
If the Internal Stereo Coder
Adjustment fails and the Synthesis
Adjustment succeeds, check the
Stereo coder signal path (see page
3.36). If the Synthesis Adjustment
fails, most probably the RF Board is
defective. Check the RF Board
being supplied correct (see
page 3.24).
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