5
FRDA Series
Instruction Manual
Internal Attenuator Selection
The RF output level from the optical receiver module varies
considerably over its operational optical input range. It is
also dependent upon the transmitter’s channel loading,
its resultant RF input level and the FRDA’s RF output
capability. In order not to overload the amplifier section
input, an internal attenuator must be installed. To find the
recommended attenuator value, first determine the nodes
optical input level as noted in the Input Optical Power”
section of this manual. Refer to the FRDA Configuration
Table in Figure 4, locate the power monitor voltage or
input dBm in the left hand columns. Read across on the
corresponding row to find the value required for the
particular FRDA model used.
To install the attenuator, first make sure that AC power
has been disconnected. Remove the top cover and the
factory installed “0 dB” jumper wire (J1-J3, see Figure
3). Install the flat attenuator (Blonder Tongue Stock No.
9320-xx). Replace cover, reapply AC power and set RF
output level and slope per specifications.
Figure 4
Configuration Table
Flat Attenuator
Figure 3
Optical Input
dBm
mW
-10
0.10
-9
0.13
Increase Optical Input Power
Orange Optical LED Indication
-8
0.16
-7
0.20
-6
0.25
0 dB
-5
0.32
2 dB
-4
0.40
4 dB
G
R
E
E
N
L
E
D
-3
0.50
6 dB
Recommended
Attenuator
Plug-in Value
(9320-xx)
-2
0.63
8 dB
-1
0.79
10 dB
0
1.00
12 dB
1
1.26
14 dB
2
1.58
16 dB
3
2.00
18 dB
4
2.51
Decrease Optical Input Power
Red Optical LED Indication
5
3.16
1310/1550 Wavelength Setting
Receivers are shipped from the factory configured for 1310 nm operation to compliment Blonder Tongue’s FIBT-S3A Series
Transmitters. If it is necessary to change the wavelength of operation setting to 1550 nm, first disconnect AC power, then
remove the top cover and locate the locate the 1310nm/1550nm 3 pin header near the receiver module. Using needle nose
pliers, move the shunt from the 1310 position to the 1550 position. Refer to Figure 3. Replace cover and re-apply AC power.
Optical RX
FIGURE 3
Содержание FRDA Series
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