Linear AT7400 User manual

AT7400 Owner Manual Rev. 2.0 – October 2006-10-23 1/1 1
ADVANCED TV
LINE
Model AT7400
400W ATSC UHF Transmitter
OWNERS MANUAL
Linear Industries Incorporation
www.linear-tv.com
Made in USA

AT7400 Owner Manual Rev. 2.0 – October 2006-10-23 1/1 1
AT7400
400W ATSC DTV TRANSMITTER
ADVANCED TV LINE
Owner Manual
Table of Contents
Section 1: Technical Specifications
Typical Final Test Report
Section 2: Master Control Unit
Section 3: Exciter Drawer
Section 4: Intermediate Directional Coupler
Section 5: 220W UHF Power Amplifier
Section 6: Output Directional Coupler, and Filtering
Section 7: Energy Distribution and Control
Annex A: Schematics Diagrams

AT7400 Owner Manual Rev. 2.0 – October 2006-10-23 1/3
User Notices and WARNINGS
USER NOTICES
IT IS VERY IMPORTANT TO READ THE FOLLOWING MANUAL SECTIONS PRIOR TO
OPERATION OF THIS TRANSMITTER!
Notice 1
The transmitter main operating voltage setting is marked on the rear of the AT7250 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 should seek proper medical attention. It is advisable that such personnel have
familiarity with first-aid practices.
Notice 5
To call our technical support center or for other customer service issues at Linear Inc, refer to the
following number: 630 346 6698.
Notice 6
If you experience some specific difficulty and the technical information available in this manual is
not enough to help you, do not hesitate to call LINEAR technical support center.
Notice 7
The technical information presented on this manual is sole intellectual propriety of LINEAR
INDUSTRIES Inc. Reproduction of this document in full or partial is prohibiting with out written
authorization. This document is legally protected by the copy rights laws.

AT7400 Owner Manual Rev. 2.0 – October 2006-10-23 2/3
WARNING!
THE VOLTAGES AND CURRENTS IN THIS EQUIPMENT ARE DANGEROUS. PERSONEL
MUST, AT ALL TIMES, OBSERVE SAFETY WARNINGS, INSTRUCTIONS, AND ANY
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 OF ELECTRONIC EQUIPMENT.
THE INSTALLATION, OPERATION, AND MAINTENANCE OF THIS EQUIPMENT INVOLVE
RISKS TO PERSONNEL AND ALSO TO THE EQUIPMENT. LINEAR, INC. SHALL NOT BE
RESPONSIBLE FOR INJURY OR DAMAGE THAT IS THE RESULT OF IMPROPER
PROCEDURES OR USE BY PERSONS IMPROPERLY TRAINED OR LACKING THE
KNOWLEDGE TO PERFORM ASSOCIATED TASKS.
ALL LOCAL CODES FOR BUILDING, SAFETY, FIRE, OR RELATED STANDARDS MUST BE
OBSERVED. CONSULT LOCAL AUTHORITIES FOR THE STANDARDS FOR THE AREA OR
REGION WHERE THE EQUIPMENT WILL BE INSTALLED AND PUT IN USE.
WARNING!
AT ALL TIMES DISCONECT AC/MAINS POWER BEFORE OPENING COVERS, DOORS,
ENCLOSURES, PANELS, OR PROTECTIVE SHIELDS THAT EXPOSE LIVE CIRCUITS. NEVER
PERFORM MAINTENANCE, MAKE ADJUSTMENTS, OR SERVICE THE EQUIPMENT WHEN
ALONE OR FATIGUED.
WARNING!
IF ELECTROLYTIC OR OIL FILLED CAPACITORS ARE UTILIZED IN THE EQUIPMENT AND
THE COMPONENT APPEARS LEAKY, OR IS BULGING, OR IF THE CASE OR COVERING OF
THE COMPONENT APPEARS DAMAGED OR DISTRESSED ALLOW SUFFICIENT TIME FOR
THE UNIT TO COOL OR FULLY DISCHARGE BEFORE SERVICING. SERVICING HOT OR
LEAKY CAPACITORS CAN CAUSE A RUPTURE OF THE CASE AND POSSIBLE INJURY.

AT7400 Owner Manual Rev. 2.0 – October 2006-10-23 3/3
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.

AT7400 Owner Manual Rev. 2.0 – October 2006-10-23 Section 1 - 1/7 1
Section 1 – AT7400 Technical Specifications
1. Introduction
The AT7400 is a 400W UHF ATSC/8VSB transmitter assembled and tested in United States by LINEAR
INDUSTRIES INC. (www.linear-tv.com).
Fig1.1: AT7400 Front View, cabinet wheels are optional.

AT7400 Owner Manual Rev. 2.0 – October 2006-10-23 Section 1 - 2/7 2
2. AT7400 RF line Up
3. AT7400 Cabinet Air Flux: 0.25m3/sec. - 21ft3/sec.
Fig. 1.4: Air flux path at AT4700 cabinet, (lateral view). Darker area denotes the internal heat source, or the RF drawers,
(1) Exciter and (2) PA’s.
Cold Air Inlet
Air Outlet

AT7400 Owner Manual Rev. 2.0 – October 2006-10-23 Section 1 - 3/7 3
4. AT7400 – 400W UHF ATSC/8VSB Transmitter - Technical Specifications
Electrical
Main 220/240 VAC, bi phase, 50-60 Hz. 3w.
Consumption 3200W.
PFC 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 75ȍ(BNC),
Reference Input Connector 50ȍ(BNC),
RF
RF Output Power 400w (rms)
Modulation Mode 8VSB. All-Digital Complex IF modulation
IF 18.833916 MHz.
Channel Bandwidth 6MHz.
Test Signal PRBS. Pseudo Random Bit Sequence
Frequency Range UHF. Ch14 to Ch69, (4 bands).
Frequency Step 1 Hz. ± 220kHz
Symbol Rate 10.76 MSymbol/sec.
Digital/Analog Converter 16 bit
All –Digital Linear. Pre-Correction Included
Pilot frequency stability overall ± 0.3 ppm.
Peak to peak frequency response 0.15 dB.
Peak to peak group delay response 15 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.
39dB (modulator output) typical.
39 dB (exciter output) typical.
MER (Modulation Error Rate)
29 dB (transmitter output) typical.
RF output connector EIA 7/8” Flanged.
Output sample connector N
Remote Control
RS-232 Dial-up network interface via hyper-terminal
Ethernet SNMP. IP network interface via Web Browser.
Mechanical
Internal drawer’s air speed: 400 ft/minute.
Air Refrigeration Overall Air flow: 21ft3/sec.
Dimensions 58”(H), 28”(W), 43”(D)
Weight Gross: 286.7 Kg NET: 236.70 Kg
Foot print 28”(W), 7’(D)

AT7400 Owner Manual Rev. 2.0 – October 2006-10-23 Section 1 - 4/7 4
5. AT4700 Available Models and Options
Models
AMono-phase; 220Vac.
B3-phase; 220Vac – 380Vac; 3 wires.
C3-phase; 220Vac – 380Vac; 4 wires.
Options:
01 Integrated GPS receiver
02 Adaptive digital pre-correction
03 Dual Exciter
04 Analog Transmission Mode
05 Cabinet 4 wheels
6. AT7400 Typical Test Report
6.1.Out of Channel Emissions

AT7400 Owner Manual Rev. 2.0 – October 2006-10-23 Section 1 - 5/7 5
6.2.Frequency Response and Group Delay
6.3.Carrier Phase Noise

AT7400 Owner Manual Rev. 2.0 – October 2006-10-23 Section 1 - 6/7 6
6.4.Digital Modulation Error Rate

AT7400 Owner Manual Rev. 2.0 – October 2006-10-23 Section 1 - 7/7 7
6.5.Conducted Spurious Emissions

AT7400 Owner Manual Rev. 2.0 – October 2006-10-23 Section 2 - 1/9 1
Section 2 – Master Control Unit
Module 4459
1. General Description
The main control unit, MCU, is the logical master unit acting all over the transmitter operational functions. The
MCU is constantly connected and exchanging information via RS485 with the UHF power amplifiers units and the
UHF exciter unit. External keyboard allows local changing on parameters and monitoring, displayed on a LCD
screen. Via a RS232, it is also possible to implement telemetry using either the Windows Hype Terminal, or via
Ethernet Web Server.
Fig.2.1: – Front View MCU module 4459
2. Following, the main functions of MCU
2.1. Monitor and display the alarm status on each of the transmitter units.
2.2. Monitor the direct and reverse RF power, out from the intermediate directional coupler, module 4488,
avoiding a potential over driver to the power amplifiers.
2.3. Monitor the direct and reverse RF power, out from the output directional coupler, module 4429, and
inhibiting excessive RF power level on either direction.
2.4. Send to the exciter driver local control unit, via RS485 protocol, the set of programmed software instructions
related with the broadcasting channel, and the associated power level.
2.5. MCU is composed by the following printed circuit boards:
2.5.1. 01 control unit; CIM3297.
2.5.2. 01 SNMP interface; CIM3453.
2.5.3. 01 Keyboard; CIM3112.
2.5.4. 01 LCD Display; CIM3108.

AT7400 Owner Manual Rev. 2.0 – October 2006-10-23 Section 2 - 2/9 2
2.6.Module 4459 Block Diagram
Fig.2.2: – Module 4459 block diagram and PCBs displacement.

AT7400 Owner Manual Rev. 2.0 – October 2006-10-23 Section 2 - 3/9 3
2.7.Unit Control Board CIM3297 at Module 4459
This is the principal board on the MCU module. See Fig.2.5 for the PCB CIM3297 connections. The logic functions
performed by the PCB CIM3297 are as follows:
(YL) BLACK L IGHT DISPLAY ? POI NTA –LC D DISPLAY – CIM3 10 8 (GR) +8V ?PIN7–P1 (WH)GNDTODISPLAY? POINT B – LCD DI SPL AY– CIM31 08 (BL) +15V ?PIN8–P1 ( GY) OUTPUT REF LECTED POWER READING ?PIN5–P1 ( RD) OUTPU T F ORWARD PO WER READING ?PIN6–P1 ( VL) 12 V BATT ER Y READING ?PIN6–P2 ( BR) +8 V DC/DC CO NVERTER READING ?PIN4–P2 ( BL) + 15V DC /DC CO NVERT ER READING ?PIN3–P2 ( YL) EXCITER F ORWARD PO WER READING ? PIN1–P1 (OR) EXC ITER REFLECTED POWER READING ?PIN2–P1 (WH) GND ?PIN9–P2
(B R) ? PIN4–CON1–KEYBOARD–CIM3112
( RD) ? PI N 3 – CON 1 – KEYBOARD – CIM 31 12 (BL) ? PI N 2 – CON 1 –KEYBOIARD – CIM 31 12 ( BK) ? PI N 1 – CON 1 – KEYBOARD – CIM 31 12
(O R) ? PIN 6 – C ON 1 – CIM31 12 –KEYB OARD (GY) ? PIN 5 – C ON 1 – CIM31 12 –KEYBOARD
(Y L) C O AXI AL RELAY COMMANDER ( OPTIO NAL DOUBLE EXC ITER) ?PIN1–P2
(BR) PHASE DETECTOR ?PIN4–P1
( GR) FAN FUSE 1 DETE CTOR ?PIN8–P1 ( OR) FAN FUSE 2 DETE CTOR ? PIN7–P1
FLAT CABLE 14 VIAS ? CON1– LCD DISPLAY –CIM3108
CO N - 1
BL
7
CON-2
1991
3
6CON-7 CON- 8 CO N - 9
1
GND
VCC
DA1
DA2
+15V
IRQ
CON- 3 1 6 CON-4 8
CON-5 8
1
CON-6
8 1
PA 21 PA3 1 PA41 PA51 PA61 PA71
1
PA02 PA12 PA2 2 PA32 PA42 PA52 PA62 PA72 PB01 PB11 PB21 PB31 PB 41 PB51 PB61 PB71 PB 72 PB62 PB 52 PB42 PB3 2 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
123
TPO-1
AJUSTE LU M . DISPLAY
XTAL1
1
14
SCL
SDA
PM4
PM3
PJ1
PJ0
16MHzDTR
CTS RX TX GND RTS DC D
CO N - 1 1
1
6
CON-10
1
7
J1 VM
BDM I N
M C 34 06 4
LM358
-
Q1
BCX 5 3
CON-12
1
1
.
DS2 29
..
RS2 32
RS48 5
J4 J5
.
DS22 9
CI -6
CI-2
.
CI-3
.
( BL ) CTR SNMP ? PIN3–CON-1–CI M3 453 – SNMP INT ERFACE
(BL) RS485 A ?PIN8–P3 A
B
GND
(GY) RS485B ?PIN7–P3
( BK) DTR SN MP ? PIN7–CON-1–CIM3453–SNMPINTERFACE ( OR) DCD SN MP ? PIN4–CON-1–CIM3453–SNMPINTERFACE ( GR) RTS SNMP ? PIN5–CON-1–CIM3453–SNMPINTERFACE ( YL) CTS SNMP ? PIN6–CON-1–CIM3453–SNMPINTERFACE ( RD) RXD SNMP ? PIN8– CON-1– CIM3453– SNMP INTERFACE (VL) TXD SN MP ? PI N 9 – CON- 1 – CIM345 3 – SNMP I NTERFACE (W H) GND SNMP ?PIN2–CON-1 –CIM3453 –SNMPINTERFACE
(YL) BL ACK L IGHT DISPL AY ? POI NTA – LC D DISPLAY – CIM3 10 8 (GR) +8V ?PIN7–P1 (WH)GNDTODISPLAY? POINT B – LCD DI SPL AY– CIM 31 08 (BL) +15V ?PIN8–P1 ( GY) OUTPUT REF LECTED POWER READING ?PIN5–P1 ( RD) OUT PU TF ORWARD PO WER READING ?PIN6–P1 ( VL) 12 V BATTER Y READING ?PIN6–P2 ( BR) +8 V DC/DC CO NVERTER READING ?PIN4–P2 ( BL) + 15V DC /DC CO NVERT ER READING ?PIN3–P2 ( YL) EXCITER F ORWARD PO WER READING ? PIN1–P1 (OR) EXC ITER REFLECTED POWER READING ?PIN2–P1 (WH) GND ?PIN9–P2
(B R) ? PIN4–CON1–KEYBOARD–CIM3112
( RD) ? PI N 3 – CON 1 – KEYBOARD – CIM 31 12 (BL) ? PI N 2 – CON 1 –KEYBOIARD – CIM 31 12 ( BK) ? PI N 1 – CON 1 – KEYBOARD – CIM 31 12
(O R) ? PIN 6 – C ON 1 – CIM31 12 –KEYB OARD (GY) ? PIN 5 – C ON 1 – CIM31 12 –KEYBOARD
(Y L) C O AXI AL RELAY COMMANDER ( OPTIO NAL DOUBLE EXC ITER) ?PIN1–P2
(BR) PHASE DETECTOR ?PIN4–P1
( GR) FAN FUSE 1 DETE CTOR ?PIN8–P1 ( OR) FAN FUSE 2 DETE CTOR ? PIN7–P1
FLAT CABLE 14 VIAS ? CON1– LCD DISPLAY –CIM3108
CO N - 1
BL
7
CON-2
1991
3
6CON-7 CON- 8 CO N - 9
1
GND
VCC
DA1
DA2
+15V
IRQ
CON- 3 1 6 CON-4 8
CON-5 8
1
CON-6
8 1
PA 21 PA3 1 PA41 PA51 PA61 PA71
1
PA02 PA12 PA2 2 PA32 PA42 PA52 PA62 PA72 PB01 PB11 PB21 PB31 PB 41 PB51 PB61 PB71 PB 72 PB62 PB 52 PB42 PB3 2 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
123
TPO-1
AJUSTE LU M . DISPLAY
XTAL1
1
14
SCL
SDA
PM4
PM3
PJ1
PJ0
16MHz16MHzDTR
CTS RX TX GND RTS DC D
CO N - 1 1
1
6
CON-10
1
7
J1 VM
BDM I N
M C 34 06 4
LM358
--
MC9S 12A128B
Q1
BCX 5 3
CON-12
1
1
.
DS2 29
.
DS2 29
....
RS2 32
RS48 5
J4 J5
.
DS22 9
.
DS22 9
CI -6
CI-2
.
CI-2
.
CI-3
.
CI-3
.
( BL ) CTR SNMP ? PIN3–CON-1–CI M3 453 – SNMP INT ERFACE
(BL) RS485 A ?PIN8–P3 A
B
GND
(GY) RS485B ?PIN7–P3
( BK) DTR SN MP ? PIN7–CON-1–CIM3453–SNMPINTERFACE ( OR) DCD SN MP ? PIN4–CON-1–CIM3453–SNMPINTERFACE ( GR) RTS SNMP ? PIN5–CON-1–CIM3453–SNMPINTERFACE ( YL) CTS SNMP ? PIN6–CON-1–CIM3453–SNMPINTERFACE ( RD) RXD SNMP ? PIN8– CON-1– CIM3453– SNMP INTERFACE (VL) TXD SN MP ? PI N 9 – CON- 1 – CIM345 3 – SNMP I NTERFACE (W H) GND SNMP ?PIN2–CON-1 –CIM3453 –SNMPINTERFACE
Fig. 2.3: - Module 4459 connection diagram for PCB CIM3297.

AT7400 Owner Manual Rev. 2.0 – October 2006-10-23 Section 2 - 4/9 4
Fig.2.4: – Module 4459, CIM 3297 the transmitter main microcontroller.
2.7.1. Digital Control
oThe integrated circuit CI-4 (A128) is a 16 bit microcontroller, programmed on assembler language. This
integrated circuit controls this module, 4459, and also the entire transmitter. This IC carries a controlled software
version, and is programmed on factory.
oIn case of substitution of the CI-4 or even the entire PCB CIM3297, it is mandatory to inform the factory
prior replacement, the programming identification number that is clearly indicated at the CI-4 body.

AT7400 Owner Manual Rev. 2.0 – October 2006-10-23 Section 2 - 5/9 5
2.7.2. Analog Readings
Information on analog format is available at the connectors P1 and P2 on the module 4459’s panel, which are
routed to CON-9 at the PCB CIM3297. On P1-P2 connectors are available the following analog reading from
external measurements:
Fig. 2.5: - Module 4459 external connections and internal connections view.

AT7400 Owner Manual Rev. 2.0 – October 2006-10-23 Section 2 - 6/9 6
2.7.2.1 Direct RF power, and reverse RF power. From the RF output directional coupler, module 4429.
2.7.2.2 Direct RF driver power, and reverse RF driver power. From the RF intermediate directional coupler,
module 4429.
2.7.2.3 +8V, from the DC/DC converter; module 4147.
2.7.2.4 +15V, from the DC/DC converter; module 4147.
2.7.2.5 The 12V/7Ah battery voltage.
From the connector CON-9 these readings feed the microcontroller CI-4, from where those are digitalized and
processed. By software decision, the microcontroller sets the nominal value for these readings always +4V,
meaning, to all nominal values the +4V will be assigned, and will be available at the CON-9. These values are
transferred to the main LCD display on the MCU.
On the intermediate and final directional couplers, module 4488 and 4429, as well on the mains module, 4147,
there are test points where the +4V nominal reference voltage are set. For instance:
Once on operation and at the time the transmitter is set for its nominal RF output
power, the trim pot TP01 at PCB CIM3128A located at the module 4429 should be
adjust on such way that the +4V is measured at pin 8, on the connector CON-9 located
at PCB CIM3297. More details will be shown on specific sections of this manual.
2.7.3. Alarm Detection
The system alarms are routed to MCU module 4459 via P1 and P2 connectors. These alarms are routed to CON-
5 at PCB CIM3297. These alarms are:
2.7.3.1 Lack of AC phase on mains, detected at module 4147.
2.7.3.2 Open fuse for fan #1, detected at module 4147.
2.7.3.3 Open fuse for fan #2, detected at module 4147. (For 2 racks systems only).
At the time when the system is on normal operation, no alarms, a +5V voltage is sent to the CON-5 via P1-P2
connectors. When an abnormal condition happens, that requires attention and generates an alarm status; a
lower voltage is than sent, usually 0V. When a lower voltage is detected by the microcontroller, the transmission
is halted.
2.7.3.4 The alarm status is shown at the LCD screen on the front panel of the MCU. The alarms events are
classified in two categories regarding the time line occurrence:
2.7.3.4.1. On going alarm situation, noted by the sign “!”.
2.7.3.4.2. Old alarm situation, noted by the sign “#”.
At the time when an alarm source cease, the transmission is reestablished, and the “!” sign is switched to a “#”
sign, and registered. Old records can be manually erased by pressing the key “CLEAR” on the MCU front panel
keyboard.

AT7400 Owner Manual Rev. 2.0 – October 2006-10-23 Section 2 - 7/9 7
2.7.4. RS485 Communication bus
On the PCB CIM3297, pin 1 and pin 2, at the CON-12 perform the RS485 communication link among the MCU,
the UHF exciter driver drawer and the UHF power amplifier drawers.
2.7.5. Interface SNMP
The interface SNMP is the PCB CIM3453. The connectors CON-4 and CON-10 located at the PCB CIM 3297
links the 2 PCBs.
Fig. 2.6: - Module 4459 SNPM interface, PCB CIM3453, internal and external view.

AT7400 Owner Manual Rev. 2.0 – October 2006-10-23 Section 2 - 8/9 8
2.7.6. Displaying the Exciter and Power Amplifier Drawers Alarms
Each drawer has its own local control units. The local processed data is link to the MCU via RS485 protocol. The
MCU unit analyze, command actions and display at the LCD, the overall system status.
Alarms from the drawers, are displayed as drawers alarms, followed by one of each signs “!”, or “#”. Any alarm
originated on any internal module belonging to the UHF exciter drawer, that is followed by the sign “!”, (on going
alarm), will cease the transmission. On other hand, any alarm originated on the UHF power amplifier drawer, also
followed by the sign “!”, will cause a proportional RF power reduction, implemented by the MCU logic control.
2.7.7. Keyboard, PCB CIM3112
This PCB holds the 8 key pads, which externally allows local manual interface with the transmitter MCU. This
PCB is a switch matrix. CON-1 transfers the CH1-CH8 keyboard ON/OFF operations to the MCU main board.
Fig. 2.7: - Module 4459 local command keyboard, external view.
2.7.8. LCD board, PCB CIM3108
This board is 4 rows, 40 columns liquid crystal display, LCD. The board is DC powered by the PCB CIM 3297, a
+5V feed into the point A, (yellow wire) and ground at point K (white wire). A multi-via connector receive a pin-
to-pin data out from CON-2 at PCB CIM 3297, exception for the pin 13 and pin 14 that have each other
exchanged its positions by the flat cable.
Fig. 2.8: - Module 4459 local command keyboard and LCD panel external view.