ABSTRACT

In military it is important to use state of the art communications test techniques to successfully support the Militarys Tactical Communications requirements. In the current conditions experienced in a tactical battlefield environment, with the need to transmit not only voice but also data and position information, a reliable communications link is of paramount importance. Automatic or Automated Test Equipment (ATE) is a reliable testing methodology which is used in military radio testing. ATE is any apparatus that performs tests on a device, known as the Device under Test (DUT), using automation to quickly perform measurements and evaluate the test results. The aim of this project Automation of HF Transceiver (TR2400) Testing is to develop the algorithms for the test procedures and realize it. Programming languages like C are used for this purpose. The setup consists of a native radio communication test set and computer consisting of GPIB interface. It is used to evaluate the radio units to their specifications. There are totally 19 to be done in the transceiver which consumes a lot of time for the procedures, tabulations & calculations all together. Typical field results demonstrate test time reductions on complex radios from 4 to 6 hours to less than 25 minutes Hence the automation of the transceiver testing helps speed up the testing process nearly to 25 minutes.

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INDEX

ORGANIZATION PROFILE PROJECT APPROACH CHAPTER 1: A Brief study of HF Transceiver Introduction to HF Transceiver Block diagrams of HF Transceiver HF transceiver specifications Study of Present System Need for Automation Proposed System Resources Required

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9 10 11 - 12 13 - 16 17 18 19 20 - 22

CHAPTER 2: Interfaces Used RS-232-C GPIB SYSTEM SETUP

23 24 - 26 27 - 36 37

CHAPTER 3: HF Communication

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5

Basics of HF communication Sky wave communication NVIS (Near vertical incidence sky wave)

39 - 40 41 - 43 44 45 46 47 - 48 49 - 55 56 - 58

CHAPTER 4: AUTOMATION OF TESTING PROCESS Automated test procedure Develop User Interface Test procedures Develop Flow charts for Test procedures

TESTING Test Results 59 - 60 61 - 80 81 82

FLOW CHARTS CONCLUSION BIBILIOGRAPHY

ORGANIZATION PROFILE

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The Electronics Corporation of India Limited (E.C.I.L) pioneered the advent of a variety of sophisticated and precision electronic instruments and systems based on indigenous research and development and production capabilities.

History Of E.C.I.LThe E.C.I.L was founded in the year 1967, as a Government of India enterprise under the Department of Atomic Energy (DAE). Right at the time of inception, the E.C.I.L undertook a bold decision of opting for self-reliance at every level of its operation. This helped the E.C.I.L to get off the ground quickly without any foreign collaboration and convincingly demonstrate the techno-commercial viability of indigenous technology. Subsequently, due to changes in the business environment, the E.C.I.L went in for selective foreign collaboration in critical areas like mainframe computers and other sophisticated electronic equipments with embedded chips. The company became synonymous with the finest in the Indian electronics arena, beginning with Rajasthan Atomic Power Project. The E.C.I.L, has been supplying control and instrumentation for all the nuclear power stations, thus enabling India to become self reliant in nuclear power generation technology.

E.C.I.L has six different project groups viz.,(1) Control system group (2) Computer maintenance group (3) Communication systems group (4) Components group (5) Strategic Electronics group (6) Instrument group Some of the main products brought out by E.C.I.L are- a wide range of computer systems varying from micros, super minis and mainframe systems, which have utilities in all most all the sectors.

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It has also developed and manufactured special purpose hardware and software for applications like message switching systems, air defense, automatic data handling systems, stores and forward telegraph/telex systems, remote telemetry applications at S.H.A.R., fatigue analyzers and wind tunnel testing systems for NAL, production of parallel processing computer systems (PACE) based on 68XXX to meet the needs of fluid dynamics, imaging, simulation and modeling artificial intelligence. E.C.I.L is striving to achieve quality levels required to compete in the International market and it has achieved the ISO 9001 certificate for international quality levels, which is indeed, a giant step forward in this direction. ECIL, had earlier received NATIONAL AWARDS FOR EXCELLENCE IN

COMMUNICATION (1990) and EXCELLENCE IN STRATAGIC ELECTRONICS (1992) both instituted by the department of electronics, Govt. of INDIA.

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CHAPTER -1A BRIEF STUDY OF HF-TRANSCEIVER

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INTRODUCTION TO HF TRANSCEIVERHF Transceivers operate in the HF (1.6 to 29.9999MHz.) Band and provides 99 programmable channels. The operating modes are USB, LSB, CW, AM and DATA. The high frequency, transceiver series, together with its support ancillary equipments can be developed in various configurations to satisfy a large variety of roles. The transceiver were developed provide a portable communication system for various applications such as military, patrol communication, air, traffic etc. This new generation HF equipment is designed to meet the requirements of the model digital battlefield. Based on the latest DSP technology, this range of equipment is more reliable and also provides flexibility and leaves room for future growth. The rugged construction and small size of the transceiver allows the user maximum mobility even in rough terrain. Enhanced intelligibility is obtained by applying speech processing and noise blanking technologies in the software domain. Error free, high-speed data transfer in a network environment is ensured.

HF Transceiver Applications(1) Manpack Application (2) Base Station Application (3) Mobile Application The aim of this project Automation Of HF Transceiver in to automate the system for testing thus reducing the time to perform the tests. This is done by developing programs in C using GPIB interface and file handling. The complete test procedure consists of 19 tests including the transmitter tests and the receiver tests performing all this tests takes a lot of time including the test procedures, tabulations and the calculations . this may take nearly 2 or more Hrs. so, by automating the system the time can be minimized. The other main advantage of this automated system is that persons with minimum knowledge also can operate the system.

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BLOCK DIAGRAMS OF HF TRANSCEIVER

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HF TRANSCEIVERS PERFORMANCE SPECIFICATIONS GENERAL:1. FREQUENCY RANGE 2. FREQUENCY ERROR 3. CLASS OF EMISSION : : : 1.6MHz-29.9999MHz. + 1PPM. USB,LSB,AM,CW, DATA.

TRANSMITTER CHARACTERISTICS:4. POWER OUTPUT : 100W PEP +/-1dB into 50 Ohms power output in SSB and CW. 100W PEP +1dB 2dB into 50 Ohms power output at 80% modulation in AM mode. 5. CURRENT CONSUMPTION : Less than 12.3Amps for 100W power output. Less than 3.27Amps for 25W power output. 6. CARRIER SUPPRESSION 7. UNWANTED SIDEBAND SUPPRESSION 8. HARMONICS AND SPURIOUS : OUTPUTS:. 9. AM MODULATION 10. TX AUDIO RESPONSE : : 80% (+/- 5%) at 5 mV rms , 1 Khz. 50 dB below PEP. : : 50 dB below PEP. 50 dB below PEP.

Voice: 300 Hz 2700 Hz within 3 dB.

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RECEIVER CHARACTERISTICS:11.CURRENT CONSUMPTION 12. SENSITIVITY mode. -100dBm for 10dB SINAD at 1KHz with 30% depth of modulation in AM mode. -117dBm for 10dB SINAD at 1 KHz in CW mode. 13. IMAGE AND IF REJECTION 14. AGC : : -80dB. Variation of RF input from 103 dBm to 0 dBm produces not more than 3 dB output change . 15. AUDIO OUTPUT 16. AUDIO RESPONSE 17. DIMENSIONS : : : 600 Line Output level adjustable between 20dBm+ 2dB and +6dBm +2dB. Voice: 300Hz 2700Hz within 3dB. HEIGHT WIDTH DEPTH : 140 mm. : 235 mm. : 380 mm. : : 160mAmps max. without RF input. -113dBm for 10dB SINAD at 1KHz in SSB

VISUAL CHECKS:Examine the transceiver front panel and ensure that it is free of dirt, grease and fungus. Check identity of the unit and front panel controls for looseness or damage or scratches on the unit. Check the handset and antenna connecters.

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FUNCTIONAL CHECKS: PRIMARY FUNCTIONS:NET/CHAN : 1.NET- Selects Net functions. 2.CHAN - Selects channel. FREQUENCY MODULATION : : Set up/ Change Tx Rx Frequencies. Selects modulation mode from the following: USB, LSB, CW USB, CW LSB and AM. SQUELCH CALL/ABORT PWR LINK TRAFFIC SYNCRONIZATION : TUNE/ANT ENT : : : : : : : Selects nine levels of squelch. Initiates ALE link. Selects between high or low power in Tx. Selects link type. Selects traffic type. Sends Sync signal. Initiates antenna tuning. Enters the Selections.

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SECONDARY FUNCTIONS:

FUNCTIONS SET EXTENDED CALL/ABORT * TUNE/ANT

: : : : : : :

Primes the Secondary functions Selection. Selects Channel programming. Selects extended control operation. Exits functions menus and erases code. controls display contrast. Selects back lighting ON/OFF. Selects antenna type.

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STUDY OF PRESENT SYSTEM Present Test Procedure:The transceiver unit is currently being tested manually. There are in all 19 tests to be performed. The whole setup will be made with an RCTS, RADIO, Power supply, Signal Generator etc and different connections are to be made for different tests. If done manually, each test takes around 40 minutes to complete. Also the user must remember not only the commands used in each test but also the sequence in which they occur. Since manual method of measuring these specifications is a time consuming process and requires various equipments for different specifications,

Important Drawbacks:1. Consumes lot of time. 2. Very tedious process.

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NEED FOR AUTOMATIONTesting of transceivers involves the measurements of many parameters like sensitivity,, AF in band ripple power, RF power out put ,modulation, harmonic measurements, MIC measurements etc. For all these measurements appropriate screens are to be selected manually every time in the radio set and also the signals are to be routed through the appropriate ports.

Therefore manual testing, which is more traditional and which consumes appreciable amount of time, has been replaced by automatic testing which eliminates the need of the presence of unit frequency and unit serial number. This method of testing is automatically by any operator after initiating test by giving the necessary data, that is to select the appropriate data in the RTS and also route the signals through appropriate ports with the aid of relays in the interface unit.

After the testing is completed, the measured parameter values are displayed and the operator can proceed with testing of another transceiver. Hence this method of testing of eliminates the need of the operator with sound knowledge of transmitted and received circuit and also the operation of the Radio test set. Hence this method of testing is more efficient than the traditional manual testing.

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PROPOSED SYSTEMThe proposed system automates the testing process by writing code that automatically initializes and operates the RTS as well as sends frequencies to the transceiver unit being tested. The user who uses this software does not need to know the exact commands required to manipulate the unit and the RTS. The user has to only follow the instructions given by the software during the course of testing and to choose from the options given to him. This testing software has been developed in order to reduce the time taken to perform each test and thus increase the number of transceiver units tested per day. The proposed system incorporates the Graphical User Interface and has been designed to facilitate the use of the software by people without any programming knowledge.

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RESOURCES REQUIRED: Hardware Resources :a) A PC equipped with GPIB. b) One Radio Communication Test Set c) RS-232 C port. d) PC Parallel Port

Software sources:a) Operating System: MS-DOS. b) Programming Language: C.

Interfaces Used:a) RS-232-C (Between PC and Transceiver) b) GPIB IEEE 488.2 (Between PC and RTS)

RADIO COMMUNICATION TEST SET Introduction:The test set combines up to 24 separate test instruments and an instrument basic controller into one package. All the test sets function can be automatically controlled through application programs running on the builtin IBASIC controller or on an external controller connected via GPIB Developing programs for the test set is simplified if the programmer has a basic understanding of how the test set operates. An overview of the test sets operation is best presented in terms of how information flows through the unit. The test set has two operating modes: Manual control mode. Automatic control mode

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Manual Control Mode:In this mode the test sets operation is controlled through the front panel key pad/rotary knob. There are two classes of instruments in the test set: Signal Analyzers (RF Analyzer, AF Analyzer, Oscilloscope, Spectrum Signal Sources (RF Generator, AF Gen#1, AF Gen#2, Signal Encoder). Analyzer, and Signal Decoder). Since so many instruments are integrated into the test set, it is not feasible to have an actual front panel for each instrument. Therefore each instruments front panel is maintained in firmware and is displayed on the CRT whenever the instrument is selected. Only one instrument front panel can be displayed on the CRT at any given time.

There are two Automatic Control Modes Internal Automatic Control Mode. External Automatic Control Mode.

Automatic Control Mode: Internal Automatic Control Mode:In internal automatic control mode an application program running on the built-in IBASIC controller controls the test sets operation. The architecture of built-in IBASIC controller is similar to that of other single tasking Instrumentation controllers. Only one program can be run on the IBASIC controller at any given time. The program is loaded into RAM memory from some type of mass storage device. Five types of mass storage devices are available to the test set: SRAM & ROM memory cards, external disk drivers connected to the GPIB interface, internal RAM disc and internal ROM disc. Three types of interfaces are available for connecting to external instruments and equipment: GPIB, RS-232, 16-bit parallel interface card.

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External Automatic Control Mode:In External Automatic Control an external controller connected to the Test Set via the GP-IB interface controls mode the test sets operation. When in External Automatic Control mode the Test Sets internal configuration is same as in manual control mode with two exceptions. Configuration and setup commands are received via the external, selected code rather than from the front panel key pad/ rotator knob. The Measure command issued to obtain measurement results and DUT data through the external GP-IB interface

TEST AUTOMATION SOFTWAREThis software has been developed for the purpose of automating the final testing of the HF transceiver equipment using the Hewlett Packard Radio Communication Test Set (HP RTS). The transceiver equipment is connected to the PC through the RS-232-C serial cable and the RTS is connected to the PC through General Purpose Interface Bus (GPIB) - IEEE 488 interface. This Software mainly contains one module. It is MENUS

The header files used in the software are: TXRX.H

There are 7 transmitter tests, 10 receiver tests, 1 manual test and 1 Front Panel Test. Each of the transmitter and the receiver tests, and the manual test has been written as a separate program.

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CHAPTER -2INTERFACES USED

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INTERFACES USED: RS-232 GPIB RS-232-C:RS-232 (ANSI/EIA-232 standard) is the serial connection found on IBMcompatible PCs. It is used for connecting a mouse, printer or modem as well as industrial instrumentation. Because Improvements in line drivers and cables , applications often increase the performance of RS-232 beyond the distance and speed listed in the standard .RS-232 communication up to distances of 50 feet DB-9Pin connector 12345 6789

Pin functions:

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Data: Handshake: Common: Other:

TxD on pin 3,RxD on pin 2 RTS on pin 7,CTS on pin 8,DSR on pin 6, DCD on pin 1,DTR on pin 4 com on pin 5 RI on pin 9

Serial communication: Serial communication is the standard communication used on almost every PC. It is differ with universal serial bus (USB). Most computers include two RS-232 based serial ports. Serial is also a common communication protocol that is used by many devices for instrumentation; Nemours GPIB-compatible devices also come with an RS-232 port. Furthermore, serial communication can be used for data acquisition in conjunction with a remote sampling device. The concept of serial communication is simple. The serial port sends and receives bytes of information one bit at a time. Although this is slower than parallel communication, which allows the transmission of an entire byte at once, it is simpler and can be used over long distances. For example the IEEE 488 specifications for parallel communication state the cabling between equipment can be more than 20 meters total, with no more than 2 meters between any two devises. However, it can extend as much as 1200 meters Typically, serial is used to transmit ASCII data. Communication is accomplished using 3 transmission lines: 1) Ground, 2) Transmit, and 3) Receive. Since serial is asynchronous the port is able to transmit the data on one line while receiving data consists of data bits, stop bits and parity. For efficient communication two ports must match these parameters.

Baud rate:

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Baud rate is used for speed measurement of communication. It indicates the number of bits transfer per second. For example, 300 baud is 300 bits per second. When we refer to a clock cycles we mean the baud rate. For example, if the protocol calls for a 4800Hz baud rate, then the clock is running at 4800Hz. This means that the serial port is sampling the data line at 4800Hz.common baud rates for telephone lines are 14400,28800 and 33600. Baud rates are greater than these are possible, but these rates reduce the distance by which devices can be separated. These high rates are used for devise communication where the devices are located together, as is typically the case with GPIB device

Data bits:A measurement of the actual data bits in a transmission. When the computer sends a packet of information. The amount of actual data may not be full 8 bits. Standard values for the data packets are 5,7,and 8 bits. Which setting you choose depends on what information you are transferring. Since the no of bits depends on the protocol selected .

Stop bits: stop bits represent end of communication for a single packet. Typically the no ofstop bits can differ by user selection i.e. 1, 1.5 and 2 bits. The more stop bits are used, the greater the lenience in synchronizing the different clocks, but slower the data transmission rate.

Parity: parity used for the simple form of error checking in serial communication. There arefour types of parity used i.e. even, odd, odd marked and spaced .no parity is also used. For even and odd parity, the serial port sets the parity bit to a value to ensure that the number of logic-high bits. Marked and spaced parity bit does not actually check the data bits, but simply sets the parity bits high for marked parity or low for spaced parity.

Handshaking:

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The method used by RS-232 for communication allows for a simple connection of three lines Tx, Rx and ground. However, for the data to be transmitted, both sides have to be clocking the data at the same baud rate. Even though this method is sufficient for most applications, it is limited in being able to problems such as the receiver getting overloaded. Three of the most popular forms of hand shaking with RS-232 are software handshaking, hardware handshaking and X modem

GPIB-GENERAL PURPOSE INTERFACE BUS INTRODUCTION:The IEEE standard 488, also known as GPIB, describes a standard interface for communication between instruments and controllers from various vendors. It contains information about electrical, mechanical and functional specifications .The GPIB is a digital, 8-bit parallel communications interface with data transfer rate of 1 MB/sec .The bus supports one system controller, usually a computer and up to 14 additional instruments. The original GPIB was designed by Hewlett Packard to connect and control programmable instruments manufactured by Hewlett Packard. Because of its high data transfer rates of up to 1MB/sec, the GPIB became very much popular in the applications such as controlling different types of test equipment through computers.

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TALKERS, LISTENERS AND CONTROLLERS:GPIB devices can be Talkers, Listeners or Controllers. A Talker sends out data messages. Listeners receive data messages. The Controller, usually a computer manages the flow of information on the bus .It defines the communication links and sends GPIB commands to devices. Some devices are capable of playing more than one role. E.g.: A digital voltmeter for example can be Talker and Listener. If a PC has a National Instruments GPIB interface board and NI 488.2 software installed, it can function as a Talker, Listener and a Controller.

CONTROLLER-IN-CHARGE AND SYSTEM CONTROLLER:We can have multiple Controllers on the GPIB, but only one Controller at a time can be active Controller or Controller-In-Charge (CIC). When a Controller is not active it is considered as an idle controller. Active controller can pass from the current CIC to an idle controller. The system controller, usually a GPIB interface board is the only device on the bus.

SENDING MESSAGES ACROSS THE GPIB:Devices on the bus communicate by sending messages. Signals and lines transfer these messages across the GPIB interface, which consists of 16 signal lines and 8 ground return (shield drain) lines .The 16 signal lines are

1. Data lines:Eight data lines, DIO1 through DIO8, carry both data and command Messages.

2. Hand shake lines:Three hardware handshake lines asynchronously control the transfer of message bytes between devices.

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A. NRFD

: (not ready for data)

Listening device is ready / not ready to receive a message byte. Also used by the Talker to signal high-speed GPIB transfer.

B. NDACC. DAV data.

: (not data accepted) Listening device has/has not accepted a message byte. : (data valid) Talking device indicates signals on data line stable (valid)

3. Interface Management Lines:Five GPIB hardware lines manage the flow of information across the Bus. A. ATN: (attention) Controller drives ATN ' true ' when it sends commands and ' false when it sends data messages. B. IFC: (interface clear) System controller drives the IFC line to initialize the bus and make itself CIC. C. REN: (remote enable) System controller drives the REN line to place devices in remote or Local program mode. D. SRQ: (service request) Any device can drive the REN line to asynchronously request Service from the controller. E. EOI: (end of identifies) Talker uses the EOI line to mark the end of a data message. Controller uses the EOI line when it conducts a parallel poll.

GPIB ADDRESSING:All GPIB devices and boards must be assigned a unique GPIB Address .A GPIB address is made up of two parts: a primary and an optional secondary address. The primary address is a number in the range 0 to 30. The GPIB controller uses this address to form a talk or listen address that is sent over the GPIB when communicating with device. The configuration of GPIB address bits is: Bit position Meaning 7 0 6 TA 5 4 3 2 1 0

LA 29 GPIB Primary Address (Range 0 -30)

A talk address is formed by setting bit 6,TA (talk active) bit of the GPIB address. Setting bit 5. the LA (listen active) bit of the GPIB address, forms a listen address

SETTING UP AND CONFIGURING YOUR SYSTEM:Devices are usually connected with a cable assembly of a shielded 24-conductor cable with both a plug and receptacle connector, or a combination at each end .we can link devices in a linear configuration, a star configuration, or a combination of the two. The figure below shows the linear and star configurations. Computer With GPIB Computer With GPIB

CONFIGURATION REQUIRMENTS:Device A

Device B

Device A 30

Device B

To achieve the high data transfer rate that the GPIB was designed for, we must limit the physical distance between devices and the number of devices on the bus .

The restrictions are: A maximum separation of four meters between any two devices and an average separation of two meters over the entire bus. A maximum total cable length of 20m. A maximum of devices connected to each bus, with at least two-thirds powered on.

For high-speed operation, the following restrictions apply: All devices in the system must be powered on. Cable lengths as short as possible up to a maximum cable for system. With at least one equivalent device load per meter of cable.

INTRODUCTION OF NI-488 FUNCTIONS:The NI-488 functions consist of high level (or device) functions that communicate with control devices in the GPIB.

HIGH LEVEL FUNCTIONS AND DEVICE FUNCTIONS:Device functions are easy to learn and use. These functions free us from having to know the GPIB protocol or bus management details involved. They automatically execute sequences of commands that handle bus management operations required to perform activities such as reading from and writing to devices are nothing than for status . Device functions access a specific device and take care of the addressing and bus management protocol for that device. Device functions are functions that access or control a device .The descriptors of the device is one of the functions arguments .All high level functions are high level. Some device functions however are not involved in GPIB bus management, thus they are low-Level bus functions.

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LOW LEVEL FUNCTIONS AND BOARD FUNCTIONS:In contrast, board functions perform rudimentary or primitive operations that require you to know something about GPIB protocol before you can use them effectively. They are needed because high level functions do not always meet the requirements of applications .In such cases, low level functions offers the flexibility you need to solve most of your application problems. Board functions access the GPIB interface board directly and require you to do the addressing and bus management protocol for the bus .All board functions are low-level functions.

IMPORTANT NI-488 FUNCTIONS: IBDEV: Purpose:Open and initialize a device descriptor.

Syntax:int ibdev (int BdIndx ,int pad,int sad,int tmo,int eot,int eos)

Input:bdIndx pad Sad tmo SSS eot eos : Index of the access board for the device. : The primary GPIB address of the device. : The secondary GPIB address of the device. : : : The I/O time out value. EOI mode of the device. Eos character and modes.

Output:Function returns the device descriptor.

Description:'ibdev' acquires a device descriptor to use in subsequent device Level NI-488 functions .It opens and initializes a device

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Descriptor and configures it according to the input parameters. IBWRT:

Purpose:Write data to a device from a user buffer.

Syntax:int ibwrt(int ud, void*wrtbuf,long count)

Input:ud count : Board or device descriptor. : Number of bytes to be written. wrtbuf : Address of the buffer containing the bytes to write.

Output: Function returns the value of 'ibsta'.

Description: Device level:If ud is a device descriptor , ibwrt addresses the GPIB and write count bytes from the memory location specified by 'wrtbuf' to a GPIB device .The operation terminates normally when count bytes have been sent .The operation terminates with an error if count bytes could not be sent within the time out period .The actual number of bytes transferred is returned in the global variable 'ibcntl'.

Board level:If baud is a board descriptor, ibwrt writes count bytes of data from the buffer specified by wrtbuf to a GPIB device ; a board level 'ibwrt' assumes that the GPIB is already properly addressed. The operation terminates normally when count bytes have been sent .The operation terminates with an error if count bytes could not be sent within the timeout period or , if the board is not CIC ,the CIC sends device clear message on the GPIB .The actual number of bytes transferred is returned in the global variable 'ibcntl'.

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IBRD: purpose:Read data from a device into a user buffer.

Syntax:int ibrd(int ud ,void *rdbuf ,long count)

Input:ud : board or device descriptor. number of bytes to be read from the GPIB. Address of the buffer into which data is read. count : rdbuf :

Output:Function returns the value of 'ibsta'.

Description: Device level:If ud is a device descriptor ,ibrd addresses the GPIB , reads up to count bytes of data and places the data into the buffer specified by rdbuf. The operation terminates normally when count bytes have been received or END is received .The operation terminates with an error if the transfer could not complete within the time out period .The actual number transferred is returned in the global variable 'ibcntl'.

Board level:If ud is a board descriptor , ibrd reads up to count bytes of data from aGPIB device and places the data into the buffer specified by rdbuf. A board-level ibrd assumes that the GPIB is already properly addressed .The operation terminates normally when count bytes have been received or END is received .The operation terminates with an error if the transfer could not complete with in the timeout period or, if the board is not CIC, the CIC sends a Device clear on the GPIB. The actual number of bytes transferred in the global variable 'ibcntl'.

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IBCLR: Purpose:Clear a specific device.

Syntax:int ibclr(int ud)

Input:ud: A device unit descriptor.

Output:Function that returns the value of 'ibsta'.

Description:'ibclr' sends the GPIB Selected Device Clear (SDC) message to device described by ud.

IBLOC: Purpose:Go to local.

Syntax:int ibloc (int ud)

Input:ud: board or device descriptor.

Output:Function returns the value of 'ibsta'.

Description: Board level:

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If The board is not in a lockout state ( LOK does not appear in the status word 'ibsta'), 'ibloc' places the board in the local mode . Otherwise , the call has no effect.The ibloc function is used to stimulate a front panel RTL(return to local).Switch if the computer is used as an instrument.

Device level:Unless the REN (Remote Enable) line has been unasserted with the 'ibsre' function , all device-level functions automatically place the specified device in remote program mode. 'ibloc' is used to move devices temporarily from a remote program mode to a local mode until the next device function is executed on that device.

IBONL: Purpose:Place the device or interface board online or offline.

Syntax:int ibonl(int ud,int v)

Input:ud : Board or device descriptor v : indicates whether board or device is to be taken online or offline .

Output :Function returns the value of 'ibsta'.

Description :'ibonl' resets the board or device and places all its software configuration parameters in their pre-configured state .In addition , if v is zero , the device or interface board is taken offline .If v is non-zero,the device or interface board is left operational or on-line. If a device or an interface board is taken offline , the board or device descriptor (ud) is no longer valid.We must execute an 'ibdev' or 'ibfind' to access the board or device again.

IBCONFIG:

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Purpose:Changes the software configuration parameters.

Syntax:int ibconfig(int ud , int option ,int value)

Input:ud : board or device unit descriptor. option : a parameter that selects the software configuration item. value : the value to which the selected configuration item is to be changed .

Output:Function returns the value of ibsta.

Description:ibconfig changes the configuration item to the specified value for the selected board or device. Option may be any of the defined constants and value must be valid for the parameter that you are configuring. The previous setting of the configured item is return in iberr

SYSTEM SET UP

GPIB INTERFACE

PC WITH GPIB & RS232 INTERFACE RS 232 INTERFACE

RADIO COMMUNICATION TEST SET(RCTS) AUDIO IN/OUT RF AUDIO PORT TRANSCIVER R 30 dB ATTENUATOR IN/OUT

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RF IN

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CHAPTER -339

HF COMMUNICATION

HF COMMUNICATION BASICS: Radio signals propagate as waves from a transmitting antenna through space at the speed of light. Frequency determines the length of a radio wave; lower frequencies have longer wavelengths and higher frequencies have shorter wavelengths. Long-range radio communications take place in the high-frequency (HF) range of 1.6 to 30 MHz. Modulation is the process whereby the phase, amplitude, or frequency of a carrier signal is modified to convey intelligence. HF radio waves can propagate as sky waves, which are refracted from the earths ionosphere, permitting communications over long distances.

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PROPAGATION:Transceiver wave propagation may be defined as the movement of electromagnetic energy from a transmitting antenna to a receiving antenna.

RADIATION:Radiation is the transfer of electromagnetic energy from an element called an antenna into free space. A transmitter, when activated, releases electrical energy into the antenna. This energy causes an electromagnetic (EM) field to be radiated by the antenna. The EM field travels (or is propagated) through space at 300 000 km/s. The EM field comprises two components, i.e., an electrical field and magnetic field. These fields are at right angles to one another.

POLARISATION:Polarisation is the orientation of the electric field with respect to the surface to the earth. This is determined by the physical orientation of the transmitting antenna. If, for example, the antenna is vertical, the electric field is vertical and the transceiver is said to be vertically polarised.

ANTENNA RADIATION PATTERN:

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A theoretical antenna, known as isotropic antenna, radiates power equally in all directions in space. But in practice, different antennas have different radiation patterns. The characteristic which describes in which directions an antenna radiates power, is known as the radiation pattern of the antenna.

ANTENNA RADIATION EFFICIENCY :Radiation efficiency is a measure of how much power an antenna radiates as a function of the amount of power available from the transmitter. Antennas that are very short compared to the wavelength in use have a very low radiation efficiency. A 2.4m whip which is 0.06 of a wavelength long at 7 MHz has a radiation efficiency in the region of 1%. (ex:- If 10W power is pumped, then only 0.1W power is radiated.)

SKY WAVE COMMUNICATION ELEMENTS IN AN HF RADIO SYSTEM: The ionosphere is a region of electrically charged particles or gases in the earths atmosphere, extending from 50 to 600 km (approximately 30 to 375 miles) above the earths surface. There are layers of varying electron density in the ionosphere that absorb, pass, or reflect radio waves, depending on the density of the layer, the angle with which the radio waves strike it, and the frequency of the signal. Ionization, caused by solar radiation, strips electrons from atoms, producing electrically charged particles.

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REGIONS OF THE IONOSPHERE The density of ionospheric layers varies with the intensity of solar radiation, which changes according to time of day, season, and sunspot cycle. The angle of radiation is determined by the wavelength of a signal and the type of antenna used. Radio waves are absorbed as they pass through the ionosphere. The absorption rate increases as frequency decreases.

43

INCIDENT ANGLE

44

HF SKYWAVE PROPAGATION & IONOSPHERE

MULTIPATH RECEPTION

45

NVIS (NEARVERTICAL SKYWAVE) :Sky wave propagation over zero to approximately 150Km known as NVIS. The most problematic ranges over which to establish communication are 30 to 150KM. It is within these ranges that NVIS can be used to provide reliable communications since the sky wave signal travels almost vertically upwards and downwards to establish a link.

A dipole antenna is set at a suitable height above the ground to radiate most of the power from the transceiver in a direction vertically upwards. The correct choice of both frequencies and antennas allows excellent link quality within this zone.

46

CHAPTER -4AUTOMATION OF TESTING PROCESS

47

AUTOMATED TEST:The HF Transceiver under test is controlled by PC system through RS 232 bus. The PC is facilitated with GPIB software. As the Transceiver is having single port for transmitter RF out and receiver RF input ,RF signals routed to Radio Communication test set via attenuator. In case of receiver parameter testing, modulated RF signal from Radio communication test set is applied to TxRx antenna port. In case of Transmitter parameter testing, modulated RF signal from TxRx antenna port is applied to Radio communication test set via attenuator. Audio OUT and Audio IN of TxRx are connected to Audio IN and Audio OUT of Radio Communication test set respectively called Transmitter and Receiver lines.

48

DEVELOP USER INTERFACE: About User Interface:The user interface is developed using the FILE HANDLING of C language. The interface developed is based on Keyboard interaction of the user with the PC. The main purpose of this interface is to ease the work of user. Using this interface, user can select the test that she/he wants to perform by just entering the choice and the serial numbers.

Execution:When the program is executed, the Equipments and Interfaces list screen is displayed. The user is initially asked to enter the serial number Where the files contains the test results are required to be stored .The serial number being assigned to the file is limited to 8 characters in accordance with the DOS file naming conventions. If the file does not exist, it is created. If the file exists, the message FILE ALREADY EXISTED is displayed. Once the serial number is entered, the main menu is displayed. This Menu contains the four options given below.

MAIN MENU: 1. CONTINUOUS TESTING 2. SELECTIVE TESTING 3. PRINT 4. EXIT ENTER THE CHOICE: Selective Testing:Choosing the selective mode results in another menu being displayed that contain a list of all the transmitter tests to be performed. The user can choose the test to be performed. Once the test is performed and the results stored in a file, the control is passed back to this menu.

49

Continuous Testing:In the continuous mode the tests are automatically performed one after the other. The user, however, has the option to quit to the main menu containing the modes on choosing the choice exit.

Print:Choosing the print mode results in the control being passed to the printer to print out the results that are stored in the file. The file consists of the results of the total tests performed by the automated system in a tabulated format and this is printed out on the result sheets. The selective mode menu consists of three options, Transmitter Tests, Receiver Tests, and option to return to the main menu. such as:

SELECTIVE TESTING 1. TRANSMITTER TESTING 2. RECEIVER TESTING 3. EXIT Transmitter Testing:The transmitter tests are executed if the first option is selected and the tests are Performed, the results are stored in a file as well as displayed on the screen.

Receiver Testing:The receiver tests will be executed if the second option in the selective menu is Selected. Each receiver test has been written as a separate program and accepts the serial number and the file name as the command line arguments. After each test is performed, the results are stored in a file as well as displayed on the screen. The Results can be printed immediately after the test is over or at a later time by using the print mode option in the main menu.

50

TEST PROCEDURES: I. RECEIVER: A) RECEIVER CURRENT CONSUMPTION:Connect the set-up as shown in Fig.1 Insert DMM in the 27V supply line. Switch off the RF input. Switch on the radio. Measure the current drawn from the power supply line and note down. It should be 160mAmps max.

B)

SENSITIVITY (USB):1. 2. 3. 4. 5. 6. 7. Connect the set-up as shown in Fig.1 Set the HF Transceiver to 3.000 MHz, USB, Low power, AGC to OFF. Set in RCTS RF frequency 3.001 MHz, RF level-93dBm(i.e. -113dBm at radio input) Select in RCTS, SINAD and AC level(power in dBm) Adjust the audio power to 0 dBm with volume control of HF Transceiver on the front panel. Note down the SINAD value. It should be greater or equal to 10dB

Note:1. Repeat the above procedure for LSB mode. Set the HF Transceiver frequency to 3.000 MHz, RF frequency from RCTS to 2.999 MHz. 2. Repeat the test for HF Transceiver 12.800 MHz and 29.600 MHz frequencies.

C)

SENSITIVITY (CWU) :The procedure is same as given in (B). Set the HF Transceiver frequency to

3.000 MHz, RF frequency from RCTS to 3.001 MHz with RF level -97dBm. SINAD should be greater or equal to 10dB.

Note: For CWL , set HF Transceiver frequency to 3.000 MHz , RCTS RF frequency to2.999 MHz

51

D)

SENSITIVITY (AM) :The procedure is same as given in (B). Set the HF Transceiver frequency to

3.000 MHz, RF frequency from RCTS to 3.000 MHz with RF level -80 dBm and audio frequency of to 10dB. 1 KHz with 30% of depth or modulation. SINAD should be greater or equal

E)1. 2. 3. 4. 5.

AF FREQUENCY RESPONSE (USB):Connect the set-up as shown in Fig.1 Set the HF Transceiver to 3.000 MHz and USB, AGC to OFF. Set in RCTS RF frequency 3.001 MHz, RF level -80 dBm (i.e. -100dBm at radio input). Adjust the audio power to 0 dBm with volume control of HF Transceiver on the front panel Change the modulating frequency to 300 Hz and 2700 Hz. Note the change in AC levels. It should be within 3dB.

F)

AF FREQUENCY RESPONSE (CW):1. 2. 3. 4. 5. Connect the set-up as shown in Fig.1 Set the HF Transceiver to 3.000 MHz, CWU, Low power, AGC to OFF. Set in RCTS RF frequency 3.001 MHz, RF level -80 dBm . Adjust the audio power to 0 dBm with volume control of HF Transceiver on the front panel. Change the modulating frequency to 750 Hz and 1250 Hz. Note the change in AC levels. It should be within 3dB.

G)1. 2. 3. 4. 5.

IF REJECTION :Connect the set-up as shown in Fig.1 Repeat the sensitivity (B) test from Sl.Nos. 1 to 5. Change the RCTS port to Dup (Duplex) port. Change the RF frequency or RCTS to IF frequency. Increase the RF level to obtain 0 dBm AC level.

52

6. 7.

Note down the change in increase of RF level. It should be greater or equal to 80dB.

H) IMAGE REJECTION :1. 2. 3. 4. 5. 6. 7. Connect the set-up as shown in Fig.1 Repeat the sensitivity (B) test from Sl.Nos. 1 to 5. Change the RCTS port to Dup (Duplex) port. Change the RF frequency or RCTS to image frequency. Increase the RF level to obtain 0 dBm AC level. Note down the change in increase of RF level. It should be greater or equal to 80dB.

I)1. 2. 3. 4.

AUDIO OUTPUT POWER RANGE IN 600 :Connect the set-up as shown in Fig.2 Set the HF Transceiver to 12.8 MHz, USB and terminate the audio output into 600 . Set in RCTS RF frequency 12.801 MHz with an RF level of -50 dBm +/- 5 dB. Rotate the volume control to minimum and maximum positions and note down the audio output power. The range should be between -20 dBm +/- 2dB and +6 dBm +/2dB.

J)1. 2. 3. 4. 5. 6. 7. 8.

AGC RANGE :Connect the set-up as shown in Fig.3 Set the HF Transceiver to 12.800 MHz and USB. Set the noise blanker to OFF. Set the RCTS RF frequency 12.801 MHz with a RF level of -95 dBm (i.e. -105dBm applied to radio). Select AC level in RCTS. Adjust the audio power to 0 dBm with volume control of HF Transceiver on the front panel. Change the RCTS port to DUP (Duplex) mode. Increase the signal level in 10dB steps to + 10dBm (i.e. 0dBm at radio) Note down the AC level. The AC level reading on the RCTS should not vary more than 3dBm.

53

TRANSMITTER: A) TRANSMIT CURRENT CONSUMPTION:to the radio. 2. Insert current meter in the +27V supply line. 3. Set the PSU to 27V +/- 0.5V. Set the HF Transceiver to 1.6000MHz, CW, Low power. 4. PTT the radio and measure the current. It should be less than 3.27Amps. 5. Release the PTT. 6. Set the radio to High power. 7. PTT the radio and measure the current. It should be less than 12.3Amps.

1. Set-up the equipment as shown in fig 4. Ensure that the 100W heatsink has been fitted

B)1. 2. 3. 4.

POWER MEASUREMENT 100 W CW :Set-up the equipment as shown in fig.4. Ensure that the 100W heat sink has been fitted to the radio. Set the PSU to 27V +/- 0.5V. Set the HF Transceiver to 1.6000MHz, CW, Vogad to on. Select High power.. PTT the radio and measure the output power at the frequencies as indicated in Table.1 Power output should be 100W +/- 1dB.

No I Ii Iii

Frequency 1.6 MHz 12.8 MHz 29.6 MHz Table.1

C)

FREQUENCY ERROR:

54

1. Set-up the equipment as shown in fig.4. Ensure that the 100W heat sink has been fitted to the radio. 2. Set the PSU to 27V +/- 0.5V. 3. Set the HF Transceiver to 1.6000MHz, CW, Vogad to on. Select High power. 4. PTT the radio and measure the frequency error at the frequencies as indicated in Table.1 5. Frequency error should be with in 1PPM.

D)

POWER MEASUREMENT 100 W AM :1. Set-up the equipment as shown in fig.5. Ensure that the 100W heat sink has been fitted to the radio. 2. Set the PSU to 27V +/- 0.5V. 3. Set the HF Transceiver to 1.6000MHz, AM, Vogad to on. Select High power. 4. Feed 5mV rms, 1KHz audio signal to HF Transceiver from RCTS. 5. PTT the radio and measure the output power at the frequencies as indicated in Table.1 6. Power output should be 100W + 1dB, -2dB.

E)1. 2. 3. 4. 5. 6.

AM MODULATION :Set-up the equipment as shown in fig.5..Ensure that the 100W heat sink has been fitted to the radio. Set the PSU to 27V +/- 0.5V. Set the HF Transceiver to 1.6000MHz, AM, Vogad to on. High power. Set the audio generator to produce 1KHz +/- 100Hz with an amplitude of -47.4dBVrms. PTT the radio and measure the output power at the frequencies as indicated in Table.1 Modulation should be 80% +/- 5%.

F)1.

POWER MEASUREMENT 100 W SSB :Set-up the equipment as shown in fig.5. Ensure that the 100W heat sink has been fitted to the radio.

55

2. 3. 4. 5. 6.

Set the PSU to 27V +/-0.5V. Set the HF Transceiver to 1.6000MHz, USB, Vogad to ON. Select High power. Set the audio generator to produce a 1KHz +/- 100Hz with an amplitude of 10mV RMS +/- 2mV RMS. PTT the radio and measure the output power at the frequencies as indicated in Table.1 Power output should be 100W +/- 1dB.

G)

TX AF RESPONSEto the radio.

1. Set-up the equipment as shown in fig.5. Ensure that the 100W heat sink has been fitted 2. Set the PSU to 27V +/-0.5V. 3. Set the HF Transceiver to 12.8MHz, USB, High Power, VOGAD ON and S.PROC ON. 4. Feed 10mV rms,1KHz audio signal from RCTS to audio connector of TR2400. 5. Press the PTT. 6. Note down the RF power output. 7. Release the PTT. 8. Change the audio frequency to 300Hz and 2.7KHz. 9. Press the PTT. 10. Note down the RF output powers. 11. The change in RF output powers should be within 3dB.

H)1. 2.

UNWANTED

SIDE

BAND

REJECTION

AND

CARRIER

REJECTION :Set-up the equipment as shown in fig.6. Set the supply to 27V +/- 0.5V. Set the HF Transceiver to 12.8000MHz, USB, Speech processing to ON and High Power .

RF SPECTRUM ANALYSER AS FOLLOWS:i) Reference level : : : + 20dBm 60dB 12.8 MHz ii) Attenuation iii) Centre Frequency

56

iv) Resolution BW 3. 4. 5. 6. 7. 8. +/- 2mV RMS(-46dBVrms).

:

Auto (100Hz)

Set the audio generator to produce a 1KHz +/- 100Hz with an amplitude of 5mV RMS PTT the HF Transceiver and store the trace on the display of the Spectrum Analyzer. Release the PTT. Measure the level of the unwanted sideband with respect to that of the wanted sideband and note in the result sheet. Measure the level of the carrier with respect to that of the wanted sideband and note in the result sheet. Unwanted side band rejection and carrier rejection should be better than -50dBc.

I)1. 2. 3. i) ii)

HARMONICS:Set-up the equipment as shown in fig.6. Set the supply to 27V +/- 0.5V. Set the HF Transceiver to 1.6000MHz, USB, Vogad and Speech processing to ON and High Power. Set-up the RF Spectrum Analyzer as follows: : : : : : + 30dBm 50dB see Table.2 see Table.2 Auto (100Hz) Attenuation Reference level

iii) Start frequency iv) Stop Frequency v) Resolution BW 4. 5. 6. 7. 8. +/- 10% (-46dBVrms).

Set the audio generator to produce a 1KHz +/- 100Hz with an amplitude of 5mV RMS PTT the HF Transceiver and store the trace on the display of the Spectrum Analyzer. Release the PTT. Measure the level of second and third harmonics and note in the result sheet. Harmonics should be better than -30dBc No i ii iii Frequency Start Frequency 1.6 MHz 1 MHz 12.0 MHz 10 MHz 29.998 MHz 25 MHz Table.2 Stop Frequency 5 MHz 40 MHz 100 MHz

57

PSU27V DC

+ 20dB Pad

-

J2 HF TxRx J5

600ohms Audio line RCTS RF In/Out Fig No. 1 Audio In

PSU27V DC

+ 10dB Pad

-

J2 HFTxRx J5

600 ohms audio line RCTS RF In/Out Audio In

Fig No.2

58

PSU 27V DC + 10dB PadJ2 HFTxRx J3

300 ohms audio line RCTS RF In/Out Fig No.3 Audio In

PSU 27V DC

+Hand Set

-

J3 HFTxRx J2

In Line Power Meter

RCTS RF in/out

30dB Attenuator

Fig No.4

59

PSU27V DC

+Audio Out RCTS

In-Line Power Meter

J3 HF TxRx J2

RF in/out

30dB attenuator

Fig No.5

PSU27 V DC

+ RCTSAudio out J3

-

HF TxRxJ2

30 dB Attenuator

RF Spectrum Analyzer Fig No.6

60

ELECTRONICS CORPORATION OF INDIA LIMITED COMMUNICATIONS DIVISIONSlNo: Date:

TEST REPORT (HF Tx Rx) VISUAL CHECKS: Transmitter Characteristics 1.6MhzGENERAL:

OK / NOT OK 12.8Mhz 29Mhz

01. FREQUENCY ERROR : + 1PPM 02. Current Consumption in 100W Current Consumption in 25W Less than 12.3Amps for 100W. Less than 3.27Amps for 25W. 03. POWER OUTPUT: AM (100-W PEP+1dB,-2dB) SSB (100-W PEP + 1dB) CW (100-W PEP + 1dB) 04. CARRIER SUPPRESSION : 50dB below PEP. 05. UNWANTED SIDEBAND SUPPRESSION: 50dB below PEP 06. HARMONICS AND SPURIOUS OUTPUTS: 50dB below PEP 07. AM MODULATION: a) 80%(+/-5%) at 5mV rms, 1Khz 08. AUDIO RESPONSE: 300Hz 2700Hz within 3dB.

61

Receiver Characteristics 1.6MHz 01.SENSITIVITY : 10 dB SINAD SSB(for- 113dBm input) AM(for 100dBm for 30% mod) CW(for-117dBm input) 02 .IMAGE REJECTION : Better than 80dB 03. IF REJECTION : Better than 80dB. 04. AGC: SSB( 3 dB ) 05. AUDIO OUTPUT: 600Ohm 20dBm+ 2dB and +6dBm +2dB. 06. AUDIO RESPONSE: 300Hz 2700Hz within 3 dB 07. CURRENT: Rx ( 160 mA) at 27V +/-0.5V without RF input. 08. VISUAL CHECKS: Finish, cleanliness Satisfactory and identity 12.8MHz 29MHz

62

TRANSMITER FLOW-CHARTS TRANSMIT DC POWER CONSUMPTION:

START

CONFIGURATE THE SYSTEM S ETUP

INS ERT THE CURRENT MET ER IN THE +27V SUPPLY LINE

SET THE PS U TO 27V,+/-0.5 V

SET THE HFTxRx TO (1.6 MHz / 12.8MHz / 29.9 MHz) CWU ( LOW POWER / HIGH POWER)

ADJ US T THE VOLTAGE MEAS URED FROM THE PS U TO +27 v ,+/- 0.5 v

ENAB LE PTT , MEAS URE THE VOLTAGE & CURRENT ,NOTE IN THE RES ULT S HEET.

A

63

A

RELEAS E PTT

CALCULATE THE REAS ULTING DC POWER & NOTE IN THE RES ULT SHEET

STOP

64

POWER MEASURMENT 100W(CW):

START

CONFIGURATE THE SYSTEM S ETUP

SET THE PS U TO 27V,+/-0.5 V

SET THE HFTxRx TO (1.6 MHz / 12.8MHz / 29.9 MHz) CWU , HIGH POWER

ADJ US T THE VOLTAGE MEAS URED FROM THE PS U TO +27 v ,+/- 0.5 v

ENAB LE PTT , MEAS URE THE VOLTAGE & CURRENT ,NOTE IN THE RES ULT S HEET.

MEAS URE RF POWER FROM THE IN LINE POWERT MET ER & NOTE IN THE RES ULT S HEET

RELEAS E PTT

STOP

65

FREQUENCY ERROR:

START

CONFIGURATE THE SYSTEM S ETUP

SET THE PS U TO 27V,+/ -0.5V

SET THE HFTxRx TO (1.6MHz / 12.8MHz / 29.9MHz) AM LOW POWER

SET RCTS TO MEAS URE FREQ UENCY

ENABLE PTT , MEAS URE THE FREQUENCY OF THE TRANS MITED CARRIER .

RELEAS E PTT

NOTE THE TRANS MITED CARRIER FREQ IN THE RES ULT S HEET

STOP

66

POWER MEASURMENT 100W(SSB&AM):

START

CONFIGURATE THE SYSTEM S ETUP

SET THE PS U TO 27V,+/-0.5 V

SET THE HFTxRx TO (1.6 MHz / 12.8MHz / 29.9 MHz) USB ,AM , HIGH POWER

SET THE RCTS AUDIO GEN ERATOR TO PRODUCE 1 KHz +/-50Hz TONE OF AMP 10mVr ms+/- 2 mVr ms

ENABLE PTT MEAS URE THE VOLTAGE FROM PS U

ADJ US T THE VOLTAGE MEAS URED FROM THE PS U TO +27 v ,+/- 0.5 v, NOTE IN THE RES ULT S HEET.

A

67

A

MEAS URE USB RF POWER ON THE IN LIN E POWER METER

RELEAS E PTT & NOTE IN THE RES ULT SHEET

STOP

68

AM MODULATION DEPTH:

START

CONFIGURATE THE SYSTEM S ETUP

SET THE PS U TO 27V,+/-0.5 V

SET THE HFTxRx TO (1.6 MHz / 12.8MHz / 29.9 MHz) AM , LOW POWER

SET THE RCTS AUDIO GEN ERATOR TO PRODUCE 1 KHz +/- 50 Hz WITH AN AMP OF 5 mVrms

SET THE RCTS TO MONITER MODULATION INDEX

ENAB LE PTT , MEAS URE THE MODULATION INDEX OF THE RADIO

A

69

A

RELEAS E PTT

NOTE THE MODULATION INDEX IN THE RES ULT SHEET

STOP

70

UN WANTED SIDE BAND REJECTION AND CARRIER REJECTION:

START

CONFIGURATE THE SYSTEM S ETUP

SET THE PS U TO 27V,+/-0.5 V

SET THE HFTxRx TO (1.6 MHz / 12.8MHz / 29.9 MHz) USB , LOW POWER , SPEECH PROCESSOR OFF

SET THE RCTS AUDIO GEN ERATOR TO PRODUCE 2.5 KHz +/-100Hz TONE AMP OF 5mVr ms.

SET THE RF SPECTRUM ANLYS ER PARAMETERS TO THE REQUIR ED LEVEL EL

ENAB LE PTT , ,THE HF TXRX AND S TORE THE TRACE ON THE DISPLAY OF SPECTRUM ANALYS ER THE VOLTAGE & CURRENT ,NOTE IN THE RES ULT S HEET.

A

71

A

RELEAS E PTT

SET THE SPEECH PROCESSOR ON MEAS URE THE LEV EL OF THE UNWANTED SIDE B AND W.R.TO WANTED SIDE B AND & NOTE IN THE RES ULT SHEET

MEAS URE THE LEV EL OF THE CARRIER W.R.TO WANTED S IDE BAND AND NOTE IN THE RES ULT SHEET

STOP

72

HARMONICS:

START

CONFIGURATE THE SYSTEM S ETUP

SET THE PS U TO 27V,+/-0.5 V

SET THE HFTxRx TO (1.6 MHz / 12.8MHz / 29.9 MHz) USB, HIGH POWER

SET THE SPEECH PROCESSOR ON

SET UP THE RF SPECTRUM ANALYS ER REQUIRED PARAMETERS .

SET THE RCTS AUDIO GEN ERATOR TO PRODUCE 1 KHz +/-100Hz WITH AN AMP OF 5 mVr ms

A

73

A

E N A B L E P T T , T H E R A D IO A N D STO R E TH E TRA C E O N TH E S PEC T R U M A N A L YS ER

R EL EAS E P T T

M EA S UR E TH E LEV EL O F S E C O N D A N D T H IR D H A R M O N IC S & N O T E IN T H E R ES U L T S H E E T

STO P

74

RECEIVER FLOW CHARTS

SENSITIVITY:START

CONFIGURATE THE S YS TEM S ET UP

S ET THE HFTxRx TO 1.6 MHz, -93 dB / 12.8 MHz, -93 dB / 29.9 MHz, -93 dB

SET THE RCTS FREQ TO 1.601 MHz / 1.599MHz / 12.801MHz / 2.799 MHz / 29.90MHz / 29.8 MHz / -93 dB

SELECT THE S INAD AND AC LEVEL MET ER

MEAS URE S INAD

STOP

75

IN BAND RESPONSE:START

CONFIGURATE THE SYSTEM S ET UP

S ET THE HFTxRx TO 1.6 MHz, -80 dB / 12.8 MHz, -80 dB / 29.9 MHz, -80dB

S ET THE RCTS FREQ TO 1.601MHz / 1.6003MHz / 1.6027MHz / 12. 801 MHz / 12.800 3MHz / 29.601MHz / 29.6003MHz / 29.6027MHz / -80dB

SELECT THE S INAD AND AC LEVEL METER

MEAS URE ACLEVEL

X = AC LEV ELOF (1.6003/1.601or 12.8003/12.801or 1.6027/1.601 or 12.8027/12.801 or 29.9003/29.901 or 29.9027/29.901)

AF IN BAND RES PO NS E = 10Log10 (X)

STOP

76

IF REJECTION:START

CONFIGURATE THE SY STEM SET UP

SET THE HFTxRx TO 1.6MHz / 12.8MHz / 29.9MHz/ USB

SET THE RCTS TO 1.601MHz/12.801MHz/ 29.901MHz , -83dBm

SET THE OUTPORT TO DUPLEX AND FILTER 1 TO 300Hz HPF FILTER 2 TO 3KHz LPF

BSET HF TxRx VOLUME TO 0dBm

SET THE RCTS TO 69.9MHz 69.9MHz SET THE AC LEVEL METER

READ THE AC VALUE AND CONVERT IT TO dBm =P

A S

77

A

IF P < -O.5 YES

NO

NO

IF P > +0.5

YES

LEVEL=L EVEL+10

LEVEL = LEV EL-10

B

NO

IF LEVEL IS >= 15 YES

STOP

IMAGE REJECTION:LEV EL = LEVEL-10

78

IMAGE REJECTION:START

CONFIGURATE THE SYSTEM SET UP

S ET THE HF TxRx TO 1.6MHz, -93dBm/ 12.8MHz, -93dBm / 29.9MHz USB

SET THE RCTS TO 1.601MHz / 12.801MHz / 29.901MHz , 93dBm.

SET THE OUTPORT DUPLEX FILTER1 TO 300Hz HPF FILTER 2 TO 3 KHz LPF

SET THE HFTxRx TO VOLUME 0dBm

SET THE RCTS TO 141.599MHz / 152.799MHz / 169.899MHz

SET THE AC LEVEL METER

READ THE AC VALUE AND CONVERT IT TO dBm =P

A

79

A

IF P < -O.5 YES

NO

IF P > +0.5

NO

YES

LEVEL=L EVEL+10

LEVEL = LEV EL-10

B

NO

IF LEVEL IS >= 15 YES

STOP

LEV EL = LEVEL-10

80

AUDIO OUT PUT:START

CONFIGURATE THE S YS TEM S ET UP

S ET THE HFTxRx TO 1.6 MHz, 12.8 MHz,29.9 MHz,

SET THE RCTS TO 1.60 MHz, -50dB m/ 12.801 MHz,-50dBm/ 29.901MHz,-50 dBm. STOP 0dB m

S ELECT THE AC LEV EL METER

MEAS UR THE AC LEV EL OF MIN & MAX READING FOR THE ABOVE FREQUENCIES

NOTE IN TO THE RES ULT SHEET

STOP

81

CONCLUSION:In this project Automation of HF Transceiver (TR2400) Testing. We aimed at developing algorithms for testing unit specifications. There are totally 19 tests to be done in the transceiver which consumes a lot of time for the procedures, tabulations & calculations all together. Typical field results demonstrate test time reductions on complex radios from 4 to 6 hours to less than 25 minutes Hence the automation of the transceiver testing helps speed up the testing process nearly to 25 minutes.

BIBILOGRAPHY

82

1.

Manual of Hewlett Packard (HP 8920 RF communications Test Set) Programmer's Guide

2.

Manual of National Instruments "GPIB" (General Purpose Interface Bus NI-488.2).

3. Let us C by Yashwant Kanetkar 4. Programming in ANSI C by KERNINGHAM and DENNIS RITCHE 5. .Technical Manual for High Frequency Transceiver. 6. www.harris.com

83