12
of the laser is not enough.
3. The C/N index of system link
signal is too low.
the optical transmitter and adjust to
the device required input range.
(72--88dBμV). When the input
channel number less than 15, set to
the MGC control mode.
3. Use a spectrum analyzer to check
the system link C/N and make
appropriate adjustments. Make
sure the system link signal C/N
﹥
51dB.
After initial startup, the image of
several optical contact points
randomly appear obvious noises
or bright trace.
The optical contact point has open
circuit signal interference or strong
interference signal intrusions.
1. Check if there is a strong
interference signal source; change
the optical contact point location if
possible to avoid the influence of
strong interference signal sources.
2. Check the cable lines before the
optical contact point, the shielding
net or the RF connector shielding
effect is not good.
3. Close the equipment enclosure
tightly to ensure the shielding
effect; if possible add shielding
cover to the optical contact point
and reliable grounding.
After initial startup, at optical
contact points, the image of
several channels have obvious
noises.
The C/N indexes of these channels
are too low.
Check the C/N of these channels signal
and make appropriate adjustments.
After initial startup, the image of
several optical contact points
appear one or two horizontal
bright traces.
Power supply AC ripple
interference because of the bad
earth of equipment or power
supply.
Check grounding situation of the
equipment; make sure that every
equipment in the line has been reliably
grounding and the grounding resistance
is
﹤
4Ω.
After initial startup, the received
optical power of the optical
contact point is unstable and has
large continuous change. The RF
output signal is unstable too. But
the detected optical output
power of the optical transmitter
is normal.
The fiber connector types do not
match, maybe the APC type
connect to PC type, make the
optical signal cannot normal
transmission. The active fiber
connector or adapter may be
contaminated seriously or the
adapter has been broken.
1. Check the fiber connector type;
adopt the APC type fiber connector
to ensure the normal transmission
of optical signal.
2. Clean the contaminated active fiber
connector or adapter. Specific
operation methods see “The clean
and maintenance method of optical
fiber connector”.
3. Replace the damaged adapter.
Optical Transmitter
User Manual
L-RF-4mW-TX
www.questtel.com
