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5.0
ERROR AND REMEDY
1.
No RF output
a)
Check the power supply of the unit to determine whether it is normal.
b)
Insert optical connector, if the RX-Low is showing a red light, or no optical
power, you should use an optical power meter to measure the optical
power of the optical cable output connector. If optical power is normal, it
may not be seated well into the optical connector, (this unit adopts
SC/APC), or optical receiver module may be damaged, If damage is
suspected, you should contact Maxcom and return for factory
maintenance.
c)
Insert optical connector, if the RX-Low is still showing a green light, and
optical power is within normal range, you may check FL, EQ, ATT1, or red
RF adjustment knob on top of the units chassis .
2.
RF output level too low(<20dBmV)
a)
Check received optical power to determine if too low. (<-12dBm)
b)
If optical power is normal you may check all connections. If all are normal,
power double module BGD702 may be damaged. When BGD702 working
in high current (435mA) such as the units installation of grounding is poor,
electrostatic may lead to damaged module (may need to be returned for
factory maintenance)
c)
Check FL, EQ, ATT1, or red RF adjustment knob on top of the unit’s
chassis .
3.
RF output level too high causing the distortion index to be deteriorated
a)
Check received optical power to determine if too high, such as >3dBm
you should install an optical attenuator.
b)
Check the head-end optical receiver’s RF drive level whether too high.
Optical receiver’s RF drive level determines the modulation, it also
determines the system index (CNR, CTB, CSO). Designing should meet
optical receiver manufacture requirement.
c)
Manufacture presented RF drive level Si when in full channel (NTSC/77ch,
PAL-D/59ch). When system transfer N channel practice, RF drive level SiN
should amend as follows:
SiN=Si+10Lg(77/N) (NTSC/77ch)
SiN=Si+10Lg(59/N) (PAL-D/59ch)
d)
If received optical power and optical receiver RF drive level are all normal,
optical receiver RF output power can modulated through ATT1, or red RF
adjustment knob on top of the units chassis
