RF RF-T860 User manual

Optical Transmitter
RF-T860/24
Installation & Operation Manual
Caution
These servicing instructions are for use by qualified personnel only.
To reduce the risk of electrical shock, please do not perform any
serving other than that contained in the installation manual unless you
are qualified to do so. Refer all servicing to qualified service
personnel.

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Content
Caution...................................................................................................... 1
1. TECHNICAL SUPPORT............................................................................. 0
2. GENERAL DESCRIPTION......................................................................... 1
2.1 I NTRODUCTION ............................................................................................ 1
2.2 F EATURES :.................................................................................................. 2
2.3 B LOCK D IAGRAM ......................................................................................... 2
2.3.1 ATC Loops....................................................................................... 3
2.3.2 APC Loops....................................................................................... 3
2.3.3 RF loops .......................................................................................... 3
2.3.4 Data Collection, Control and Internet .............................................. 3
3. SPECIFICATION ........................................................................................ 4
4. BOARD ILLUSTRATION ........................................................................... 5
4.1 F RONT P ANEL ............................................................................................. 5
4.2 R EAR P ANEL ............................................................................................... 6
5. INSTALLING............................................................................................... 7
6. TESTING..................................................................................................... 9
6.1 T EST E QUIPMENT CONNECTION FOR R ESPONSE AND R ETURN L OSS T ESTING 9
7. TROUBLE SHOOTING ............................................................................ 10
Trouble.................................................................................................... 10

1. Technical Support
Before you begin using the RF-T860, familiarize yourself with this
user’s manual.
If you need assistance while working with RF-T860, please contact us.
Please do not open the unit and verify any circuit yourself, and it is
necessary to make some simple check before calling service.
When shipping equipment for repair, please follow below steps:
 Pack the unit security.
 Enclose a note describing the exact problem.
Ship the unit prepaid to us.

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2. General Description
2.1 Introduction
RF-T860 is an intelligent high performance fiber Transmitter. It is widely
used at node locations of a fiber optic link to convert the RF signal to optical
signal in the HFC plant.
The capability of RF-T860 is:
 Laser power ON/OFF can be adjusted by the lock. While the Lock is at
OFF position, the laser is cut off, the AC power still can be fed into the
unit.
 LCD shows the working status, including eight working messages,
working address, warning message. Press the Status Display Switch
could select the showing of the status. When working status is
abnormal, the message on the LCD flashes, the Status Display Switch
is invalid, the RF circuit and laser power would be cut off
automatically.
 Reset key is used to reset the working of the transmitter while the
Applied power is on, which commonly be used in the start and the
alarm status.
 Three Indicating LED show the status of the unit, including the Applied
power, working status, RF level. Green lamp shows the status is
normal, while red lamp shows the status is abnormal. These LED are
monitored by the CPU.
 ALC/MGC switch. Set the ALC/MGC switch to “MGC” side before you
adjust the RF attenuation. One RF Test Port is on the front panel.
Measure the RF input level to find the optical modulation depth. User
can obtain the accordant specification stipulate on this manual by
adjusting the RF attenuation. Set the ALC/MGC switch to “ALC” side,
none manual work is needed. Input the RF signal, the Unit adjust the
Gain of the RF to maintain the RF Input Level and the general depth of
the optical modulation index.
 RS232 port is installed for the monitor control of the CPU.

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Figure 1. RF-T860
2.2 Features:
Low Input RF Level
ALC/MGC
APC/ATC
Pre-distortion circuit
CPU monitor control the working statues
LCD shows the working status and the alarm message
Cut off the optical power automatically when the work is abnormal
RS232 port for the monitoring status through remote computer
2.3 Block Diagram
The transmitter is based on 6 functional blocks. Optical laser temperature
controlled (ATC), Optical power control electronics(APC), Data Collection,
Controller, Communication Circuit, RF Circuit, and so on.
The Block Diagram is in Figure 2.
Figure2: RF-T860 Block Diagram

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2.3.1 ATC Loops
There is one loop for operating the laser diode at constant optical output
power, as well as at constant temperature, by means of an Auto Temperature
Control Loops (ATC). The Optical Power and the life-span would be influenced
by the temperature of the heat Optical Laser. The feasible temperature of the
chip is 25 ℃ . The semi conductor Laser is sealed in the parts, a temperature
detector resistance is stored in this parts.
2.3.2 APC Loops
Due to the aging of the laser diode, the Optical power will drop down, the
Carrier Noise will declined, on the same time the CSO, CTB would get bad. The
Auto Power Control Loop is mandatory to maintain the stable of the optical
power, to control the optical power of the laser automatically. One optical fiber
detector circuit is sealed in the semi-conductor laser parts, which could
supervise the laser diode.
In case of an optical output power failure, an alarm is generated on the
front case LCD.
2.3.3 RF loops
The RF circuit is used for the amplify of the RF signal, ALC/MGC function,
Pre-distortion of the RF signal.
a) MGC Manual Gain Control.
b) ALC Auto Level control.
c) Pre-distortion circuit
2.3.4 Data Collection, Control and Internet

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3. Specification
3.1 Optical Out put
1) Optical Wavelength 1310
± 20nm
2) Conversion Efficiency
>0.1mW/mA(6mW)
>0.2mW/mA(8-14mW)
3) Optical Output Power
4 5 6 7 8 9 10 11 12 13 14 15
16 20 24mW
4) Optical Fiber Type Single Module (9/125µm)
5) Fiber Connector Type SC/APC or FC/APC
3.2 RF Input
1) Frequency Range 45-870MHz
2) Frequency response
<± 0.75dB
3) Input Return Loss >14 dB
4) Input Impedance 75
Ω
5) Attenuator Adjustment
Range 10 dB
6) Input Level Adjustment
Range 75dBµV-80dBµV
7) Connector Type F
3.3 Link Specification
1) CNR > 52 dB @59 channel PAL B/G Carrier;
-1dBm Optical power Receiving
2) CSO <
– 61dBc
3) CTB <
– 65dBc
3.4 LED and Alarm
1) Power Normal=
Green Abnormal= red
2) Working Status Normal=
Green Abnormal= red
3) RF Status Normal=
Green Abnormal= red
3.5 Circuit
1) Operating Temperature -10
℃ -50 ℃

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1 2 3 4 5
6 8 9 10
2) Storage Temperature -15
℃ - +55 ℃
3.6 Power Supply
1) Input Power Range 100V-260V
2) AC Power Frequency 50Hz
The machine should be safely grounded.
4. Board Illustration
Front Panel
Figure 3. RF-T860 Front Panel
1. Laser Power ON/OFF Lock
2. Power Indicating Lamp
The Lamp lit green when the power is normal, or else, the lamp turn red, and
the LCD shows warning message.
3. Working Indicating Lamp
The Lamp lit green when the working is normal, or else, the lamp turn red,
and the LCD shows warning message.
4. RF working status Indicating Lamp
The Lamp lit green when RF Input signal is available, or else, the lamp turn
red. The lamp lit red also when the laser power is off.
5. Reset Key
Press the key to reset the CPU. The LCD alarm massage is caused by the

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control of the software, Reset Key could resume the normal working status.
6. LCD
The LCD shows the status of laser temperature, cooler current, laser optical
output power, laser bias, and switching power voltage when the transmitter’s
working status is normal, otherwise, the LCD shows the warning massage.
7. Status Display Switch
The LCD shows the status of laser temperature, cooler current, laser optical
output power, laser bias, and switching power voltage. Press this switch to
select the other status on the LCD.
8. RF Attenuator
Adjust the RF attenuation with is switch.
9. ALC/MGC Switch
Set the “ALC/MGC “Switch to “MGC” side before you adjust the RF
attenuation. Put the “ALC/MGC “Switch to “ALC” side to maintain the
general RF input to the laser.
10. RF Test Port
RF Test Port is used for monitoring the inject RF Level. When the testing RF
Level equals with the value offered by the supplier, users can obtain the
accordant specification stipulated on this user’s manual.
4.2 Rear Panel
Figure 4. RF-T860 Rear Panel
1. FC/APC / SC/APC Mating Receptacle.
Optical signal Output Port. The adaptor is installed on a movable panel. It is
easy for the changing and clearing the Optical Connector.
2. Heat Sink
To keep the temperature of the amplify module.
1 2
3 4 5 6

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3. RF Input Port( F type)
4. RS232(1)
Preinstalled for the use of the CPU, convenient for monitor control.
5. RS232(2)
Preinstalled for the use of the CPU, convenient for monitor control.
6. AC power socket (220VAC 50Hz)
The Voltage range should be 100~250VAC.
5. Installing
Invisible optical beam comes out from the end of the optical
connector, permanent damage would happen to eyes if see it directly.
1. Fiber connection
Power off, carefully remove the protective cap from the end of the FC/APC /
SC/APC connector, insert the clean optical connector into the mating
receptacle and tighten the connector securely.
2. Power
Turn the “power ON/OFF” Lock to ON position. Apply power to this
transmitter, the Power Indicating Lamp lit green when the power is normal.
Otherwise, cut off the power immediately(and so on in the abnormal power
in the future), and contact with supplier.
This machine should be safely ground.
3. LCD display and lamp indication
LCD shows “PLEASE WAIT…”.
After a moment, shows “LASER TEMP 2× ℃ ”(between 23 ℃ ∼27 ℃ ) and
“COOL CUR ××× mA”.
Press the “Status Indicating” switch again, the LCD will show “OPT POWER
×× mW” and “BIAS CUR ×× mA”.
Press the “Status Indicating” switch again, the LCD will show “LOCAL
ADDRESS××××××H”.
Press the “Status Indicating” switch again, the LCD will show “POWER ××.×V
×.×V ×.×V”.
Repeat the above steps for several times, if the specifications are almost the
same, it means the transmitter is on normal working status.
4. The alarm lamp on the front panel is lit red first then turns green after the
LCD shows massage.

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5. The “RF Level”(Refer to the RF input signal) lamp is lit red first and turns
green when the RF input signal is applied.
6. Reset or resort to the supply
If the transmitter is not in proper order, the above three lamps are lit red, the
LCD show alarm message and remind the user to turn off the machine, the
software would reset automatically, otherwise, please press the RESET key
to repeat step 3 above. Important: If the machine still can not work after
you press the RESET key for several times, please cut off the power
and contact the supplier.
7. Input RF Signal
When the transmitter is in normal working status, input RF signal and the
“RF Level” Lamp will turn green.
8. MGC/AGC
Set the “ALC/MGC Switch” to “MGC” side and adjust the RF attenuator until
the RF Test Port level equals the value listed in Table below: (the suggested
monitoring frequency is 543.25MHz)
Also you can set the “ALC/MGC Switch” to “ALC” side and do not need any
adjustment. (The RF Test Port Level should be maintained on 75-85dB μ V).
Please note that in this case the laser input level Vi= P √ N, P represents the
level of one channel, N stands for the channel number. The supposed channel
number of this transmitter is 59. If the channel number is below 59, the machine
will automatically boosts the laser input level to maintain the same Vi, so the RF
Test Port Level will increase, and the output level of the Optical Receiver in this
system will also increase.
4.5 dBm Link Loss via per 10 kilometers
Address:
RF Test Port Level dBµV
Laser Bias Current mA
Optical Power mW

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6. Testing
6.1 Test Equipment connection for Response and Return Loss
Testing
Figure 5 Test Link of Response and Return Loss
1. Referring the Figure 5 to connect the Test Equipment. Accurate the
Network Analyzer.
2. Optical power had been factory reset. Use Attenuator to select
corresponding attenuation, make sure the receiving power is 0dB(not above
3dB)
3. Connect optical transmitter and receiver with optical attenuator. Connect
Network Analyzer with optical transmitter’s RF input port. Connect Network
Analyzer with optical receiver’s RF input port.
4. In the Frequency Range 45M-750/860MHz , frequency response is within
±0.75dB, Return Loss is above 14dB .(Note: When ALC/AGC switch is at
MGC side, adjust the RF attenuation with RF Attenuator. Be sure the
Flatness is in ±0.75dB from lowest loss to 10dB loss.)
Network
Analyzer
8711
Optical
Transmitter
RF-T860
Optical Receiver
（ used in Test ）
Optical
Attenuator
Optical Output .
RF Input
RF Output
Optical Input
RF Output
RF Input

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7. Trouble shooting
Trouble Reason. Solution
Power on, the LCD
is off.
Switch Power
is abnormal.
Check the power socket,
connect the supplier to get help.
Power on, alarm
signal shows on the
LCD.
1.The
Operating
Temperature is
too low, waiting
for a moment.
2.Waiting for
a moment after
power on.
The software would reset the
automatically, otherwise, please
press the RESET key.
If the machine still can’t work
after you press the RESET key for
several times, please cut off the
power and contact the supplier.
Power on, LCD
shows normally, but
Optical Power is
abnormal
The optical
connector is
dirty.
Clean connector ends with a
lint free tissue and alcohol (above
99%) before mating. Loose
screws fixing the optical connector
plate to clean the connector when
it is necessary.