Linear Industries, Inc.
AT725P Owner’s Manual Linear AT725P 25W UHF 8VSB-ATSC EXCITER/TRANSMITTER Owner Manual Table of Contents Section 1: General Description, Technical Specifications, Typical Final Test Report Section 2: Control Unit Section 3: DTV Modulator Section 4: Up Converter Section 5: Power Amplifier Section 6: Power Supply Section 7: DC-DC Converter Section 8: Memory Interface Annex A: Annex B: Annex C: Operational Software Checking the LDMOS transistors Typical Final Test Report Results © 2009 Linea
AT725P Owner’s Manual User Notices and WARNINGS USER NOTICES IT IS VERY IMPORTANT TO READ THIS MANUAL PRIOR TO OPERATION OF THIS TRANSMITTER! Notice 1 The transmitter main operating voltage setting is marked on the rear of the AT73501 chassis. Notice 2 The transmitter operating frequency is set from the factory. Notice 3 For adjusting the RF output power setting a qualified technician should always employ the use of an RF Wattmeter and a calibrated dummy load.
AT725P Owner’s Manual WARNING! THE VOLTAGES AND CURRENTS IN THIS EQUIPMENT ARE DANGEROUS. PERSONNEL MUST, AT ALL TIMES, OBSERVE SAFETY WARNINGS, INSTRUCTIONS, AND ANY LOCAL REGULATIONS. THIS OWNER’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.
AT725P Owner’s Manual 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 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.
AT725P Owner’s Manual Section 1 – AT725P General Description 1.
M O DULE 4281 OCXO 10MHz R E A D IN G S E X C IT E R F O R W A R D P O W E R 20W M O D U LE 4549 M ASTER CLO CK +32V AT725P_OM_08/09 FROM U N IT C O N TR O L C IM 3 2 9 7 ( C IP 8 2 3 1 ) +32V -1 8 V+ 1 8 V F I X O CS ASDI D A TA R FO U T M EM ORY CARD C IP 8 4 2 1 C IP 8 4 3 7 +32V +18V -1 8 V +9V R E S .
AT725P Owner’s Manual Module 4549 8VSB Modulator section The 8VSB modulator automatically recognizes the incoming transport stream, either SMPTE310M or ASI. The transport stream input is a BNC connector located on the rear panel of the unit. The modulated output signal of this module is composed by two IF orthogonal carriers termed; signals (I) and (Q). The central frequency of the 8VSB modulated IF signal is 18.83339MHz.
AT725P Owner’s Manual The external reference input is a BNC connector located on the rear panel of the unit. In the absence of this external source, automatically the commutation for the internal source of 10MHz will be made generated by OCXO. Module 4408 25W UHF band multistage amplifier section The IF modulated signal already converted into UHF is amplified by an UHF amplifier of 25W.
AT725P Owner’s Manual Power Supply The power supply module is a switching power supply type, running on half-bridge topology. It measures and informs the control unit, the current nominal value of the +32volts DC power supply, and also measures the electrical current demanded by the entire exciter. Both the voltage and the current data are routed to the control unit card to be processed and displayed.
AT725P Owner’s Manual AT725P - Modules and Parts Displacement Power Switch Fuse & GND +32V Power Supply Module 4401 Ref. 10MHz OCXO Module 4281 Up Converter & Master Clock Module 4492 Key Pad CIM3003 8VSB Modulator Module 4549 LCD Screen CIM3004 DC/DC Converter Module 4567 RF Power Amplifier Module 4408 Digital Control Card CIM3297/CIP8231A DC Fan Filter CIM6673 LUT Module 3535 Fig.1.4: AT725P Modules and Parts displacement © 2009 Linear Industries, Inc.
AT725P Owner’s Manual AT725P - 25W UHF ATSC/8VSB Exciter- Transmitter - Technical Specifications Electrical Main Consumption Power Factor Correction, FPC. Signal Input Transport Stream Input Input Data Rate External Reference Signal Input Connector Reference Input Connector RF Modulation Mode IF Channel Bandwidth Test Signal Frequency Range Frequency Step Symbol Rate Digital/Analog Converter Linearization Pre-Correction Pilot frequency stability overall Initial tolerance Vs.
AT725P Owner’s Manual Section 2 – Control Unit General Functional Description The DIGITAL CONTROL UNIT is responsible for all the digital management of AT725P excitertransmitter. Management and operability of the transmission is performed via key pad access located on the front panel or via the RS232 through the hyper-terminal. Its main attributes include: • • • • • • Management of the alarm of loss of the Lock of the PLL of Up-Converter.
AT725P Owner’s Manual The PCB board CIP8231 is called generically the CONTROL UNIT, as it is the main component of the DIGITAL CONTROL UNIT within the AT725P. Fig.2.1, profiles the main components and connections of the Control Unit. Fig.2.1 control unit board - CIP8231 (CIM3297) Fig.2.2. Keypad board - CIP8002 (CIM3003) © 2009 Linear Industries, Inc.
1 3 DS229 CON-7 6 PIN 4 – CON-2 – CIP8437 – MEMORY INTERFACE PIN 6 – CON-2 – CIP8437 – MEMORY INTERFACE PIN 5 – CON-2 – CIP8437 – MEMORY INTERFACE RS232 1 RS485 .. 6 . 1 CON-8 9 1 CI -6 CON-12 J4 J5 CON-6 8 VM 1 MCS12A128B MC9S12A128B CI-2 (YL) CS MEMORY (OR) DCLK_MEM (RD) ASDI_MEM CON-5 XTAL1 16MHz BDM IN 8 1 A B GND 1 . . CON-9 DS229 7 1 9 1 2 3 LM7805 BCX53 .
AT725P Owner’s Manual The function of the CIP8231 board can be described in the following parts: ➢ The integrated circuit CI-4 (A128) is a 16 bit microcontroller programmed to perform the total management functions of the equipment. This component is programmed in the factory by a numeral designation and its current associated software version. The software version corresponds to any updates that the control software may receive in the future for the CIP8231 board.
AT725P Owner’s Manual For the listed alarms below, the CIP8231 control unit board shuts down the transmission by making the ALC voltage 0Volts at the up-converter module, 4492. For more details see the power control description on the next page. The possible alarms to be interpreted by the CIP8231 are: • • • • • • • Lack of lock voltage of the PLL at the Up-converter - Module 4492. Excessive temperature of the 25W UHF amplifier - Module 4408 – (above 65ºC). Excessive reverse power (above +4V at CON-9).
AT725P Owner’s Manual The communication between the CIP8231 board and the 8VSB modulator module 4549 has the objective to make the reading and the configuration of determined parameters of this module, as for example, the adjustment of the pilot programming stream, or the 8VSB signal, and adjustment of the rejection of superior lateral band. Setting the FCC/UHF operational channel The programming of operational channel of the equipment is made on the CIP8231board.
AT725P Owner’s Manual For some failures, or malfunctions, the power control is responsible for the immediate action to reduce to zero the RF power level of transmission that is, zeroing the trellis voltage, in the following situations: • Lack of Lock of the PLL of the UP Converter - Module 4492. • Temperature of the UHF Amplifier of - Module 4408 - above 65°C • Imperfection in the generation of master clock in the 8VSB modulator - Module 4549.
AT725P Owner’s Manual This connector is linked to connector printed circuit connector CON-10, located at CIP8231 board. Keypad – CIP8002 board The CIP8002 board contains five key bottoms SW1 to SW5, located on the front panel of the exciter. This board is a matrix of electrical ON/OFF contacts. The responses are made available at the CON-3 connector. LCD - CIM3004 board CIM3004 board is a LCD - Liquid Crystal Display - of 20 columns for 02 lines.
AT725P Owner’s Manual Section 3 – 8VSB Modulator and Master Clock Module 4549 Introduction The Module 4549 is composed by an 8VSB MODULATOR including an IF pre-correction circuitry CIP8357 board (CIM3510) and also a MASTER CLOCK UNIT, CIP8358. Each one of these printed circuit boards are located below of one out of the two lateral covers of module 4549, as it shows the drawing of external connections of this module. 8VSB IF Modulated - 18.
AT725P Owner’s Manual General Functional Description The module 4549 can be break down in 2 printed circuit boards. This section describes the 8VSB modulator only. These boards are physically located below of each side of the top covers, as shown on the figure below: CIP8412 board - 8VSB Modulator/Pre-corrector. The CIP8412 is part of the Module 4549. It is the 8VSB modulator that process the transport stream (TS) that carries up to 4 broadcast programming including, audio, video and data.
AT725P Owner’s Manual The entire 8VSB modulation process is digital. This process includes the FIR filters, and do not uses SAW filters to create the VSB band. Digital modulation increase the quality of the modulated signal measured via a proportional increase of the MER, (Modulation Error Rate). The modulation process generates 2 identical but orthogonal signals, termed signals; I and Q. The frequency of the IF carrier is 21.52MHz, and the center of the channel is 18.8MHz.
AT725P Owner’s Manual Synchronism Insertion: The synchronism insertion built the symbol overall structure, creating the fields and frames as specified on the A/53E standard. Pilot Insertion: This part of the circuit adds a small DC level into the carrier to allow a safer and robust reception of the signal. This DC level is equivalent to 1.25 CU (Constellation Units).
AT725P Owner’s Manual Section 4 – IF/UHF Up-Converter Module 4492 Introduction The module 4492 performs the basic functions: This module translates the incoming I and Q IF carries, from the 8VSB modulator, to a desirable FCC/UHF operational channel. Controls the RF output power of the exciter. The desirable channel configuration is defined via the keypad and the LCD display on the factory. Channel changes are not allowed to the end user. 2 x LO sample (I) IF input Ref.
AT725P Owner’s Manual The main features associated with this module are: Simple conversion. Orthogonal mixing, that perform the image rejection, and LO rejection. Synthesized local oscillator via PLL, 22 bits serial fractional. Allow channel programming @ 1Hz resolution when using GPS reference. The LO frequency is divided by 2, that insures 6dB improvement on the LO phase noise. 10MHz internal reference oscillator, technology OCXO, (Oven Controlled Crystal Oscillator).
AT725P Owner’s Manual The already modulated IF carrier I and Q feed the 2 inputs of the up converter 4492 module. The output signal of this module is a FCC/6MHz/UHF channel (14-69). Besides this main function, it also controls the potential overdrive into the final 25W amplifier. The up-conversion circuit consists of an orthogonal mixer fed by the 2 orthogonal IF carriers, I and Q fixed center frequency and 6MHz bandwidth. The mixer bit the IF signal with the suitable local oscillator CW signal.
AT725P Owner’s Manual PCB CIM3442 – UHF Mixer The mixing operation translates the IF modulated signal frequency up to the assigned UHF broadcasting channel, the operation utilizes the complex approach considering the orthogonal pair of signals (I-, I+) and (Q-,Q+) allowing rejection of one side band, and the oscillator itself. The rejection is around 40dB, facilitating the post filtering steps.
AT725P Owner’s Manual PCB CIM3442 – UHF Mixer – adjustment procedures: The mixer-ALC circuitries have 2 types of adjustments. The first one is a DC level that polarizes each branch of the input of the complex mixer. Each one of the DC levels must be adjusted seeking for the max rejection on the un-desired vestigial side band, in conjunction with the LO rejection as well. The level adjustments are performed by the trim pots: TPO-1, TPO-2, TPO-3, and TPO-4. Voltage range of +1.4V to +1.
AT725P Owner’s Manual Section 5 – 25W UHF Multistage Amplifier Module 4408 General Functional Description Introduction The module 4408 was developed to act as driver of DTV in standard ATSC in all the band of UHF. It is composed by three stages of amplification. The module 4408 has high linearity with a satisfactory performance for TV signals.
AT725P Owner’s Manual Second amplifier on class A The transistor LDMOS T2 (MRF-373) is the main device of the second amplifier on the module 4408. This transistor also is polarized on class A. The drain voltage is gotten from +32V main power supply. This voltage is available at pins 2, 3, 4 and 5 of connector CON-2 of module 4408. The trimmer TPO-2 adjusts VGS voltage of T2 and, consequently, the drain bias current of (ID) of this transistor.
AT725P Owner’s Manual module 4408 exceeded the 650 C. Under this occurrence, the control unit will no longer allow to the +32V power supply to feed the module. RF Power Measurements Through a PCB type directional coupler at CIP8209 board, a RF output sampling is collected. This RF sampling is sent to the circuits of direct and reversed power readings.
AT725P Owner’s Manual Technical specifications PARAMETERS SPECS INPUT FREQUENCY 470 to 860MHz IMPEDANCE CONNECTOR SMB MALE RETURN LOSS ≥ 10dB RF OUTPUT 43dB ≤ ±2dB GAIN ATSC RMS POWER HARMONICS 2 nd Up to 23W ≤ -30dBc GENERAL CONSUMPTION 324VA Module 4492 block diagram Fig.5.1: 25W UHF ATSC Multistage Amplifier © 2009 Linear Industries, Inc.
(CABLE BELDEN 50 ) INPUT RF © 2009 Linear Industries, Inc.
CON-4 – UPCONVERTER UHF (CABLE BELDEN 50 ) RF INPUT CON-1 TPO-1 T1 VGS ADJ TPO-2 T2 VGS ADJ 12 3 4 5678 +30V CON-2 R9 R10 C17 C15 4 1 R17 5 8 4 1 CI-7 T2 C32 C33 H1 TPO-3 T3 VGS ADJ PIN 1 – CON9 – POWER SUPPLY PIN 1 – CON14 – POWER SUPPLY T3 C54 (YL) FOWARD POWER READING PIN 4 – CON9 – CONTROL UNIT (GY) REFLECTED POWER READING PIN 2 – CON9 – CONTROL UNIT (BL) +18V PIN 1 – CON13 – POWER SUPPLY (GR) TEMPERATURE ALARM PINO 7 – CON-6 – CONTROL UNIT (WH) GND PIN 1 – CON9 – POWER SUPPLY (WH
AT725P Owner’s Manual CIP8209 card – adjustment procedures Connect a coaxial load 50Ω/100W (minimum) at RF output having a good frequency response (470MHz 860MHz). Adjusting bias ID of T1, T2 and T3 For T1: TPO-1 makes the adjustment of the chain of drain (ID) of T1. This adjustment is made measuring the drop of tension in the resistive parallel set formed by R9 and R10 (2 x 10Ω /1W), being the adjusted one for 1.5V, what it corresponds 300Ma of ID. This is a class A polarization adjustment.
AT725P Owner’s Manual NETWORK ANALYZER RFOUT RFIN 30dB / 100W ATTENUATOR -20dBm 20W ATSC TRANSMITTER – AT720P TPO-2 T2 VGS ADJ C67 1 D2 4 H2 8 5 CI-4 1 4 T2 C33 8 5 CI-5 C68 CI-6 . CI-3 8 5 C42 TPO-4 REF ADJ TPO-5 FWD ADJ R28 R29 +30V CON-2 R17 CON-1 12 3 45 67 8 CON-3 MODULE 4408 123 5 . . 8 4 . 1 1 T4 4 C43 H1 C17 R9 R10 LED 2 LED 1 T3 C32 TPO-1 T1 VGS ADJ S1 D3 TPO-3 T3 VGS ADJ 4 56 78 CON-4 RF OUT FW REF +15V TEMP 4 1 CI-7 CON-5 5 8 C54 CI-8 4 1 .
AT725P Owner’s Manual Section 6 – Power Supply Module 4401 General Functional Description The Power supply - Module 4401 - is of the switching type configured in the topology half bridge, having overall efficiency above 80%. The module 4401 is responsible for the generation and distribution of following voltage DC: • • • • • +32V FIXED +32V RE-CONNECTABLE +18V -18V +9V The module 4401 can be connected to the electric AC network of 120Vac or 240Vac, according with internal jump positions.
AT725P Owner’s Manual The varistors V1, V2 and V3 prevent over-voltage damages potentially caused by occurrences on the AC network. The group of diodes D1/D4 rectifies the AC voltage from the AC network and delivers this rectified voltage to the capacitors C9 and C10 for filtering. These capacitors could be connected in parallel or in series, according with the set of the jumps for 120/240Vac.
AT725P Owner’s Manual Feedback The resistors R10, R13, R12 and TPO-1 form a voltage divider that take a sample of +32V output of the power supply and delivery to the comparator CI-1, compares that it with its reference of +5V via R39. As the value of this sample, the modulation circuit will create a variation in the width of the switching pulses, having compensating voltage variations in the output voltages. Protection and Readings The set of protection acts in case of over-current in the outputs.
GND CON-2 NETWORK READING 110/220VAC CON-1 CON-5 LM555 LM393 LM393 LF353J CI-3 CI-4 CI-5 CI-10 CI-9 CI-8 CI-7 4N28 LM358J LM358J LM358J LM353D T4 T3 T2 T1 (D5-D7; T3) SG3525 (CI-1) CONTROL SUPPLY CI-2 CONTROL (TF-3) (T1;T2) SWITCHING TRANSISTORS (TF-4) CI-6 (D1-D4) NETWORK RETIFIER ISOLATOR TRANSFORMER 220V CON-3 110V NETWORK TRANSFORMER CON-4 CI-1 (TF-1) LINE FILTER IRFP150 TIP29C IRFP450 IRFP450 +32V PROTECTION CIRCUIT (CI-2) (CI-3) (CI-4) (L2-A; L2-B) (L2-C;
CON8 TPO-6 (RD) +32V (OR) +32V REL CON14 CON15 (BL) +18V CON13 CON12 (GR) +9V (BK) -18V * CON11 TPO-2 Adjustment reading output current +32V TPO-3 ** Adjustment reading output current +18V TPO-4 ** Adjustment reading output current +9V TPO-5 Adjustment reading output voltage +32v TPO-6 ** Adjustment reading output voltage +32V RESTART TPO-7 Adjustment reading output voltage -18V TPO-8 Adjustment reading output voltage +18V TPO-9 Adjustment reading output voltage +9V CI-2 .
AT725P Owner’s Manual MODULE 4401 – Technical Specifications FEATURE SPECIFICATION INPUT AC VOLTAGE 90 TO 140VAC / 180 TO 250VAC SWITCHING FREQUENCY 50kHz LINE REGULATION BETTER THAN 2% FOR ALL OUTPUTS +32V / 10A +18V / 1A OUTPUTS NOMINAL VOLTAGES -18V / 1A AND CURRENTS +9V / 1A RIPPLE 300mV (+32V) 120mV (+18V / +9V) 80mV (-18V) LOAD REGULATION BETTER THAN 2% FOR +32V BETTER THAN 25% FOR +18V, -18V, +9V EFFICIENCY BETTER THAN 80% OUTPUT OVER CURRENT LIMIT 30% UPPER NOMINAL VALUE RESTART VO
AT725P Owner’s Manual MODULE 4401 – Changing the Mains Voltage Operation The module 4401, on its rear side, is built in such way that it is possible access the 110/220Vac switching voltage jump. The figures below illustrate the position for the jump for each desired operational voltage. This is the only required maneuver to change the voltage operation on the AT725P unit. Fig.6.3: Jump connection for 110Vac operation, (CON5-CON4) Fig.6.4: Jump connection for 110Vac operation, (CON4-CON3) Fig.6.
AT725P Owner’s Manual Section 7 – DC/DC Converter Module 4567 General Functional Description This module has as function to generate specific voltages not present at the main power supply module 4401. The module 4567 generates +2.5V and +5V, via standard IC regulators, see below: GND wire +18V Input +5V Output Yellow wire +2.5V Output Brown wire Fuse Fig.7.1: DC/DC Converter Board CIM3490 (CIP8390) INPUT OUTPUT +18V © 2009 Linear Industries, Inc. All Rights Reserved +2.5V (CON-2/2) +5.
AT725P Owner’s Manual Section 8 – Memory Interface Module 3535 General Functional Description The connectors CON-4 and CON-10 at the modulator – module CIM3510 – are the communication connectors with the memory interface CIM3535 mother printed circuit board. Module CIM3516 – General Functional Description The 1Mbit LUT memory card – module CIM3516 - is connected to the memory interface - module 3535.
AT725P Owner’s Manual Annex A – AT725P Operational Software AT1012_ASM version 1.2 1. Introduction The LINEAR family of ADVANCED TV transmitter/Exciter equipment possesses a system for measurement (measures), configuration (SETUP) and alarms (alarms) all controlled by a microprocessor controlled system. This document will demonstrate the navigation, operation and configuration of these functions. 2. Navigation and Signals 2.1 Keypad and Display 2.1.
AT725P Owner’s Manual 2.2 Display The display navigation is made by the following: The cursor must be located on the first character of each function to access that function. MEASURES NXT SETUP ESC It is then activated by pressing the yellow “ENTER” key During the navigation there will appear in the display special functions that assist navigation, these are: ESC – Used to return to the previous menu NXT – Used to access the next screen CLEAR – Used to clear old alarms 2.
AT725P Owner’s Manual 3. Screen Flow Charts 3.1 Main screens L I N E A RI N D U S T R I E S I N C . [ A n yK e y ] A T 7 2 0 P [ E s c ] M E A S U R E SS E T U P N X T E S C [ E s c ] A L A R M S N X T R E M O T E E S C Main screens 3.2 Measurement Screen 1 [Measures ] MEASURES NXT SETUP ESC [Esc] POWER NXT P.SUPPLY ESC [Power ] FWD. PWR.: RFL. PWR.: [P.Supply ] W W +32V: + +18V: + V V V + 9V: + -18V: - V V I1: A [Up and Down Keys ] ALC STATUS: ALC R.V: P.A.
AT725P Owner’s Manual 3.3 Measurement Screen 2 TR.STR. STATUS NXT SOFTWARE ESC [Tr.Stream ] DATA PACKETS RATE: Mbps [Status ] PASSWORD ON: [Up and Down keys ] NULL PACKETS RATE: Mbps PILOT LEVEL: FIFO OCCUPATION: % CHANNEL: TRANSPORT STREAM: LO N.I: LO N.Q: [Enter Key] [Software ] mV mV TX.BAL.I: PHASE I: SOFTWARE: VERSION: TX.BAL.Q: PHASE Q: DPD SCALE : DPD ACTIVE: © 2009 Linear Industries, Inc.
AT725P Owner’s Manual 3.4 Configuration Screen MEASURES NXT ESC [Wrong Password and TYPE PASSWORD: [Esc] SETUP Enter Key ] [Correct Password and Enter Key ] WRONG PASSWORD ! NXT YES PREV ESC TYPE PASSWORD: [Yes] ENABLE PASSWORD: YES NO [Enter Key] TYPE PILOT LEVEL: TYPE CHANNEL: FACTORY SETUP TYPE LO NULL I: TYPE LO NULL Q: TYPE AMPLITUDE I: TYPE PHASE I: TYPE AMPLITUDE Q: TYPE PHASE Q: TYPE DPD SCALE: DPD ACTIVE: YES ALC. R.V.: POWER : NO [V] [W] TYPE CONFIG.
AT725P Owner’s Manual 3.5 Alarm Screen ALARMS NXT REMOTE ESC [Alarms ] CURRENT [Esc] PAST ESC [Current ] [Past] [Esc] [Esc] NXT NXT ESC CLR. ALL ESC 4. Initialization When the equipment is initially switched on the screen backlight lights automatically and the message “LOADING”… is displayed, indicating the load process of the modulator has begun.
AT725P Owner’s Manual 4.1 MEASURE MENU The measure menu allows access to the general equipment configuration parameters; power levels, TS feed and status, qualification of passwords, cancellation of the L.O signal., rejection of image frequency signal, level of scale, activation of look up tables (LUTs) for pre-distortion and the name and version of the installed software on the central microcontroller. Navigation through these screens is made with the keys UP and DOWN.
AT725P Owner’s Manual To return to the previous screen, press the UP key. To return the POWER option presses “ENTER”. NOTE: The screens above are a rolling type, allowing access to all of the voltage measurements by using the UP and DOWN keys. 4.1.2 POWER SUPPLY MENU This screen displays the voltages and currents of the principal equipment power supplies. To have access to the P.SUPPLY screen the sequence of screens are: M E A S U R E S S E T U P N X T E S C Access MEASURES P O W E R N X T P .
AT725P Owner’s Manual 4.1.5 MENU TR.STR. TR STR shows information about the input digital signal. M E A S U R E S S E T U P N X T E S C Select NXT and press ENTER T R . S T R .S T A T U S N X T S O F T W A R E E S C Select TR.STR and press ENTER DATA PACKETS RATE: Mbps NULL PACKETS RATE: Mbps FIFO OCCUPATION: % TRANSPORT STREAM: To return to the previous screen press the UP key. To return to the TR.STR options press ENTER. 4.1.6 MENU STATUS 4.1.6.
AT725P Owner’s Manual PASSWORD ON: NO - indicates that the requirement of a password is not necessary to enter into the SETUP MENU and open access is available. Below is the sequence necessary for this option: T R . S T R .S T A T U S N X T S O F T W A R E E S C Select STATUS and press ENTER PASSWORD ON: 4.1.6.2 Amplitude level of the ATSC Pilot carrier: This is a numerical value relative to the carrier pilot level.
AT725P Owner’s Manual PILOT LEVEL: CHANNEL: 4.1.6.4 DC voltage level adjustment for the cancellation of the L.O signal: This level indicates the voltage programmed in the Up Converter for the cancellation of the local oscillator signal. LO N.I.: and LO N.Q. <0.00 to 49.75 mV>: To have access this menu, select the option STATUS CHANNEL: LO N.I: LO N.Q: mV mV CHANNEL: press UP and DOWN key 4.1.6.
AT725P Owner’s Manual 4.1.6.6 Pre-distortion scale level: This is a scale (or intensity) of the pre-distortion level applied to the transmission signal. DPD SCALE: < 0000 to 4095> TX.BAL.Q: PHASE Q: DPD SCALE : DPD ACTIVE: 4.1.6.7 Qualification of pre-distortion tables: DPD ACTIVE: YES – indicates the signal pre-distortion tables are active DPD ACTIVE: NO - - indicates the signal pre-distortion tables are not active. TX.BAL.Q: PHASE Q: DPD SCALE : DPD ACTIVE: 4.1.6.
AT725P Owner’s Manual To verify the name and version of software select the option SOFTWARE after that press ENTER. T R . S T R .S T A T U S N X T S O F T W A R E E S C S O F T W A R E : V E R S I O N : Select SOFTWARE and press ENTER 4.2 MENU SETUP This menu allows access to the configuration functions and parameters of operation of the equipment.
AT725P Owner’s Manual Select SETUP and press ENTER T Y P E P A S S W O R D : Type the password number and then press “ENTER” 4.2.2 LIST OF MENU OPTIONS: The following allows navigation in the equipment configuration options: NXT: PREV: YES: ESC: executes the navigation option returns to the previous menu indicates access to that particular option returns to the main options menu NXT YES PREV ESC To see the options select NXT and press “ENTER”.
AT725P Owner’s Manual YES: confirms the requirement of the password to have access to the SETUP options menu. NO: Indicates that no password is required to have access to the SETUP options menu. . ENABLE PASSWORD: YES NO 4.2.2.3 < SET PILOT LEVEL? > This option allows the configuration of the desired level of the ATSC signal pilot carrier with the following band of values: < +511 TO -2048 >. TYPE PILOT LEVEL: 4.2.2.
AT725P Owner’s Manual 4.2.2.6 < SET LO NULL Q? > This menu allows the DC voltage adjustment for “nulling” the “Q” signal from the local oscillator intermodulation in the Up Converter. The adjustment has the following potential values: < 0.00 to 49.75 mV >. TYPE LO NULL Q: 4.2.2.7 < SET TX BAL. AMP. I? > This menu allows the adjustment of the “I” amplitude of the image rejection signal in the 8VSB modulator with the following band of values: < 00000 to 32767 >. TYPE AMPLITUDE I: 4.2.2.
AT725P Owner’s Manual 4.2.2.11 < SET DPD SCALE? > This menu allows the configuration of the DPD (Digital Pre-distortion) scale (or intensity) of digital predistortion applied to ATSC signal, with the following band of values : < 0000 to 4095 > TYPE DPD SCALE: 4.2.2.12 < SET DPD ACTIVE? > This menu allows the activation or not of the digital pre-distortion tables.
AT725P Owner’s Manual WARNING: It is important not to set the programmed values of the ALC and consequently the final RF power level above the nominal value of the equipment: this may caused damage to the internal modules and may void the warranty on the unit. 4.2.2.14 < SET CONFIGURATION? > This menu allows the operating mode of the equipment to be configured with regard to including or not an ATSC compliant mask filter. Key ENTER: TRANSMITTER Key UP and DOWN: EXCITER TYPE CONFIG.
AT725P Owner’s Manual When the * is displayed on the screen access should be made to the current alarm screen to verify which alarm is occurring. 4.3.1) CURRENT MENU This menu displays the current alarm messages i.e. alarms that indicate are still present and have not yet been normalized or cleared. The current alarm messages are updated when entering the CURRENT MENU.
AT725P Owner’s Manual Select ALARMS and press ENTER CURRENT PAST ESC Select CURRENT and press ENTER NXT ESC 4.3.2 PAST MENU This menu displays the past or old alarm messages, i.e. alarms that indicate some equipment alarm occurrence that has been normalized or cleared. The current alarm messages are updated when entering the PAST MENU. To update the list, you must leave the menu and then return to the ALARMS menu using the ESC option and then access the PAST menu option again.
AT725P Owner’s Manual Below shows the screens necessary to display the PAST alarms menu: MEASURES NXT SETUP ESC Select NXT and press ENTER ALARMS NXT REMOTE ESC Select ALARMS and press ENTER CURRENT NXT CLR. ALL PAST ESC ESC Select PAST and press ENTER 4.4 Remote Menu It allows the display of the parameters to be configured in the Windows® Hyper-terminal emulator in order to connect a computer with an RS232 port and have access to all the configuration and monitoring of the equipment. 5.
AT725P Owner’s Manual Pin 3 is TX and pin 2 is RX. In the both connectors pin 5 is GND. The figure below illustrates the RS232 cable and connector: The configuration of the Window® Hyper-terminal must in accordance with following: PROPERTIES OF COM4 Configuration of Port Bits per Second Bits of data Parity Bits of Parity Flow Control 19200 8 None 1 None To access the data of the equipment and to bring up to date the screens in the Hyper-terminal use ENTER on the keyboard.
AT725P Owner’s Manual When the password of the equipment is qualified screen 2 will be displayed. A password of 4 digits must be entered to access the SETUP environment. In the case where the entered password is incorrect, the message “WRONG PASSWORD" will be shown. When the password is correct a warning question is asked. Reply YES (y), which then allows access to the SETUP environment. A NO (n) reply will return to the menu to the previous screen 1. © 2009 Linear Industries, Inc.
AT725P Owner’s Manual To configure the parameters of screen 3 the characters in the parentheses should be selected by using standard keyboard keys. Select the option desired and then use the keyboard characters U (up) and D (down) or Y (Yes) or N (No) to display the values of configuration. For safety reasons the values entered are only confirmed when exiting from the screen. Exit from the screen by using the ESC key. The W Key will refresh the screen. © 2009 Linear Industries, Inc.
AT725P Owner’s Manual Annex B – Checking the RF Power LDMOS Transistors All 3 main RF transistors on the module 4408 are LDMOS technology type. The manipulation of these transistors requires some special care, for instance avoiding manual bare finger direct contact with the parts. Instead, prioritize the usage metal parts tools and grounded care procedures. Gate-to-ground conductance test With the transistors in place it is possible with a digital multimeter perform this test.
AT725P Owner’s Manual Annex C – Typical Final Test Reports Results Out of Channel Emissions © 2009 Linear Industries, Inc.
AT725P Owner’s Manual Frequency Response and Group Delay Carrier Phase Noise © 2009 Linear Industries, Inc.
AT725P Owner’s Manual Digital Modulation Error Rate: © 2009 Linear Industries, Inc.
AT725P Owner’s Manual Conducted Spurious Emissions © 2009 Linear Industries, Inc.
