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AT8001 User Manual - Hitachi Kokusai Electric America, Ltd.

1. This is a three dimensional measurement representing the Power Density Z axis vs Frequency X axis vs Time Y axis The viewing angle can be rotate to any position Spectrogram Power Spectral Density dB Hz Time 9 ic l 0 3 6 9 Frequency MHz Figure 23 Spectrogram Measurement AT8001 Technical Manual August 2011 Spectrogram Contour That s the Spectrogram in the X Frequency Y Time view where the color gives the Power Density Spectrogram Contour Normalized Time 9 6 3 0 3 6 g Frequency MHz Figure 24 Spectrogram Contour Measurement AT8001 Technical Manual August 2011 Time Domain This measurement shows both input and feedback IF signals at the same time in a time domain The information bar will show two additional pieces of information e Error Shows the Mean Squared Error between the Input and Feedback signals Time Domain L Input Feedback Normalized Amplitude 35 40 45 50 Time ps Figure 25 Time Domain Measurement AT8001 Technical Manual August 2011 3 4 Calibration Every AT8001 unit presents a internal linear distortion on feedback path This distortion is compensated during linear pre correction However is not present at the mask filter It generates an error that may be avoided using the calibration process Set the output power do 0 dBm Make an external loop connect the RFoutput on After Filter Feedback Sampl
2. Communication Settings Automatic Pre Correction _ _ _ Port COMBE v Non Linear Pre Correction Software Version Linear Pre Correction Disconnect Hardware Version m Measurements Software _ Signal Measurements Successfully Connected Figure 4 AT8001 connected with all options enabled 3 1 Non Linear Pre Correction This is the process is used to compensate for the power amplifier non linearity in order to reduce the intermodulation at the output signal and thus improve PA efficiency With the automatic non linear digital pre correction the PA linearity is improved and extended so that the PA can be operated at higher power This means that a lower power lower cost linearized PA can be used in place of a higher power higher cost PA Furthermore the linearized PA operates more efficiently since it is operated closer to saturation The benefits are compounded because a lower power PA operating more efficiently consumes substantially less power than an inefficient higher power PA gt When the Non Linear Pre Correction screen is opened the software read and display the pre correction curves stored on the non volatile memory The Memory Effects Compensation checkbox is not going to be enabled if this option is not included AT8001 Technical Manual August 2011 Si Figure 5 shows the non linear pre correction main window Linear Industries Inc Automatic Non
3. Hit key v to view the last screen of this menu Password Setup 2 2 1B00 gt Disable password DIGITAL EXCITER AT8001 Technical Manual August 2011 The option Disable password if selected dispenses the use of password Press key ESC to return to Setup Menu and hit key v to view the next screen 6 12 Restore Web Password to Default Setup 12 18 1000 gt Restore web Password to Default DIGITAL EXCITER Select Restore Web Password to default and press ENTER The screen below will appear WARNING You are about to restore web password default Continue lt 4 No DIGITAL EXCITER To access the Restore Web Password to default screen select Yes by using the keys lt or gt Restore web Password to Default 1C00 Default web Password Restored DIGITAL EXCITER Press key ESC to return to Setup Menu and hit key v to view the next screen 6 13 time and date configuration Setup 13 18 1000 gt Time and Date Setup DIGITAL EXCITER Select time and Date Setup and press ENTER AT8001 Technical Manual August 2011 Time and Date Setup 1 1 1D00 Time 10 45 Date 26 04 11 MM DD YY DIGITAL EXCITER To program the date and time use the or w keys To change between the parameters press the lt or gt keys Press key ESC to return to Setup Menu and hit key v to view the next screen 6 14 Alarms Mask Setup 14 18 1000 g
4. If the equipment and or packing has signs of damage that is suspected to have happened during transport evidence of such must be immediately written down on appropriate documentation provided by the delivery or transportation service and Linear Industries Inc must be notified at the earliest possible time Failure to do so may possibly void any warranty The unit has been tested thoroughly in the Linear Industries Inc factory to make sure of no defects and to ensure the unit is functioning according to its intended specification and mode of operation However if the equipment when placed into operation does not function and has no evidence of transportation damage the unit must be returned to Linear Industries Inc factory with an explanation of the defect and given attention to the department of technical assistance Protection against risk of electric shock e As with all equipment fed with the electrical current the risk of electric shock may arise To prevent electric shock please take the following precautions e Any maintenance on this equipment must only be carried out by a fully technician e Inthe event that the cover is removed do not touch any area or region near where an AC mains enters the unit The AC input is located near the ON OFF switch and transformer etc e Switch off the main and disconnect the AC cord before changing the AC input mains fuse e Use only the correct fuse i e exactly the same type and value of the fuse
5. o oF N 6 4 2 D 2 4 6 Real Part Figure 16 Constellation Measurement AT8001 Technical Manual August 2011 Constellation Contour the constellation is a diagram of the sampled baseband modulating symbols where the Cartesian plan is plotted by its real vs imaginary part The real part In Phase of those sampled symbols carry the transmitted information while the imaginary part Quadrature carry the necessary information to generate the vestigial side band For 8VSB modulation the eight regions represents the eight possible symbols and the seven dashed lines indicates the decision threshold The Constellation Contour differs from the Constellation in the sense it shows probability regions for a demodulated symbol to fall in coded in colors A red area means high probability as the blue area means low probability This measurement reflects the signal quality Use it to realize non linear linear and amplitude distortions The information bar will show the additional information e MER Modulation Error Rate It is the mean squared error in dB considering the perfect symbol as the reference signal Constellation Contour Imaginary Part Real Part Figure 17 Constellation Contour AT8001 Technical Manual August 2011 Eye Diagram The Eye Diagram is the purely real modulating symbols filtered with a raised cosine filter and persisted with a symbol period multiple The open eyes points indicate
6. superior lateral band Both amplitude adjustments are set in dB and both phase adjustments are set in degrees Setup 03 18 1000 gt Image Frequency Suppression DIGITAL EXCITER Starting at the setup menu screen 1000 Select Image Frequency Suppression and press ENTER The screen below will appear warning Changing these parameters may damage the equipment Continue No gt DIGITAL EXCITER ATTENTION When accessing this screen by selecting option YES the operator will be responsible for the changes done on this parameter as well as the effects that these changes may cause in the equipment if not using the appropriate instruments and test point To access the screen Image Frequency Suppression select YES using the keys lt or gt Image Frequency Suppression 1 4 1300 gt I Amplitude 0 000 dB DIGITAL EXCITER To program the values use keys lt and gt To change between the parameters AT8001 Technical Manual August 2011 use keys amp or v Image Frequency Suppression 2 4 1300 gt Q Amplitude 0 000 dB DIGITAL EXCITER To program the values use keys lt and gt mag e Suppression 3 4 1300 gt Phase 0 00 DIGITAL EXCITER To program the values use keys lt and gt Image He Suppression 4 4 1300 gt Q Phase 0 00 DIGITAL EXCITER To program the values use keys lt and gt Press ESC to return to the S
7. to the Main Menu screen and then to the screen 2000 is reached as below Measurements 10 10 2000 gt Communication Status DIGITAL EXCITER Select Communication Status and press ENTER Drawers Communication Status 1 1 2A00 gt POLE P02 P03 DIGITAL EXCITER Press the ESC key to return to the Main Menu 5 The alarm system An alarm is indicated by one of the 3 red LEDs located on the front panel of the digital exciter The first LED alarm is for transport stream TS absence SYNC LOSS The next LED alarm is for a current malfunction present on the equipment and requires investigation see CURRENT ALARM The third LED indicates a past alarm see PAST ALARM This situation that past alarm is no longer present On normal operation just a green LED is ON which confirms that the AC input power is present Once a CURRENT ALARM LED is ON the origin of the alarm should be investigated From the Main Menu screen access the System Alarms Log Main Menu 3 5 0000 gt System Alarms Log DIGITAL EXCITER Access System Alarms Log AT8001 Technical Manual August 2011 System Alarms Log 1 4 3000 gt Current Alarms DIGITAL EXCITER Select Current Alarms and press ENTER Current Alarms 1 5 3100 gt Sync Loss TS 1 DIGITAL EXCITER e Hit key w to view the other current alarms e The Alarm List Empty means the alarm is no longer present Press ESC to re
8. Correction Non linearity is present when the AM AM and AM PM transfer functions are not straight lines i e when the DUT Device Under Test has not a constant gain and a constant output phase delay with respect to the input amplitude When such distortions don t change with time they re called memoryless non linearity or static non linearity It means the output signal at the present moment depends only on the input signal at the present moment also However some amplifiers present a dynamic behavior Their AM AM and AM PM behavior change with time in a short time range nano micro seconds It happens because the output signal at the present moment doesn t depend on the input signal at the present moment only but also on its previous values It generates more distortion and a memoryless pre corrector is not able to compensate for these memory effects This pre correction is an automatic procedure It uses a signal taken from a feedback sample located between the power amplifier output and the mask filter input Perform the following steps to run the pre correction 1 Connect the AT8001 RF output to the amplifier to be linearized If an output filter is used run the algorithm with the filter connected to the amplifier because the reflected signal coming from the filter may change the amplifier behavior Set the desired power 3 Take the Before Filter Feedback Sample and make sure is connected the AT8001 rear panel before running the
9. F Linearization ON and OFF Non Linear Pre Correction It is possible to confirm and to switch off the non linear pre correction from the front panel When using the GUI7001 software it is important to confirm that this parameter is operative in order that the linearization of the transmitter amplifiers can take place Linear Pre Correction It is possible to confirm and to switch off the linear pre correction AT8001 Technical Manual August 2011 from the front panel When using the GUI7001 software it is important to confirm that this parameter is operative in order that the linearization to compensate for the output RF Mask filter can take place 2 9 Communication A Via Ethernet The exciter driver includes an Ethernet connection on the rear panel allowing access to its Ethernet Web page The web page contains all the functionalities of the interface keyboard and display such as SETUP s MEASUREMENTS and ALARMS etc This interface can be used for remote management B Via Exciter Driver USB port Communication to the exciter driver via the USB port is only possible utilizing the GIU7001 software system For more details on this configuration consult annex A Operational Software 3 Alarms The table below provides the respective steps to be taken when an alarm occurs and how to cancel or normalize any alarms AT8001 Technical Manual August 2011 ol Linear Industries Inc AT8001 User Manual Sectio
10. Linear Pre Correction Pre Correction Properties y C Enable Correction Amplitude Trigger 0 100 4 Automatic Algorithm V Memory Effects Compensation Run 4 Control Phase 0 4 0 5 0 6 Normalized Amplitude 1 Turn on non linear pre correction at front panel 2 Connect the feedback sample at Before Filter 10 0 dBm Figure 5 Non Linear Pre Correction Window mn ee at Reset Download linear LUTs Look Up Tables Used to bypass the corrections Enable Non Linear Pre Correction Used to bypass the corrections or not without downloading linear LUTs Amplitude Trigger Adjust the amount of peak power used to trigger the signal capture Run Single iteration algorithm to compensate for non linear distortions Memory Effects Compensation Check this box to compensate for memory non linear distortions Uncheck to compesante for memoryless distortions only Save Push this button to save the result on the non volatile memory Back Close current window AM AM Figure that shows the AM AM behavior for the pre correction AM PM Figure that shows the AM PM behavior for the pre correction DUT If the Memory Non Linear Pre Correction option is enabled two PA memory models may be selected Type A and Type B try both to compare which one fits better AT8001 Technical Manual August 2011 Memoryless vs Memory Pre
11. and press ENTER to check past alarms Drawer 4 01 01 Past Alarms 1 1 3420 Alarm List Empty DIGITAL EXCITER Use the keys 4 lt or 2 gt to select one among many RF power drawers AT8001 Technical Manual August 2011 5 6 Setup The SETUP screens permits for selection and changes on the configuration and operational parameters The menu below profiles the possible operations under SETUP Items on the SETUP menu Description Power Setup Program the RF output power level Frequency Setup Program the RF UHF Channel of the transmitter Image Frequency Suppression and Q unbalance correction in order to reject the image frequency at the mixer output TX Balance eliminated the image frequencies band LO Leakage Suppression Reduces the LO undesirable spurious Pre Correction Enable and Disable the pre correction circuitry Crest Factor Reduction Configure Crest Factor parameters to reduce the Peak to Average Power Ratio in order to improve inter modulation on PA output at the expense of MER degradation Modulation Settings Turn ON and turn OFF the modulation NASC pilot level configurnaion Programa o do nivel da piloto entre 2 048 511 Transmitter Setup Turn ON and turn OFF the ALC Automatic Level Control Mute the or not the RF power output on the event of absence of Transport Stream Select local or remote the transmitter output leve
12. characteristic is caused by noise and memory effects The red line is the Memoryless Transfer Function that best fits the blue points This is a powerful tool to evaluate a power amplifier transfer function and thus its linearity Check how spread the blue points are in order to realize how much memory effects the amplifier has Always perform this measurement using Feedback Before Filter sample The information bar will show the additional information e Peak to peak amplitude distortion Shows the Memoryless Transfer Function peak to peak value AM AM Instantaneous Transfer Function Memoryless Transfer Function Gain dB 30 25 20 15 10 5 0 Normalized Power dBFS Figure 13 AM AM Measurement AT8001 Technical Manual August 2011 AM PM AM PM stands for Amplitude Modulation Phase Modulation it represents the phase deviation in vs normalized input amplitude in dB Full Scale The blue points show the Instantaneous Transfer Function as it has a dynamic behavior Their spread characteristic is caused by noise and memory effects The red line is the Memoryless Transfer Function that best fits the blue points This is a powerful tool to evaluate a power amplifier transfer function and thus its linearity Check how spread the blue points are in order to realize how much memory effects the amplifier has Always perform this measurement using Feedback Before Filter sample The information bar will sh
13. level AT8001 Technical Manual August 2011 8 It is a good idea at this time to record all measurements before and after filter sample feedback This can be done via the file function on the measurements page or simply by pressing Print Screen on the PC and saving to a third party software such as PowerPoint Excel or Word 9 Ensure the transmitter operates in a stable and safe condition for up to one hour before leaving the exciter system in operation on a permanent basis AT8001 Technical Manual August 2011 LINEAR Industries Inc 2531 Technology Dr Suite 310 Elgin IL 6012 USA SERVICE 1 847 428 5793 1 847 428 5785 service linear tv com SALES 410 750 2165 info linear tv com www linear tv com AT8001 Technical Manual August 2011
14. operation 2 Impedance of the sample ports must be 50 ohms 3 The RF level of the sample before and after the filter must be between 10dBm and 0dBm average level When the exciter driver RF output is connected correctly to the transmitter pre amplifier and the correct RF level samples before and after the output RF mask filter are connected to the applicable sample input ports the operator can then use the GUI7001 software optional to make linear and nonlinear pre corrections and the performance measurements AT8001 Technical Manual August 2011 Possible operations with the exciter driver Below are the possible operations of the exciter driver available when installed in a transmitter A Power adjustment POWER SETUP 1100 Power adjustment of the exciter driver which may alter the transmitter output power is possible and accessible through the POWER SETUP screen 1100 and accessed from the Main Menu for the Menu on the display digital Instructions are given in the annex Operational Software It is important to note that if the power of the transmitter is altered the modulation level and consequently the non linear distortion will change which will require the pre correction to be recalculated This can be done through the SCALE adjustment 1520 The recalculation of the correction must be done after all final power level changes For best results and the software GUI7001 optional for performance measuremen
15. pre correction gt The coupler used for the sample must be directional with isolation greater than 15 dB in order avoid miscalculation created by a reflected signal The coupling port must have 50 Q impedance in order to avoid a linear distortion in the feedback path Also the coupling port response must be as flat as 0 3 dB in a 30 MHz range The feedback sample level must be between 10 and 0 dBm You can use the Signal Measurements software to check if the feedback sample is present Press Reset to bypass the last correction Check or uncheck the Memory Effects Compensation checkbox lf Memory Effects Compensation is checked select between Type A or Type B at the DUT menu This option is not available if the memoryless pre correction is selected Memory Effects Compensation unchecked gt There differences between IOT and Solid State amplifiers regarding its memory non linearities As a rule of thumb Type A achieves better results for IOT amplifiers and Type B for Solid State 7 Click on Run The whole process consists of single iteration After a few seconds the results will be applied automatically Both algorithms works independently gt Crest Factor Reduction will be automatically bypassed when the algorithm is running AT8001 Technical Manual August 2011 8 Once the correction performed satisfied results click on Save push button to save the curves on the non volatile memory gt After running the algori
16. removed e Do not immerse the unit in water or operate in areas of very high humidity Care Please observe the standard and documented precautions for electrostatic sensitive devices Electrostatic discharges ESD can damage the electronic components It is strongly recommend working with this unit in a area with protection against electrostatic discharge For the place and location of the connectors please see internal layout diagram of equipment Input Mains The input mains voltage of the exciter driver is set at the factory it is not necessary to alter its configuration This equipment can be fed with a voltage of 90 240 VAC at a mains frequency of 41 63 Hz without interruption or damage to the equipment The exciter driver includes a standard three pin AC input The central pin is ground and is connected to the chassis of the assembly An external ground lug is also included for additional grounded recommended AT8001 Technical Manual August 2011 Power Switch 3 pins Connector Partial view of rear panel AC switch and mains entrance Handles and Connectors Handles should be installed with care in order that they do not get bent or twisted during installation If 7 8 or handles are use care must be taken not to damage during installation inside the cabinet or final installed location It is not recommended to try to install into a smaller space than 31 4 or 80cm No force should be applied to th
17. 0 018 DIGITAL EXCITER Configure the desired IP by using the keys lt or gt and a or w Press ESC to the Remote Access screen Hit key v to view the next screen 7 2 Mask Configuration Remote Access 2 3 4000 gt Subnetwork Mask DIGITAL EXCITER Select Sub network Mask and press ENTER Subnetwork Mask 1 1 4200 255 255 255 000 DIGITAL EXCITER AT8001 Technical Manual August 2011 Configure the Mask using the keys lt or gt and a or vw Press ESC to the Remote Access screen Hit key v to view the next screen 7 3 Gateway Configuration Remote Access 3 3 4000 gt Gateway DIGITAL EXCITER Access the Gateway and press ENTER Gateway 1 1 4300 192 168 100 001 DIGITAL EXCITER Configure the gateway address using lt or gt and a or vw 8 Options Main Menu 5 5 0000 gt Options DIGITAL EXCITER Select Options and press ENTER Options 1 4 5000 gt Serial Number DIGITAL EXCITER Select Serial Number and press ENTER Options 1 4 5000 Serial Number must be configured DIGITAL EXCITER Hit key v to view the next screen AT8001 Technical Manual August 2011 Options 2 4 5000 gt Options List DIGITAL EXCITER Select Option List and press ENTER Options List 1 9 5200 gt v Linear Pre Correction DIGITAL EXCITER Hit key v to view the other screens that are part of thi
18. 0 4 0 5 0 6 0 7 0 8 09 1 0 l 0 4 0 5 0 6 0 7 0 8 0 9 Normalized Amplitude Normalized Amplitude Figure 7a Memoryless curves Figure 7b Memory curves The memory curves Figure 7b are three dimensional plots where the color means amplitude in dB for AM AM and phase in for AM PM A distortion is present when horizontal parallel lines present different colors When Crest Factor Reduction is used intermodulation may be reduced However there is a trade off with three collateral effects e MER reduction e Frequency response distortion e Image frequency rejection AT8001 Technical Manual August 2011 Figure 8 represents typical results when Crest Factor Reduction is used Eh AC __ SENSE INT ALIGNAUTO 02 11 46 PM Jun 03 2009 Avg Type Log Pwr TRACE Input RF PNO Fast C Trig Free Run IFGain Low Atten 6 dB Center 563 00 MHz Span 20 00 MHz Res BW 30 kHz VBW 100 Hz Sweep 5 20 s 1001 pts Figure 8 Crest Factor Reduction 3 2 Linear Pre Correction This is the process is used to compensate for linear distortions for example not constant frequency response and group delay inside the channel A Mask Filter is used at a transmitter output to limit the signal bandwidth and comply with an emission mask The sharper it is the greater the group delay distortion A small amount of attenuation is also introduced at channel edges Linear pre correction is used to compensate for these eff
19. 43 100 order of magnitude 1500ppb Time Lock Time counter since achieved lock The voltage at the variable gain amplifier which Automate Teve ALC Vout controls the output power Control Sensor Vin The voltage at the average power detector output used to close the Automatic Level Control ALC loop Programmed Measure the Programmed Power Forward Measure the Reflected Power Power 7 Reflected Measure the Direct Power ALC Reference Voltage Measure the ALC control voltage 50V Power Supply drawer input power supply measurement 50V Power Supply Drawers 28V Driver Power Supply driver input power supply measurement 28V Current Measure the electrical current of the drawer modules Temperature Temperature measurements of the drawers Communication Status Drawers Communication Status Indicate the communication status among the RF drawers and the MASTER Control Unit To access the menu above see item 4 1 below AT8001 Technical Manual August 2011 ATTENTION ce For SFN operation it is mandatory feed the Exciter with an external reference signal locked on a GPS signal 4 1 Transport Stream related measurements To gather information about the status of the incoming transport stream follow the instructions below starting on the main menu screen Main Menu 2 5 0000 gt Measurements DIGITAL EXCITER Access Measurements Measurements 01 10 2000 gt Transport Stream DIGIT
20. 500 DIGITAL EXCITER Use the keys lt or gt to program the value Hit key v to view the next screen Clock Reference Setup 7 8 1100 gt PPBmin Cal 1500 DIGITAL EXCITER Use the keys lt or gt to program the value Hit key v to view the last screen of this menu Clock Reference Setup 8 8 1100 gt Zero PPB Cal 131072 DIGITAL EXCITER Use the keys lt or gt and or to program the value Press key ESC to return to Main Menu 7 Remote Management System Tele supervision All of the equipment parameters such as transmission power level power supply measurements alarm verification and all the possible functional selections may be accessed two different ways Frontal Panel Through the frontal panel all of the equipment measurements and configurations may be accessed as shown in the operation section Local or remote PC vi It is possible to change and or monitor all of the parameters and measurements as is done at the frontal panel through the WEB server AT8001 Technical Manual August 2011 To accomplish this it is necessary to configure the IP Mask Gateway 7 1 IP Configuration Start from the Main Menu Main Menu 4 5 0000 gt Remote Access DIGITAL EXCITER Select Remote Access and press ENTER Remote Access 1 3 4000 gt IP Address DIGITAL EXCITER Select IP Address and press ENTER IP Address 1 1 4100 192 168 10
21. AL EXCITER Select Transport Stream and hit ENTER Transport Stream Meas 1 4 2100 gt Transport Stream Sync Loss DIGITAL EXCITER Hit key v to view the other screens that are part of this menu Transport Stream Meas 2 4 2100 gt Data Packets Rate 0 00 Mbps DIGITAL EXCITER Transport Stream Meas 3 4 2100 gt Null Packets Rate 0 00 Mbps DIGITAL EXCITER AT8001 Technical Manual August 2011 Transport Stream Meas 4 4 2100 gt FIFO Ocupation 0 00 DIGITAL EXCITER Hit ESC key to return to the Measurements screen The use of the keys 4 e allows changes on the desired function to be performed 4 2 Status on the Exciter Power Supplies Out from the Measurements menu select Exciter Power Supply and hit ENTER Measurements 02 10 2000 gt Exciter Power Supply DIGITAL EXCITER Power Supply Measurements 1 3 2200 gt 3 3V OK 15V OK DIGITAL EXCITER e Use the Up and Down keys and to check the voltage status on the DTV exciter gt 5V OK 27V OK DIGITAL EXCITER Power Supply Measurements 2 3 122001 Power Supply Measurements 3 3 2200 gt 8V OK DIGITAL EXCITER Hit ESC key to return to the Measurements screen AT8001 Technical Manual August 2011 4 3 Software Version This screen indicates the time of the software and its version Three families of software are shown the FPGA software presen
22. AT8001 Technical Manual August 2011 This field displays NO SIGNAL or UNKOWN SIGNAL in the absence of a proper input signal When validated shows the frequency difference between a PPS generated with this reference and the current PPS obtained with the internal control system of the OCXO delivered on PPS output connector When this input is configured as current reference a message identifies if the OCXO is in the frequency or phase locking process and the phase difference is also available This field displays NO SIGNAL or UNKOWN SIGNAL in the absence of a proper input signal When validated shows the frequency difference Cur TS between a PPS generated with this reference and the current PPS obtained with the internal control system of the OCXO delivered on PPS output connector When this input is configured as current reference a message identifies if the OCXO is in the frequency or phase locking process and the phase difference is also available urrent value of the frequency control of the Cur Cal C t val f the f trol of the OCXO range comprehended between O 0 order of magnitude 1500ppb and 262143 100 order of magnitude 1500ppb ast calibrated value zero frequency difference an Last Cal Last calibrated value f diff d less then 100ns phase difference of the frequency control of the OCXO range comprehended between 0 0 order of magnitude 1500ppb and 2621
23. ATSC M H and hit ENTER SFN over ATSC M H 1 3 2500 gt Maximum Delay 0000 000 ms DIGITAL EXCITER Hit key v to view the other screens that are part of this menu SFN over ATSC M H 2 3 2500 gt STL Delay 0000 000 ms DIGITAL EXCITER SFN over ATSC M H 3 3 2500 gt Automatic Delay 0000 000 ms DIGITAL EXCITER AT8001 Technical Manual August 2011 4 6 Clock Measurements Measurements 06 10 2000 gt Clock Measurements DIGITAL EXCITER Select Clock Measurements and hit ENTER Clock Measurements 1 7 2600 gt Int GPS No Signal DIGITAL EXCITER Hit key v to view the other screens that are part of this menu Clock Measurements 4 7 2600 gt Cur TS No Signal DIGITAL EXCITER Clock Measurements 2 7 2600 gt Ext PPS No Signal DIGITAL EXCITER Clock Measurements 3 7 2600 gt Ext 10M No Signal DIGITAL EXCITER gt Cur Cal 000000 0 0 warm Up DIGITAL EXCITER Be Measurements 5 7 Ta AT8001 Technical Manual August 2011 Clock Measurements 6 7 2600 gt Last Cal 000000 0 0 DIGITAL EXCITER Clock Measurements 7 7 2600 gt Time Lock __d__h _m __ s DIGITAL EXCITER 4 7 Automatic Level Control Measurements 07 10 2000 gt Automatic Level Control DIGITAL EXCITER Select Automatic Level Control and hit ENTER Automatic Level Control 1 1 2700 gt ALC Vout 0 00 V Sens
24. DY BE UNDERSTOOD BY TRAINED OR EXPERIENCED PERSONNEL IN USING THIS OR OTHER TYPES OF ELECTRONIC EQUIPMENT THE INSTALLATION OPERATION AND MAINTENANCE OF THIS EQUIPMENT INVOLVE RISKS TO PERSONNEL AND ALSO TO THE EQUIPMENT LINEAR INC SHALL NOT BE RESPONSIBLE FOR INJURY OR DAMAGE THAT IS THE RESULT OF IMPROPER PROCEDURES OR USE BY PERSONS IMPROPERLY TRAINED OR LACKING THE KNOWLEDGE TO PERFORM ASSOCIATED TASKS ALL LOCAL CODES FOR BUILDING SAFETY FIRE OR RELATED STANDARDS MUST BE OBSERVED CONSULT LOCAL AUTHORITIES FOR THE STANDARDS FOR THE AREA OR REGION WHERE THE EQUIPMENT WILL BE INSTALLED AND PUT IN USE WARNING AT ALL TIMES DISCONNECT AC MAINS POWER BEFORE OPENING COVERS DOORS ENCLOSURES PANELS OR PROTECTIVE SHIELDS THAT EXPOSE LIVE CIRCUITS NEVER PERFORM MAINTENANCE MAKE ADJUSTMENTS OR SERVICE THE EQUIPMENT WHEN ALONE OR FATIGUED WARNING IF ELECTROLYTIC OR OIL FILLED CAPACITORS ARE UTILIZED IN THE EQUIPMENT AND THE COMPONENT APPEARS LEAKY OR IS BULGING OR IF THE CASE OR COVERING OF THE COMPONENT APPEARS DAMAGED OR DISTRESSED ALLOW SUFFICIENT TIME FOR THE UNIT TO COOL OR FULLY DISCHARGE BEFORE SERVICING SERVICING HOT OR LEAKY CAPACITORS CAN CAUSE A RUPTURE OF THE CASE AND POSSIBLE INJURY Returns and Exchanges Equipment Damaged or undamaged should not be returned unless written approval and a Merchandise Return Authorization MRA Number is received from your Linear Sales representative or Linear Customer
25. Frequency MHz READ THE USER MANUAL before performing this operation Figure 27 Calibration window Press Save on the Non Volatile Memory Panel Close the Calibration window Back to the measurement window measure the frequency response again Now with the compensation taking place a flat response will appear The calibration will take effect on Linear Precorrection and on measurements like Frequency Response Group Delay MER Constellation etc AT8001 Technical Manual August 2011 Sl Linear Industries Inc AT8001 User Manual Section 5 OEM Implementation Recommendation August 2011 4 OEM Implementation Recommendation Part 1 Test Bench set up 1 10 11 12 Ensure the correct version of MATLAB is installed Refer to LINEAR service department for details Ensure the correct GUI is available on the PC desktop Connect 50 ohm RF coax cable between Exciter RF output and Sample after filter input Connect USB cable provided between AT8001 and external PC not provided Switch on AT8001 and ensure the RF power output is turned to OdBm For navigation procedure see General operation in this manual Double click AT8001 GUIX XX software Establish communication link between PC and AT8001 and confirm by running signal measurements This is done by clicking on the Feedback after filter check circle selecting a measurement from the Measurements drop down box and clicking
26. Industries Customer Service Output Power Indication that the transmitter is gt Check the Power Meter and directional coupler supply Zero See Bi Mere So OUlpUt gt Verifiy control voltage at the PC board 15V Eqp Fail Failure on the 15V equipment power gt Check FUSE supply gt Check Module 12035 8V Eqp Fail Failure on the 8V equipment power gt Check FUSE gt Check Module 12035 Drawers Alarms Failure on the RF Power Drawer gt Via LCD check which RF Power Drawer listed is as the failure one Access Main Menu System Alarms Log Drawers Alarms AT8001 Technical Manual August 2011 5 1 Drawer Alarms While in the System Alarms Log screen it is possible to check and review all alarms current and past on the RF power drawer From the System Alarms log screen 3000 System Alarms Log 4 4 3000 gt Drawers Alarms DIGITAL EXCITER Select Drawers Alarms and ENTER Drawers Alarms gt Current Alarms DIGITAL EXCITER 1 2 ae Select Current Alarms and press ENTER to check current alarms Drawer 4 01 01 Current Alarms 1 1 3410 Alarm List Empty DIGITAL EXCITER Use the keys 4 lt or 2 gt to select one among many RF power drawers Press key ESC to return to the previous screen Drawers Alarms Drawers Alarms 2 2 3400 gt Past Alarms hold Enter to Clear DIGITAL EXCITER Select Past Alarms
27. Linear Industries Inc AT8001 User Manual For the AT8001 Digital Exciter umea DIGITAL EXCITER Rev A August 2011 Revision History REV DESCRIPTION DATE BY Initial Version 2011 1 08 Henry Douglas How to Contact Linear LINEAR INDUSTRIES INC NORTH AMERICA DIVISION 2531 Technology Drive Suite 310 Elgin IL 60124 Web site www linear tv com Phone 847 428 5793 Toll Free 847 428 5793 Fax 847 428 5785 gt Indicates a hint A Indicates important information AT8001 Technical Manual About this document August 2011 ol Table of Contents Section 1 User Notices and Warnings Section 2 General Introduction Section 3 General Operation Section 4 Graphical User Interface GUI Operation Section 5 OEM Implementation Recommendations AT8001 Technical Manual August 2011 Sl Linear Industries Inc AT8001 User Manual Section 1 User Notices and Warnings August 2011 Section 1 User Notices and WARNINGS USER NOTICES IT IS VERY IMPORTANT TO READ THE FOLLOWING MANUAL SECTIONS PRIOR TO OPERATION OF THIS EXCITER Notice 1 The exciter AC mains operating voltage setting is marked on the rear panel of the chassis Notice 2 For adjusting the RF output power setting a qualified technician should always employ the use of an RF Wattmeter and a calibrated dummy load Notice 3 Should accide
28. Service Special shipping instruction will be provided which will assure proper handling The circumstances and reasons for the return must be included in the request for return Equipment that is special or custom ordered may be not returnable In situations where return or exchange is at the request of the customer a restocking fee may be charged All returns must be sent freight prepaid and properly insured by customer When communicating with Linear please refer to your Order or Invoice Number Unpacking Use care when unpacking the equipment First perform a visual inspection of the AT8001 Technical Manual August 2011 item s to determine if any damage occurred during shipment Be sure to retain all the shipping materials crates and boxes or cartons until such time that it has been determined that the received equipment arrived undamaged Find all PACKING LISTS and keep them to assist in locating and identifying any components or assemblies that may have been removed for shipping and might need to be reinstalled in the equipment Make sure that all shipping traps supports and packing materials are completely removed from the equipment prior to initialization and use AT8001 Technical Manual August 2011 Sl Linear Industries Inc AT8001 User Manual Section 2 General Introduction August 2011 Section 2 General Introduction 1 Introduction The objective of this manual is to supply information necessar
29. Transmitter Setup DIGITAL EXCITER 08 18 cael Select Transmitter Setup and press ENTER Transmitter Setup 1 3 1800 gt Automatic Level Control On DIGITAL EXCITER AT8001 Technical Manual August 2011 Use the keys lt or gt to Enable or disable the ALC Hit key v to view the other screens that are part of this menu Transmitter Setup 2 3 1800 gt Mute on TS Loss On DIGITAL EXCITER Use the keys lt or gt to Enable or disable the Mute Transmitter Setup 3 3 1800 gt Output Level Control Local DIGITAL EXCITER Use the keys lt or gt to select the option Press key ESC to return to Setup Menu 6 9 ATSC M H Setup Setup 09 18 1000 gt ATSC M H Setup DIGITAL EXCITER Select ATSC M H Setup and press ENTER ATSC M H Setup 1 2 1900 gt Enable M H Mode No DIGITAL EXCITER Use the keys lt or gt to enable or disable the Mute Hit key w to view the next screen AT8001 Technical Manual August 2011 ATSC M H Setup 2 2 1900 gt MHE Packet Pid DIGITAL EXCITER Press key ESC to return to Setup Menu 6 10 SFN over ATSC M H Setup 10 18 1000 gt SFN over ATSC M H DIGITAL EXCITER Select SFN over ATSC M H and press ENTER SFN over ATSC M H 1 3 1A00 gt Enable SFN Mode No DIGITAL EXCITER Use the keys lt or gt to enable or disable SFN Mode Hit key v to view the next scre
30. UP Lock Check for mal function on the Converter UP Converter Fail Substitute the module Check for eventual cabling bad Clock Lock Lack of LOCK Clock contact Full analysis of the circuitry will be Fail modulator necessary Call Linear Industries Customer Service FIFO Overflow Full analysis of the circuitry FIFO Overflow will be necessary modulator Call Linear Industries Customer Service Tare PS failure 415V 8V Follow the basic procedure with 3 3V 427V i i voltmeter looking for some clear i 3 3V 27V or 5V evidence of mal function Replace the 5V i module if necessary AT8001 Technical Manual August 2011 transmission ALARM ALARM DESCRIPTION FOLLOWING ACTION MESSAGE FPGA Comm No communication with Full analysis of the circuitry will be necessary Fail the FPGA Call Linear Industries Customer Service Lack of external Check the associated connections Ext Ref Fail reference Call Linear Industries Customer signal Service Level or quality Error on the Check the BTS input BTS SEN TS Info SFN Check the 10MHz Reference and parameters 1PPS signal Error caused by Check if the max delay on the network power reduction still compatible with the system delay on the PATCH DELAY and OFFSET DELAY Fifo Underflow Self explanatory gt No local action Clock CXO Fail Self explanatory gt No local action R
31. a case the lightning can discharge enormous amounts of destructive electrical energy on the transmitter and it s peripheral equipment To protect the input of the equipment for such peak voltages sufficient grounding and isolation should be provided on the input mains and output RF connection When installing the grounding system the following should be observed I Connect all equipment chassis low resistance and appropriately sized ground wire Il Connect all the wires of the grounding system to one point and connect to the building ground point and to the outside ground system Ill Connect the incoming mains neutral to the grounding system at the point of the building ground IV Connect the RF output cable to the main building ground system V The structure of the tower must also be connected to the external grounding system AT8001 Technical Manual August 2011 VI Isolate cables from the lightning rods with porcelain or equivalent high voltage insulators Mechanical Drawings In this section the mechanical drawings will be presented showing the external structure of the unit Front Panel B CEE eee M umea ee Came _ E i ame Ss DIGITAL EXCITER s On the front display panel is located the display keyboard and signaling LED s Rear Panel The rear panel of the exciter includes the following elements 310M ASI OUT Electric interface DVB ASI C Function Sample of ASI signal Type Femal
32. able Document Format 7 Information Bar This bar shows additional information regarding the last measurement AT8001 Technical Manual August 2011 Amplitude Modulus Shows the normalized complex envelope modulus for the Input and a Feedback signal where J n Q m is the modulus for a complex signal with real part I n and imaginary part O n It is useful to evaluate the signal compression caused by the amplifier non linearity as it gets close to the saturation region Perform this measurement using the Feedback Before Filter sample Figure 12 shows a signal that has been compressed at the saturation level and expanded at the turn on region typical in class AB amplifiers The information bar will show two additional important pieces of information e Error Shows the Mean Squared Error between the Input and Feedback signals e Peak Compression shows in dB how much the maximum peak found was compressed Amplitude Modulus 0 6 Input Feedback 0 5 D a o i Normalized Amplitude 0 2 0 1 o 5 10 15 20 Time us Figure 12 Amplitude Modulus Measurement AT8001 Technical Manual August 2011 AM AM AM AM stands for Amplitude Modulation Amplitude Modulation it represents the normalized output input amplitude ratio amplifier gain in dB vs normalized input amplitude in dB Full Scale The blue points show the Instantaneous Transfer Function as it has a dynamic behavior Their spread
33. an amplifier is used run the non linear pre correction first and then the linear pre correction This will make linear calculation more accurate Make sure the After Filter Feedback Sample is connected the AT8001 rear panel before running the pre correction AT8001 Technical Manual August 2011 i gt The coupler used for the sample must be directional with an isolation greater than 15 dB in order avoid miscalculation created by a reflected signal The coupling port must have a 50 QO impedance in order to avoid a linear distortion in the feedback path Also the coupling port response must be as flat as 0 5 dB in a 30 MHz range The feedback sample level must be between 10 and 0 dBm You can use the Signal Measurements software to check if the feedback sample is present 4 Click on Run The whole process consists of single iteration After a few seconds the results will be applied automatically gt Crest Factor Reduction will be automatically bypassed when the algorithm is running 5 Once the correction achieves satisfying results click on Save push button to save the curves on the non volatile memory Figure 10 presents the corresponding curves used to compensate a mask filter Frequency Response Magnitude dB Frequency MHz Group Delay Group Delay ns Frequency MHz Figure 10 Typical Linear Pre Correction Curves AT8001 Technical Manual August 2011 Si
34. are is memory effect compensation that in some circumstances may improve the MER by up to 6dB or the shoulder level but by up to 3dB To implement memory effect compensation please follow the instructions below Memory effect correction procedure 1 After completing the above procedure correctly reduce the transmitter output power via the AT8001 front panel to 80 2 Inthe Linear Correction display un check the Enable Linear Pre correction box 3 Re measure the MER via the Eye Diagram measurement and the shoulder power levels via the Power Spectrum Density measurement and note the values 4 On the Non Linear Correction display check the Memory enable box and click Run Wait 10 15 seconds or until the process is complete The process will be complete when the AM AM and AM PM curves disappear and amplitude color bars appear A distortion is present when the horizontal parallel lines present different colors along the horizontal access 5 Re measure the MER and shoulder levels to see if there is any improvement If there is improvement then increase the power to 100 power level and re run all the corrections in the following order Non linear memory and linear correction 6 If there is no improvement in MER or shoulder level the un check the enable memory correction and repeat xxiv through xxxv again 7 The transmitter now should be corrected to obtain maximum performance in terms of a balance between MER and shoulder
35. arrier is of 18 833916 MHz All processing is compatible with ATSC A 53E standard The modulated and Q IF signal is passed from the 8VSB modulator to the RF UHF up converter which up converts the IF signal to the final UHF channel This up conversion occurs by multiplying the and Q signal with the local oscillator frequency which is generated by a PLL synthesized oscillator which in turn is referenced by an internal OCXO Oven Controlled Crystal Oscillator or via an external source The on channel RF UHF signal passes from the Up converter to a Linear amplifier The signal then is fed from the linear amplifier to the rear panel allowing it to be connected directly to the pre amplifier of any UHF TV transmitter All the management functions and controls of the exciter driver are accomplished through the through the front panel display and push buttons The AT8001 s main control unit receives information from all the main transmitter modules modulator up converter pre amplifier final power amplifiers reflectometer processes the information and allows through the keyboard push buttons and the digital display the complete control and operation of the equipment The control unit can process the information in such a way when installed in a transmitter that it makes it possible for the user the access readings like forward and reverse power voltage and current of PSU s transistor currents current and past alarms and some set u
36. culation created by a reflected signal The coupling port must have 50 O impedance in order to avoid a linear distortion in the feedback path Also the coupling port response must be as flat as 0 5 dB in a 30 MHz range The feedback sample level must be between 10 and 0 dBm 3 Connect a cable between the output of the 10dB attenuator at the AT8001 RF output and the input to the Transmitter intermediate power amplifier This should be the same port where the previous analog or digital exciter was connected If previous analog or digital exciter output was greater than analog 400mW output peak of sync or digital 100mW rms then an additional RF linear amplifier will be required This is an optional accessory that can be provided by LINEAR Industries 4 Ensure the exciter output is turned down to OdBm 1mW 5 Confirm that any intermediate drive power level adjustments are in the normal positions 6 If possible disenable any feed forward or pre correction circuits in the intermediate amplifier stages 7 Switch on the transmitter and check all meter readings are normal without RF being applied 8 Ensure the RF output power meter is reading lower than 10 of the required digital RF power output If the transmitter was previously calibrated for analog operation an external power meter not supplied that measures average power will be required at the output of the transmitter If the transmitter is reading above 10 power level switch off trans
37. d USB cable is connected between the exciter and PC E The exciter USB Port is located at the rear panel Run the executable file GUI8001vXXX exe located in the GUI8001 folder where XXX indicates the version The main screen will appear as follows AT8001 Technical Manual August 2011 Linear Industries Inc Graphic User Interface E Communication Settings Automatic Pre Correction Port Software Version Hardware Version Measurements Software Figure 2 GUI Software Main Window Choose the correct Serial Port number and Click on Connect If the communication is ok the information bar displays Successfully Connected and Hardware Version Text Box is updated gt The Serial Port number may vary between computers All features in this software are optional The prompt screen will show which options are included which are not AT8001 Technical Manual August 2011 et C WProjetosWigital_Exciter matlab GUIw4 00 GUI7001 v400 distrib GUI7001 400 exe Oo x E Linear pre correction INCLUDED Memoryless non linear pre correction INCLUDED Memory non linear pre correction INCLUDED ia Measurement software INCLUDED Crest Factor Reduction INCLUDED Succeeed Figure 3 Prompt Window If an option is included the corresponding button is enabled AT8001 Technical Manual August 2011 Linear Industries Inc Advanced Graphic User Interface
38. e Channel 01 Output Power 0 w 02 05 11 14 57 30 DIGITAL EXCITER While no other key is pressed these 2 presentation screens will be succeeding each other on the LCD After pressing any key on the keypad the next screen that appears is Main Menu 1 5 0000 gt Setup DIGITAL EXCITER Note It is always possible to return to the initial LCD screen by pressing the ESC key After 5 minutes the initial LCD screen menu is displayed AT8001 Technical Manual August 2011 5 4 Measurement System Table Measurements Menu Indications Measurements Sub Set Indications Description Transport Stream Transport Stream Shows the INPUT transport stream protocol or none Data Packets Rate Measure the input Data Rate 0 19 39 Mbps Null Packets Rate Measure Nulls packages 0 19 39 Mbps FIFO Occupation 0 100 3 3V 3 3V voltage power supply measurement 415V 15V voltage power supply measurement Exciter Power Supply Voltage 45V 5V voltage power supply measurement 427V 27V voltage power supply measurement 48V 8V voltage power supply measurement uController Microcontroller Software Version Software Version FPGA FPGA Software Version Drawer Drawer Power Software Version ATS MIH Service Present Indicates whenever the incoming transport stream contains the M H structure with the MHE packets PID equal to the exciter co
39. e BNC 10MHz REF OUT Function 10MHz output reference Type BNC female 310M ASI IN DVB ASIl electrical interface Function Transport Stream TS Input Type BNC female Impedance 75Q 10MHz REF IN Function 10MHz input reference Type BNC female Impedance 50Q RF SAMPLE OUT Function RF output sample Type N female Impedance 50Q RF OUT Function RF output signal Type N female Impedance 50Q AFTER FILTER SAMPLE Function RF input sample taken from after output RF mask filter Used to make the linear pre correction Type N female AT8001 Technical Manual August 2011 Impedance 509 Level 10 OdBm BEFORE FILTER SAMPLE Function RF input sample taken from before output RF mask filter Used to make the Non linear pre correction Type N female Impedance 50Q Level 10 OdBm Ventilation Output Input mains disconnect 3 Pin AC mains input Ground lug RF output amplifier heat sink ventilation output USB USB connection ETHERNET Ethernet for remote control optional CONTROL I O Input and output control Installing Exciter Driver into a transmitter For more information see OEM implementation recommendation Section For the installation of the exciter driver into a transmitter the following conditions are necessary 1 Two samples of feedback before and after the filter The amplitude frequency response should have less than 1dB of ripple within 15MHz of the channel of
40. e correction will act over the ATSC signal on the modulator Press key ESC to return to Setup Menu 6 6 Crest Factor Reduction Setup i gt Crest Factor Reduction DIGITAL EXCITER 06 18 cake The screen below will appear Warning Changing these parameters may damage the equipment Continue lt No gt DIGITAL EXCITER ATTENTION When accessing this screen by selecting option YES the operator will be responsible for the changes done on this parameter as well as the effects that these changes may cause in the equipment if not using the appropriate instruments and test point To access the Crest Factor Reduction screen select Yes by using the keys lt or gt Crest Factor Reduction 1 3 1600 gt CFR status Bypass DIGITAL EXCITER AT8001 Technical Manual August 2011 Use the keys lt or gt to configure the option and hit key wY to view the next screen Crest Factor Reduction 2 3 1600 gt Reduction 0 00 dB I Max MER DIGITAL EXCITER Use the keys lt or gt to adjust the value and hit key Y to view the next screen Crest Factor Reduction 3 3 1600 gt Factor 100 I 45 9 dB DIGITAL EXCITER Use the keys lt or to adjust the value Press key ESC to return to Setup Menu 6 7 Modulation Settings On this screen option it s possible to turn the modulation process on and off It is also possible to adju
41. e handles or input and output connectors The installation of this unit should be done in such away to ensure that if any liquid drains on the unit it immediately drains to the side and does not enter into the unit Any connectors must be installed and mounted in accordance with the manufacturers specifications The completed connections inside any cabinet must be isolated with from one another particularly those of containing RF to those not containing RF All cables used on this unit must be of professional quality Isolation between cables should not be made with silicone coating as this has been found to dry up rubber coatings of other cables and fittings Lightning protection of the equipment Grounding should be made through a separate and specific cable and terminated correctly at both ends The ground is labeled GND on the exciter driver unit As TV transmitter sites are normally located on higher altitude points such as mountains hills and tall buildings there is a higher incidence probability of static and electrical discharge from lightning Lightening discharges typically carry large amounts of electric energy and place enormous risk on the safety of personnel as well as the equipment Most lightening is conducted through the tower and guy structure of the antenna and the likelinood of damage to the equipment is increased because the tower structure is located nearby the transmitter building To minimize the effect of the lightning a
42. e in Bypass the Non Linear and Linear Pre Corrections Pe OS Open the Signal Measurements window and Measure Frequency Response between Input and Feedback After Filter The result is going to be the internal linear distortion to be calibrated Measurement Software E Frequency Response f Signal Selection T T T T T Input E E dese pedsasuessenssthessatssucsuereses Feedback Before Fitter Feedback After Fiter Measurements i Persist i i Frequency Response v a o i 3 i S S i i D i i E E PASS Shae Sensestes i a E E eeeenen eens eee feaneeecneceeeeee nee ee Measure r E E EE fon seacnnecnccnens bec ncennenneneenebacnscnsecncenes 1 1 li li 3 2 1 0 1 2 3 Frequency MHz Peak to peak frequency response distortion 0 78 dB Figure 26 Internal feedback linear distortion 5 At the main screen click on Advanced and the on Calibration The Calibration window will open 6 Press Run the calculate the distortion The inverse response will appear compared to the last Frequency Response measurement Next Figure shows the results AT8001 Technical Manual August 2011 Feedback Path Calibration E Frequency Response Calibration T T T T Run Magnitude dB 3 2 1 0 1 2 3 Frequency MHz Group Delay 5 l T T 7 w gt 2 a Non Volatile Memory a 3 j Save i i i i i i 3 2 1 a 1 2 3
43. ects gt When the Linear Pre Correction screen is opened the software read and display the pre correction curves stored on the non volatile memory The next figure shows the linear pre correction main window AT8001 Technical Manual August 2011 Linear Industries Inc Ee Automatic Linear Pre Correction m Pre Correction Properties Frequency Response T 2 Enable Pre Correction 6 Magnitude dB Automatic Algorithm 8 i Run Group Delay T Control Group Delay ns Figure 9 Linear Pre Correction Window TORR ee a Reset Download an all pass filter Used to bypass the linear correction Enable Linear Pre Correction Used to bypass the linear correction or not without downloading an all pass filter Run Single iteration algorithm to compensate for linear distortions Save Button used to save the result on the non volatile memory Back Close current window Frequency Response Figure that shows the pre correction frequency response which is the inverse filter response Group Delay Figure that shows the pre correction group delay which is the opposite filter group delay This pre correction is an automatic procedure It uses a signal taken from a feedback sample located at the mask filter output Perform the following steps to run the pre correction Connect the AT8001 RF output to the DUT Set the nominal power If
44. emote Mute The transmitter output power was reduced to OW via remote action gt No local action AT8001 Technical Manual August 2011 System Alarms ALARM ALARM DESCRIPTION FOLLOWING ACTION MESSAGE gt Check the physical connection on the RS485 cabling These connections are located on the Exciter read panel green connector On the other end at the rear Ak leasto ne drawer isnot panel of the RF Power Drawers DB 9 Drawer Comm connector communicating with the Exciter gt Using the Hyper Terminal check the parameters on the RF Power Module gt Call Linear Industries Customer Service gt Check the presence of 208Vac on each RF Power Drawer Indication that the transmitter gt Check the IRUSH circuit and or the does not have enough RF interlock Too Few Drawers Power Drawers to operate at the minimum reduction power gt Check the physical connection on the level RS485 connector DB 9 These connections are located on the RF Power Drawer rear panel The cables connect the RF Power Drawer to the Exciter AT8001 Technical Manual August 2011 gt Call Linear Industries Customer Service Reduced Power Indication that the transmitter is not operating at the nominal power At least one RF Power Drawer is not contributing gt Check the physical connection on the RS485 cabling These connections are located on the Exci
45. en Use the keys lt or gt to select Manual or automatic Hit key v to view the last screen of this menu SFN over ATSC M H 2 3 1A00 gt SFN Delay Mode Manual DIGITAL EXCITER SFN over ATSC M H 3 3 1A00 gt Local Delay 000 0000 ms DIGITAL EXCITER To program the operator must use the amp or w keys To alternate the digits press the lt or P keys Press key ESC to return to Setup Menu AT8001 Technical Manual August 2011 6 11 Password Setup Once a password is composed by four numbers it will become the set password for the equipment Please be certain to capture and store your password in a safe place To access the password configuration screen the operator must follow the sequences below starting from the SETUP MENU Setup 11 18 1000 gt Password Setup DIGITAL EXCITER Access to the Password Setup and press Enter Password Setup 1 2 1800 gt Enable Choose new password DIGITAL EXCITER To Enable the password or set a new one select Enable Choose new password New Password 1 1 1B10 write new password 0000 DIGITAL EXCITER To set the password use the keys lt and gt keys to move the arrow head under each one of the 4 password positions The and w keys increase or decrease the numerical value of the each position Once a password is selected the screen will return to the main menu screen Press key ESC to return to Password Setup
46. ent gt Crest Factor Reduction will be automatically bypassed when this measurement is being performed AT8001 Technical Manual August 2011 Power Spectrum Density This is a spectral analysis using the Power Spectrum Density estimation of the IF signal The in band signal average power is normalized to be the 0 dB point The information bar will show the additional information e Shoulders attenuation 3 25 MHz shows the shoulder attenuation 3 25 MHz from channel center frequency relative to the in band average power with a 500 kHz equivalent resolution bandwidth Power Spectral Density Power frequency sample dB Hz Frequency MHz Figure 21 Power Spectrum Density Measurement AT8001 Technical Manual August 2011 Symbols This measurement represents the purely real demodulated symbols over time Figure 22 shows the demodulated symbols after a mask filter without linear pre corrections and then with Straight indicates a high MER signal The information bar will show the additional information e MER Modulation Error Rate It is the mean squared error in dB considering the perfect symbol as the reference signal sila Amplitude g A tr t so z 3 4 z Pg amp f y az as pig e lt 0 500 1000 1500 2000 2500 3000 3500 Symbol Number Figure 22 Symbols Measurement AT8001 Technical Manual August 2011 Spectrogram
47. etup Menu Setup 04 18 1000 gt LO Leakage Suppression DIGITAL EXCITER Select LO Leakage Suppression and press ENTER The screen below will appear warning Changing these parameters may damage the equipment Continue lt No gt DIGITAL EXCITER ATTENTION When accessing this screen by selecting option YES the operator will be responsible for the changes done on this parameter as well as the effects that these changes may cause in the equipment if not using the appropriate instruments and test point To access the LO Leakage Suppression screen select Yes by using the keys 4 or gt AT8001 Technical Manual August 2011 6 4 LO Adjustment LO Leakage Suppression Sets the DC voltage configuration of the signal leakage suppression adjustment system for the local oscillator of the Up Converter with the following range of values 60 mV to 60 mV Use the keys lt or to adjusts the value LO Leakage Suppression 1 2 1400 gt I offset 0 00 mv DIGITAL EXCITER Hit key v to view the next screen LO Leakage Suppression 2 2 1400 gt Q offset 0 00 mv DIGITAL EXCITER Through these screens it is possible to activate or de activate the linear and non linear pre correction ON activate the pre correction OFF de activate pre correction To access this screen start at the SETUP MENU screen 1000 Setup 05 18 1000 gt Pre Co
48. gital display Automatic linear and non linear pre correction PLL synthesized oscillator from a 10 MHz OCXO or by an external 10MHz reference for example GPS Highly linear and efficient and UHF transistorized power amplifier module Automatic Level Control of power ALC keeps the system power level constant Front panel error indication current and past alarms Low acoustic noise air ventilation system Part of the ADVANCED TV family of transmitters designed with all national and international standards taken into consideration Conforming to ITU and FCC and all other recognized international standards Chassis constructed to fit into standard 19 rack mount assemblies External supervision possible via optional Ethernet or Web server Compatible with ASI and SMPTE 310M inputs AT8001 Technical Manual August 2011 1 3 General Functional Description The Digital Exciter Driver provides 20dBm 100mW RF signal with level to drive transmitter pre amplifier system For the ATSC 8VSB transmission standard the exciter driver must receive a Transport Stream TS MPEG 2 of either SMPTE 310M or ASI The modulator automatically recognizes which of the two standards is being used The TS input identification is only accomplished via the signal input connector which is a female BNC located on the back panel of chassis This module generates two IF signals I In phase i and Q Quadrature The central frequency of the modulated c
49. gnal Measurements This software is used to perform measurements at the signals generated by the AT8001 Digital Exciter There are fourteen measurements avaiable Linear Industries Inc Measurement Software Signal Selection Input Feedback Before Filter Feedback After Filter r Measurements Amplitude Modulus O Concatenate Control 4 3 Measure Figure 11 Signal Measurements Window 1 Signal Selection Select which signal is going to be measured Input is the signal at the DUT input or the modulator output The Input signal is always the reference Both feedback samples are also available Some measurements allow just one signal selection In order to make a comparison others allow two signals at the same time 2 Measurements This pop up menu shows all fourteen measurements available For each measurement there is an additional option like Concatenate Persist or Average the consecutive measurements Measure Push Button Click once to start measuring Click again to stop Back Close current window Measurement Window This Figure shows the last active measurement ou fF w File gt Export Use this option to export the measurement to one of the following formats e emf gt Enhanced Metafile e eps gt Encapsulated Postscript e jpeg gt Joint Photographic Experts Group AT8001 Technical Manual August 2011 e pdf gt Port
50. has compressed or clipped a signal The information bar will show the additional information e PAPR Stands for Peak to Average Power Ratio and represents the ratio between the maximum peak power found and the average power Shown for both Input and Feedback signals Complementary Cumulative Distribution Function Probability Instantaneous Power Average Power Ratio dB Figure 15 CCDF Measurement AT8001 Technical Manual August 2011 Constellation the constellation is a diagram of the sampled baseband modulating symbols where the Cartesian plane is plotted by its real vs imaginary part The real part In Phase of those sampled symbols carry the transmitted information while the imaginary part Quadrature carry the necessary information to generate the vestigial side band For 8VSB modulation the eight regions represents the eight possible symbols and the seven dashed lines indicates the decision threshold This measurement reflects the signal quality Use it to realize non linear linear and amplitude distortions The information bar will show the additional information e MER Modulation Error Rate It is the mean squared error in dB considering the perfect symbol as the reference signal Constellation AAP u 7 o e e Pyrat A Apoy w ey 1 n ot eat seg EAK 09 Shey Imaginary Part ot V A ARAL OE SRY Te EWS Gees ae o
51. l control ATSC M H Setup AT8001 Technical Manual Enable or disable M H mode and configure MHE M H Encapsulated packets PID This feature is an option August 2011 SFN over ATSC M H Enable or disable SFN over M H mode and configure static delays This feature is an option Password Setup Password configuration Restore Web Password to Default Reset web page user time and password to default values User user Password linear Time and Date Setup Set time and date Alarms Mask Enable or disable conditions to generate alarms Selects one of three USB ports available on the 8001 USB Setup Device Rear Device Frontal PC software GUI8001 Host Frontal USB flash drive for software upgrade USB Host Access Setup With USB Host Frontal selected use this menu and follow further instructions to make a software upgrade Transport Stream Input Configure three parameters with respect to the 2 TS inputs TS input Selects with one is preferable Mode Automatic automatically switches in the case one fails Manual does not switch even if it fails Hold On hold the last input even if the preferable input stopped failing Off go back to the preferable input if has stopped failing Clock Reference Set the priority list for exciter time base reference User cal free running internal OCXO without a reference 50ppb Internal GPS p
52. lug the antenna cable at the rear panel External 10 MHz External 1PPS Incoming TS this mode is useful for M H since pre processor and post processor must be in the same time base AT8001 Technical Manual August 2011 6 1 Power Setup This section commands the software to set the transmission power of the equipment Starting from the Main Menu Main Menu 1 5 0000 gt Setup DIGITAL EXCITER Select Setup and press ENTER Setup 01 18 1000 gt Power Setup DIGITAL EXCITER Select Power Setup and press ENTER Power Setup 1 1 1100 Program 000 w Output 0 w DIGITAL EXCITER To reach the desirable output power level press the key 2 to increase the power or 4 lt to decrease the power Once the desirable power level is adjusted press ENTER for software acknowledgement otherwise the change will not become effective 6 2 Frequency Setup The channel frequency change is a parameter that cannot be changed by the operator in the field It is factory adjusted only Starting at the setup menu screen 1000 Setup 02 18 1000 gt Frequency Setup DIGITAL EXCITER Select Frequency Setup and press ENTER AT8001 Technical Manual August 2011 Setup 02 18 1000 Factory Setup Only DIGITAL EXCITER 6 3 Image Frequency Suppression Allows the configuration of numeric values related to the amplitude and phase of the signal for the suppression of the image frequency
53. mitter and exciter and increase the attenuation at the output of the AT8001 to 20dB 9 Increase RF drive power level using front of AT8001 See technical manual for navigation procedure Adjust power level to 50 or required output power If insufficient drive level is available switch off transmitter and exciter and remove 10aB attenuator Ensure the RF drive power level is at zero and begin procedure again 10 Measure using the AT8001 measurement software Feedback before filter the following performance Eye Diagram MER should be better than 25dB Il Power spectrum density Average shoulder power at 3MHz relative to mask should be lower than 45cB Ill CCDF Difference in PAPR input to feedback should be less than 0 8dB IV AM AM peak to peak amplitude distortion should be less than 1 0dB V AM PM peak to peak phase distortion should be less than 2 0 degrees VI Constellation symbol plot should be very narrowly spaced with no curvature or difference in width VII Group Delay less than 50nS between 2 5MHz VIII Frequency Response less than 1dB between 2 5MHz AT8001 Technical Manual August 2011 11 Select on the Measurements software Feedback after filter and measure and select the Eye Diagram measurement again and check the MER MER should be better than 18dB If any of these measurements are significantly out of specification then it may not be possible to correct the transmitte
54. n 4 4 Moves the arrow to the next LEFT position 5 ENTER Confirms the chosen selection 6 ESC Cancel the selection and return to the previous screen 2 2 LCD Display To browse over the LCD screen follow the instructions below e Move the arrow up or Down to the item listed by pressing the A or W buttons Identification Main Menu gt Setup L onn DIGITAL EXCITER e Hit ENTER Remarks Please note that all screens are assigned a 4 digit number on the top right of the LCD screen These numbers represents the screen position on the command menu AT8001 Technical Manual August 2011 2 3 Signaling Besides the LCD screen and the command keypad the front panel of AT8001 also shows a set of 4 LED s These LED s when ON indicate POWER ON External AC line voltage is present SYNC LOSS The INPUT transport stream is not present CURRENT ALARM One or more alarm situations are occurring PAST ALARM Alarm log screen 3 Initialization The first screen that appears when powering ON the transmitter is Linear Industries Inc AT73 1K5 8VSB ATSC Digital Exciter DIGITAL EXCITER The First Presentation Screen shows the time of the manufactures and the model of the transmitter and the system it was set for For the sample screen above Model AT73 1K5 System 8VSB ATSC The Second presentation Screen as seen below shows the channel the current output power date and tim
55. n 3 General Operation August 2011 Section 3 General Operation 1 Introduction The DTV Exciter AT8001 provisions a Measurements b Configurations c Alarms and d Remote control via microcontrollers not applicable in standalone configurations Below is a detailed description about the operational software configuration and operation system installed within the AT8001 exciter IO On the front panel of the AT8001 Exciter there is a LCD Display with 2 lines and 40 columns Also a circular keypad with a set of 4 command keys in grey and one centered button labeled ENTER black an escape key ESC complete the set of 6 keys that allows an easy operator interaction umea DIGITAL EXCITER AT8001 Exciter Front Panel amp el wil The LCD display can be used to check the operational status of many parameters and make changes on some parameters using the 5 button keypad AT8001 Technical Manual August 2011 2 Digital Exciter The Master Control Unit DIGITAL EXCITER 2 1 Keypad Below the description of each key located on the front panel of the AT8001 Exciter The manipulation of these keys allows the operation to have access of the status and configuration of the transmitter 1 lt Moves the arrow UP to the next function shown on LCD screen 2 P Moves the arrow to the next RIGHT position 3 Y Moves the arrow DOWN to the next function shown on LCD scree
56. nd atmospheric discharges the use of a lightning protection system is strongly recommended Such lightning system should be in place to ensure the continuity of transmission during a lightning storm The phenomenon of lightning is basically that the electrical energy is conducted by the electrostatic induction AT8001 Technical Manual August 2011 between the earth and clouds therefore the most important part of the protection system should be a good grounding system made up of metal rods electrodes or an arrangement of wire mesh which should allow minimum ground resistance so that any electrical lightning discharge flows directly to the ground system rather than that of the building and equipment The key elements necessary for protection of equipment and personnel from lightning are Use current division to control the dissipation of lightning strike energy on an antenna tower grounding system through multiple paths Separate the antenna tower from the equipment building by a minimum of 30 feet Use only a single point grounding system for the equipment building Use a bulkhead panel waveguide hatch for all coaxial cable entry into the equipment building Coordinate the location of the 1 bulkhead panel bond 2 power and telecommunications entry bond 3 bond between antenna amp equipment building at the single point ground connection 6 Isolate all wire line communication services from remote ground with optical devices
57. nfiguration Total Number of Groups Shows the total number of Groups i e the number of M H Slots that contains M H Groups ATSC M H Service MH Slots With M H Groups One M H Sub frame have 16 M H Slots This measurement shows the location of each M H Group within an M H Sub frame E gt M H Group NOT present check symbol gt M H Group IS present Maximum Delay Maximum Delay set by the M H Mux Calculated STL delay based on the GPS 1PPS SFN over ATSC M H STL Delay signal Automatic Delay Automatic calculated Delay in order for all transmitters in the network have the same delay Int GPS This field displays NO SIGNAL or UNKOWN SIGNAL in the absence of a proper input signal When validated shows the PPS phase and frequency difference between this reference and the current PPS obtained with the internal control system of the OCXO delivered on PPS output connector When this input is identified as current reference a message identifies if the OCXO is in the frequency or phase locking process Clock Measurements Ext PPS This field displays NO SIGNAL or UNKOWN SIGNAL in the absence of a proper input signal When validated shows the PPS phase and frequency difference between this reference and the current PPS obtained with the internal control system of the OCXO delivered on PPS output connector When this input is configured as current reference a message identifies if the OCXO is in the frequency or phase locking process
58. nt or injury occur to the personnel engaged in the installation operation or service of the equipment should seek proper medical attention It is advisable that such personnel have familiarity with first aid practices Notice 4 To call our technical support center or for other customer service issues at Linear Inc refer to the following number 847 428 5793 or e mail to support linear tv com Notice 5 If you experience some specific difficulty and the technical information available in this manual is not enough to help you do not hesitate to call LINEAR technical support center Notice 6 The technical information presented on this manual is sole intellectual propriety of Linear Industries Inc Reproduction of this document in full or partial is prohibited with out prior written authorization from Linear Industries Inc This document is legally protected by US copyright laws WARNING THE VOLTAGES AND CURRENTS IN THIS EQUIPMENT COULD BE DANGEROUS PERSONEL MUST AT ALL TIMES OBSERVE SAFETY WARNINGS INSTRUCTIONS AND ANY REGULATIONS THIS OPERATION S MANUAL IS INTENDED AS A GENERAL GUIDE FOR TRAINED AND QUALIFIED PERSONNEL WHO ARE AWARE OF THE DANGERS THAT ARE INHERENT IN THE HANDLING AND OPERATION OF POTENTIALLY HAZARDOUS ELECTRICAL AND ELECTRONIC CIRCUITS IT AT8001 Technical Manual August 2011 IS NOT THE INTENT OF THIS MANUAL TO PROVIDE A COMPLETE SET OF SAFETY INSTRUCTIONS OR PRECAUTIONS THAT SHOULD ALREA
59. on the Measure icon in the bottom left corner Ideally check the Constellation or Eye Diagram measurements for confirmation of operation Ensure the calibration procedure is completed correctly as described previous section Go back to the Graphic User Interface display Select Non Linear Pre Correction and select Reset and Save Wait 10 15 seconds before attempting to move to the next window Go back to the Graphic User interface display Select Linear Pre Correction and select Reset and Save Wait 10 15 seconds before attempting to move to the next window You are now ready to connect the exciter to the transmitter Part 2 Transmitter set up 1 Connect a cable between the output of the RF Mask filter and the After Filter Feedback Sample The coupler used for the sample must be directional with isolation greater than 15 dB in order avoid miscalculation created by a reflected signal The coupling port must have 50 Q impedance in order to avoid a linear distortion in the feedback path Also the coupling port response must be as flat as 0 5 dB in a 30 MHz range The feedback sample level must be between 10 and 0 dBm AT8001 Technical Manual August 2011 2 Connect a cable between the input of the RF Mask filter and the Before Filter Feedback Sample The coupler used for the sample must be directional with isolation greater than 15 dB in order avoid miscal
60. or isolation transformers 7 Use AC power surge protection at main power entry and critical secondary panels IRN To accomplish the best grounding and provide the best protection of the transmission equipment it is important to consider the characteristics of the surrounding land It is recommended to determine the character of the soil specifically its resistance The resistance of a grounding system to should not exceed 5Q but the ideal value is obviously as close to zero as possible In general the best method of grounding can be accomplished with a single steel rod of approximately 2 73 yards or 2 5 meters placed in the ground nearby the transmitter building There maybe the case where the resistivity of the ground is too high in which case it is recommended that the complete grounding of the building and grounding system be studied in detail by a professional and authorized electrical grounding organization It is important to obtain the correct grounding system by using such methods as lightning rods and making sure they are completely isolated from the transmission equipment An incorrect grounding system may not sufficiently protect the transmission equipment and damage caused by static discharge or lightning will not be covered by the equipment guarantee Grounding of the electric Installation Lightning can enter the transmitter building via many routes including the transmission line via the antenna and or tower structure In such
61. or Vin 0 00 V DIGITAL EXCITER 4 8 Power Shows the programmed and direct reflected power measurements in the equipment output ALC Reference Voltage To access the Power screen the sequence of screens below must be followed starting from the initial menu Main Menu 2 5 0000 gt Measurements Measurements 08 10 2000 gt Power DIGITAL EXCITER Access Power and hit ENTER AT8001 Technical Manual August 2011 Transmitter Power Meas 1 3 2800 gt Programmed 000 w DIGITAL EXCITER Hit key wv to view the other screens that are part of this menu Transmitter Power Meas 2 3 2800 gt Forward O w Reflected 0 w DIGITAL EXCITER Transmitter Power Meas 3 3 2800 gt ALC Reference Voltage 0 00 v DIGITAL EXCITER Hit ESC key to return to the prior screen 4 9 RF Power Drawer Measurements For RF Power Module it is possible to measure a electrical current b RF delivery power c temperature Hit the ESC key to return to the measurements screen menu or return to the main menu screen and select measurements Measurements 09 10 2000 gt Drawers DIGITAL EXCITER Select Drawers and presses ENTER Drawer Measurements 1 3 2900 gt Power Supply DIGITAL EXCITER Select Power Supply and presses ENTER Drawer 401 01 Power 1 2 2910 gt 50V Power Supply 0 0 v DIGITAL EXCITER Hit key v to view the o
62. ow the additional information e Peak to peak amplitude distortion Shows the Memoryless Transfer Function peak to peak value Instantaneous Transfer Function Memoryless Transfer Function 10 beeeeeeeccseeeeee 3 pacestests Phase 30 25 20 15 10 5 0 Normalized Power dBFS Figure 14 AM PM Measurement AT8001 Technical Manual August 2011 CCDF CCDF stands for Complementary Cumulative Distribution Function It represents the probability vertical axis of the Instantaneous Power be x dB above the average power where x is the value in the horizontal axis For example suppose an amplifier is driving 1 kW into a dummy load and the Feedback Sample was taken from its output In the measurement below Figure 15 the O dB point has a probability around 40 It means 40 of time the Instantaneous power is above 1 kW or 0 dB and thus 60 of time the Instantaneous power is below the average power 1 kW Now another example the 6 dB point for the Feedback signal red dashed line has a probability of 0 07 It means that 99 93 of time the Instantaneous Power is below 4 kW 6 dB but for very few time or 0 07 of time the amplifier will drive a power above 4 kW It is clear that the amplifier compressed the high amplitudes because the red line is below the blue one Use this measurement to evaluate how much an amplifier
63. p and configurations such as adjustment of power and password etc although the majority of these configurations are carried fixed in the factory and do not have to be modified by the user In the case that it is necessity to alter some configuration of the equipment such as a channel change in the case of a LINEAR transmitter the technical department at Linear Industries Inc must be first consulted The exciter driver is available with optional software GUI7001 that will allow automatic daily pre correction of linear and non linear distortion as well as a series of transmitter signal measurements AC INPUT The AC input module 4573 used in the AT8001 exciter driver is a full wave bridge rectifier capable of input from 85 to 250VAC and is constructed using fly back plus buck regulator techniques The module 4573 is composed of two supplies CIP8455 CIM3555 providing 27V and AT8001 Technical Manual August 2011 15V and the second converter buck regulator CIP8390 CIM3584 with and input of 27V provides outputs of 15V 8V and 3 3V The module possesses fast output voltage surge protection and voltage metering information for the software VENTILATION SYSTEM The cooling of the exciter driver is provided by ventilated forced air through a venting system that encourages good interior air circulation The front and rear covers vents also assist in the cooling of the unit making it possible to direct output
64. peak group delay 20ns Conducted spurious and harmonics lt 60 dBc FCC 47 Part 74 Radiated spurious and harmonics lt 60dBc FCC 47 Part 74 August 2011 1 6 AT8001 100mW UHF ATSC 8VSB Exciter Technical Specifications Continued lmage Frequency Supression GENERAL Line input voltage OPTIONAL Line input frequency v External 10MHz reference input allows optional GPS Temperarture range measurement synchronization AC consumption Humidity range INCLUDED Dimensions inches v English manual Weight kg INPUTS Transport Stream Input ATSC MPEG2 compliant to SMPTE310M or ASI Transport Stream connector 752 BNC Transport Stream data rate 19 39Mbps SMPTE310M 270Mbps ASI External time base 10MHz 0 to 10dBm External time base connector 502 BNC Feedback sample level from 10dBm to 0dBm Feedback sample connector 50 N AT8001 Technical Manual 90 to 240Vac automatic selection 41 to 63Hz from 40 F to 90 F 55W from 0 to 80 3 5 H 19 W 20 D NET 6 6 August 2011 1 7 AT8001 Block Diagram August 2011 AT8001 Technical Manual 1 8 Picture 1 9 Identification MODEL SERIAL DATE FCC ID INPUT STANDARD OP stom rasi arse eves O POWER LINE VOLTAGE OUTPUT Cian oor zavod oH AT8001 Technical Manual August 2011 Initial inspection It is important to inspect all the packing and verify no visible damage to the equipment immediately upon receipt
65. r 2 Installation System Requirements for Windows Table 1 Minimum System Requirements Windows Server 2003 Service Pack 2 or R2 Windows Vista Service Pack 1 Windows Server 2008 Intel Celeron Intel Xeon Intel Core AMD Athlon 64 AMD Opteron AMD Sempron Operating Systems Processors Disk Space RAM Windows XP Intel Pentium 466 MB 1024 MB Pentium 4 and Service Pack 2 or 3 above 2048 MB recommended To install MCR perform the following steps 1 Install the MATLAB COMPONENT RUNTIME Execute the MCRinstaller exe file located in the MATLAB Component Runtime folder 2 Install the USB Driver Execute the CDM 2 04 06 exe file located in the USB Driver folder This is a Virtual COM Port driver Microsoft WHQL certified and compatible with the following operating systems e Windows Server 2008 e Windows Server 2008 x64 e Windows Vista e Windows Vista x64 e Windows XP e Windows XP x64 e Windows 2000 AT8001 Technical Manual August 2011 e Windows Server 2003 e Windows Server 2003 x64 mov a Preparing to Install MATLAB R Compiler Runtime 7 11 Setup is preparing the InstallShield Wizard which will guide you through the program setup process Please wait Extracting MATLAB R Compiler Runtime 7 11 msi Cancel Figure 1 MATLAB Component Runtime Installation Window 3 Operation Before running the software be certain that the AT8001 is on an
66. r for a performance that meets or exceeds the FCC recommendations for ATSC transmitter performance as delineated in ATSC document A65 B Go back to the Graphic User Interface display Il On the AT8001 front panel ensure the Non Linear Pre correction via the Set Up menu is set to ON Refer to AT8001 technical manual for navigation instructions Click on Non Linear Pre Correction Click on Run and view the bottom left hand screen to ensure the application is working Wait up to 15 seconds or until the processing is complete It is complete when the display of AM AM and AM PM curves significantly change shape from the previous straight line Ill Click on Save and wait 10 15 seconds until Save is complete IV Re check all the measurements as noted in xxii above Significant improvements should have been made in all performances Before Filter Feedback Sample V Go back to the Graphic User Interface display VI On the AT8001 front panel ensure the Linear Pre correction via the Set Up menu is set to ON Refer to AT8001 technical manual for navigation instructions On the GUI software click on Linear Pre correction Click on Run and view the bottom left hand screen to ensure the application is working Wait up to 15 seconds or until the processing is complete It is complete when the display of Frequency Response and Group Delay curves significantly change shape f
67. rom the previous straight line VII Click on Save and wait 10 15 seconds until Save is complete VIIl Re check the MER measurement using either the constellation or Eye Diagram and ensuring that the Feedback After Filter is selected Significant improvements should have been made on the SNR Typical performance should exceed 27dB IX Leave for 5 10 minutes to ensure the transmitter is operating safely and shows no signs of instability Then increase via the AT8001 front panel the RF drive power until the transmitter output power has reach 80 of the required output X Repeat xxii through xxxi Leave for 5 10 minutes to ensure the transmitter is operating safely and shows no signs of instability Then increase via the AT8001 AT8001 Technical Manual August 2011 front panel the RF drive power until the transmitter output power has reach 100 of the required output XI Repeat xxii through xxxi again XII Certain transmitter RF amplifier devices have an inherent non linearity that is caused by a memory effect i e the RF output amplitude is dependent on present and past input amplitude values This can be typically caused by bias coupling matching networks instantaneous variation on junction temperature and others system component variants XIII If the memory effect is significant it can cause non linearity that manifests in decreased the MER or increased RF shoulder level Included in the AT8001 GUI softw
68. rrection DIGITAL EXCITER Select Pre Correction and press ENTER The screen below will appear warning Changing these parameters may damage the equipment Continue No gt DIGITAL EXCITER AT8001 Technical Manual August 2011 ATTENTION When accessing this screen by selecting option YES the operator will be responsible for the changes done on this parameter as well as the effects that these changes may cause in the equipment if not using the appropriate instruments and test point To access the Pre Correction screen select Yes by using the keys or P Pre Correction Setup 1 2 1500 gt Linear DIGITAL EXCITER Select Linear and press ENTER Linear Pre Correction 1 1 1510 gt Linear Pre Correction On DIGITAL EXCITER Use the keys lt or gt to Enable or disable the Linear pre correction Press ESC to return to Pre correction Setup Pre Correction Setup gt Non Linear 2 2 ee DIGITAL EXCITER Select Non Linear and press ENTER Non Linear Pre Correction 1 2 1520 gt Non Linear Pre Correction On DIGITAL EXCITER AT8001 Technical Manual August 2011 Use the keys lt or gt to Enable or disable the Non Linear pre correction Hit key w to view the next screen Non Linear Pre Correction 2 2 1520 gt Scale 000 DIGITAL EXCITER The scale listed on the screen above is related with how intense the pr
69. s menu Options List 2 9 5200 gt Memoryless Non Line Pre Correction DIGITAL EXCITER Options List 3 9 5200 gt Memory Non Linear Pre Correction DIGITAL EXCITER Options List 4 9 5200 gt Measurement Software DIGITAL EXCITER Options List 5 9 5200 gt Crest Factor Reduction DIGITAL EXCITER Options List 6 9 5200 gt ATSC M H DIGITAL EXCITER Options List 7 9 5200 gt SFN over ATSC M H DIGITAL EXCITER Options List 8 9 5200 gt Scheduler DIGITAL EXCITER AT8001 Technical Manual August 2011 Options List gt Internal GPS DIGITAL EXCITER 9 9 asi Press ESC to return the Options screen Hit key v to view the next screen Options 3 4 5000 gt Enable Option DIGITAL EXCITER Select Enable Option and press ENTER Options 3 4 5000 Serial Number must be configured DIGITAL EXCITER Hit key v to view the next screen Options 4 4 5000 gt Time Limited Options DIGITAL EXCITER Select time Limited Options and press ENTER AT8001 Technical Manual August 2011 AT8001 User Manual Section 4 Graphical User Interface GUI August 2011 Section 3 Graphical User Interface GUI 1 Introduction GUI8001 is the software developed by Linear Industries Inc and is used to perform non linear and linear pre correction and signal measurements with the AT8001 ATSC 8VSB digital excite
70. s the exact moment for the receiver to sample and decide in order to extract the message Eyes wide open are desired This measurement reflects the signal quality Use it to realize non linear linear and amplitude distortions The information bar will show the additional information e MER Modulation Error Rate It is the mean squared error in dB considering the perfect symbol as the reference signal Eye Diagrarn Amplitude Symbol Figure 18 Eye Diagram Measurement AT8001 Technical Manual August 2011 Frequency Response This measurement will show the Frequency Response existent on your device under test typically a filter Use it to measure linear distortions The information bar will show the additional information e Peak to peak frequency response distortion self explained Frequency Response Magnitude dB 3 2 4 0 1 2 3 Frequency MHz Figure 19 Frequency Response Measurement gt Crest Factor Reduction will be automatically bypassed when this measurement is being performed AT8001 Technical Manual August 2011 Group Delay This measurement will show the Group Delay existent on your device under test typically a filter Use it to measure linear distortions The information bar will show the additional information e Peak to peak group delay distortion self explained Group Delay Group Delay ns Frequency MHz Figure 20 Group Delay Measurem
71. st the pilot level rating from 2048 to 511 Press ESC up to the SETUP MENU screen Setup 07 18 1000 gt Modulation Settings DIGITAL EXCITER Select Modulation Settings and press ENTER The screen below will appear warning Changing these parameters may damage the equipment Continue lt No gt DIGITAL EXCITER AT8001 Technical Manual August 2011 ATTENTION When accessing this screen by selecting option YES the operator will be responsible for the changes done on this parameter as well as the effects that these changes may cause in the equipment if not using the appropriate instruments and test point To access the Modulation Settings screen select Yes by using the keys lt or gt Use the keys lt or gt to Enable or disable the modulation Hit key v to view the next screen Modulation Settings gt Modulation On DIGITAL EXCITER 1 2 e Modulation Settings 2 2 1700 gt Pilot Level offset 0000 DIGITAL EXCITER Use the keys lt or gt to adjust the pilot level Press key ESC to return to Setup Menu 6 8 Transmitter Setup not applicable in standalone operation Under this menu it is possible to turn ON and turn OFF the ALC Automatic Level Control mute the or not the RF power output on the event of absence of Transport Stream and also select being local or remote the transmitter output level control Setup gt
72. t Alarms Mask DIGITAL EXCITER Select Alarms Mask and press ENTER Alarms Mask 1 1 1E00 gt Activate TS IN TS 1 TS2 DIGITAL EXCITER Use the keys lt or gt to select TS1 TS2 or TS1 TS2 Press key ESC to return to Setup Menu and hit key v to view the next screen 6 15 USB Setup Setup 15 18 1000 gt USB Setup DIGITAL EXCITER Select USB Setup and press ENTER USB Setup 1 1 1F00 gt Config USB Device Rear DIGITAL EXCITER Use the keys lt or gt to configure USB Press key ESC to return to Setup Menu and hit key AT8001 Technical Manual August 2011 w to view the next screen 6 16 USB Host Access Setup Setup 16 18 1000 gt USB Host Access Setup DIGITAL EXCITER Select USB Host Access Setup and press ENTER USB Host Access 1 1 1600 Activate Host Frontal Port at USB Setup DIGITAL EXCITER Press key ESC to return to Setup Menu and hit key to view the next screen 6 17 Transport Stream Input Setup 17 18 1000 gt Transport Stream Input DIGITAL EXCITER Select Transport Stream Input and press ENTER Transport Stream Input Setup 1 3 1H00 gt TS Switch Mode Manual DIGITAL EXCITER Use the keys lt or gt to configure automatic or manual Hit key v to view the next screen Transport Stream Input Setup 2 3 1H00 gt TS Switch Hold Off DIGITAL EXCITER Use the keys lt or gt
73. t on the ATSC modulator the Micro controller software on the digital exciter unit and the micro controllers unit installed on the RF Power Drawers All these times and version should be available to be report to the factory when necessary The sequence below indicates how to access the software version screen Measurements 03 10 2000 gt Software Version DIGITAL EXCITER Select Software Version and hit ENTER Software Version 1 3 2300 gt uController AT1A0002v1 00 DIGITAL EXCITER Hit key v to view the other screens that are part of this menu Software Version 2 3 2300 gt FPGA i DIGITAL EXCITER Software Version 3 3 2300 gt Drawer 401 01 No Answer DIGITAL EXCITER To return to the Measurements press ESC key 4 4 ATSC M H Service Measurements 04 10 2000 gt ATSC M H Service DIGITAL EXCITER Select ATSC M H Service and hit ENTER AT8001 Technical Manual August 2011 ATSC M H Service 1 4 2400 gt ATSC M H Service Present No DIGITAL EXCITER Hit key v to view the other screens that are part of this menu ATSC M H Service 2 4 2400 gt Total Number of Groups 00 DIGITAL EXCITER ATSC M H Service 3 4 2400 gt M H Slots with M H Groups DIGITAL EXCITER ATSC M H Service 4 4 2400 DIGITAL EXCITER 4 5 SFN over ATSC M H Measurements 05 10 2000 gt SFN over ATSC M H DIGITAL EXCITER Select SFN over
74. ter read panel green connector gt Call Linear Industries Customer Service Reflected Power Reflected power is present at the RF output of the transmitter gt Check other alarms status that can help for a better diagnostic gt Check the RF Power passives connections looking for overheating on potential bad contacts on the transmission line gt Call Linear Industries Customer Service Fan Failure 4 Fans Module failure gt Check the connection on this Module The correction action involved change of the damage single fan or change of the entire set Note The transmitter could temporarily operate under this condition This set of AT8001 Technical Manual August 2011 fans produce refrigeration for the reject loads on the power combiner circuitry which under normal operation does not need refrigeration Low Battery Battery Failure gt Check the wiring between the battery and the circuitry around gt Check if the Battery Charger is working Power Amp OFF The POWER ON OFF switch is set on the OFF position Green Switch locates on the bottom part of the front panel of the transmitter cabinet gt Check if the Green Switch POWER ON OFF Switch is OFF gt Check interlock gt Call Linear Industries Customer Service Phase Loss Main Breaker is disconnected gt Check Main Breaker OFF gt Call Linear
75. ther screen that is part of this menu Drawer 401 01 Power 2 2 2910 gt 28V Driver Power Supply 0 0 Vv DIGITAL EXCITER AT8001 Technical Manual August 2011 Press ESC to return to the Drawer Measurements screen Drawer Measurements 2 3 2900 gt Current DIGITAL EXCITER Select Current and press ENTER Drawer 401 01 Current 1 3 2920 gt I1 0 00 A I2 0 00 A DIGITAL EXCITER Hit key v to view the other screens that are part of this menu Drawer lt 4 01 01 Current 2 3 2920 gt I3 0 00 A I4 0 00 A DIGITAL EXCITER Drawer 401 01 Current 3 3 2920 gt ID 0 00 A DIGITAL EXCITER Press ESC to return to the Drawers Measurements screen Drawer Measurements 3 3 2900 gt Temperature DIGITAL EXCITER Select Temperature and press ENTER Drawer 401 01 Temperature 1 3 2930 oc T2 0 0 C gt T1 0 0 DIGITAL EXCITER Hit key v to view the other screens that are part of this menu gt T3 0 0 C T4 0 0 C DIGITAL EXCITER Drawer 401 01 Temperature 2 3 2930 AT8001 Technical Manual August 2011 Drawer 401 01 Temperature 3 3 2930 gt TD 0 0 C DIGITAL EXCITER 4 10 Communication among RF drawers From the LCD screen it is possible to conduct and view a diagnostic check of the communication link between the master control unit and the RF power amplifier drawer Press ESC
76. thm the presence of unbalanced shoulders means that there are memory effects left 9 If Crest Factor Reduction option is enabled make it active on AT8001 front panel and set a reduction level When the amplifier operates above the saturation level i e clipping the signal peaks the CFR may reduce intermodulation However be aware there is a trade off between intermodulation reduction and MER using CFR The more the reduction the worst the MER The next Figure shows typical results using the Memoryless and the Memory Pre Correction Usually the Memory correction achieves better results than the Mermoryless correction Center 563 MHz Span 28 MHz Res BH 3 kHz VBH 300 Hz Sweep 1 805 s 401 pts Figure 6 Memoryless vs Memory Comparison A There is no guarantee to achieve better results using the Memory Pre Correction It depends on the amplifier to be linearized AT8001 Technical Manual August 2011 Figure 7 presents the corresponding curves used to compensate for the non linearities of Figure 6 This curve holds the inverse DUT characteristic i e the necessary characteristic to compensate for the distortion AM AM y o oo Gain Normalized Memor i i i 0 1 0 2 g3 0 4 0 5 0 6 0 7 0 8 0 9 1 I I 0 4 0 5 0 6 Normalized Amplitude Normalized Amplitude AM PM AM PM o o Phase o gt ormalized Memory oD D N o N 5 05 i i i i i i 0 0 1 02 03
77. to select On or Off Hit key v to view the next screen Transport Stream Input Setup 3 3 1H00 gt TS Switch Sel TS 1 DIGITAL EXCITER AT8001 Technical Manual August 2011 Use the keys lt or gt to select TS 1 or TS 2 Press key ESC to return to Setup Menu and hit key v to view the next screen 6 18 Clock Reference Setup 18 18 1000 gt Clock Reference DIGITAL EXCITER Select Clock Reference and press ENTER Clock Reference Setup 1 8 1100 gt Ist Priority Current TS DIGITAL EXCITER Use the keys lt or gt to select Hit key v to view the next screen Clock Reference Setup 2 8 1100 gt 2nd Priority External PPS DIGITAL EXCITER Use the keys lt or gt to select Hit key v to view the next screen Clock Reference Setup 3 8 1100 gt 3rd Priority External 10M DIGITAL EXCITER Use the keys lt or gt to select Hit key v to view the next screen Clock Reference Setup 4 8 1100 gt 4th Priority Internal GPS DIGITAL EXCITER Use the keys lt or gt to select Hit key v to view the next screen AT8001 Technical Manual August 2011 Clock Reference Setup 5 8 1100 gt User Cal 131072 50 0 0000 PPB DIGITAL EXCITER Use the keys lt or gt to program the values Hit key v to view the next screen Clock Reference Setup 6 8 1100 gt PPBmax Cal 1
78. ts should be used Note that some transmitters may have an ALC around the pre amplifier or final amplifier or combination thereof which will disenable any power adjustment from the exciter B Pre correction of transmitter The corrections for linear and non linear distortion will have been tested and temporarily set up in the factory for typical operational characteristics When installed into a transmitter if there is significant change in the RF output characteristics of linear and nonlinear distortions thus affecting its frequency response group delay and levels of inter modulation is suggested to carry through a new process of pre correction of the transmitter This process can be made through optional GUI7001 Software Optional D SCALE adjustment This parameter adjusts the amount of non linear pre correction being a applied to the signal The inter modulation of the signal varies with the power output This scale adjustment can be used to optimize the levels of shoulder without the need to recalculate the pre correction curves using software GUI7001 optional The value of this adjustment must be proportionally reduced when the transmitter output power is reduced E Adjustment of the Pilot Level This adjustment allows for the configuration in the level desired ATSC signal pilot carrier level with the following band of values 2048 the 511 For more details on this configuration consult annex A Operational Software
79. turn to the System Alarms Log menu System Alarms Log 2 4 3000 gt Alarm Log DIGITAL EXCITER Access the Alarm Log and press ENTER e Hit key V to view all alarms current and past alarms Alarm Log Since 04 26 11 13 34 56 3200 gt 04 26 11 13 34 56 Too Few Drawers DIGITAL EXCITER The symbol is an indication that the alarm is current LED ON for alarms with date and time of its occurrence The symbol is an indication that any alarms are no longer present LED ON for past alarm LED OFF for current alarms and the date and time mark when it ceased to occur The alarm log keeps up to 100 registers The Clear Alarm Log if selected erases the alarm log registers and then registers the date and time when the alarms were erased The ATS tables following will show the possible alarms and the respective steps that are necessary at the moment the alarm occurs and the moment it is normalized AT8001 Technical Manual August 2011 Exciter alarms The table below shows all possible alarms generated on the Digital Exciter and the associated suggested action to cease its occurrence ALARM MESSAGE ALARM DESCRIPTION FOLLOWING ACTION Sync Loss TS 1 Lack of sync with the input transport screen Check for the presence of TS 1 on the rear BNC connector of the Exciter Further action if necessary check inside the exciter for malfunction LO Lack of LOCK
80. warm air directly into environment 1 5 AT8001 Module and parts location Rear panel 1 6 AT8001 100mW UHF ATSC 8VSB Exciter Technical Specifications FEATURES Control Interface 4x40 text LCD display and keyboard Ethemet Web Server v Performance 20dBm Shoulder Attenuation gt 63dB MER 237dB TS OUTPUT Transport Stream Output ATSC MPEG2 compliant to ASI Transport Stream connector 7 amp 2 BNC Transport Stream data rate OUTPUT Frequency Range 270Mbps ASI UHF Ch14 to Ch69 RF Output Power adjustable from 10dBm to 20dBm v Indicators RF output connector N Female Power Supply Status Modulation 8VSB All Digital Complex IF Input Transport Stream Satus modulation Current Past Alarms IF 18 833916MHz lt v Self cooling Channel Bandwidth 6MHz Jv IF Complex Modulation Test Signal PRBS Pseudo Random Bit sequence vy Automatic Linear and Non Linear corrections One shot algorithms Before after filter feedback samples ON OFF feature for both corrections independetly lt y Soft Start 10MHz OCXO Internal Reference v External 10MHz reference input x Power Supply of high efficiency and low noise _ASI SMPTE310M compatible y Front Panel adjustments LO Leackage Supression AT8001 Technical Manual Digital Analog Converter 16 bit Pilot frequency overall stability 0 3 ppm Peak to peak frequency response lt 0 2dB Peak to
81. y for the installation and operation of the digital exciter model AT8001 providing a digital UHF signal of 100mW rms LINEAR INDUSTRIES INCORPORATION recommends that the user carefully reads the sections of this manual before installing or operating this equipment 1 1 General Description Equipment AT8001 is an exciter driver providing a digital signal of 100mW rms UHF in the ATSC TV 8 VSB standard The model AT8001 is developed by LINEAR INDUSTRIES INCORPORATION and provides the most up to date and state of the art technology for transmission of digital TV signals The Model AT8001 is modular in construction and employs 100 digital technology and automatic nonlinear and linear pre correction An optional comprehensive performance and characteristic measurement software system can also be included The system of intelligent digital control using microprocessors allows the supervision in real time of all the functions of the exciter driver Its operation is completed through a keyboard and display located on the front panel through which there is access to all the readings alarms and configurations The software for pre correction and performance measurement operates within the software of the computer external computer not provided 1 2 Principle Characteristics If contained in a LINEAR transmitter it will provide the management all of the functions of that transmitter and each of its amplifiers It contains 2 line and 40 column di

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