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3

3. Block Diagram

Note: Adopts butterfly DFB laser or coaxial DFB laser.

4. Technology Parameters

4.1 Link test conditions

Special instructions:

The performance parameters of this manual according to

the measuring method of GY/T 143-2000 <Specifications and methods of
measurement on AM optical transmitter and receiver used in CATV systems>, and
tested under the specified test conditions.

Test condition:

With standard optical fiber and standard optical receiver

composed the test link. Set 84 PAL-D analog TV channel signal at 750MHz frequency
range under the specified link loss. When the optical input power of optical receiver is
-1dBm, measure the C/CTB, C/CSO and C/N.

4.2 Technique Parameters Table

Item

Unit

Technique parameters

Optical output power

mW

4

6

8

10

12

14

16

18

20

22

24

26

Optical link loss

dB

7

9

10

11

11.8

12.5

13

13.6

14

14.4

14.8

15.1

Optical wavelength

Nm

1310±20

Laser type

DFB laser

Optical modulation

mode

Direct optical intensity modulation

Optical connector

type

FC/APC or SC/APC

Frequency range

MHz

47-750/862/1003

RF input level

dBµV

72-88

Flatness in band

dB

±0.75

RF input impedance

Ω

75

Optical Transmitter

 User Manual

 L-RF-4mW-TX

www.questtel.com

[email protected]

Содержание L-RF-16mW-TX

Страница 1: ...User Manual CATV 4 mW RF Optical Transmitter 47 750 862 1003 MHz L RF 4mW TX www questtel com sales questtel com ...

Страница 2: ...While the optical transmitter is working there is an invisible laser beam from the optical output adapter on the front panel Avoiding permanent harm to the body and eye the optical output should not aim at the human body and human should not look directly at the optical output with the naked eye Please make sure that the ground terminal of the case and power outlet has been reliably grounding befo...

Страница 3: ...according to the RF input signal level and the number of channels 15 84 channels make the CSO CTB and C N index always at the optimal value to ensure the overall performance Advanced multi frequency RF pre distortion technology combined with the GaAs device effectively improve the CATV system most important CTB and CSO index C N index also gets the maximum upgrade Adopt advanced 32 bit processor c...

Страница 4: ...alog TV channel signal at 750MHz frequency range under the specified link loss When the optical input power of optical receiver is 1dBm measure the C CTB C CSO and C N 4 2 Technique Parameters Table Item Unit Technique parameters Optical output power mW 4 6 8 10 12 14 16 18 20 22 24 26 Optical link loss dB 7 9 10 11 11 8 12 5 13 13 6 14 14 4 14 8 15 1 Optical wavelength Nm 1310 20 Laser type DFB l...

Страница 5: ...egradation table Optical power Optical link loss dB 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 4mW 53 8 52 8 51 8 51 50 1 49 2 48 2 6mW 53 0 52 0 51 0 50 1 49 1 48 1 8mW 52 8 51 9 51 0 50 1 49 2 48 2 10mW 52 9 51 9 51 0 50 1 49 1 48 2 12mW 52 7 51 8 50 8 49 9 49 0 48 0 14mW 52 4 51 5 50 5 49 5 48 6 47 8 16mW 52 0 51 0 50 1 49 1 48 1 18mW 52 5 51 6 50 6 49 7 48 7 47 9 20mW 51 9 51 0 50 0 49 0 48 0 22mW...

Страница 6: ... means the RF input signal is warned green light means RF input signal is normal 5 160 32 dot matrix LCD screen used to display all the parameters of the machine 6 Display the exit or cancel key of the setup menu 7 Display the up or increase key of the setup menu 8 Display the down or decrease key of the setup menu 9 Display the enter key of the setup menu 10 Laser switching key used to control th...

Страница 7: ...l output port of the device The connector type is FC APC There is an invisible laser beam from this port while working normal So the port should not be aligned to human body or naked eye to avoid accidental injury 5 Power input 1 Reserved port configured dual power or not is decided by the user 6 Power input 2 7 Ground stud of the chassis used for the connection of the device and ground wire 8 Fan...

Страница 8: ...Press Enter key into the menu index 1 Parameter menu 2 Set parameters 3 Alarm menu 5 Sub menu of parameters Press Enter key into the menu Content Meaning Optical output power of the laser at present Bias current of the laser at present Internal temperature of the laser Operating current of the laser thermoelectric cooler Transmission channel number of the system Laser RF signal level at present Op...

Страница 9: ...ode Switching power supply output 5V supply voltage Switching power supply output 5V supply voltage Switching power supply output 24V supply voltage Serial number Internal temperature at present IP address Subnet Mask Gateway MAC address Software system version Optical Transmitter User Manual L RF 4mW TX www questtel com sales questtel com ...

Страница 10: ...AGC or MGC Set the attenuation of MGC Set the offset of AGC start control level Set system transmission channels number This parameter is used to correct the accuracy of displayed laser RF signal level Set IP address Set subnet mask Set gateway 7 Warning menu Press ENTER into the alarm menu Optical Transmitter User Manual L RF 4mW TX www questtel com sales questtel com ...

Страница 11: ...it to the rack and reliably grounding The grounding resistance must be 4Ω 3 Use the digital multimeter to check the supply voltage make sure the supply voltage comply with the requirements and the switch key is on the OFF position Then connect the power supply 4 Input the RF signal turn the switch key to the ON position and observe the front panel LED status After the LED working status indicator ...

Страница 12: ...netlike curve or large particles highlights 1 The received optical power of the optical contact point is too high the output level of the optical receiver module is too high and intermodulation index of RF signal deteriorates 2 The RF signal input of the optical transmitter is too high beyond the device AGC control range results in deterioration of the intermodulation index 3 The intermodulation i...

Страница 13: ...us 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...

Страница 14: ...optical power is on the low side after clean the adapter may be polluted clean it Note Adapter should be carefully operated so as to avoid hurting inside fiber 6 Use compressed air or degrease alcohol cotton to wash the adapter carefully When use compressed air the muzzle aims at china tube of the adapter clean the china tube with compressed air When use degrease alcohol cotton insert directions n...

Страница 15: ...ock 7 Object and Liquid Entry Never push objects of any kind into this product through openings as they may touch dangerous voltage points or short out parts resulting in a fire or electric shock Never spill liquid of any kind on the product 8 Servicing Do not attempt to service this product yourself as opening or removing covers may expose you to dangerous voltage or other hazards Refer all servi...

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