A total of 8 main operational functions are performed by the circuitry assembled on the module 4456. Please refer to the module 4456 block diagram. 3.10.1.1 Module 4456 – CIM3347 - Power Factor Corrector, PFC The PFC circuit is a power supply built according with the “boost regulator in continuous mode (CCM)” topology. Under the CCM topology, is possible guarantee a power factor, cosij above than 0.9.
3.10.1.5 Shut Down When an abnormal failure situation occurs inside the exciter drawer, the SCU generate a SHUT DOWN command that is a +5V direct connected to the pin # 1 at the connector CON-5 located at the PCB CIM 3429. Since this voltage is present, the switching pulses will be inhibit and as consequence, all the DC output available at the submodule 4456 will be disabled and be no longer available, exception for the +15Vdc DIRECT, that feeds the SCU.
.10.1.8 Module 4456 – Technical Specifications 3.11. PCB CIM3297 – Subordinate Control Unit (SCU) on Module 4456 The module 4456 is equipped with its own control unit. This control unit is assembled as the same of the master control unit MCU, both CIM3297, however the software that runs each one are not the same. The SCU is on constant two ways communication with the MCU. Fig.3.14: SCU assembled at the exciter drawer GV4456 – module 4456 AT7400 Owner Manual Rev. 2.
DS2 29 CO N-7 6 1 RS23 2 .. RS48 5 6 . 1 C O N-8 M CS112 2A12 8B8B MC9S A 12 9 1 CI -6 CO N-12 3 1 J4 J5 CON- 6 8 1 6MHz XTA L1 VM A B G ND 1 1 ( YL ) RS485 A ĺ PIN 3 – CON DB9 RS48 5 – REAR PANEL ( OR) RS485 B ĺ PIN 2 – CON DB9 RS48 5 – REAR PANEL CON- 5 8 BDM IN ( YL) EXCIT ER T EMPERAT UREAL ARM ĺ PIN 6 – CON- 1 – CIM3 446 – MOD.4 453 – 30W UHF EXCITER 1 . LM3 58 . CO N-9 DS22 9 7 1 9 1 2 3 L M78 0 5 BCX53 .
Assemble on the PCB CIM 3297 on the 20W UHF ATSC exciter drawer, module 4456, are the following controlling functions: 3.11.1. Digital Control The CI-4, (MC9S12A128B) is the microcontroller that manages all the sub-modules assemble on the module 4452. CI-4 is factory pre-programmed, carrying an assigned number and software version. Regarding to the UHF exciter, the software number is AT1002 version 1.0, when available further upgrades will be issued as new version numbers.
All alarms listed above, are available at the connector CON-6 at the PCB CIM 3297, as digital format. Normal operation is logic level 1, (or +5V). Alarm is set, meaning abnormal operation is logic level 0, (or 0V). In the sequence of the alarm processing, from the connector CON-6 the signals are routed to the microcontroller CI-4. Throughout of serial interface RS485 these alarms information are routed and displayed on the LCD at the front panel of the MCU unit termed as “drawer’s alarms”. 3.11.4.
x x x x x Event Drawer TEMPERATURE. Phase Lock Loops. 8VSB IF Signals (I/I’) or (Q/Q’). Master clock Fan fuse Location Module 4455 Module 4453 Module 4454 Module 4454 Transmitter rack Alarm set Above 149°F (+65°C) Unlock Absence of any Erratic Open The procedure described on this section is validated only if the transmitter operation mode is configured as AUTOMATIC MODE. (SetUp/Transmit/ReStart: AUTO). At the time when the transmitter is powered ON, there is a 5s time lapse termed as RAMP TIME.
3.11.6.3 Serial RS485 Communication The SCU (CIM 3297) is run by the MCU (Module 4459). The communication between these 2 command units is made via RS485 and on both units by the CON-12. For the SCU at the exciter drawer, the CON-12 is connected to the DB9 connector located at the drawer rear panel, labeled as RS485. Fig.3.16: MCU-SCU communication access RS232 & RS485 connectors 3.11.6.4 Serial RS232 communication It is possible to access the SCU’s command at the exciter drawer locally.
3.13. GV4452 – Schematic Diagram: SEE ANNEX A 3.11.2. 3.11.3. 3.11.4. 3.11.5. 3.11.6. 3.11.7. 3.11.8. AT7400 Module 4454 - 8VSB Modulator and MASTER Clock Generator Module 4453 - IF/UHF Up-Converter Module 4466 – DDS Module 4464 - 20W UHF / ATSC Module 4456 - Power Supply PCB CIM3297 - Subordinate Control Unit (SCU) PCB CIM3458 – Multiple voltage regulator Owner Manual Rev. 2.
Section 4 – Intermediate Directional Coupler, RF Power (1:2) Splitter & (2:1) Combiner Module 4488 4. General Description The readings for direct and reverse RF power transmission on the exciter drawer on the ADVANCED TV line of transmitters are display on the frontal panel of the main control unit, module 4459. The shown values for direct and reverse power levels are RMS values, referred to the 8VSB modulated carrier.
Fig.4.2: Module 4488 block diagram 4.1. Module 4166 - Directional Coupler Cells Fig. 4.2: Intermediate coupler cells – Module 4166 - spatial view, DP and RP sensors AT7400 Owner Manual Rev. 2.
The adjustments at the module 4166 are very simple; however they are very important for the correct performance of the entire equipment. The module come already adjusted from the factory according with ATSC procedures as stated on the recommendation A53/E. If complementary adjustments become necessary, please contact the factory for a complete set of instructions and guidelines. Coupling wattmeter should NOT be used to measure ATSC power levels; instead LINEAR recommends absorption type wattmeter. Fig. 4.
4.2. Module 4482 – 1:2 RF Splitter & 2:1 RF Combiner The splitter-combiner gizel networks are fully passive and are both assembled on the same mechanical structure, located at the rear of the rack structure. Fig.4.3: Module 4482 internal view, at right the combiner network Fig.4.4: Module 4482 - block diagram AT7400 Owner Manual Rev. 2.
4.2.1. AT7400 Care When Connecting the Splitter/Combiner Module Owner Manual Rev. 2.
Section 5 – 220w UHF ATSC Power Amplifier Unit/Drawer GAV4445 4. General Description The unit GV5555 is a drawer that is powered by 208Vac voltage from the main breaker. The overall gain of this unit is in the range of 14dB up to 20dB depending of the assigned UHF channel. The amplification circuitry is factory tuned for one band among 4 UHF channels bands. It has stable input and output 50ȍ impedance and it is ready to be combined with others same channel equal channels. Fig.5.
Fig.5.2: GAV4445 modules displacement AT7400 Owner Manual Rev. 2.
Owner Manual Rev. 2.
6. GAV4445 - Module 4451 – 75W UHF ATSC Pallet Amplifier 6.1.General Functional Description The 75W UHF/ATSC, sub-module 4451 is present on all the RF power amplifier drawers on the ADVANCED TV line of transmitter UHF models. On the module 4445, 250W ATSC UHF RF Power amplifier drawer, there are 4 sub-modules 4451 that combined are able to delivery 300W/UHF/ATSC. Fig.5.3: Module 4451 - 75W UHF ATSC pallet amplifier The module 4451 is highly linear on all UHF frequency band.
AT7400 Owner Manual Rev. 2.
The module 4451 is composed of 2 amplifier cells, polarized on class AB, on push-pull configuration, connected in parallel. Each cell carries 2 LDMOS transistors; assemble on the same die, delivering 37.5W each or 75W on total. 6.3.
6.4. Module 4451 – Tuning and DC Setup Instructions R11 R FOUT The module 4451 can either be adjusted connected to the equipment or out of it. On both cases, it is mandatory to keep the RF out put correctly loaded (50ȍ). A +32V/2A power supply must be ready to be driving the drawer, during the proposed adjustments, done under reduced RF power conditions. While doing one pallet adjustment, disconnect the DC main power out from the other modules 4451. +3 2V CON- 2 . S1 T1 T2 CI-8 . .
6.4.5. Module 4451 – Drain Current Adjustment No RF signal should be present at the input of the sub-module 4451 during the ID adjustment procedures. Power the sub-module on, and wait 3 minutes for thermal stability. Take a multi-meter, and set for mVdc scale, avoid using the auto-range scale. Transistor T1: 1) Turn the trim pot TPO-1 all course anti-clockwise, as result the ID at T1 will be set 0. 2) Set the multi-meter scale for 100mV, and measure the voltage drop over R9.
NETWORK ANALYZER RFIN RFOUT 30dB / 50W ATTENUATOR T1 C13 C9 TPO- 1 VGS ADJ T1 BLF 861A C5 R11 CON- 2 +32V T3 . R9 . CI-7 S1 +32V / 2A T4 CI-8 RFIN C39 R10 +32V CON-2 +32V / 2A RFOUT B LF861A C42 TPO-2 T2 VGS AD J C35 ID1 ID2 TEMP CI-5 CON- 3 HC -1 CI-4 . CI- 2 . . . CI- 3 CI- 1 T2 MODULE 4451 Fig. 5.6: Set up for tuning procedures – module 4451 Adjust the network analyzer for -20dBm RF out put level. Connect the RF signal to the RF input of the submodule.
7. GAV4445 – Board CIM3452 – Subordinate Control Unit, SCU 7.1. CIM3452 General Functional Description For each GAV4445 installed on the series ADVANCED TV transmitters, there is also a SCU associated with, termed CIM3452. FIG. 5.7: Board CIM3452 installed on GAV4445 at bottom side, lateral right panel The SCU installed on the RF power drawer, GAV4445, maintain a constant communication with the master control unit, MCU, module 4459. The SCU manage and monitor the drawer according with MCU commands.
1 CON 1 8 6 (SH) RS232 GND ? PIN 5 – CON DB9 RS232 – REAR PANEL (GR) +8V ? PIN 5 – CON-5 – CIM3429 – MOD. 4275 – POWER SUPLLY (OR) RS485 B ? PIN 2 – CON DB9 RS485 – REAR PANEL (YL) RS485 A ? PIN 3 – CON DB9 RS485 – REAR PANEL (RD) RS232 TX ? PIN 3 – CON DB9 RS232 – REAR PANEL (WH) RS232 RX ? PIN 2 – CON DB9 RS232 – REAR PANEL 1 CO N6 B DM I N VM C I-2 .
7.1.7.2 Analog Readings At the connectors CON-2, C0N-3 and CON-4, on PCB CIM 3452, as part of the RF power amplifier drawer, analogs information is driven in regarding the following parameters generated out of the power supply, submodule 4456. The CIM 3452 at the RF power amplifier drawer read the following analog parameters: 1. Voltage referring to +32V (VA/VB) out from the power supply, sub-module 4275. 2. Current out from VA power supply, sub-module 4275. 3.
7.1.7.4 Serial RS485 Communication The PCB CIM 3452 located at the RF amplifier drawer, is subordinated to the PCB CIM 3297, located at the MCU (Module 4459). The communication between these 2 command units is made via RS485 and pins # 3, 4 and 5 at the connector CON-5 on each one of the PCBs is the gate for IN and OUT of data streams.
7.2. Board CIM3452 Schematic Diagram: SEE ANNEX A 8. GAV4445 - Module 4275 – Power Supply 8.1. Module 4275 – General Functional Description Module 4275 is a switching high power DC supply, type full-bridge powered by 208 Vac, showing overall efficiency above 80%. As part of the power supply design, there is a power factor corrector, PFC, circuit. Besides correct the power factor to close to 1, this circuit also contributes to reduce the harmonic content returning from the unit into the AC mains.
AT7400 GRO UND AC 180 to260V IND U CT OR +18V C IM 3427 PFC C ONT ROL SW IT C HIN G TR AN SIS TORS R ET IFIER TR AN SFOR MER RE TIF E I RS +18V RE GUL AT OR +1 5V R EGU LAT OR Owner Manual Rev. 2.
8.3. CIM3238 – Power Phase Control Unit – PFC The PFC circuit is located at PCB CIM 3238, at sub-module 4275. The PFC circuit is a power supply built according with the “boost regulator in continuous mode (CCM)” topology. Under the CCM topology, is possible guarantee a power factor, cosij above than 0.9. The PFC circuit is composed by a full diode bridge that performs a full-wave rectification on the AC signal, which than is routed to the boost inductor. The voltage is so boosted up to +385V.
On maintenance situation the sub-module 4275 the automatic operation, (independently of the SCU status), AUT, can be turned on a manual MAN, operation by changing the position of the jump CON-3. The AUT position must be re-state as soon as the maintenance is over. The shut down operation is fundamental to protect the power supply and the UHF amplifiers as well, sub-modules 4451. 8.8. Module 4275 – Technical Specifications 8.9. Module 4275 –Schematic Diagrams: SEE ANNEX A AT7400 Owner Manual Rev. 2.
Section 6 – Output Directional Coupler, UHF Low Pass Filter & Band Pass Mask Filter 6.1. Module 4429 – Output Directional Coupler - General Description The UHF output related power readings direct and reverse, are shown on the LCD screen at the MCU (module 4459) located on the frontal part of the ADVANCED TV line of transmitters. All the readings are RMS values of the 8VSB modulated carrier.
6.2. Module 4429 – Technical Specifications 6.3. Module 4429 – Block Diagram AT7400 Owner Manual Rev. 2.
6.4. Module 4429 - Drawings AT7400 Owner Manual Rev. 2.
6.5. Module 4429 – Calibration 6.5.1. Introduction The calibration procedure is quite simple however very important for the overall transmitter operation. Usually this procedure should not take place on the field. The criterions of calibration follow the recommendation as ATSC A53/E. In case of re-calibration, it is mandatory the utilization of absorption type wattmeter. LINEAR utilizes the Agilent model E4418B EPM series single power meter in conjunction with the 8481A power sensor.
6.5.2. Module 4429 – Calibration Step-by-Step To reach the MAIN MENU screen, Fig.6.4, hit the CANCEL yellow key (not shown below) up to 4 times in sequence, any time. Fig. 6.4: Main menu LCD screen at MCU unit 6.5.2.1 Direct Power Calibration 1. Using the keyboard (soft-keys) and LCD on the MCU, manage to disconnect the ALC operation. Follow the selfexplanatory screen instructions. Start with the main menu screen, striking in sequence the gray keys as going to SETUP ĺ75$160,7ĺ$/&ĺ2))ĺ(17(5 Fig.6.
2. Adjust the RF power via menu (ALC is OFF at this point) to the desired nominal level read at the calibrated external wattmeter. Fig.6.5: Reference output power reading on the power meter absorption Check if the readings on the LCD screen of the transmitter are also displaying the same value. To get to this screen start out from the main menu and go to SETUPĺ32:(5 reaching the POWER TRANSMITTER SETUP screen as shown on Fig.6.6 below: Fig.6.
3. To make the power reading coincidence among the 3 readings, (a) the wattmeter, (b) the [program], and (c) [output] where (b) and (c) are present on the LCD screen, will be necessary adjust the DC level that represents the coupling coefficient between the sampler and the 50ȍ transmission line at the output directional coupler hardware. Look for the indication of FORWARD POWER opening the case of the output directional coupler, (Module 4429).
6.6.1. Module 4428 – UHF Low Pass Filter Fig.6.9: UHF low pass filter The module 4428 is a 7/8” rigid transmission line, no tuning points. Depending of the UHF assigned band the filter is specified as: x x P/N 21802 for Channels 14 up to 39: …….....416.5 mm. P/N 23045 for Channels 40 up to 69: …….….373.3 mm. These filters have NO adjustment to be done. Pay attention for mechanical damages that may occur on the main line, or also on the IN/OUT connectors. Fig.6.
6.6.2. Module FC6E80C – UHF Band Pass Filter – ATSC Mask Filter Featured AT7400 Owner Manual Rev. 2.
AT7400 Owner Manual Rev. 2.
FEATURES • UHF 500W Digital TV band pass filter • ATSC FCC Mask applications • 6 poles elliptical response (cross coupling) • Dual Cross technique (four transmission zeros) • Combline topology • High selectivity and low loss (Typ. 0.
Section 7 – Energy Distribution and Control 7. General Description The energy distribution circuits on the transmitter can be configured on the following possibilities: x x x x 208VAC 208VAC 208VAC 360VAC -220 VAC – 240 VAC mono-phase. -220 VAC – 240 VAC bi-phase. -220 VAC – 240 VAC three-phase. three-phase. Fig.7.1: Energy Distribution – Bipolar Main Breaker on left, manual starter on the center and module 4147 – battery charger.
7.1. Energy AC Mains Connection Fig.7.2: Typical 3 wires bi-phase AC energy source connection diagram OPTION 1 – INTERLOCK CLOSED BY A JUMPED WIRE 208V TO EXCITER DRAWER GROUND STARTING SWITCH FROM IRUSH MÓDULE NEUTRAL 208V TO POWER DRAWER (PA1) R S T MAIN T RIPHASIC CONTACTOR R S T PHASE 1 BIP OLAR MAINBREAKER PHASE 2 PHASE 3 green wire is connected INTERLOCK Fig. 7.3: Bi-phases type energy ADVANCE TV LINE internal up-front connection diagram, no isolation powertransformer required.
12 0V 12 0V +3 2V +15V +15V M ODULE 4456 +5V M ODUL E 4455 M ODULE 4453 Owner Manual Rev. 2.
7.2.2. Main Parts List for Bi-Phase Configuration x x x x x x 01 bi-polar breaker; 30A. 01 three-phase main breaker. 01 I Rush sub-module 4443. 01 interlock, or jump 01 battery 12V / 7Ah. 01 AC main sub– Module 4147. 7.2.2.1 Bi-Polar Breaker When turned ON, this device connects the 2 phases that are routed directly to the exciter drawer, module 4452, to the fan on the top of the transmitter rack, and to the I-Rush circuit. 7.2.2.
Parts list for the module 4443 is as follows: x x x x x Secondary breaker. Timer, 2.5 seconds. Mechanical delay 2 seconds. Two 18ȍ/50W resistors in parallel. On ON/OFF switch with 2 independent contacts. No matter which version is choose, 208/220/240 Vac will always be voltage to be delivered for the exciter drawer, and power amplifier drawers. Fig. 7.6: On the right the drawer AC power connector, on the right AC mains reading on the center pins of the same connector. 7.2.3.
Fig. 7.7: Manual bi-polar energizer breaker and the manual start switch, both located on the bottom of the front panel. When the POWER ON/OF switch is press, the 2.5s timer is activated energizing the coil of the secondary breaker. In sequence the 2 rush resistors are connected in series with the AC mains. 2.5s pass by and the breaker is disabled opening its contacts protection the rush resistors.
Owner Manual Rev. 2.
(BL) +15V ĺ PIN 8 – P1 –MOD 4459 – MCU (GR) +8V ĺ PIN 7 – P1 – MOD 4459 – MCU (WH) GND ĺ SCREW GROUND TERMINAL – AC PANEL (WH) GND ĺ SCREW GROUND TERMINAL – AC PANEL (BR) FLOATING +15V ĺ PIN 1 – CON-4 – CIM6241 – PHASE DETECTOR (VL) FLOATING GND ĺ PIN 2 – CON-4– CIM6241 – PHASE DETECTOR (VL) FLOATING GND ĺ PIN 3 – CON-4 – CIM6241 – PHASE DETECTOR (GY) +15V READING ĺ PIN 3 – P2 –MOD 4459 – MCU (OR) +8V READING ĺ PIN 4 – P2 – MOD 4459 – PHASE DETECTOR (BR) +5V (COMMUM) ĺ PIN 1 –CON-3 – CIM6241 – PHASE DETECTO
3.8.2. Battery 12V/7Ah The 12V battery feeds the input of the DC-DC converter, module 4147, for continuous generation of voltages for the MCU even on absence of +32V that normally comes from the exciter drawer, sub-module 4452. Fig.7.10: 12V/7AH Battery – shown with + cable disconnected AT7400 Owner Manual Rev. 2.
ANNEX A ADVANCE TV Line Schematic Diagram Index Reference Description 1 CIM 3112 Keyboard 2 CIM 3113D Switching Power Supply 3 CIM 3118 DC Filter 4 CIM 3128B RF Detector 5 CIM 3297 Digital Control 6 CIM 3390 UHF Amplifier 7 CIM 3427 Switching Power Supply 8 CIM 3429 Switching Power Supply 9 CIM 3440 UHF Amplifier 10 CIM 3442 Up-Converter 11 CIM 3443 Local Oscillator 12 CIM 3444 8VSB Modulator 13 CIM 3445 172MHz Clock Generator 14 CIM 3446 UHF Exciter Amplifier 15 CIM 3447 Switching Power Supply 16 CIM 3452
