User’s manual
③
RF input signal requirements:
Nominal RF input signal of this transmitter is 75(+3/-3)dBuv for each
channel with loading 59 channels. To achieve ideal transmission
characteristics, transmitting signal level difference among channels should
be within ±0.5dB
It is particularly stressed that RF input level in each channel can not be
more than 82dBuv, or the laser might be damaged
Generally one test report will be offered, in which there is laser RF drive
level of this device, detection port on the front panel is the -20dB detection
port of drive level that is stated above
Before RF signal goes into the RF input of optical transmitter, carefully
adjust the level of drive signal by frequency spectrometer and RF lever
meter, to ensure RF input level in each channel in 75(+3/-3)dBuv
Attention, the RF level we stated above is the level with 59 channels
loaded, in actual usage, the quantity of loaded channel might change, then
the RF level requirement on each channel will change too, please refer to
the following picture for specific changes and correspondences: It means
different loading channel number corresponds different RF level for each
channel, but this device can always remain laser general
optical
modulation constant when there is at least 5dB input level difference.
输入电平变化
-
实际加载频道数
0.0
1.0
2.0
3.0
4.0
5.0
20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60
实
际的
加载
频道
数（
c h
)
输入
电平
增加
值（
dB
)
