Hitachi Kokusai Electric America AT725P 25 Watt UHF ATSC Transmitter User Manual AT725P Owner s Manual

Linear Industries, Inc.

AT725P

Owner’s Manual

August 2009

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:

Operational Software

Annex B:

Checking the LDMOS transistors

Annex C:

Typical Final Test Report Results

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 AT7350-

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.

Notice 4

Should accident or injury occur to the personnel engaged in the installation,

operation, or service of the equipment, they should seek proper medical attention. It

is advisable that such personnel have familiarity with first-aid practices.

Notice 5

For technical support please call the Linear technical support customer service line

at 847/428-5793 ext. 105.

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

without written authorization. This document is legally protected by the copyright

laws.

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. IT IS NOT THE

INTENT OF THIS MANUAL TO PROVIDE A COMPLETE SET OF SAFETY

INSTRUCTIONS OR PRECAUTIONS THAT SHOULD ALREADY BE

UNDERSTOOD BY TRAINED OR EXPERIENCED PERSONNEL IN USING THIS

OR OTHER TYPES AND FORMS 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 INDIVIDUALS

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/MAIN 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.

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. 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

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 straps, supports and

packing materials are completely removed from the equipment prior to initialization

and use.

AT725P Owner’s Manual

Section 1 – AT725P General Description

1. General Description

The ATSC DTV exciter model AT725P is part of the ADVANCED TV line, with modular construction to fit in a

19” EIA standard rack and including the following modules:

• 01 Main Control unit - CIM3297

• 01 Keypad - CIM3003

• 01 Display LCD 20 columns x 02 lines - CIM3004

• 01 Memory interface - CIM3535

• 01 1Mbits memory card - CIM3516

• 01 25W RMS UHF/ATSC - Module 4408

• 01 up-Digital Converter - Module 4492

• 01 Power Supply - Module 4401 (versions M110/M220/B220)

• 01 8VSB Modulator and Master Clock Generator - Module 4549

• 01 DC/DC Converter (+2.5V and +5V)

When an AT725P is installed as a TRANSMITTER, a 6 poles elliptical filter is installed at its RF Output. The

additional insertion loss is considered and the unit is pre-corrected and equalized accordingly. In this

application, the overall performance of the unit will meet or exceed the FCC requirements for out of the

channel spurious emission. Please refer to Annex C.

One will also need to perform an operational software operation, to set the unit as TRANSMITTER. Please

refer to Annex A, SET CONFIGURATION at page 64.

AT725P Owner’s Manual

AT725P Block Diagram:

C O N T R O L U N IT

C IM 3 2 9 7

(C I P 8 2 3 1 )

+8V

+15V

R E S T A R T

R F O U T

2 0W A M P .T E M P E R A T U R E

M A S TE R C L O C K L O C K D E T E C T

E X C I T E R F O R W A R D P O W E R

E X C I T E R R E F LE C T E D P O W E R

2 0W E X C I T E R ID C U R R E N T

+ 32 V P O W E R S U P P L Y

+ 18 V P O W E R S U P P L Y

-1 8V P O W E R S U P P L Y

+ 9V P O W E R S U P P L Y

+32V

O U T P U T

CURRENT

R E A D IN G

+9V-18V

+18V

+32V

F IX O

+32V

R E A D IN G

+18V

R E A D IN G

-18V

R E A D IN G

+9V

R E A D IN G

+32V

R E S .

P O W E R S U P P L Y

M O D U L E 4 40 1

110V / 220V

M O N O P H A S IC

A N D B IP H A S IC

O N /O F F

S W I C T H

5 A / 2 2 0 V

1 0 A / 1 1 0 V

F U S E

R E A D IN G S

A L A R M S

+32V

R E S T A R T E D

2 0 W U H F A T S C A M P L IF IE R

M O D U L E 4 40 8

T E M P E R A T U R E

A L A R M

F O R W A R D P O W E R

R E A D IN G

F A N

F IL T E R

C I M 6 6 7 3

+24V

+32V

F IX O

IN O U T

8 V S B

M O D U L A T O R A N D

M A S T E R C L O C K

U H F U P C O N V E R T E R

M O D U L E 4 49 2

+18V-18V

QIN

RF

O U T

S W 2

T E M P

E N A B L E Q D A C

E N A B L E I D A C

C L O C K D A C

D A TA D A C

A L C

+32V

F IX O

IIN

S W 1

E N A B L E

D A TA P L L

C L O C K P L L

L O C K D E TE C T

K E Y B O A R D

C I M 3 0 0 3

LI N E AR E QU I P A M E N TO S E L E T R Ô N IC O S

D IS P L A Y

C I M 3 0 0 4

S M P T E IN

A S I IN

1 0 M H z R E F IN

M O D U L E 4 54 9

+32V

M O D U L E 4 5 6 7

D C C O N V E R T E R

+5V+ 2 .5 V

+5V+ 2 .5 V +18V-18V

R E F L E C TE D P O W E R

R E A D IN G

1 0 M H z

O C X O

M O D U L E 4 2 8 1

R S 2 3 2

E X T E R N A L

F U N C TIO N S

P A IN E L

T R A S E IR O

RD

E N A

C L K

D IN

DO

LD

M E M O R Y

C A R D

C IP 8 4 2 1

M E M O R Y IN T E R F A C E

C IP 8 4 3 7

+5V

D C L K

A S D I

C S

D A T A

F R O M

C O N T R O L

U N IT

RD

E N A

C L O C K

D IN

DO

M O D U L A TO R

C O N T R O L U N IT

D C L K

A S D I

CS

D A T A

T O

M E M O R Y

IN T E R F A C E

Fig. 1.1: AT725P - Block Diagram

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. The signal processing and modulation performed on

this module follows the ATSC recommendation A/53 E.

In this modulator, the in-factory non-linear pre-correction that may be necessary to enhance

the equipment’s efficiency and meet the FCC’s spurious emissions’ requirements are

performed. If an RF output filter is required (AT275P being set up as a transmitter), the

recommended linear equalization is also factory performed in this section.

Master Clock section

The master clock unit generates via PLL and VCO’s type oscillator at 172.16MHz. The PLL

loop is locked to a 10MHz reference, externally or internally generated. This signal is the

time base for the 8VSB modulator

Module 4492

IF to UHF up-Converter section

The IF orthogonal carriers (I) and (Q) are generated on module 4549, (8VSB Modulator

section), and are routed to the up-converter module. The output signal of this module is set

on the FCC/UHF operational 6MHz channel of the exciter AT725P.

Internally, the modulated IF band mixes with the continuous wave local oscillator LO. As

result of this mixing, the IF translation to the UHF band is performed. The LO is a free

oscillator, that has its frequency locked via PLL. The LO/PLL use a 10MHz OCXO (oven

controlled crystal oscillator) type, or an external reference.

10MHz reference automatic switching section

Both circuits, the 8VSB modulator and the up-converter share the same source of reference

signal they need. The use of the same reference allows a perfect synchronization and

stability during the DTV transmission process. The internal 10MHz signal is gotten from an

OCXO oscillator @ 0.3ppm. The external 10MHz signal can use as reference a GPS signal

for instance.

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. This module uses transistors built with LDMOS technology operating in class AB, with

excellent ratio between efficiency and linearity. The RF OUT connector of the unit is the

output of this module.

RF Output sample section

The module 4408’s RF sample, detects the direct and reverse RF power present on the RF

OUT connector of the unit. These two detected samples are then converted on

correspondent DC levels before being routed to the master control unit, where they will be

processed and displayed on the front panel, LCD screen in unit watts.

CIM3297

Control unit card

The digital management of the transmitter of DTV AT725P is made by the control unit card

CIM3297. This control unit utilizes an A128 microcontroller programmed in the assembler

language, which makes the process data related with the following parameters:

• Alarm of loss of the lock of the PLL of up-converter.

• Alarm of excess temperature of the 25W amplifier.

• Monitor and exhibit the RF direct and reflected powers, out from the 25W amplifier, muting

the transmission in case of extreme levels.

• Exhibits of level electrical current, I1 from the main power supply.

• Process and exhibit the voltages generated by the power supplies.

• Set the Up-converter unit with the operational channel and transmitted power level via ALC.

The control unit is directly connected to a keypad and LCD screen both located on the front

panel of the exciter AT725P, from where monitoring and parameters can be set. The same

functions can be performed via the RS232 communication connection to a HyperTerminal.

Module 4401

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 External Interfaces

Fig.1.2: AT725P Front View

Fig.1.3: AT725P Rear Panel View

20 X 2 - LCD Screen – Visual Interface for

SETUP and MEASUREMENTS

Power Switch

Command KEYPAD – Interface for readings and

data entry.

ID Tag

External 10MHz

Reference Input

GND

Main Fuse

ASI/SMPTE310M Transport

Stream Input

Internal DB-9

Not Used

ON/OFF the air External

Functions (DB-9)

AC Power Cord

RF Output

Connector

(DB-9) RS232

Hyper-terminal Interface

Hot Air Outlet

AT725P Owner’s Manual

AT725P - Modules and Parts Displacement

Fig.1.4: AT725P Modules and Parts displacement

Key Pad

CIM3003

RF Power Amplifier

Module 4408

LCD Screen

CIM3004

LUT

Module 3535

DC/DC

Converter

Module 4567

DC Fan Filter

CIM6673

Digital Control Card

CIM3297/CIP8231A

+32V Power

Supply Module

4401

Ref. 10MHz OCXO

Module 4281

Power Switch

Fuse & GND

Up Converter &

Master Clock

Module 4492

8VSB Modulator

Module 4549

AT725P Owner’s Manual

AT725P - 25W UHF ATSC/8VSB Exciter- Transmitter - Technical Specifications

Electrical

Main

110/220 VAC, bi phase, 50-60 Hz.

Consumption

400W.

Power Factor Correction, FPC.

Included

Signal Input

Transport Stream Input

ATSC/MPEG2, compliant to SMPTE310M

Input Data Rate

19.39 Mbps

External Reference Signal

10MHz. (0 to +10 dBm).

Input Connector

75Ω (BNC),

Reference Input Connector

50Ω (BNC),

RF

Modulation Mode

8VSB.

IF

18.833916 MHz.

Channel Bandwidth

6MHz.

Test Signal

PRBS

Frequency Range

UHF. C14 to Ch59, (3 bands).

Frequency Step

1 Hz. ± 220kHz

Symbol Rate

10.76 MSymbol/sec.

Digital/Analog Converter

16 bit

Linearization Pre-Correction

Included

Pilot frequency stability overall

± 4.6 ppm.

Initial tolerance

± 1.0 ppm.

Vs. temperature in operating temperature range (steady state)

± 10 ppb.

Holdover 24 hours, full temp. range

± 12 ppb.

24 hours drift (after 30 days)

± 1.0 ppb.

Long term stability over 15 years

± 3.5 ppm.

Peak to peak frequency response

0.15 dB.

Peak to peak group delay response

10 ns.

Phase noise

⁭⁭≤ -104 dBc/Hz @ 20kHz offset.

Conducted spurious and harmonics

< -60 dBc, FCC 47 Part 74.

Radiated spourious and harmonics

< -80 dBc, FCC 47 Part 74.

MER (Modulation Error Rate)

≥ 29 dB (transmitter output) typical.

RF output connector

N

Communication

Hyper-terminal

RS232 (DB-9)

External Command – ON/OFF

(DB-9)

Mechanical

Air speed over drawers

25 ft/minute.

Dimensions

3UR (H), 19”(W), 26”(D)

Weight

Gross: 11 Kg

AT725P Owner’s Manual

Section 2 – Control Unit

General Functional Description

The DIGITAL CONTROL UNIT is responsible for all the digital management of AT725P exciter-

transmitter. 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.

• Management of the alarm of excess of temperature of the 25W amplifier.

• Monitor and exhibit the direct and reverse RF power at 25W level. In case of extreme

levels, the transmission will shut down.

• Display the main electrical current value, I1, drained from the main power supply.

• To process and show the power supply voltages.

• Perform the IF/RF Up-conversion control and transmitted power level control, (ALC).

Control unit block diagram

Fig.2.1: Control unit general block diagram

CONTROL

UNIT

CIP8231

(CIM3297)

MICROCONTROLLER

DISPLAY

CIM3004

KEYBOARD

CIP8002

(CIM3003)

EXCITER FORWARD POWER READING

EXCITER REFLECTED POWER READING

EXC.20W ID CURRENT READING

VOLTAGES SUPPLY READINGS

RS232 REMOTE CONTROL

EXTERNAL FUNCTIONS

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)

AT725P Owner’s Manual

Fig.2.3 20 x 2 LCD display board - CIM3004

CIP8231 Connections

(BK) SW2 PIN 3 –CON 6 –CIP8388 –MOD. 4492 –UHF UPCONVERTER

(GR) TEMPERATURE ALARM PIN 4 –CON-5 –CIP8209 –MOD.4408 –UHF AMPLIFIER

(GY) RESTART PIN 6 –CON-8 –CIP8111 –MOD. 4401 –POWER SUPPLY

CON-1

BL

7

CON-2

1 9

9

1

3

6CON-7 CON-8 CON-9

1

GND

VCC

DA1

DA2

+15V

IRQ

CON-3

1

6

CON-4

8

CON-5

8

1

CON-6

8

1

PA21

PA31

PA41

PA51

PA61

PA71

1

PA02

PA12

PA22

PA32

PA42

PA52

PA62

PA72

PB01

PB11

PB21

PB31

PB41

PB51

PB61

PB71

PB72

PB62

PB52

PB42

PB32

PB22

PB12

PB02

GND

TX

RX

PC6

PC5

GND

A16

A15

A14

A13

A12

A11

A10

A09

GND

A08

A07

A06

A05

A04

A03

A02

A01

CI -7

LM7805

CI-1

1 2 3

TPO-1

AJUSTE

LUM. DISPLAY

XTAL1

1

14

SCL

SDA

PM4

PM3

PJ1

PJ0

16MHz DTR

CTS

RX

TX

GND

RTS

DCD

CON-11

1

6

CON-10

1

7

J1 VM

BDM IN

MC34064

LM358

CI -4

MCS12A128BMCS12A128B

MC9S12A128B

Q1

BCX53

CON-12

1

.

DS229

..

RS232

RS485

J4

J5

.

DS229

CI -6

CI-2

.

CI-3

.

(GY) DATA PLL PIN 6 –CON-3 –CIP8388 –MOD. 4492 –UHF UPCONVERTER

A

B

GND

(WH) RX RS232 PIN 2 –CON DB9 RS232 –REAR PANEL

(RD) TX RS232 PIN 3 –CON DB9 RS232 –REAR PANEL

(SH) GND RS232 PIN 5 –CON DB9 RS232 –REAR PANEL

(WH) GND PIN 1 –CON-6 –CIP8388 –MOD. 4492 –UHF UPCONVERTER

(BL) +15V PIN 1 –CON-13 –CIP8111 –MOD. 4401 –POWER SUPPLY

(GR) +8V PIN 1 –CON-11 –CIP8111 –MOD. 4401 –POWER SUPPLY

(YL) ENABLE QDAC PIN 8 –CON 6 –CIP8388 –MOD.4492 –UHF UPCONVERTER

(GY) SW1 PIN 4 –CON 6 –CIP8388 –MOD.4492 –UHF UPCONVERTER

(OR) CLOCK DAC PIN 7 –CON-6 –CIP8388 –MOD.4492 –UHF UPCONVERTER

(OR) LD CLOCK GENERATOR PIN 1 –CON-7 –CIP8358 –MOD. 4549 –8VSB MODULATOR

(BK) DATA OUT PIN 3 –CON-2 –CIP8357 –MOD. 4549 –8VSB MODULATOR

(BR) ENABLE PLL PIN 5 –CON-3 –CIP8388 –MOD. 4492 –UHF UPCONVERTER

(YL) CLOCK PLL PIN 7 –CON-3 –CIP8388 –MOD. 4492 –UHF UPCONVERTER

(VL) LOCK DETECT PIN 8 –CON-3 –CIP8388 –MOD. 4492 –UHF UPCONVERTER

(OR) DATA IN PIN 2 –CON-2 –CIP8357 –MOD.4549 –8VSB MODULATOR

(RD) MODULATOR CLOCK PIN 4 –CON-2 –CIP8357 –MOD.4549 –8VSB MODULATOR

(GR) MODULATOR ENABLE PIN 5 –CON-2 –CIP8357 –MOD.4549 –8VSB MODULATOR

(VL) MODULATOR READ PIN 6 –CON-2 –CIP8357 –MOD.4549 –8VSB MODULATOR

(VL) DATA DAC PIN 6 –CON-6 –CIP8388 –MOD.4492 –UHF UPCONVERTER

(YL) TX ON PIN 3 –CON DB9 –REAR PANEL

(RD) ENABLE IDAC PIN 9 –CON 6 –CIP8388 –MOD. 4492 –UHF UPCONVERTER

(YL) BACK LIGHT DISPLAY POINT A –LCD DISPLAY–CIM3004

(YL) CS MEMORY PIN 4 –CON-2 –CIP8437 –MEMORY INTERFACE

(YL) ROW1_KEYBOARD PIN 1 –CON-3 –CIP8002 –KEYBOARD

(BL) LINE1_KEYBOARD PIN 6 –CON-3 –CIP8002 –KEYBOARD

(GY) ROW3_KEYBOARD PIN 3 –CON-3 –CIP8002 –KEYBOARD

(OR) DCLK_MEM PIN 6 –CON-2 –CIP8437 –MEMORY INTERFACE

(OR) LINE3_KEYBOARD PIN 4 –CON-3 –CIP8002 –KEYBOARD

(WH / RD) ALC PIN 2 –CON-6 –CIP8388 –MOD. 4492 –UHF UPCONVERTER

(RD) ASDI_MEM PIN 5 –CON-2 –CIP8437 –MEMORY INTERFACE

(VL) DATA_MEM PIN 3 –CON -2–CIP8437 –MEMORY INTERFACE

(RD) +32V OUTPUT VOLTAGE READING PIN 5 –CON-8 –CIP8111 –MOD. 4401 –POWER SUPPLY

(OR) +32V OUTPUT CURRENT READING PIN 1 –CON-7 –CIP8111 –MOD. 4401 –POWER SUPPLY

(BL) +15V READING PIN 2 –CON-8 –CIP8111 –MOD. 4401 –POWER SUPPLY

(BR) TEMPERATURE READING PIN 5 –CON-6 –CIP8388 –MOD. 4492 –UHF UPCONVERTER

(BL) FORWARD POWER READING PIN 1 –CON-5 –MOD. 4408 –UHF AMPLIFIER

(WH) GND INPUT EXTERNAL PIN 5 –CON-DB09 –PANEL

(GY) REFLECTED POWER READING PIN 2 –CON-5 –MOD. 4408 –UHF AMPLIFIER

(GR) +8V READING PIN 1 –CON-8 –CIP8111 –MOD. 4401 –POWER SUPPLY

(BK) -15V READING PIN 3 –CON-8 –CIP8111 –MOD. 4401 –POWER SUPPLY

(BK) LINE2_KEYBOARD PIN 5 –CON-3 –CIP8002 –KEYBOARD

(BR) ROW2_KEYBOARD PIN 2 –CON-3 –CIP8002 –KEYBOARD

Fig.2.4: CIP8231- the control unit board - components and connections.

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.

➢ The analogical readings function: All available analogical readings are sent via the connector

CON-9 on the CIP8231 board. Analogical readings include the following parameters:

• Direct power – 25W Amplifier.

• Reverse power - 25W Amplifier.

• (+9V) - Power supply.

• (+18V) - Power supply.

• (-18V) - Power supply.

• (+32V) - Power supply.

• (I1) – the main power supply drain electrical current.

All these seven analogical information are sent to microcontroller CI-4, where they are first

digitalized and then processed. The software of this microcontroller establishes that the nominal

value of the readings is 4Volts, that is, in connector CON-9 the reading information will have to

be of 4V in the way to express nominal values of each readings at the LCD display located at

the front panel of the equipment.

On each module of the equipment that generates some type of control-analogical information,

there is an associated test point. When during the calibration process external instruments

measurements indicate the correct nominal value for that function, a trimmer is adjusted in such

way that the voltage on the test point is set on +4Volts.

On the test point associated with reflected power, if the voltage becomes higher than +4Volts,

the control unit will process this event as an alarm. This will occur every time that the reverse

power exceeds 10% of the direct power.

Alarm detection

In case of substitution of the CI-4 or even the entire PCB CIP8231, it is mandatory to

inform the factory prior replacement, the programming identification number that is

clearly indicated at the CI-4 body.

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).

• Overflow of the FIFO in the 8VSB modulator (informing for communication between

microcontroller and modulator).

• Lack of synchronism of the transport stream, MPEG.

• Presence of not programmed hardware (it can appear in the warm-up phase of the

equipment).

• Imperfections associated with the generation of the master clock signal in the

modulator 8VSB - Module 4549.

The alarms above reach the connectors CON-4, CON-5 and CON-6 at the CIP8231 board as

digital information.

The microcontroller (CI-4) receives the alarm(s) information, processes them into the system,

and the software makes the decision to incapacitate the transmission or not.

The presence of +5V in the pins of alarm of connectors CON-4 and CON-6 and, therefore, in

connector CON-5 means that the status of alarms is empty and the transmitter operates

normally. In the event of one of these points of alarm falls for a value below of +5V, being

generally the zero, the microcontroller inhibits the transmission.

The alarms generated in the system are displayed as - alarms - in the Master Control Unit

window (MCU) on the front of the AT650P. The corresponding identification symbol of alarms is

“*” for current alarms - CURRENT - or “#” for old alarms - PAST. In the occurrence of an alarm

“*” in Alarms the transmission automatically will be inhibited. When the causing problem of the

identified alarm “*” is resolved, the “#” symbol will appear and the transmission will return

(slowly) to its full power. To erase old alarm records, key “CLR.ALL” in the MCU panel of the

AT725P, or in the hyper-terminal (keyboard key “1”).

Communication with 8VSB modulator

The CIP8231 board makes the communication with the 8VSB modulator - Module 4549 -

through a set of serial interface gates, (SPI). These connections are present on the pins 2 to 5

on the connector CON-3 and also on pins 5 and 6 of CON-5 connector.

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. Out

from this board the generated channel code will program the up-converter - Module 4492 - for

one determined UHF canal of/ATSC. This stream of information is composed by data, clock,

and enabling code, and are present at pins 1, 2 and 3 of CON-4 connector on CIP8231 board.

The control board sends the right channel operational information to program de fraction-base

PLL circuit at CIP8388, which will synthesize the local oscillator frequency suitable for the

desired channel.

All time that the equipment is turned on, the CIP8231 board automatically makes the

programming of the PLL at the module 4492.

It is important to remember that the initial programming that CIP8231board sets for the exciter

AT725P is made in the up converter is factory procedures. These programming procedures are

made in the act of the configuration of the equipment and although to be done it saw panel

frontal (keypad and display), they are not accessible to the end user.

In turn, the module 4492 sends to CIP8231 board, the lock detected information, as response

that the PLL circuitry is in lock and ready for operation. This information is packaged as voltage

level of approximately of +3,6V and is routed to the pin 5 of CON-4 connector CON-4 on the

CIP8231 board. The absence of this voltage will trigger the lock alarm that will cause the

reduction to 0 of the RF power of the module and at the same time will be signaled in the LCD

display located in the front panel of the exciter.

RF power control

The programming of transmitted power made by the end user, and can be made via the front

panel. The CIP8231 board converts this digital input programming information into analogical

level of voltage. This voltage is then sent to the up converter of the exciter. This specific voltage

level is called as ALC REFERENCE VOLTAGE or trellis voltage, being shown in the LCD digital

display as V.P. Adj.

The trellis voltage is directly proportional to the RF power level at the output the exciter, that is,

higher the trellis voltage higher the exciter RF power level. The typical value of trellis voltage

when the transmission is under the normal rated power is between 3V and 4V.

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.

When the equipment is turned on and the warm up period starts, around 5 seconds, the exciter

reaches the nominal RF power value. This period of time, is also known as SLOPE UP time, it is

the time necessary for the trellis voltage increases from its initial 0V up to its the corresponding

value to set the programmed RF power level at the output of the exciter.

Programming the off-set operational frequency

The AT725P exciter is factory adjusted in a given FCC/UHF operational channel, under ATSC

standard 8VSB modulation process, and no off-set is set. This channel can or not suffers

change in its off-set frequency, under the end user discretion. The offset can shift the RF

channel band up to 30 kHz, in 1Hz increments. The shift of frequency can increase or decrease

the start frequency of the band of the UHF channel. The offset is programmed at the CIP8231

board, and acts at the up-converter module 4492, on the pins 1, 2, 3 at CON-4 connector.

All time that the equipment is turned on, the CIP8231 board automatically re-confirms the last

set of programmed data at the 4492 up-converter module. It is important to say that

programming instructions generated by the CIP8231 board of the exciter are initially set via the

keypad/LCD screen located on the front panel of the exciter. However, those are procedures set

on the factory and, therefore, not accessible to the user.

+32V power supply ON/OFF control.

The CIP8231 board sends to the power supply, module 4401, a command to switch it ON. It is a

+5V level command. It is present at pin 6 on CON-3 connector.

The absence of this command voltage will make that the power supply module 4401 stops to

supply the switched +32V line, which feeds the 25W UHF amplifier module 4408. The others

voltages generated by other power supplies are always present during the exciter operation.

Serial communication RS232

The access to CIP8231 board is possible made through a PC that has the Windows Hyper

Terminal. Located on the rear panel of the exciter there is a DB9 connector tag as RS232.

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. The luminosity of

deep (back light) of this display is made by CIP8231 board that sends +5V between the test

point termed A+ (yellow wire) and ground test point termed K- (white wire). The multi-way

connector CON-2 receives the pin-to-pin from the CIP8231 board. The trimmer TPO-1 present

at CIP8231 board controls the intensity of the characters of the display and the jumper J1, also

present at CIP8231 board, must be set on the R61 position, if is desirable that the LCD back

light stays ON all time.

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.

(a)

(b)

Fig.3.1: Module 4549, (a) top view, (b) connectors, from rear panel

Internal 10MHz TCXO ref. input

10MHz OCXO ref. output to Up Converter

172MHz Master Clock

8VSB IF Modulated - 18.8339 MHz

IF (I) carrier

IF (Q) carrier

8VSB Modulator

Section

Master Clock

Section

Transport Stream Input

10MHz External Reference Input

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. All information compressed and

multiplexed in a MPEG2 format.

Fig.3.2: CIP8412 – 8VSB Modulator Block Diagram

The 8VSB channel modulator inserts the forward error correction, (FEC), into the transport stream MPEG2.

The modulator follows the ATSC standard A/53 annex D.

CIP8412 board - general functional description

The input transport stream signal to be modulated must be either ASI or SMPTE310M format at with

19.39Mbps of bit rate, and with 800mVpp @ 75 ohms. The ASI/SMPTE 310M input is located on the rear

panel by a BNC connector.

First the circuit to recover the clock rate is used to perform the protocol interface. After that there is a rate

equalization of the transport stream, TS, performed by the insertion or delete of the null packets, at the end

the symbol rate is ready to be stabilized and locked with a external/local reference of 10MHz and no longer

with the TS stream that is limited to 2.8ppm accuracy. During this processing is also used the re-stamping

for multiple programs, termed as PCR.

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.

The value for the system when working with 2 orthogonal carriers is because it is possible to implement

corrections on non-linear distortions, or simply implement digital pre-distortion. The digital pre-correction is

possible using LUT, (Look up Tables) refer to Section 7. This table synthesizes inverted responses regarding

the RF power amplifier transfer function, reducing the IMD products.

The digital processing generates I and Q distorted, and these 2 signals are then converted to the analog

format via a 16 bits DAC, with 2 balanced outputs, on a total of 4 output analog signals. These signals are

termed; I, I’, Q and Q’, and are respectively present at the CN9, CN8, CN6, and CN5 connectors at CIM3444.

These 4 signals will become the UHF Up-Converter input signals, Module 4453.

After the data processing as described below, the data stream is ready to receive the channel coding, that is

break down on the following steps:

Frame synchronization:

For each 188 bytes on the MPEG2 package, this circuit identifies and removes the 47th byte.

Randomizer:

This circuit equally spread the modulated signal energy over the channel band. The final energy density is

similar to a AWGN noise, with this technique, it is possible to achieve a higher bandwidth usage efficiency.

Reed-Solomom:

Reed-Solomon is a block coder, (207,187) that adds 20 redundant bytes on each 187 bytes of the MPEG2

package. With this method it is possible to correct on the reception site, some possible data errors that may

had occurred during the transmission of the RF signal.

Interleaving:

The interleaving technique helps to spread the errors around the time line, making them even less

susceptible to burst errors.

Trellis Code:

Trellis code is closely related to the channel modulation. It is a convolution coder using 2/3 rate, meaning for

each 2 bits at the input, there are 3 coded bits at the output creating the 8 symbols used on the 8VSB

modulation process, (-7, -5, -3, -1, +1, +3, +5, +7), having as ultimate goal improve the threshold on the

signal-to-noise ratio of the system.

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).

Master Clock – CIP 8358 board – (CIM 3445)

Introduction

The CIP8358 board, embedded into the module 4549, out from a 10MHz internal/external reference signal,

synthesizes a 172.16MHz oscillator that represents 16 times the symbol rate of the modulator 8VSB.

This oscillator signal is squared by a Schmitt-trigger circuit with amplitude equal to 0-3.3 volts. This square

wave type signal is the master clock signal that will synchronizes all the digital circuits on this equipment

except the control signals.

Fig.3.3: CIP8358 master clock – block diagram

CIP8358 board – general functional description:

The 172.16MHz frequency is synthesized via a PLL, a VCO and a DDS circuit. The 10MHz reference is one

out of the two inputs of the phase comparator. This signal comes to CIP8358 via a SMB connector, CON-1.

The second input is also a 10MHz generated by the DDS circuit out from the free running 172.16MHz

oscillator.

The loop filter performs the integration of the phase comparator output, generating the error signal that is

feed back to the VCO. On this way the VCO is locked to the external reference signal.

The oscillator signal is delivery via 3 connectors located on the CIP8358 board. Two of those signals are

routed to the 8VSB Modulator, CIM3510 board.

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.

Fig.4.1: Module 4492, RF connections.

RF Output

Ref. 10MHz input

2 x LO sample

(Q) IF input

(I) IF input

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).

Uses hybrid amplifiers with high linearity.

Overdrive protection circuit, acts maintaining the RF power via power reduction.

Automatically reduces the exciter RF output power in absence of IF signal, either Q or I carriers.

Stand-by for local oscillator, in case of some failure on the external reference signal.

Meet or exceed the phase noise requirements for DTV transmission.

Module 4492 - General functional description - Refer to Fig.4.2.

Fig.4.2: Module 4492 – block diagram

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.

The result is two RF lateral bands. The superior lateral band is not desirable and is attenuated by 35dB.

The resultant RF signal is filtered and amplified. The serial data stream that program the PLL circuit are

transferred via MICROWIRE interface, composed by 3 high speed transfer lines, 20MHz. The

microcontrollers inside the up-converter perform the following function controlling the up-converter:

PCB CIM3443 – Local Oscillator:

The local oscillator is designed based on a PLL circuit. This oscillator is able to synthesize frequencies within

the band from 450MHz up to 900MHz. To guarantee a high quality signal generation out from the local

oscillator, 4 VCO’s (voltage controlled oscillator) were implemented with a shift frequency range of 125MHz

each. Just one VCO works at the time to avoid interferences. On this arrangement, a 102dBc@20Hz phase

noise is achieved. The synthesizer on the feedback loop select the desired frequency inside the choose VCO

band.

The VCO’s signal outputs are isolated among them via a sum and inverted circuits. The reference frequency

generated by a DDS circuitry complete the Up-conversion frequency process. The output local oscillator

signal power is +5dBm.

PCB CIM3443 – Local Oscillator – block diagram:

Fig.4.3: CIM3443 local oscillator – block diagram

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.

Right after the mixing operation, the now RF signal is 10dB broadband (VHF and UHF) amplified under a

typical 2dB roll-off characteristic. The RF output pass through a 25dB dynamic range variable attenuator.

The control of this attenuator is related with the DC level generated by the ALC (Automatic Level Control). In

case of absence of a IF signal or valid IF signal (locked via PLL) of any of the 4 possible IF signals, the

attenuator assumes it higher level of attenuation, and shutting down the RF chain of amplification.

PCB CIM3442 – UHF Mixer – block diagram

Fig.4.4: CIM3442 UHF mixer – block diagram

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

+1.6V should be present on the following test points.

TPO-1: readings on L17

TPO-2: readings on L18

TPO-3: readings on L19

TPO-4: readings on L20

The second set of adjustments follows the first one. Once the first set is completed, the fine tuning

adjustment should be performed. It is necessary to connect the spectrum analyzer to the UHF RF output of

the sub-module 4453. At this point, either the LO signal, as the superior RF spectral image of the UHF/ATSC

RF channel, must be attenuated by 40dBc.

40dBc

UHF / ATSC

CHANNEL DTV

(BELOW MIXING)

LOCAL OSCILATOR

SIGNAL

UHF / ATSC

CHANNEL DTV

(ABOVE MIXING)

40dBc

UHF / ATSC

CHANNEL DTV

(BELOW MIXING)

LOCAL OSCILATOR

SIGNAL

UHF / ATSC

CHANNEL DTV

(ABOVE MIXING)

Fig.4.4: Level references for mixer-ALC fine tuning

The second adjust detects the protection signal at the center of the band. In absence of 1 out of 4

controls IF signals, this DC level exceed the min threshold and shut down the RF output signal. The DC

threshold adjust is performed by TPO-5, and should be set for +2.5V.

Module 4466 – Direct Digital Synthesizer (DDS)

The module 4466 is a signal reference generator based on a DDS circuit. This module is able to

synthesize frequencies up to 50MHz under mHertz precision range. The signal is used as PLL reference on

the UHF Up-Converter module 4453 – PCB CIM3442. The RF channel 10kHz off-set if necessary, is pre-set

on the DDS circuitry. The phase noise on the reference signal generated on this module is better than

110dBc/Hz.

The SCU unit – PCB CIM3297 – configures the DDS’s circuitry parameters via a serial

communication port. The DDS module receives a signal out from the master clock module 4454 - PCB

CIM3445; perform the programming operation for the RF output channel as required under mHertz precision.

At the end, is expected a frequency error around 1Hz max., when measured at the output of the UHF mixer

circuit. Before leaves the module, the DDS signal is amplified and filtered.

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. This module was developed to operate in three bands of UHF, which are:

• LOW BAND (LB): channels 14 to 44

• HIGH BAND (MB): channels 45 to 59

For the two bands of UHF described above, the same PCB is used.

25W UHF / ATSC AMPLIFIER - MODULE 4408

CIRCUIT

CIM

CIP

DRIVER

3392B

8209

What defines which one UHF band the module 4408 must operate, are determined by the PCB’s

components.

Module 4408 is divided in the following parts:

3dB input attenuator, (3dB PAD)

This attenuator is composed by 3 resistors connected as type π topology, R1, R2 and R3, this attenuation

guarantee 6 dB isolation. The input matching circuit also has 4dB isolation. The total isolation between the

PCB input and gate of the transistor T1, is at least 10dB.

First amplifier on class A

This section uses the transistor LDMOS, T1 (PD57006) with operating with a power gain close to 22dB. The

class A polarization insures a high linearity amplification behavior.

The transistor T1 is connected to the +32V power supply, module 4401. This voltage is available at the pins

2, 3, 4 and 5 at the connector CON-2 – module 4408. The trimmer TPO-1 adjusts the VGS voltage of the

transistor T1 and, consequently, the drain bias current (ID) of this same transistor. By trimmer C15 the gain

of T1 is optimized for the highest value.

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.

To trimmers C32 and C33 adjust the gain associate with T2, being optimized for the highest value.

Third amplifier on class AB

This final amplifier device is the LDMOS transistor T3 (BLF-861A) type GEMINI, that is, in the same die it has

two transistors. The polarization of T3 is made in class AB, what it guarantees higher efficiency without a

significant loss of linearity.

The +32V power supply for this amplifier is also gotten from the main power supply. This voltage is available

at the pins 1, 2, 3, 4, 5 and 6 out of the CON-3 connector of the module 4408. The trimmer TPO-3

simultaneously adjusts the VGS voltage for each one of the gates of transistor T3 and, consequently, the

drain bias current of T3.

LDMOS’s VGS voltage soft start circuit

Module 4408 is endowed with a protection system that approximately delays in 2.2 seconds the release time

of the polarization voltage VGS of the LDMOS transistors. On doing that it is guaranteeing protection against

potential undesirable voltage spikes during the transient turn on period.

The +12V voltage regulator CI-8 sees from pin 1 of the connector CON-2, the +18V voltage originated on the

main power supply module 4401. The +12V at the output of CI-8 suffers the 2.2 seconds delay caused by the

circuitry composed by the operational CI-7B, D5 diode and the soft started time constant caused by R73 and

C91 . This voltage is presented to the (+) non-inverting input (pin 3) of the op-amp CI-7A that compares that

it with the +6V threshold voltage on the (-) inverting input (pin 2). At the moment that pin 3 voltage is higher

than pin 2, the op-amps changes its state and deliver at its pin 1 +10.8V approximately. This voltage will

energize the VGS’s polarization circuits.

Temperature alarm

The module 4408 is protected against risk of over temperature operation. If the temperature raises and

exceeds 65˚C (140˚F) the protection circuit acts and disconnect the module.

The protection circuit is composed basically for the thermal sensor S1 and the CI-5. The temperature of the

module converted into a DC voltage can be measured at pin 4 at CON-5 connector. This voltage is routed to

pin 7 of CON-6 connector at the control unit PCB. The lack of this voltage means that the temperature of

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. The detector circuit for direct power is

basically composed by the diode D1B, the operational amplifier CI-3B and the trimmer TPO-5 that fine

adjusts the detected DC level. The detected voltage will be displayed as RF power level on the LCD screen

on the front panel. The reverse RF power reading is performed by diode D1A, the operational CI-3A and for

trimmer TPO-4, which adjusts the level of reading measured in pin 2 of CON-5 connector.

Protection against high reverse power

In an event of reverse power at the RF output, meaning reading of RF equal or above 20% of the direct

power the reflected protection circuit will act. The action with no longer provide VGS for the LDMOS

transistors, enforcing the 0 current condition. The diode D1A detects the reversed RF power converting it into

a DC voltage. This voltage is amplified by the CI-3A op-amp, and sent to the non-inverting input (pin 5) of

comparator CI-4B where is compared with the +6V fixed voltage at the inverting input (pin 6) of this

comparator. Any time that the reverse power spike up the voltage at pin 5 above +6V the CI-4B output (pin7)

will assume a +Vcc level enforcing T5 to the saturation point. Once saturated T5, it will no longer provide any

positive voltage to pin 3 of CI-7A op-amp so, consequently, the +10.8V will no longer be present and the

VGS voltage will not be available for the transistors LDMOS. On this case the RF power is not present.

RF balancing monitor

Module 4408 has a error detector circuit for phase and amplitude unbalancing. This circuit constantly

monitors the RF output of the pair of transistors part of T3. If the phase and amplitude are not correct, the

power combination will not happen as desirable at max efficiency, excess of heating will be generated then.

Two monolithic LED will go off according with the current operational condition. If the RF power combination

is running correctly the green LED will be ON, if not than the red LED will be ON.

R30 is the dummy load for the hybrid H2. On ideal conditions, there is no RF power present on it. Under

unbalance condition, some RF power will start to be present on R30. The unbalance condition is

consequence of a less than ideal tuning of the RF network surrounding T3. In this situation D3 diode detects

this power converting it into level DC in the not inverting entrance (pin3) of the DC amplifier CI-4A, causing

saturation into transistor T4 and, consequently, the red LED LED1 will be lighted. An ideal tuning correctly

achieved via trimmers C50, C54, C64 and C68, it will not allow any unbalanced RF power by R30 and the T4

transistor will remain cut, what it makes with that the green LED - LED2 be lighted.

AT725P Owner’s Manual

Technical specifications

PARAMETERS

SPECS

INPUT

FREQUENCY

470 to 860MHz

IMPEDANCE

CONNECTOR

SMB MALE

RETURN LOSS

≥ 10dB

RF OUTPUT

GAIN

43dB ≤ ±2dB

ATSC RMS POWER

Up to 23W

HARMONICS 2nd

≤ -30dBc

GENERAL

CONSUMPTION

324VA

Module 4492 block diagram

Fig.5.1: 25W UHF ATSC Multistage Amplifier

AT725P Owner’s Manual

Module 4492 external connections

Fig. 5.2: 25W Amplifier – The Module

(WH) GND PIN 1 –CON9 –POWER SUPPLY

(GR) TEMPERATURE ALARM PINO 7 –CON-6 –CONTROL UNIT

(BL) +18V PIN 1 –CON13 –POWER SUPPLY

(YL) FOWARD POWER READING PIN 4 –CON9 –CONTROL UNIT

(OR) +32V RES PIN 1 –CON14 –POWER SUPPLY

(WH) GND PIN 1 –CON9 –POWER SUPPLY

(OR) +32V RES PIN 1 –CON14 –POWER SUPPLY

(WH) GND PIN 1 –CON9 –POWER SUPPLY

1 2 3 4 5 6 7 8 12 3 4 5 6 7 8

CON-1 CON-2 CON-3

CON-4

CON-5

RFIN

RFOUT

(CABLE BELDEN 50 ) INPUT RF CON-4 –UP CONVERTER UHF

9

RF OUTPUT N FEMALE CONNECTOR –REAR PANEL

(GY) REFLECTED POWER READING PIN 2 –CON9 –CONTROL UNIT

AT725P Owner’s Manual

CIP8209 card

Fig. 5.3: 25W Amplifier – DC & RF connections diagram

(OR) +32V RES PIN 1 –CON14 –POWER SUPPLY

(WH) GND PIN 1 –CON9 –POWER SUPPLY

(OR) +32V RES PIN 1 –CON14 –POWER SUPPLY

(WH) GND PIN 1 –CON9 –POWER SUPPLY

(BL) +18V PIN 1 –CON13 –POWER SUPPLY

(YL) FOWARD POWER READING PIN 4 –CON9 –CONTROL UNIT

(GR) TEMPERATURE ALARM PINO 7 –CON-6 –CONTROL UNIT

TPO-1

T1 ID ADJUST CURRENT:

1,5V in R9 // R10 with or without RF signal input

TPO-2

T2 ID ADJUST CURRENT:

5V in R17 // R75 with or without RF signal input

TPO-3

T2 ID ADJUST CURRENT:

37,5mV in R28 // R29 without RF signal input

TPO-4

ADJ READING OF REFLECTED POWER

TPO-5

ADJ READING OF DIRECT POWER

T2

C32

R28

TPO-4

REF

ADJ TPO-5

FWD

ADJ

CON-1 CON-2

CON-3

CON-4

RF OUT

CON-5

T4

R17

.

1

45

8

CI-3

.

1

4 5

8

.

1

45

8

CI-4

CI-6

.

1

45

8

CI-5

S1

LED 2

LED 1

R29

FW

REF

+15V

TEMP

+30V

C33

H1

C42 C43

T3

C54

C68

C67

H2

TPO-3

T3 VGS

ADJ

TPO-2

T2 VGS

ADJ

C17

C15

.

1

4

5

8

CI-7

.

1

4

5

8

CI-8 D3

D2

TPO-1

T1 VGS

ADJ

T1

R9

R10

123 45678

(CABLE BELDEN 50 ) RF INPUT CON-4 –UPCONVERTER UHF

RF OUTPUT CON N FEMALE –RF OUT –REAR PANEL

123 4 5

(GY) REFLECTED POWER READING PIN 2 –CON9 –CONTROL UNIT

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.

For T2:

TPO-2 adjusts the voltage VGS of the T2 and, consequently, the bias drain (ID). This adjustment is made

measuring the voltage drop in the resistive parallel set R17 and R75 (2 x 10Ω)/10W), being adjusted for 5V,

what it corresponds to a bias current of drain ID equal 1.0A. This is a class A polarization adjustment.

For T3:

TPO-3 adjusts the voltage VGS of transistor T3 and, consequently, the chain of drain (ID). This adjustment is

made measuring the voltage drop in the resistive parallel set R28 and R29 (2 x 0.12Ω)/10W), being adjusted

for 3.7Mv, what it corresponds to a bias current of drain ID equal 600Ma, or 300Ma for each branch of T3.

This is a class AB polarization adjustment.

CIP8209 card – frequency response adjustment

Module 4408 is a UHF broadband amplifier that must have its frequency response optimized for higher gain

focused on the operational transmission channel. The factory adjustments must stay even when a LDMOS

transistor replacement becomes is necessary.

The capacitors trimmers present at the module 4408 are the tuning elements to be set for higher possible

gain, at the same time achieving flatness response at the desired UHF operational channel. Below we see

one possible set up suitable for the adjustment of frequency response.

AT725P Owner’s Manual

T2

C32

R28

TPO-4

REF

ADJ TPO-5

FWD

ADJ

12345678

12345

CON-1 CON-2

CON-3

CON-4

RF OUT

CON-5

T4

R17

.

1

45

8

CI-3

.

1

45

8

.

1

45

8

CI-4

CI-6

MODULE 4408

20W ATSC TRANSMITTER –AT720P

RF OUTPUT

.

1

45

8

CI-5

S1

LED 2

LED 1

R29

FW

REF

+15V

TEMP

+30V

C33

H1

C42 C43

T3

C54

C68

C67

H2

TPO-3

T3 VGS ADJ

TPO-2

T2 VGS ADJ

C17

C15

.

1

4

5

8

CI-7

.

1

4

5

8

CI-8 D3

D2

TPO-1

T1 VGS ADJ

T1

R9

R10

RFIN

RFOUT

NETWORK ANALYZER

30dB / 100W

ATTENUATOR

-20dBm

Fig.5.3: Frequency Response Adjustment Factory Set Up

Set the network analyzer output level at -20dBm, and connect it at the module 4408 RF input. Tune the

capacitor trimmer for the most flat frequency response over the operational channel. The overall gain should

be 44dB ± 2dB. Remember the bands which the amplifier was designed for:

• LOW BAND (LB): channels 14 to 44

• HIGH BAND (MB): channels 45 to 59

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.

The module 4401 is self-protected against DC short-circuit. The protection acts inhibiting the generation of

the switching pulses, shutting down the power supply; 0 volts at the DC’s outputs. The output +32V RE-

CONNECTABLE is commanded by the Control unit.

The re-connection command is sent to the power supply, to turn the +32V RE-CONNECTABLE on.

This voltage is responsible for the feeding of the 25W amplifier - module 4408. The consumption in Amps out

from the +32V RE-CONNECTABLE is basically the consumption associated with the drain electrical current

of the LDMOS transistors of the amplifier. Because of this configuration, the LDMOS currents are measured

at the power supply module 4401.

These currents measurements are routed to the control unit. In case of extremes measured values the

control unit inhibits the +32 RE-CONNECTABLE. Power supply.

Module 4401 – Block Diagram

Input AC filter

The C1, C6 and TF-1 components together assemble the line filter. This filter minimizes the noise generated

by the power supply into the AC network.

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.

The resistances R1 and R2 are the loads for the capacitors C9 and C10 at the time that the power supply is

powered ON. R3 and R4 provoke a fast discharge of C9 and C10 when the power supply is OFF.

The control of the switching function over the PWM modulator is performed by the components TF-3, D5, D6,

D7, R9, T3, C20, C18 and C46.

Switch and Power

The switching function over the DC input voltage is performed by the Mosfets, T1 and T2. The trigger pulses

are generated by control integrated circuit CI-1, through the transformer TF-4 that also isolates the

modulation circuit from the AC network.

The switching voltage in the transistors is applied in the transformer TF-5 that through the convenient turn’s

ratio, it will generate the voltages in its secondary.

The capacitors C15 and C16 divide the entrance voltage, reducing the voltage over the transistors. C14

prevents the direct-current flow towards TF-5.

The “Snubbers” formed by R7, C17, R34, C31, R37, C35, R43 and C42, help to reduce high frequency noise

generated by the fast and short time switching pulses present on the mosfet transistors as in TF-4.

Rectification and Filtering

The pulses delivered by the several switching and power devices, will be than rectified by D8 to the D14 and

filtered by C32 the C47.

The inductor L2 in its multiple sections, stores the transfer energy that help to filter the signal.

The resistors at the output act as bleeders avoiding undesirables’ transients and oscillations.

Pulse Width Modulation

This block is composed basically by the integrated circuit CI-1 that performs the PWM switching process

control.

CI-1 output (pins 11 and 14) supply the switching pulses that are applied to the transformer TF-4. The “Soft-

Start" system prevents a fast rise of the exit voltage. In this circuit, this function is carried through by C23.

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.

In the event of over-current, in any one of the outputs, the voltage in the inverting input of comparators CI-3

and CI-4, transferred by the electrical current readings, will be greater that the voltage of reference in the not

inverting entrance.

This event take the output of the comparator to a low level will trigger a timer formed by CI-2, R26 and C28

that will a voltage at pin 10 of the CI-1 inhibiting the switching process. The electrical current readings are

detected over the power resistors (R44, R45, R36, R40, and R38) and amplified by op-amps getting deep of

scale (4V) proportional the nominal current of each output. All the electrical current readings possess its

proper adjustment:

- TPO-2: +32V/10A

- TPO-3: +18V/1A

- TPO-4: +9V/1A

The readings of output voltage are constituted by operational amplifiers (CI-8, CI-9, CI-10) and each one with

a TPO for full scale adjustment (4V) proportional to the nominal the output voltage.

- TPO-5: +32V

- TPO-6: +32V RECONNECTED.

- TPO-7: -18V

- TPO-8: +18V

- TPO-9: +9V

* NOTES:

1) The current reading is only for the exit of +32V.

2) It does not have reading for the voltage of +32V RECONNECTED.

Reconnection Process

The output of +32V RECONNECTED power supply of the Module 4401 is used to exclusively feed the UHF

amplifier - Module 4408.

AT725P Owner’s Manual

The +32V RECONNECTED output is a derivation of the +32V FIXED output. This exit is enabled or disabled

by control unit - CIP8231 card board - through the reconnect command. In normal conditions this command

sends +5V to pin 6 of connector CON-8 of CIM3388 (CIP8111) card board of module 4401. Having this

voltage, the switch transistor will be saturated and, consequently, the exit of +32V RECONNECTED will be

enabled.

Fig.6.1: Module 4401 Block Diagram

LF353JCI-5

LM393CI-4

LM393CI-3

LM555CI-2

SG3525CI-1

LM358JCI-10

LM358JCI-9

LM358JCI-8

LM353DCI-7

4N28CI-6

IRFP150T4

TIP29CT3

IRFP450T2

IRFP450T1

TRANSFORMER

12V FOR FAN

LINE

FILTER NETWORK

RETIFIER SWITCHING

TRANSISTORS

SWITCHING

RETIFIER INDUCTOR

FILTER

SWITCHING

RETIFIER

PROTECTION

CIRCUIT

ISOLATOR

TRANSFORMER

CONTROL

NETWORK

TRANSFORMER

CONTROL

SUPPLY

(TF-1) (D1-D4) (T1;T2) (TF-5) (D8; D9)

(D10; D11; D12)

(D13;D14)

(L2-A; L2-B)

(L2-C; L2-D;

L2-F)

(C47)

(CI-1)

(TF-4)

(TF-3)

(D5-D7; T3)

(CI-2)

(CI-3) (CI-4)

CURRENT

DETECTION

+32V RESTARTED

+32V

CON-6

1

2GND

TPO-1

ADJUSTMENT +32V

(R35; R36;R44)

(R38)

CON-4 110V

CON-5

CON-3

220V

110/220VAC

CON-1

CON-2

GND

+32V

+18V

+9V

CURRENT

READING

(CI-5; CI-7)

CON-7

123

TPO-3 TPO-4

TPO-9

ADJUSTMENT READING +9V

TPO-8

ADJUSTMENT READING +18V

TPO-7

ADJUSTMENT READING -18V

TPO-5

ADJUSTMENT READING +32V

+9V

+18V

-18V

+32V

FILTER

VOLTAGE

READING

(CI-8; CI-9; CI-10)

SWITCH

TRANSISTOR

(T4)

CON-8

1 2 34 5

RES

6

NC

ISOLATOR

(CI-6) (CI-4A)

CON-12

CON-13

CON-14

+18V

-18V

COMPARATOR

CON-11 +9V

(C32; C33)

(C36; C37)

(C39; C40)

(C43; C44)

TPO-8

TPO-9 TPO-7 TPO-5

+32V

CON-9

CON-10 +GND

+GND

CON-15 +32V

NETWORK

READING

AT725P Owner’s Manual

Fig.6.2: Module 4401 – Main components board displacement

1A

2A

3A

1B

2B

3B

4B

5B

6B

(GY) RESTART PIN 6 –CON-3 –CONTROL UNIT

(RD) +32V READING PIN 9 –CON-9–CONTROL UNIT

(OR) CURRENT READING (+32V) PIN 8 –CON-9 –CONTROL UNIT

CON9

CON10

CON11

CON12

CON13

CON14

CON15

WH) GND

(WH) GND

(GR) +9V

(BL) +18V

(OR) +32V REL

(RD) +32V

CON1

GND

CON2

(BR) AC

(WH) GND

(BK) AC

1

2

CON6

CON7 CON8

CON5

110V

CON4

0V

CON3

220V

(BK) GND FAN

(RD) +12V FAN

TPO-2 TPO-4 TPO-3

TPO-1

TPO-6

TPO-5

TPO-7

TPO-8 TPO-9

(BK) -18V *

CI-1

SG3525

.

10

SDG

T1

SDGT2 D8 D12 D9

VENT.

T3

~ +14V

.

CI-2

0V: normal

1,5V: inhibited switching 0V: normal

5V: inhibited switching

3

TEST OF THE INTERNAL DIODES OF T1 AND T2

SWITCH OFF the power!

Digital Multimeter in the scale of diode test.

Test made with T1 and T2 soldiers in the board

Tip (+) in S and tip (-) in D: ~500

Tip (-) in S and tip (+) in D: infinite resistance

CI-1 SG3525

Switching Pulse11, 14

Shut Down 10

Oscillator5

+4,5V (soft-start)8

Ground (GND)12

+15V (supply)13,15

+5V

2

PINS

16 +5V (reference voltage)

CI-1 pin 14 –OUTPUT +32V WITH LOAD

CI-1 pin 14 –OUTPUT +32V WITHOUT LOAD

TPO-1

Adjustment output voltage +32V

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

FUNCTION (MEASURE)

(BK) –18V READING PIN 6 –CON-9 –CONTROL UNIT

(GR) +8V READING PIN 5 –CON-9 –CONTROL UNIT

(BL) +18V READING PIN 7 –CON-9 –CONTROL UNIT

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

OUTPUTS NOMINAL VOLTAGES

AND CURRENTS

+32V / 10A

+18V / 1A

-18V / 1A

+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 VOLTAGE

HIGH LEVEL: > 3.5 TO 5Vdc

LOW LEVEL: < 3.3Vdc

SHUTDOWN VOLTAGE

HIGH LEVEL: > 0.7 TO 5Vdc

LOW LEVEL: < 0.7Vdc

POWER SUPPLY

CIRCUIT

CIM

CIP

POWER

3388A

8111A

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.6.5: Module 4401 - +32V Switching Power Supply

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:

Fig.7.1: DC/DC Converter Board

CIM3490 (CIP8390)

INPUT

OUTPUT

+18V

+2.5V (CON-2/2)

+5.0V (CON-2/3)

Fuse

+2.5V Output

Brown wire

+5V Output

Yellow wire

+18V Input

GND wire

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. This module holds all the non-volatile parameters data related with the digital linear and non-

linear pre-correction.

Fig.8.1: LUT Memory card & 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

2.1.1 Keypad

 Moves the cursor up

 Moves the cursor right

 Moves the cursor left

 Moves the cursor down

Yellow Key  “ENTER”

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.

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

2.3 Signals

During the navigation there will appear in the display signal characters these are:



* – Indicates the presence of a current alarm

# – Indicates the presence of an old alarm

(LOCK) – Indicates that the equipment is configured with password, and that to have access to

that part of the menu the password must be entered.

– The UP and DOWN arrows assist in the movement between screens. When they appear the

UP or DOWN key must be used to move between screens. If in a measurement screen, to return to the

previous menu, any key can be pressed.

MEASURES SETUP

NXT ESC

MEASURES SETUP

NXT ESC

MEASURES SETUP

NXT ESC

AT725P Owner’s Manual

3. Screen Flow Charts

3.1 Main screens

Main screens

3.2 Measurement Screen 1

LINEAR INDUSTRIES

INC.

AT720P

MEASURES SETUP

NXT ESC

ALARMS REMOTE

NXT ESC

[Esc] [Esc]

[Any Key]

LINEAR INDUSTRIES

INC.

LINEAR INDUSTRIES

INC.

AT720P

MEASURES SETUP

NXT ESC

MEASURES SETUP

NXT ESC

MEASURES SETUP

NXT ESC

ALARMS REMOTE

NXT ESC

ALARMS REMOTE

NXT ESC

ALARMS REMOTE

NXT ESC

[Esc] [Esc]

[Any Key]

MEASURES SETUP

NXT ESC

POWER P.SUPPLY

NXT ESC

FWD. PWR.: W

RFL. PWR.: W

ALC STATUS:

ALC R.V: V

P.A. TEMPERATURE:

+32V: + V

+18V: + V

+ 9V: + V

-18V: - V

I1: A

[Measures ]

[Esc]

[Power ] [P.Supply ]

[Up and Down Keys ]

[Enter Key ]

MEASURES SETUP

NXT ESC

MEASURES SETUP

NXT ESC

MEASURES SETUP

NXT ESC

POWER P.SUPPLY

NXT ESC

POWER P.SUPPLY

NXT ESC

FWD. PWR.: W

RFL. PWR.: W

FWD. PWR.: W

RFL. PWR.: W

ALC STATUS:

ALC R.V: V

ALC STATUS:

ALC R.V: V

P.A. TEMPERATURE:P.A. TEMPERATURE:

+32V: + V

+18V: + V

+32V: + V

+18V: + V+18V: + V

+ 9V: + V

-18V: - V

+ 9V: + V

-18V: - V

I1: AI1: A

[Measures ]

[Esc]

[Power ] [P.Supply ]

[Up and Down Keys ]

[Enter Key ]

AT725P Owner’s Manual

3.3 Measurement Screen 2

TR.STR. STATUS

NXT SOFTWARE ESC

DATA PACKETS RATE:

Mbps

NULL PACKETS RATE:

Mbps

FIFO OCCUPATION:

%

TRANSPORT STREAM:

SOFTWARE:

VERSION:

PASSWORD ON:

PILOT LEVEL:

CHANNEL:

LO N.I: mV

LO N.Q: mV

TX.BAL.I:

PHASE I:

TX.BAL.Q:

PHASE Q:

DPD SCALE :

DPD ACTIVE:

[Status ][Tr.Stream ]

[Up and Down keys ]

[Enter Key]

[Software ]

TR.STR. STATUS

NXT SOFTWARE ESC

DATA PACKETS RATE:

Mbps

NULL PACKETS RATE:

Mbps

FIFO OCCUPATION:

%

TRANSPORT STREAM:

SOFTWARE:

VERSION:

PASSWORD ON:

PILOT LEVEL:

CHANNEL:

LO N.I: mV

LO N.Q: mV

TX.BAL.I:

PHASE I:

TX.BAL.Q:

PHASE Q:

DPD SCALE :

DPD ACTIVE:

[Status ][Tr.Stream ]

[Up and Down keys ]

[Enter Key]

[Software ]

TR.STR. STATUS

NXT SOFTWARE ESC

TR.STR. STATUS

NXT SOFTWARE ESC

DATA PACKETS RATE:

Mbps

DATA PACKETS RATE:

Mbps

NULL PACKETS RATE:

Mbps

NULL PACKETS RATE:

Mbps

FIFO OCCUPATION:

%

FIFO OCCUPATION:

%

TRANSPORT STREAM:TRANSPORT STREAM:

SOFTWARE:

VERSION:

SOFTWARE:

VERSION:

PASSWORD ON:PASSWORD ON:

PILOT LEVEL:PILOT LEVEL:

CHANNEL:CHANNEL:

LO N.I: mV

LO N.Q: mV

LO N.I: mV

LO N.Q: mV

TX.BAL.I:

PHASE I:

TX.BAL.I:

PHASE I:

TX.BAL.Q:

PHASE Q:

TX.BAL.Q:

PHASE Q:

DPD SCALE :

DPD ACTIVE:

DPD SCALE :

DPD ACTIVE:

[Status ][Tr.Stream ]

[Up and Down keys ]

[Enter Key]

[Software ]

AT725P Owner’s Manual

3.4 Configuration Screen

[Enter Key]

MEASURES SETUP

NXT ESC

TYPE PASSWORD:

NXT YES PREV ESC

WRONG PASSWORD !

TYPE PASSWORD:

ENABLE PASSWORD:

YES NO

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 NO

ALC. R.V.: [V]

POWER : [W]

TYPE CONFIG.:

[Yes]

[Enter Key ]

[Wrong Password and Enter Key ]

[Correct Password

and Enter Key ]

[Esc]

[Enter Key]

MEASURES SETUP

NXT ESC

MEASURES SETUP

NXT ESC

MEASURES SETUP

NXT ESC

TYPE PASSWORD:TYPE PASSWORD:

NXT YES PREV ESCNXT YES PREV ESC

WRONG PASSWORD !WRONG PASSWORD !

TYPE PASSWORD:TYPE PASSWORD:

ENABLE PASSWORD:

YES NO

ENABLE PASSWORD:

YES NO

TYPE PILOT LEVEL:TYPE PILOT LEVEL:

TYPE CHANNEL:

FACTORY SETUP

TYPE CHANNEL:

FACTORY SETUP

TYPE LO NULL I:TYPE LO NULL I:

TYPE LO NULL Q:TYPE LO NULL Q:

TYPE AMPLITUDE I:TYPE AMPLITUDE I:

TYPE PHASE I:TYPE PHASE I:

TYPE AMPLITUDE Q:TYPE AMPLITUDE Q:

TYPE PHASE Q:TYPE PHASE Q:

TYPE DPD SCALE:TYPE DPD SCALE:

DPD ACTIVE:

YES NO

DPD ACTIVE:DPD ACTIVE:

YES NO

ALC. R.V.: [V]

POWER : [W]

ALC. R.V.: [V]

POWER : [W]

TYPE CONFIG.:TYPE CONFIG.:

[Yes]

[Enter Key ]

[Wrong Password and Enter Key ]

[Correct Password

and Enter Key ]

[Esc]

AT725P Owner’s Manual

3.5 Alarm Screen

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. In the unlikely case that

the equipment continues showing this message, the possibility of software error has occurred in the load

process of the modulator and the equipment may not enter into correct operation. Please report this status to

Linear Industries Inc for the necessary steps of action. Following the LOADING message, the name of the

manufacturer, the type number of the equipment, normal rated RMS power and the operating channel are

displayed.

This information alternates approximately every 2 seconds. The backlight switches off after approximately 20

seconds. After this initialization of the equipment these indications will remain indefinitely until another key is

pressed. When pressing another key the backlight will light again. Depending on the type of screen the

cursor will automatically locate itself in one of the options. To execute some of these options, after the

backlight has extinguished it may be necessary to press any key again. If no option is chosen, the backlight

will switch off in approximately 20 seconds and then after approximately five minutes the screen returns to

the initial display.

ALARMS REMOTE

NXT ESC

CURRENT PAST

ESC

NXT CLR. ALL ESC

NXT ESC

[Esc]

[Alarms ][Past]

[Esc]

[Current ][Esc]

ALARMS REMOTE

NXT ESC

ALARMS REMOTE

NXT ESC

ALARMS REMOTE

NXT ESC

CURRENT PAST

ESC

CURRENT PAST

ESC

NXT CLR. ALL ESCNXT CLR. ALL ESC

NXT ESC

[Esc]

[Alarms ][Past]

[Esc]

[Current ][Esc]

AT720P

20W UHF

AT720P

20W UHF

LINEAR INDUSTRIES

INC.

LINEAR INDUSTRIES

INC.

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. When these are displayed it

is not possible to configure any parameters. The “ENTER” key must be pressed to return to the main screen.

4.1.1 POWER MENU

The power menu displays the forward and reflected power at the output of the equipment, measured

at the output power reflectometer. Also displayed are the ALC reference voltage and the temperature of the

final RF output amplifier.

To have access to the POWER screen, the following sequence of screens is necessary:

Access MEASURES

Access POWER

Use the key “DOWN” to see the next set of screens.

POWER P.SUPPLY

NXT ESC

POWER P.SUPPLY

NXT ESC

MEASURES SETUP

NXT ESC

MEASURES SETUP

NXT ESC

MEASURES SETUP

NXT ESC

FWD. PWR.: W

RFL. PWR.: W

ALC STATUS:

ALC R.V: V

P.A. TEMPERATURE:

FWD. PWR.: W

RFL. PWR.: W

FWD. PWR.: W

RFL. PWR.: W

ALC STATUS:

ALC R.V: V

ALC STATUS:

ALC R.V: V

P.A. TEMPERATURE:P.A. TEMPERATURE:

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:

Access MEASURES

Access P.SUPPLY

Use the key “UP and DOWN” to move between screens.

To return to the previous screen press the key UP. To return to the option P.SUPPLY press “ENTER”.

4.1.3 MENU ESC

Pressing ESC returns the cursor to the previous screen.

4.1.4 MENU NXT

Selecting the “NXT” option provides access to more options of measurement. The sequence for

access of these measurements is shown below:

POWER P.SUPPLY

NXT ESC

POWER P.SUPPLY

NXT ESC

MEASURES SETUP

NXT ESC

MEASURES SETUP

NXT ESC

MEASURES SETUP

NXT ESC

+32V: + V

+18V: + V

+ 9V: + V

-18V: + V

I1: A

+32V: + V

+18V: + V

+32V: + V

+18V: + V+18V: + V

+ 9V: + V

-18V: + V

+ 9V: + V

-18V: + V

I1: AI1: A

AT725P Owner’s Manual

4.1.5 MENU TR.STR.

TR STR shows information about the input digital signal.

Select NXT and press ENTER

Select TR.STR and press ENTER

To return to the previous screen press the UP key. To return to the TR.STR options press ENTER.

4.1.6 MENU STATUS

4.1.6.1 Password qualification state

This screen shows the information on the configured parameters:

PASSWORD ON: YES - indicates that a password is required to enter into the SETUP MENU, and will be

asked for to each attempt of access this menu.

MEASURES SETUP

NXT ESC

MEASURES SETUP

NXT ESC

MEASURES SETUP

NXT ESC

TR.STR. STATUS

NXT SOFTWARE ESC

TR.STR. STATUS

NXT SOFTWARE ESC

DATA PACKETS RATE:

Mbps

NULL PACKETS RATE:

Mbps

FIFO OCCUPATION:

%

TRANSPORT STREAM:

DATA PACKETS RATE:

Mbps

DATA PACKETS RATE:

Mbps

NULL PACKETS RATE:

Mbps

NULL PACKETS RATE:

Mbps

FIFO OCCUPATION:

%

FIFO OCCUPATION:

%

TRANSPORT STREAM:TRANSPORT STREAM:

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:

Select STATUS and press ENTER

4.1.6.2 Amplitude level of the ATSC Pilot carrier:

This is a numerical value relative to the carrier pilot level.

PILOT LEVEL: <+511 TO -2048>

Access to the STATUS menu can be via the far left option or from the PASSWORD ON screen: following

viewing the programmed level press the UP and DOWN keys to navigate to other STATUS screens.

4.1.6.3 Transmission channel

This screen displays the factory programmed transmission channel.

CHANNEL <2 to 59>

To have access to this menu navigate via the STATUS option and then select PILOT LEVEL: pressing the

UP and DOWN key and then the factory programmed channel can be viewed.

TR.STR. STATUS

NXT SOFTWARE ESC

TR.STR. STATUS

NXT SOFTWARE ESC

PASSWORD ON:PASSWORD ON:

PASSWORD ON:

PILOT LEVEL:

PASSWORD ON:PASSWORD ON:

PILOT LEVEL:PILOT LEVEL:

AT725P Owner’s Manual

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: press UP and DOWN key

4.1.6.5 Rejection of the frequency image:

The following are numerical values related to the amplitude and phase signal for rejection of the image

frequency.

TX. BAL. Q: - <00000 to 32767>

PHASE Q: - <-32767 to +32767>

TX. BAL. I: - <00000 to 32767>

PHASE I: - <-32767 to +32767>

PILOT LEVEL:

CHANNEL:

PILOT LEVEL:PILOT LEVEL:

CHANNEL:CHANNEL:

CHANNEL:

LO N.I: mV

LO N.Q: mV

CHANNEL:CHANNEL:

LO N.I: mV

LO N.Q: mV

LO N.I: mV

LO N.Q: mV

LO N.I: mV

LO N.Q: mV

TX.BAL.I:

PHASE I:

TX.BAL.Q:

PHASE Q:

LO N.I: mV

LO N.Q: mV

LO N.I: mV

LO N.Q: mV

TX.BAL.I:

PHASE I:

TX.BAL.I:

PHASE I:

TX.BAL.Q:

PHASE Q:

TX.BAL.Q:

PHASE Q:

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>

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.

4.1.6.8 Name and version of software:

This menu indicates the name and the version of recorded software in the central microcontroller. This

information must be provided to the factory in the case of any maintenance request.

SOFTWARE: < ATXXXX >

VERSION: < X.X >

TX.BAL.Q:

PHASE Q:

DPD SCALE :

DPD ACTIVE:

TX.BAL.Q:

PHASE Q:

TX.BAL.Q:

PHASE Q:

DPD SCALE :

DPD ACTIVE:

DPD SCALE :

DPD ACTIVE:

TX.BAL.Q:

PHASE Q:

DPD SCALE :

DPD ACTIVE:

TX.BAL.Q:

PHASE Q:

TX.BAL.Q:

PHASE Q:

DPD SCALE :

DPD ACTIVE:

DPD SCALE :

DPD ACTIVE:

AT725P Owner’s Manual

To verify the name and version of software select the option SOFTWARE after that press ENTER.

Select SOFTWARE and press ENTER

4.2 MENU SETUP

This menu allows access to the configuration functions and parameters of operation of the equipment. The

RIGTH ARROW and LEFT ARROWkeys locate the cursor in each one of the four possible digits and the “+”

and “-” keys and the ENTER and UP and DOWN keys change the digits. The “ENTER” key finalizes the

numerical value to the control system. Without pressing the “ENTER” key the value is not remembered.

Before the “ENTER” key is pressed the parameter is only adjusted in real time for review of the measured

results. If the equipment is switched off during a parameter configuration before pressing the “ENTER” key

the configuration will not be saved in the memory and the same values will be as previously stored.

4.2.1 MENU TYPE PASSWORD

This menu is to set the four numerical password digits to have access to the SETUP functions. This menu is

active only when option YES in the ENABLE PASSWORD menu is indicated. The RIGTH ARROW and

LEFT ARROW keys position the cursor in each one of the four possible digits and the ENTER and UP and

DOWN keys edit the digits. The “ENTER” key transmits the value of the password to the control system.

It is only possible to leave this screen after entering the numerical password.

If the correct password is entered access to the SETUP options is available. If the incorrect password is

entered the following is message is shown “WRONG PASSWORD” and the equipment returns automatically

to the main options menu.

TYPE PASSWORD: <XXXX>

Below is the sequence of access for this menu:

TR.STR. STATUS

NXT SOFTWARE ESC

TR.STR. STATUS

NXT SOFTWARE ESC

SOFTWARE:

VERSION:

SOFTWARE:

VERSION:

MEASURES SETUP

NXT ESC

MEASURES SETUP

NXT ESC

MEASURES SETUP

NXT ESC

AT725P Owner’s Manual

Select SETUP and press ENTER

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: executes the navigation option

PREV: returns to the previous menu

YES: indicates access to that particular option

ESC: returns to the main options menu

To see the options select NXT and press “ENTER”. When the required option is shown, locate the cursor on

the “YES” and press “ENTER”.

4.2.2.1 < SET NEW PASSWORD? >

This menu allows the four numerical digits to be configured as a new password for the equipment. The

RIGTH ARROW and LEFT ARROW keys locate the cursor on one of the four digits to be changed and the

ENTER and UP and DOWN keys change the digits. Pressing “ENTER” key then informs the new password

to the control system and returns to the main options menu.

It is only possible to leave this screen after entering the numerical password.

4.2.2.2 < ENABLE PASSWORD? >

This option allows the qualification or not of the password programmed in SET NEW PASSWORD option.

TYPE PASSWORD:TYPE PASSWORD:

NXT YES PREV ESCNXT YES PREV ESC

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.

.

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 >.

4.2.2.4 < SET CHANNEL? >

For equipment safety reasons changing channel is not allowed in the on-site configuration. This procedure

can only be configured in the factory. Changing the channel without the permission of a factory trained

engineer can potentially void any warranty on the product.

4.2.2.5 < SET LO NULL I? >

This menu allows the DC voltage adjustment for “nulling” the “I” signal from the local oscillator inter-

modulation in the Up Converter. The adjustment has the following potential values: < 0.00 to 49.75 mV >.

ENABLE PASSWORD:

YES NO

ENABLE PASSWORD:

YES NO

TYPE PILOT LEVEL:TYPE PILOT LEVEL:

TYPE CHANNEL:

FACTORY SETUP

TYPE CHANNEL:

FACTORY SETUP

TYPE LO NULL I:TYPE LO NULL I:

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 inter-

modulation in the Up Converter. The adjustment has the following potential values: < 0.00 to 49.75 mV >.

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 >.

4.2.2.8 < SET PHASE I? >

This menu allows the adjustment of the “I” phase of the image rejection signal in the 8VSB modulator with

the following band of values: < 00000 to 32767 >.

4.2.2.9 < SET TX BAL. AMP. Q? >

This menu allows the adjustment of the “I” balance of the image rejection signal in the 8VSB modulator with

the following band of values: < 00000 to 32767 >.

4.2.2.10 < SET PHASE Q? >

This menu allows the adjustment of the “Q” phase signal amplitude of image rejection signal in the 8VSB

modulator with the following band of values: < 00000 to 32767 >.

TYPE LO NULL Q:TYPE LO NULL Q:

TYPE AMPLITUDE I:TYPE AMPLITUDE I:

TYPE PHASE I:TYPE PHASE I:

TYPE AMPLITUDE Q:TYPE AMPLITUDE Q:

TYPE PHASE Q:TYPE PHASE Q:

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 pre-

distortion applied to ATSC signal, with the following band of values : < 0000 to 4095 >

4.2.2.12 < SET DPD ACTIVE? >

This menu allows the activation or not of the digital pre-distortion tables.

YES: activates the use of the digital pre-distortion look up tables (LUT’s)

NO: deactivates the use of the digital pre-distortion look up tables (LUT’s)

4.2.2.13 < SET POWER? >

This allows the configuration of normal rated power at the output of the equipment. The ENTER and UP and

DOWN key increase and decrease the power level. The RIGTH ARROW and LEFT ARROW keys do not

possess any function in this screen. The “ENTER” key memorizes the desired value.

The value of power displayed on this screen is a value fed directly from the output reflectometer and is the

same value that is provided to the ALC system (Automatic Level Control) circuit. The system allows a certain

flexibility of adjustment by providing at the same time the power level display in order to verify the actual

power level. It is not recommended to adjust for very low values of ALC voltage as this may cause the power

to become unstable.

For higher ALC values (above 1.3V) the power will vary with the variation of the ALC voltage. In case this

simultaneous variation does not occur it is likely that there is a fault in either or both the Up Converter or final

RF amplifier. This type of occurrence should be reported to the Linear Industries Inc.

In this screen the ALC is disabled for precise adjustments of the power level and for full manual

control of power using the ENTER and UP and DOWN keys. In any another environment or screen the ALC

system returns to an enabled mode in order to control the power level.

TYPE DPD SCALE:TYPE DPD SCALE:

DPD ACTIVE:

YES NO

DPD ACTIVE:DPD ACTIVE:

YES NO

ALC. R.V.: [V]

POWER : [W]

ALC. R.V.: [V]

POWER : [W]

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

Configuration TRANSMITTER: in this configuration the transmitter provides approximately 15% more power

than the normal rated power at the reflectometer output. This amount compensates for the losses of the

ATSC compliant mask filter in order that at the output of the filter the correct and nominal rated power level of

the equipment is obtained.

Although this compensation is included for the normal rated power, the system still shows the real power

level for nominal values, for example, if 23.3W is measured at the output, the display will read 25W. For this

configuration the functions in the external connector "External Functions" are disabled.

Configuration EXCITER: in this configuration, the transmitter function as a simple Exciter/Driver and it does

not take into consideration the use of an output filter. In this mode the transmitter does not compensate for

loss of power in the output reflectometer. The nominal output power value can directly measured at the

output of the reflectometer; i.e. if the output power is 25W the display will read 25W. For this configuration

the functions in the external connector "External Functions" are active. By means of this connector it is

possible disconnect the power amplifier and inhibit the transmission signal completely with all the inputs still

connected and a completely active control system.

This can be made with the input of a 5V DC level on pin 3 of the male side of the connector DB-9 (external

functions), in which pin 5 is at ground level. 5V on pin 3 disconnects the amplifier and 0V keeps the amplifier

on. With this function it is possible to externally switch on or off the EXCITER and or TRANSMITTER.

4.3 ALARMS MENU

This transmission equipment possesses a system of alarm indications. These are show by symbols at the

right side of the display screen: * and #. The signal * represents the occurrence of a current alarm. The

signal # represents an old alarm, i.e. an alarm that has already occurred and has been normalized (cleared).

Under normal operating conditions neither of these two symbols will be displayed on the screen.

TYPE CONFIG.: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.

To update the list, you must leave the menu and then return to the ALARMS using the ESC option and then

access the CURRENT menu option again.

Option NXT shows the next alarm message. If there are no alarm messages it will read as follows:

< ALARMS LIST START! >

< ALARMS LIST END! >

Option ESC returns to the previous screen.

The following messages may appear on the current alarms list:

< ALARMS LIST START! >

< OVER FIFO! >

< MPEG LOSS! >

< DWR. NOT PROGRAMMED! >

< TEMPERATURE! >

< LOCK CLOCK! >

< LOCK LO! >

< OUTPUT POWER ZERO! >

< REFLECTED POWER! >

< ALARMS LIST END! >

Below shows the screens necessary to display the CURRENT alarms menu:

Select NXT and press ENTER

MEASURES SETUP

NXT ESC

MEASURES SETUP

NXT ESC

MEASURES SETUP

NXT ESC

ALARMS REMOTE

NXT ESC

ALARMS REMOTE

NXT ESC

ALARMS REMOTE

NXT ESC

AT725P Owner’s Manual

Select ALARMS and press ENTER

Select CURRENT and press ENTER

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.

Option NXT shows the next alarm message. If there are no alarm messages it will read as follows:

< ALARMS LIST START! >

< ALARMS LIST END! >

Option CLR. ALL erases all the old alarm messages.

These messages are also erased when the equipment is turned off. Option ESC returns to the previous

screen.

The follow are messages that can appear in the past alarms list:

< ALARMS LIST START! >

< OVER FIFO! >

< MPEG LOSS! >

< DWR. NOT PROGRAMMED! >

< TEMPERATURE! >

< LOCK CLOCK! >

< LOCK LO! >

< OUTPUT POWER ZERO! >

< REFLECTED POWER! >

< ALARMS LIST END! >

CURRENT PAST

ESC

CURRENT PAST

ESC

NXT ESC

AT725P Owner’s Manual

Below shows the screens necessary to display the PAST alarms menu:

Select NXT and press ENTER

Select ALARMS and press ENTER

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. Operation of the Hyper-terminal

The AT725P transmitter system parameters can be monitored and configured using the Windows® Hyper-

terminal. The bands of values are the same as described previously in the equipment front panel operation

(LCD display and keys). It is possible to adjust the transmitter power with the Hyper-terminal interface

however the ALC system must be first disconnected using the equipment front panel and only within the

limits set from the front panel configuration.

The password configuration process is the same as described for the front panel configuration. The

password can be qualified or not, and when qualified allows access to the SETUP environment. In the

SETUP environment it is possible to qualify or to disable the password and also to define a new password

value. The insertion of new values for the password occurs with the cursor automatically moving to the next

digit when the highest value has been reached. After reaching the desired number the cursor is moved

automatically to the right, and after the last digit is reached the next typed key returns to the first position.

A cable must be connected between the transmitter RS232 output and RS232 input of the computer. The

cable end for the computer is a male DB-9 and the cable end for the transmitter is a female DB-9 connector.

Only three of the nine pins are used with pins 2 and 3 of the cable crossed. Pins used are TX, RX and GND.

MEASURES SETUP

NXT ESC

MEASURES SETUP

NXT ESC

MEASURES SETUP

NXT ESC

ALARMS REMOTE

NXT ESC

ALARMS REMOTE

NXT ESC

ALARMS REMOTE

NXT ESC

CURRENT PAST

ESC

CURRENT PAST

ESC

NXT CLR. ALL ESCNXT CLR. ALL ESC

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 19200

Bits of data 8

Parity None

Bits of Parity 1

Flow Control 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. Screen 1 indicates some measurements, states of the alarms and offers options for access

to other functions of the equipment.

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.

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.

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. Unplug the DC

connectors (CON-2 and CON-3) and measure the conductance between the gate terminal and ground.

T1:

Adjust TPO-1 for the minimum of its value; (all counterclockwise) the reading at the multimeter should be

close of 380Ω. Adjusting TPO-1 for the maximum of its value, the reading at multimeter should be close of

720Ω.

T2:

Adjust TPO-2 for the minimum of its value; (all counterclockwise) the reading at the multimeter should be

close of 370Ω. Adjusting TPO-1 for the maximum of its value, the reading at multimeter should be close of

720Ω.

T3:

Adjust TPO-3 for the minimum of its value; (all counterclockwise) the reading at the multimeter should be

close of 550Ω. Adjusting TPO-1 for the maximum of its value, the reading at multimeter should be close of

705Ω. These readings are expected remain the same for both T3 gates.

In event that these measurements does not comes true, check the possibility of some surrounding other

components be damaged, and/or proceed a careful visual inspection looking for abnormal circumstances .

Same tests suggested above could be repeated with the transistors detached out from the PCB board; on

this case measurement readings for gate-to-ground should be close of 40MΩ. Also on this situation detect a

diode type behavior measuring drain-to-source conductance as follows:

(+)

DRAIN

(-)

SOURCE

R=

580Ω

(+)

SOURCE

(-)

DRAIN

R=

∞

In case these 2 measurements cannot be verified, the transistor must be substituted.

AT725P Owner’s Manual

Annex C – Typical Final Test Reports Results

Out of Channel Emissions

AT725P Owner’s Manual

Frequency Response and Group Delay

Carrier Phase Noise

AT725P Owner’s Manual

Digital Modulation Error Rate:

AT725P Owner’s Manual

Conducted Spurious Emissions

Hitachi Kokusai Electric America AT725P 25 Watt UHF ATSC Transmitter User Manual AT725P Owner s Manual

Hitachi Kokusai Electric America LTD 25 Watt UHF ATSC Transmitter AT725P Owner s Manual

Exhibit D Users Manual per 2 1033 c3

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