Linear Industries, Inc.
AT71K0-1 Transmitter 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 AT71K0-1 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.
AT71K0-1 Transmitter 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.
AT71K0-1 Transmitter 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.
AT71K0-1 Transmitter Owner’s Manual AT71K0-1 General Description 1. INTRODUCTION AT71K0-1 is a 1000W UHF ATSC Digital Broadcast Transmitter. It uses state-of-the-art technology of transmission of the digital signal for TV broadcast. It carries an intelligent digital control using microcontrollers, which allows for remote supervision in real time of all transmitter functionality.
AT71K0-1 Transmitter Owner’s Manual Figure 2: AT71K0-1 - Rear View, back cover panel removed © Linear Industries, Inc.
AT71K0-1 Transmitter Owner’s Manual Figure 3 - AT71K0-1 - Block Diagram © Linear Industries, Inc.
AT71K0-1 Transmitter Owner’s Manual 2. Main Features Via the 4 lines x 40 columns display keypad located at the front panel it is possible to manage, configure all functions of the equipment and each one of the RF power drawers. Via the hyper-terminal it is also possible to manage, configure all of the functions of the transmitter and each one of the RF power drawers. Digital Filter, type Finite Impulse Power (FIR) built-in at the 8VSB Modulator. Automatic non linear pre-correction.
AT71K0-1 Transmitter Owner’s Manual 3. AT71K0-1 stage-by-stage 1. 2. 3. 4. 5. 6. 7. 8. Digital Exciter RF Power Splitter, 1:3 3 RF power drawers RF Power combiner, 3:1 RF Sampler Output FCC mask filter. Energy system Cooling system 4 General Description by stage 4.1 Digital Exciter, model AT7001. The digital exciter unit is also the control and monitoring system for the entire transmitter.
AT71K0-1 Transmitter Owner’s Manual The MCU receives information proceeding from several modules, as the DTV modulator, UpConverter, RF amplifiers, RF samples and the administration of passwords. Via keypad it is possible to read and program the power level delivered by the transmitter. Major changes on the transmitter configuration are possible with factory assistance. The AT7001 is factory-set in one of four (4) optional versions.
AT71K0-1 Transmitter Owner’s Manual RF path (line-up), BEFORE and AFTER the RF output filter. The second set of RF samples is the last element on the transmitter line-up, directly connected to the output transmission and antenna system. 4.5 Output Mask Filter The UHF RF channel output filter is a tunable band-pass six pole elliptical synthesis type filter. This filter reduces the unwanted spurious and harmonics signals inherent in the RF amplification process.
AT71K0-1 Transmitter Owner’s Manual 4.5.1 AC control panel & battery charger Figure 4 – AT71K0-1 AC Front Panel (panel cover removed) 4.6 Cooling System The cooling system is based on a set of fans that force air into the transmitter drawer’s heat sinks. The fans are mixed, located on the front panel and internally within the units. The air outlet holes on the top cover and the rear panel of the transmitter facilitate the air flow. © Linear Industries, Inc.
AT71K0-1 Transmitter Owner’s Manual 5. AT71K0-1 - 1000W UHF ATSC/8VSB Transmitter - Technical Specifications Electrical Main Consumption Power Factor Correction, FPC.
AT71K0-1 Transmitter Owner’s Manual Annex A – AT71K0-1 Operational Software 1. Introduction The DTV transmitter AT71K0-1 provisions: (a) measurements, (b) configurations, (c) alarms, and (d) remote control via microcontrollers. Below is a detailed description about the operational software (configuration and operation) system installed in the AT71K0-1, located within the AT7001 exciter. Figure 5 AT7001 – Front Panel 2. Digital Exciter – The Master Control Unit 6 1 4 5 2 3 2.
AT71K0-1 Transmitter Owner’s Manual 2.2. LCD Display To browse over the LCD screen follow the instructions below: Move the arrow Up or Down to the item listed by pressing the (1) or (3) buttons. Main Menu : -> Setup Menu Measurements System Alarms/Log [0000] Remote Access 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. 2.3.
AT71K0-1 Transmitter Owner’s Manual After pressing any key on the keypad, the next screen that appears is: Main Menu : Setup Menu Measurements -> System Alarms/Log [0000] Remote Access (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. 4.
AT71K0-1 Transmitter Owner’s Manual 4.1. Transmitter Power Measurements Main Menu : Setup Menu -> Measurements System Alarms/Log [0000] Remote Access Access Measurements Measurements : -> Power Transport Stream Drawers [2000] Exciter Power Supply Communication Status Power Supply Access Power and hit ENTER Hit key “3” to view the other screens that are part of this menu. Transmitter Power Measurements : [2100] Programmed: Forward: ____ [W] Reflected: ____ [W] ALC Reference Voltage : __.
AT71K0-1 Transmitter Owner’s Manual 4.2.
AT71K0-1 Transmitter Owner’s Manual 4.3. RF Power Drawers Measurements For each 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 : Power Transport Stream -> Drawers [2000] Exciter Power Supply Communication Status Power Supply Select Drawers and presses ENTER.
AT71K0-1 Transmitter Owner’s Manual Press ESC to return to the Drawers Measurements screen. Drawer Measurements : Power Current -> Temperature [2300] Select Temperature and press ENTER Drawer Temperature Measurements : [2330] Drawer : <__/__> Exciter: 0.0 °C ^°F^ Mod.1: 0.0 °C Mod.3: 0.0 °C Mod.2: 0.0 °C Mod.4: 0.0 °C Press ESC to return to the Measurements screen.
AT71K0-1 Transmitter Owner’s Manual 4.4 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 each one of the RF power amplifier drawers. Press ESC, to the Main Menu screen, and then to the screen [2000] is reached, as below: Measurements : Power Transport Stream Drawers [2000] Exciter Power Supply -> Communication Status Power Supply Select Communication Status and press ENTER.
AT71K0-1 Transmitter Owner’s Manual 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.
AT71K0-1 Transmitter Owner’s Manual Press ESC to return to the System Alarms/ Log menu System Alarm/Log Current Alarms -> Alarm Log Drawers Alarms [3000] Clear Alarm Log Access the Alarm Log and press ENTER to view all alarms, current and past alarms. Alarm Log: [3200] -> ! 25/03/08 10:55:29 Log Cleared -> ! 28/03/08 20:19:05 LO Lock Fail -> # 28/03/08 20:22:43 LO Lock Fail The symbol '!' is an indication that the alarm is current, (LED ON for alarms) with date and time of its occurrence.
AT71K0-1 Transmitter Owner’s Manual 5.1 Drawer Alarms While in the System Alarm/Log screen it is possible to check and review all alarms, current and past, on each one of RF power drawers. From the Main Menu screen select system alarm/log, screen [3000]. Main Menu : Setup Menu Measurements -> System Alarms/Log [0000] Remote Access Select System Alarms/Log and ENTER System Alarm/Log Current Alarms Alarm Log -> Drawers Alarms [3000] Clear Alarm Log Select Drawer Alarms and press ENTER.
AT71K0-1 Transmitter Owner’s Manual 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.
AT71K0-1 Transmitter Owner’s Manual Select Setup Menu and press ENTER Setup Menu : -> Power Setup Frequency Setup Image Frequency Suppression [1000] LO Leakage Suppression Pre-Correction Modulation Settings Time and Date Setup Password Setup Transmitter Setup Select Power Setup and press ENTER Power Setup : [1100] Output: 1300 [W] Program: 1300 [W] To reach the desirable output power level, press the key (2), to increase the power or (4) to decrease the power.
AT71K0-1 Transmitter Owner’s Manual Frequency Setup : -> Channel : Offset Model [1200] Select Channel and press ENTER Channel Setup : [1210] Channel : ___ Offset: + __.___ kHz Center Frequency: ____ .______ MHz Pilot Frequency : ____ .______ MHz Press ESC to return to Frequency Setup. Frequency Setup : Channel : -> Offset Model [1200] Select Offset and press ENTER Frequency Offset Adjustment: Frequency Offset: +__.____kHz [1220] The offset can be configured within 1Hz steps, in a ± 65536 Hz scale.
AT71K0-1 Transmitter Owner’s Manual Setup Menu : Power Setup Frequency Setup -> Image Frequency Suppression [1000] LO Leakage Suppression Pre-Correction Modulation Settings Time and Date Setup Password Setup Transmitter Setup Select Image Frequency Suppression and press ENTER. 6.3 Image Frequency Suppression This software feature adjusts numerical values related with the amplitude and phase optimized for maximum image frequency suppression on the superior side band spectrum region.
AT71K0-1 Transmitter Owner’s Manual 7.4 LO Leakage Suppression An RF sample for monitoring purposes must be taken before the output mask filter. An ideal voltage in the range of –60 [mV] and +60 [mV] should be sought, and will cancel the LO leakage for the main RF amplifiers LO Leakage Suppression: -> I Offset : [mV] Q Offset: [mV] [1400] Using the keys, it’s possible to activate or deactivate the linear and non-linear pre-correction. ON: Activate Pre-correction OFF: Deactivate Pre-correction 7.
AT71K0-1 Transmitter Owner’s Manual Pre-Correction Setup: Linear -> Non-Linear [1500] Select Non-Linear and press ENTER Non-Linear Pre-Correction: -> Non-Linear Pre-correction: on/off Scale: -300 ~ +300 [1520] The scale listed on the screen above, is related with how intense the pre-correction will act over the ATSC signal on the modulator. 7.6 Modulation Settings On this screen option it’s possible to turn the modulation process on and off.
AT71K0-1 Transmitter Owner’s Manual 7.7 Time and date configuration Press ESC up to Setup Menu screen. Setup Menu : Power Setup Frequency Setup Image Frequency Suppression [1000] LO Leakage Suppression Pre-Correction Modulation Settings -> Time and Date Setup Password Setup Transmitter Setup Select Time and Date Setup and press ENTER Time and Date Setup: [1700] Time: HH:MM Date: 25/02/11 DD/MM/YY To program the date and time, use keys 2 and 4.To change between the parameters, use keys 1 and 3. 7.
AT71K0-1 Transmitter Owner’s Manual Press ESC key up to activate the SETUP MENU screen: Setup Menu : Power Setup Frequency Setup Image Frequency Suppression [1000] LO Leakage Suppression Pre-Correction Modulation Settings Time and Date Setup -> Password Setup Transmitter Setup Access to the Password Setup Password Setup: -> Enable / choose new password Disable password [1800] To enable the password or set a new one, select Enable / choose new password.
AT71K0-1 Transmitter Owner’s Manual 8.1 IP Configuration Start from the Main Menu Main Menu: Setup Menu Measurements System Alarms/Log [0000] -> Remote Access Select Remote Access and press ENTER Remote Access: -> IP Address Subnetwork Mask Gateway [4000] Select IP Address and press ENTER. IP Address: [4100] 192.168.100.018 Navigate and configure the IP by using the keys 1 or 3 and 2 or 4. 8.
AT71K0-1 Transmitter Owner’s Manual 8.3 Gateway Configuration Press ESC up to the Remote Access screen Remote Access: IP Address Subnetwork Mask -> Gateway [4000] Access the Gateway and press ENTER Gateway: [4300] [4300] 192.168.100.018 Configure the gateway address using 1 or 3 and 2 or 4. © Linear Industries, Inc.
