OTPN-800CL - Olson Technology Inc.
Contents
1. HIGH VOLTAGE The power supply section bottom section of the OTPN 800CL contains no user serviceable parts There is exposed high voltage inside this section Only factory service technicians should open the power supply section SHOCK HAZARD The OTPN 800CL is designed for indoor use only Direct exposure to moisture must be avoided Connect the AC Adapter into the OTPN 800CL BEFORE plugging the adapter into the wall INTRODUCTION The OTPN 800CL is a high quality cost effective bidirectional CATV node designed around the latest optical receiver technology It is designed to operate and meet full specifications with optical input levels ranging from 8dBm to 2dBm The OTPN 800CL is available with three different band splits 1 5 42 54 1 000MHz 2 5 30 45 1 000MHZz 3 5 65 85 1 000MHz The OTPN 800CL can be equipped with an optional return laser transmitter An AC adapter with an input range of 100 240V 50 60Hz is supplied with each unit INSTALLATION ENVIRONMENTAL CONSIDERATIONS The OTPN 800CL is specified to operate from 10 C to 55 C It should be mounted in an adequately ventilated area Like any other electronic equipment it will probably have a longer life span if it is not operated at the upper limit of the temperature range Installation in wet areas or areas of extremely high humidity should be avoided The OTPN 800CL should not be installed in areas that are accessible to children The OTPN 800CL may be installed and2. 6dBm 0 25V None 2dBmV 18dBmV 4dBm 0 40V None 2dBmV 22dBmV 2dBm 0 63V None 6dBmV 26dBmV OdBm 1 00V None 10dBmV 30dBmV 2dBm 1 58V None 14dBmV 34dBmV Table 1 Setup Reference Although the node will operate at optical input levels as high as 2dBm there is little improvement in the CNR performance of the node at optical input levels above 0 dBm For optimum distortion performance it is recommended that the optical input to the node be kept at or below 0 dBm The Olson Technology Model OTOA 1000 optical attenuator are ideal for this application The OTPN 800L does not have an internal gain adjustment so the RF output is directly proportionate of the optical input level If lower output is desired the unit should be lower by adding an in line pad to the RF output to reduce the output level This will maintain optimum CNR performance This will also reduce the OMI of the return transmitter if so equipped Unlike many optical nodes the OTPN 800CL is designed to give full output perfor mance at an input of 8 dBm Figure 1 shows the approximate CNR performance at various input levels and channel loading This performance can vary considerably depending upon fiber and laser performance so itis presented as a design aid only The OTPN 800L does not have the provision for a forward equalizer and therefore has OdB of slope flat This unit is designed to go through a relatively short amount of coax Extended lengths of coax will cause do
3. operated in any position on a flat surface The unit has two slots in the bottom plate to accommodate mounting hardware The unit should be mounted by sliding over one screw and then tightening the other screw If mounting requires a wood screw use 6 or 8 maximum pan head sheet metal screws If mounting with a machine screw to tapped holes use 6 32 pan head screws 12V Input gt Forward Return SS SS SN Receiver Transmitter C C C Input Output Return Test Forward Test RF Input Output Point 20dB Point 20dB 12V Input Figure 1 OTPN 800CL Inputs and Outputs OPTICAL CONNECTORS AND CLEANING The standard optical connector is available in SC APC or FC APC type terminations The left port is for the forward band receiver The right port closest is for use with the return band transmitter The fiber ends can be damaged by the insertion of contaminated connectors Some types of customer damage to connectors are not covered under warranty Fiber connectors should never be left uncovered Prepackaged alcohol wipes are the most convenient means of cleaning optical connectors Clean alcohol and lint free wipes or swabs may also be used POWERING Apply only 12 V to either the F connector closest to the top cover of the unit or through a power inserter in series with the Main RF output connector the F connector closest to the outside edge of the housing NOTE The center conduct
4. e RF out is 28 dBmV then the T P will be about 8dBmV The Return T P is 20dB from the Return transmitter RF input Optimal input is 9dBmV 57dBmV Hz so the T P should read 11 dBmV System Setup amp Troubleshooting RETURN RECEIVER RETURN PATH FIBER 1310 nm EET l FORWARD PATH FIBER Oo P 1310 nm O li TOTO A OTPN 800C NODE TO OTHER SITES Fiber Loss at 1310nm is 0 330dB km and 1550 is 0 188dB km Using these values if the fiber run is 6km 3 73 miles then a 2dBm transmitter is required for the distance If the forward band is being split then the additional loss must be accounted for A fiber splitter generally splits the signal equally between each output If the forward path is to be split 4 ways then a 8dBm transmitter is required to cover the 6km If the links coming out of the splitter are different lengths then be sure to have enough transmitting power to reach the receiver with the longest link Those with shorter links can be attenuated to lower the signal to a level the receiver can use To be sure the receiver is in the correct range measure the Receive T P using a DVM The best operating range for most OT forward receivers is 0 5V to 0 9V approximately 3dBm to 0 5dBm Some have operating ranges down to 8dBm If the fiber run is less than a few km then the optical signal must be lowered before the system can operate correctly Failure
5. lftenwotoer Ne OTPN 800CL OLSON TECHNOLOGY PREMISE NODE INDOOR OPTICAL NODE INSTRUCTION MANUAL CE orem ET EE RT E 1 ar wide res ee oun war di man m Phone 209 586 1022 800 545 1022 Fax 209 586 1026 E Mail salessupport olsontech com 025 000493 Rev X6 www olsontech com 09 07 10 SAFETY WARNINGS LASER RADIATION A The OTPN 800CL may be equipped with a laser transmitter which emits invisible radiation that can cause permanent eye damage AVOID DIRECT EXPOSURE TO BEAM Operate the transmitter only with the proper optical fiber installed in the transmitter optical connector Power to the OTPN 800CL should be turned off or preferably disconnected whenever the optical connector cover is opened and there is no installed fiber as when the fiber connector is being installed or removed from the transmitter connector NEVER USE ANY OPTICAL INSTRUMENT TO VIEW THE OUTPUT OF THE LASER TRANSMITTER OPTICAL INSTRUMENT INCLUDES MAGNIFYING GLASSES ETC NEVER LOOK INTO THE OUTPUT OF THE LASER TRANSMITTER NEVER LOOK INTO THE OUTPUT OF A FIBER CONNECTED TO ALASER TRANSMITTER NEVER LOOK INTO OR USE ANY OPTICAL INSTRUMENT TO VIEW THE DISTANT END OF A FIBER THAT MAY BE CONNECTED DIRECTLY OR VIAAN OPTICAL SPLIT TO A TRANSMITTER THAT MAY BE OPERATING THIS SPECIFICALLY APPLIES TO FIBERS THAT ARE TO BE CONNECTED TO RECEIVERS SUCH AS THE OTPN 800CL OR OTHER DEVICES AT ANY DISTANCE FROM THE LASER TRANSMITTER
6. or of the F connector is and the shield is ground OPERATIONAL SETUP RECEIVER FORWARD PATH The OTPN 800CL optical receiver as the last component in a specific optical link will provide carrier to noise performance and an RF output level that is dependent on several parameters The RF input level to the source optical transmitter and the optical input level to the OTPN 800CL basically determine the link performance The RF input level to any optical transmitter is dependent on the number of channels being transmitted As the number of carried channels is lowered the RF input level to the transmitter can be raised This results in increased RF levels at the OTPN 800CL receiver This improves the carrier to noise ratio over the link Links should be designed and transmitters should be set up using values that represent the maximum number of channels likely to be carried The receiver output power is also affected by the amount of equalization used The use of a lower value equalizer will require reducing the output level as measured at the highest channel This is because the attenuation of the lower channels is reduced Table 1 assumes approximately 77 channels from 54MHz to 550MHz and digital loading from 550M Hz to 1 000MHz at 6 dB below the carrier Optical Input Received Forward Approx Fwd Approx RF Level Power TP Equalizer T P Level Output Level 8dBm 0 16V None 6dBmV 14dBmV
7. the return 20dB test point Adjust the pad for a 20dB test point reading of 11dBmvV return input i Figure 3 OTPN 800CL Location of Internal Adjustments Return Transmitter Setup The specification for the return band transmitter RF input level is 57dBmV Hz measured at RF Out Port This value operated the system at the NPR threshold The unit has an adjustable attenuator in the return path A 20dB test point is included in the return path The single carrier equivalent of 57dBmV Hz is 9dBmvV per carrier The return pad must be adjusted to set the carrier to 9 dBmV actual after the attenuator With a test carrier present at the port 19dBmV max measure its level at the return 20dB test point Adjust the pad for a 20dB test point reading of 11dBmvV return input External Test Points The OTPN 800CL has three external test points The received Optical Power T P is calibrated at 1V per mW 1310 nm Measure with a high impedance voltmeter This test point is for monitoring purposes as well as initial setup Measure the optical power with a at the time of installation The reading at 1550nm may be off by 15 even assuming that the internal jumper has been changed The jumper is located inside the unit near the receive level T P as shown above The position closest to the test point is for 1310nm and the position farther from the test pointis for 1550nm The Forward T P is 20 dB from the receiver RF output If th
8. to do so may cause an overloaded or distorted picture The easiest way to lower the signal is to use an optical attenuator OT makes an easy to use attenuator called the OTOA 1000 This provides for an easy way of lowering the optical signal by wrapping the fiber tightly into the slot inside of it Every fiber is different some may require more wraps then others Generally one wrap around the largest of the three post will lower the optical signal by approximated 1 75 dB The two smaller post attenuate the signal more If the received power is too low but the correct power transmitter is being used please consult the following 1 Be sure all fiber connectors are clean using an approved fiber cleaner 2 Be sure the fiber connectors are all of the same type All OT units ship with either SC APC or FC APC style connectors These will be green in color You can NOT mix green and blue connectors as the end terminations are different This can also result in low signal or snowy picture 3 Broadband RF transmitters such as those made by OT require the use of SM fiber MM will not work Attempting to use MM fiber will result in low signal or snowy picture
9. wn sloping lower RF level of higher frequen cies 64 10 Ch B 24Ch 40 Ch 77 Ch Dig 627 50 48 46 8 7 6 5 2 1 0 1 Optical Input dBm Figure 2 Typical CNR vs Optical Input Level INTERNAL TEST POINTS and ADJUSTMENTS The OTPN 800CL receiver has two user adjustments inside the unit One is used to change the Forward Receive level test point calibration between 1310nm and 1550nm optical input ranges The other is to set the OMI of the return band transmitter if equipped this will be discussed later on The unit should not be operated for extended periods with the top cover removed This is because of RF ingress and contamination from dirt or other objects When replacing the top cover be sure to firmly tighten all thumbscrews RF ingress or oscillation can be caused by loose screws Figure 3 shows the locations of the internal adjustments The specification for the return band transmitter RF input level is 57dBmV Hz measured at OTPN 800CL RF Output Port This value operated the system at NPR threshold The OTPN 800CL has an adjustable attenuator in the return path There is a 20dB test point in the return path The single carrier equivalent of 57dBmV Hz is 9dBmV The return pad must be adjusted to set the carrier to 9dBmV actual after the attenuator With a test carrier present at the port 19dBmV max measure its level at
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