Telecommunications is one of the world’s fastest growing industries andworld-wide personal communication of voice, picture and data is nowcommonplace.

The Feedback range of Telecommunications training equipment has beendesigned to provide a modern, efficient approach to training the engineersand technicians working in this field.

Feedback’s philosophy is to equip students with the fundamental ideas andprinciples that underpin modern telecommunications practice by usingversatile trainers that quickly and clearly demonstrate the requiredcharacteristics.

Paramount to all Feedback equipment is the principle that Students ofEngineering and Technology should work with hardware and be allowed totake a hands-on approach. All of Feedback’s teaching hardware is supportedby extensive teaching and theoretical courseware. This can either be in theform of paper manuals or software.

Within the Telecommunications range, Feedback offers hardware that canbe used in conjunction with conventional test and measurement equipment,using paper manuals. Alternatively, laboratory work can be carried out usingequipment connected to a PC enabling it to take advantage of Feedback’sDiscovery courseware, which offers on-screen instruction and embedded,real-time, virtual instrumentation.

Both these teaching philosophies are valid ways of demonstrating technicalcharacteristics, but the underlying principle that both share is giving theStudent the opportunity to work with real hardware and avoid simulation.

TelecommunicationWorkstation

Telephony

AntennaLab

AM & FM Radio Trainers

Transmission Lines

Antenna systems

Microstrip

Microwave

Fibre Optics

Discovery Courseware

Telecommunications

System Benefits

Ideally suited for Universityand Technical Collegecourses

Covers all areas ofTelecommunications

All products provided within-depth teaching manualsor software

Compact, bench-topsystems

Teaching material relevantto industrial practice

Telecommunications

Telecommunications

Discovery Software

Detailed explanatory layout

Integrated interactive simulations

Connecting-up the Virtual instru-ments

Real-time data capture andmeasurement

FeaturesInteractive hardware/softwareconfiguration

Browser based curriculum

Self-paced learning

Practical demonstration oftheoretical background

Simulations

Interactive patching diagrams

Shows real-time processchanges

Hands off for tutors - Hands onfor students

Embedded Virtual Instrument-ation

Automatic controllerconfiguration

Data export to spreadsheet foranalysis

Changeable timescales forplayback of results

Dual playback for comparisonof process variables

Discovery Software is Feedback’s continuously evolving software package. Thebasic and most important philosophy of Discovery is its interactivity withteaching hardware. Discovery can be applied to products within our completerange of teaching products and is used extensively within theTelecommunications range.

The Learning material is provided within the software and this includes theunderlying theory, which is written in such a way that it does not usemathematics at too high a level. An important part of the teaching programmeis to highlight the learning objectives of the various experiments and conveythe background involved to the student: This information is also included inthe software. Consequently, the student is suitably prepared to start thepractical work using the hardware.

The interactivity of Discovery means that it provides real-time, pc-basedinstrumentation and in the case of Telecommunications this includes:

Dual channel OscilloscopeSpectrum AnalyzerVoltmeterFrequency CounterPhasor and Constellation DisplaysBER MeterAntenna Polar Diagram Plotter

Discovery Software operatesin the following areas:

Basic Electricity

Analogue and DigitalElectronics

Telecommunications

Linear Control

Process Control

Electrical Machines

Frequency ResponseGain/Phase Analyzer (for Bodeand Nyquist plots)

Discovery is written in such a waythat its appearance and theinstrumentation made availabledepends on the practical beingexecuted. So, if the practical requiresthe display of a constellation or aphase meter, as in QAM experi-ments, one is made available,whereas at lower levels of studyit would not be provided.

Discovery Software can be installedeither in a stand-alone configurationor networked and centrally served.

Discovery Tools 93-400

Telecommunications

FeaturesEnables the creation andoverlaying of diagramsUses Microsoft Visio or‘Winwiz’ to to edit diagramsEnables the creation & editingof patching layoutsExisting assignments modifiedor developed new withAssignment BuilderAssignment functionalitycontrolled by AssignmentBuilderAssignments selected andallocated using LaboratoryArchitectScreen presentation modifiedwith Laboratory Architect

Discovery Tools allow full editing of supplied material, together with thecreation of new content and additional assignments.

Modified block diagramusing ‘Winwiz’ andMicrosoft Visio software.In Edit mode, Visio is usedto produce the background(JPG) and Winwiz allowschanges to the monitoringpoints and to thetest probe positions.

Typical Discovery assign-ment with the ‘Tools’ Editmode selected. MicrosoftWord is the default editor.

The look and feel of theuser screens can bepersonalised usingLaboratory Architect andthe ‘skin’ edit file.

Course PresenterProvides students with the means of selecting acourse by name from a list, as in this case AnalogueSignals.

Assignment Buildercontrols assignmentfunctionality, testequipment, test probes,monitor point mappingand board firmware.

Typical assignment patch-ing layout ‘Winwiz’ is usedto modify patching connec-tions (drag & drop) and todraw new connections usingseparate connections.

Laboratory Architect allowsthe tutor to select whichassignments the usermay access.

Discovery Course Manager consists of two sub software applications -Course Designer and Course Presenter.

Discovery Course Manager 93-410

FeaturesProvides tutors with simplecreation or modification ofcoursesIncludes Course Designer forcustomising coursesIncludes Course Presenter -the student interface thatdelivers the coursesAllows Discovery productassignments to be mixedCan be used with a networkby using a shared drive

System BenefitsUniform hardware & softwaredelivery platform reducesfamiliarisation timeStep-by-step Discoveryinstructed courseware reduceswasted instructor timeAutomatic patching sequencereduces patching errorsClassroom sets – courses canbe easily reorganised

Course DesignerResources that may be added are: - Documents likeWord or Excel, html or pdf format, multimedia materialand third party programs. Web urls, or locations onlocal intranets. The course window can have severalpages for different sections of a course, such assessions or modules.

External resources folderscan be easily created &resources may then be addedto a folder. Once added, aresource can be used in anynumber of courses.

BenefitsCustomised courses can becreatedAssignments from differentDiscovery products can beintegratedOutside resources can beincluded in the courses-video,audio, additional information etc.

The resulting course window contains resourcesorganised in pages. Clicking on a resource such asVideo Clip or Audio Clip etc. launches it.

Amplifiers and Oscillators Workboard 53-210

Telecoms Workstation

Curriculum Coverage

Voltage amplifier

Current input amplifier

Controlled gain amplifier

Oscillation criteria

Wien bridge oscillator

Tuned amplifier

LC oscillator

Crystal oscillator

Oscillator stability & buffering

Multivibrator

Tuned power amplifierThis workboard allows the construction of various Amplifiers, Oscillators andSignal Sources. The workboard shows the principles of R-C, L-C and crystaloscillators, feedback, loop gain, amplitude stabilisation, oscillation, distortionand frequency stability. Using the PC instrumentation, Nyquist and Bodediagrams can be easily shown.

Telecommunications Workstation 53-004

The Telecommunications Workstation range of products consist of aseries of open-board trainers that work in conjunction with Discovery software.

The 53-004 comprises three workboards: Amplifiers and Oscillators 53-210,Tuned Circuits and Filters 53-220 and Modulation and Coding 53-230 andthe 92-200 USB Real-time Access Terminal (RAT).

The close integration of the hardware workboard with computer-basedinstruction and instrumentation software provides the student with a richlearning environment and the tutor with a cost-effective solution in thisfield of telecommunications teaching.

Each practical experiment is configured by patching together circuit blocks onthe boards. The patching sequence is shown sequentially through the software.

The workboard connects to a personal computer via the USB Real-timeAccess Terminal (92-200 RAT), which is a fast Analogue-to-Digital converter,sampling signals on the workboard at rates from 10 to 100MHz, as required.The Terminal also provides all the necessary power supplies for the workboard.

Integrated instructions and instrumentation Further in-depth information always available

Features

Suitable for both technicianand undergraduate teaching

Comprehensive set ofLaboratory Assignments

Covers modern modulationprinciples and practice

Integrated hardware andsoftware environment

On-screen background, theoryand practical instructions

Software provides embeddedinstrumentation including aConstellation meter

Quantative measurements offundamental circuit properties

Uses Gain Phase Analyzer

No costly additionalinstrumentation required

Stand-alone workstation ornetwork operation (withFeedback’s DiscoveryLaboratory Manager)

Modulation and Coding Workboard 53-230

Modulation and Coding workboard 53-230 is a fully-featured, complete,laboratory course covering the principles of operation and the practicalimplementation of modern modulation systems required for both analogueand digital communication systems.

Curriculum Coverage

Signals in the time andfrequency domains

Sampling and TimeDivision Multiplexing (TDM)

Amplitude Modulation (AM)

AM with Suppressed Carrier

SSB generation with anIQ modulator

Amplitude Shift Keying (ASK)

Frequency Modulation (FM)

FM with an IQ modulator

Frequency Shift Keying (FSK)

Phase Modulation (PM)

Phase Shift Keying (PSK)

Multi-state Phase Shift Keying

Quadrature AmplitudeModulation (QAM)

Uncoded binary data formats

Bi-phase data format

Alternate mark inversion

Word synchronisation

Telecoms Workstation

Tuned Circuits and Filters Workboard 53-220

With these circuits students can examine the principles of passive filters,R-C and L-C tuned circuits, Q loading, low-pass crystal filters, active filters,tuned amplifiers and automatic gain control (AGC).

Curriculum Coverage

Tuned circuits

Coupled tuned circuits

Crystal filters

Ceramic bandpass filter

Audio op-amp filters

LC low pass filters

LC high pass filters

Butterworth filters

Chebyshev filters

High-order filters

Telephony Training System 58-001

Digital Switching System 58-002

Curriculum CoverageLocal signalling

Digital switch principles

Digital switch

Line scan

Call records

Line records

Line maps

State transitions

Call progress

Manual control

Testing

Traffic

Telephone and InterfaceSignalling, speech circuits and the immediate interface at the switching centreare examined. The use of a high quality, commercial telephone hybrid circuit inthe subscriber’s line interface (SLIC) allows useful measurements to be made.

TDM/PCM PrinciplesAllows the study of the principles of TDM/PCM. It is based on the use of stan-dard telephony devices but also uses special circuits to demonstrate the effectsof variable sampling rate, bit rate and filtering. PAM is used to demonstratethe concept of taking short samples to represent a continuous waveform.TDM is demonstrated by multi-channel PAM which shows the principle ofsharing a single physical link between different communication channels.

Curriculum CoverageTelephone and Interface

Telephone signallingTelephone speechSubscriber’s Line InterfaceCircuit (SLIC)Dual Tone Multi-Frequency(DTMF) SignallingSLIC HybridTesting

Curriculum CoverageTDM/PCM Principles

SamplingTime Division Multiplexing (TDM)Pulse Code Modulation (PCM)CompandingFiltering

Digital switching techniques and applications are covered, including time andspace switching and the control of a digital switch by connection memory.Call state transistion diagrams, which conform to ITU-T SDL format for callprogress, are introduced, as well as concepts of call state and state transition,and the three stages of call handling.

FeaturesRelevant to study of CentralSwitching exchanges or PABexchanges

Uses commercial CODECs

The system comprises:

n Controller

n Digital switchingcentre board

n One, four telephonehandset kit

The system comprises:

n USB Real-timeAccess Terminal (RAT)

n Telephone & Interfacen TDM/PCM board

Telephony

FeaturesUses Discovery Software

Uses commercial telephonycomponents

Automatic practical config-uration

FeaturesFour local switching centres

Can be easily upgraded from58-003

Easily configurable

Trunk Network System 58-004

Dual Switching System 58-003

The dual system adds a second switching centre board to support up to fourswitching centres, extending the curriculum covered by 58-002 to include trunkswitching & trunk traffic topics, CCITT (now ITU-T) codes and formats are used.

The system is supplied with a vertical mounting frame for ease-of-use andfuture upgrades.

FeaturesEasily configurable fordifferent exchanges

Can be easily upgraded from58-002

Uses ITU-T codes and formats

In addition to the curriculum covered by 58-002 and 58-003, the trunks networkboard has three transit switches and extends the work to cover transit switchingand signalling. The system can be configured as four local switching centres,to cover simple transit switching, two level transit switching, non-associatedsignalling and the use of ITU-T type transaction capability messages to controlsystem testing.

The system comprises:

n Controllern Two digital switching

centre boardsn Two, four telephone

handset kitsn A Trunk networks

board

The system comprises:

n Controller

n Two digital switchingcentre boards

n Two, four telephonehandset kits

Telephony

Curriculum Coverageas 58-002 plus

Trunk configuration

Trunk switching

Signal protocol controller

Trunk signal units

Signalling information field

Error control

Trunk state diagrams

Trunk call progress

Curriculum Coverageas 58-003 plus

Transit switching centre

Transit switch call progress

Two-level transit switching

Two-level transit callprogress

Non-associated signalling

System testing

Features

Unique integration ofhardware and software

Simulates, models and testsreal antennas

Hardware modellingbetween 1200 and 1800MHz

NEC-2 based simulations

PC measurement and results

Rapid graphic display ofantenna characteristics

Bench-top operation

Low, safe power output

USB interface

The AntennaLab is a unique system designed to be used in two distinct ways:for teaching and demonstrating common antenna configurations at all levels ofstudy, and as a design tool by those engaged in research and development.

The system operates in conjunction with a PC via a USB interface and issupported by Discovery Interactive Software and NECWIN simulation software.

The equipment comprises two towers, one being a low power transmitter,controlled by a frequency synthesizer. The second contains a frequencysynthesiser controlled receiver. The antenna to be investigated is mountedon top of the transmitter tower.

The PC controls the transmitter tower and rotates it through 360 degreesand displays the following characteristics:n Frequency response n Signal leveln Polar diagrams n E & H planes in three dimensionsn Return loss plots n Bandwidth

Components are provided that allow these antennas to be constructed:n Monopoles n Dipoles n Log periodicn Yagis - Stacked and bayed n Horn n Parabolic dish

Multiple polar plotsReturn loss plots

Antennas

AntennaLab 57-200

Curriculum Coverage

Familiarisation

The Dipole in free space

Effects of the surroundings

Dual sources

Gain, directivity and aperture

Ground reflections

The monopole

Phased monopoles

Resonance, impedance andstanding waves

Return loss and VSWRmeasurements

Parasitic elements

Multi-element parasitic arrays

Stacked and bayed arrays

The log periodic antenna

The horn antenna

The dish antenna

Projects

Fibre Optics Trainer EFO1101

FeaturesTeaches fibre opticmeasuring techniques

Demonstrates standardproperties of light (visibleand infra-red)

Analogue and Digital datatransmission

Self-contained trainingpackage

Fibre Optics Monitor EFO1105

The trainer investigates various aspects of fibre optic technology and its use intransmitting analogue and digital data, with reference to telecommunications.The trainer comprises an optical transmitter with an infra-red LED, a red LEDand variable output controls. It also has an optical receiver, which includes: aloudspeaker for analogue output, high and low impedance analogue outputs,variable analogue gain, buzzer, digital output and TTL, CMOS and RS232voltage level digital outputs. Two lengths of fibre optic cable, various electricalconnectors and accessories complete the kit.For organisations with no practical experience of Fibre optics, this trainer providesan effective means of obtaining a hands-on introduction to this technology.EFO1101 is supported by a Fibre Optics Monitor, EFO1105, which measuressignals carried by fibre optic cables.

The Power Meter is an accurate, versatile and low-cost unit for measuring opticalpower levels at terminated optical cables. An easy-to-read pointer scale givesreadings in both dBm and microwatts. The meter ranges between 1mW (0dBm)down to a sensitivity of better than 1nW (-60dBm). The meter is calibrated at awavelength of 820nm and permits accurate measurements between 800nm &850nm. A large area receiving diode ensures maximum light acceptance. Batterylife is typically 500 hours. Meter connector options include SMA & STRATOS.The meter comes complete with instruction manual, battery, electricalconnectors and carrying case.

The Monitor is a versatile, fully portable product used to design fibre optics andgeneral optics measurement applications. It uses SMA and STRATOS connec-tions. Accessories include instruction manual, various electrical connectors, micro-phone, batteries and robust carrying case.The Monitor consists of an optical transmitter with:

A high radiance LED that gives good measurement performance for all typesof multimode optical fibres, including 50µm core graded index fibreA variable output controlA variable frequency square wave generatorBoth digital and analogue inputs

And an optical receiver with:Loudspeaker analogue output, low impedance analogue output and variableanalogue gainMean power monitor outputSilicon p-i-n diode mounted in a connector receptacle

Fibre Optics Power Meter EFO1102

Fibre Optics

Curriculum Coverage

Shows the properties of lightand infra-red radiation

Transmission of high qualityanalogue and digital data overoptical fibres and free spaceusing visible and infra-redlight

Converting various lightsources, such as:mains lighting, torch-light,and infra-red light and thetransmitter’s variablefrequency generator to audiosignals and listening to themvia the loudspeaker in thereceiver

Construction of an alarmsystem based on the presenceof a light signal

Clarifying the importantdifferences between analogueand digital techniques

Measurement of the opticalabsorption or reflectionproperties of various materials

Testing analogue or digitaloptical receivers andtransmitters

OFSA - Optical Fibre Laboratory System

Fibre Optics

Curriculum CoverageMultimode plastic fibrecharacteristics

Multi-mode glass fibrecharacteristics

Laser diode module

Avalanche photodiode module

LED module

PIN photodiode module

OTDR and fibre event module

Digital communicationsconcepts

Fibre optic link design andanalysis for analogue anddigital systems

Features

OFSA enables unlimitedexperimentation using on-kitcircuitry and external interfaces

Individual LED, Laser, PD andAPD modules enabling studyof device characteristics

Specially designed reusablePCBs for link construction

Integrates the essential blocksof an OTDR and demonstratesits principles of operation

Compatible light source andpower meter

Comprehensive laboratorymanuals covering fibre optictheory and experimentalassignments

The OFSA is a comprehensive laboratory system designed to train users in Fibreoptic devices and digital communication systems.

It is also a useful development tool suitable for research projects and buildingprototype systems.

The Laboratory spans fibre optics and related subjects that include:n Fibre optic device characteristics

n Principles of fibre optics and digital communications

n Fibre optic equipment

n Digital and Analogue fibre optic links

The OFSA is suitable for many levels of education:

n Scientific/Technical Professionals

n Research and development personnel in industry

n Students of BE, ME, BS & MS

n Technical training centres

n Students in Polytechnics and science colleges

FeaturesEleven usable 64kbpschannels

User definable frame marker(two alternating 8-bit markers -can be set to be CCITT (UTIT)compatible)

On-board, two digitised voicechannels, one 8-bit datachannel and several userexpansion channels

Demonstrates fully operationalintegrated voice/data fibreoptic communication link

Optional RS232C communica-tions module used to demon-strate computer communica-tions over fibre

Time Division Multiplexing ofvoice, data and user-defineddata streams

Modular design, enablesconfiguration with user-designed modules

Wide scope for experimentationthrough use of externalcircuitry interfaced to kit

Comprehensive manualdescribes wide range ofexperiments

Ready-to-use kit, completewith accessories

The Optical Fibre Trainer OFT is a powerful, versatile and cost-effectiveexperimental kit used to train students in the principles of fibre optics, throughthe basics of digital base and communications, onto advanced experimentationand development in fibre optic and digital communications.

Using the standard kit it can be used to cover established digital communicationsubjects such as; Time Division Multiplexing, Transmitter and Receiveroperation, PCM voice coding at (64Kbits/sec), Manchester coding/decodingfor timing recovery, Voice coding - A-law and Pulse broadening in Fibre opticcommunications.

Channels can be switched at transmitter and receiver using time-switchingprinciples.

It is very easy to interface to external circuitry - all required inputs and outputsare provided and extensively documented.

The kit is supplied with a comprehensive Laboratory manual that clearlyexplains experiments covering the theory of fibre optics for both Analogueand digital communications.

It is supplied with all the accessories required to conduct the basic experi-ments and to interface with external circuitry.

An optional RS232C communication interface module is available to enablea PC to be connected over fibre to demonstrate Integrated voice, data and aRS232 communication link.

OFT - Optical Fibre Trainer

Curriculum CoverageBasic ExperimentsFibre Optics

Fibre optic analogue linksDigital linkLosses in optical fibreEffect of EMI interferenceNumerical aperturemeasurement

Multiplexing & Digital telecomsTime Division MultiplexingFraming in Time DivisionMultiplexingVoice coding - A-lawPulse broadening in fibre opticcommunications

Advanced ExperimentsInterfacing 8, 64, 256 kbssynchronous channels and atless than 8 kbsAsynchronous channel inter-facing using oversampling andbit stuffing

Fibre Optics

Fibre Optics

The LAN-T trainer is useful for study and development of reliable data transferprotocols, networking layers and applications. The Trainer exposes users tonetworking concepts at the physical, MAC network and transport layers, througha series of designed experiments.

The experiments reinforce the theory covered in lectures, while the ‘hands-on’programming exercises train students to industry level.

The trainer can also be used for project work involving many layers of the net-work hierarchy.

The NEU hardware emulates six nodes (two nodes per PC), which can beconfigured to Bus, Star or Ring topologies. It has error generators and delaygenerators between nodes. Each NIU card emulates two independent nodessupporting various MAC layers on a single PC. The system scales up toemulate larger networks by adding more NEUs, NIUs and PCs.

FeaturesComprehensive set of experi-ments to observe and measurethe behaviour of several LANprotocols: MAC layer, Datalink layers and connectionmanagement

User configurable data rates -8kbps, 16, 32, 64, 128, 256,512 and 1Mbps

Generation of bit errors andFrame errors between nodes -up to 10-6

Variable Network size - upto six nodes with each NEU.NEUs can be cascaded toincrease the network size

Emulation of two nodes byeach PC. Halves the numberof PCs required

User configurable delaysbetween nodes - emulates thepropagation delay in realnetworks

Curriculum CoverageExperiment Level 1Observation and measurementof behaviour of various networkprotocols. Step-by-step instruc-tions given in manual under the“Trying it out” section.

Packet transmission on apoint-to-point link

Measure throughput for thefollowing MAC Layer protocolsby varying the offered load -changing IPD, packet length,data transmission rate, bitdelay, introducing bit errors,frame errors, Token HoldingTime (THT) depending onprotocol:

ALOHA CSMA CSMA/CD

Token Bus

Token Ring

Measure of throughput andthe effect of bit errors for thefollowing DLL protocols (alsocalled as Reliable TransferProtocols) - varying the time-out period, introducing biterrors and frame errors:

Stop-and-WaitSliding Window - Go-back-N

continues

LAN-T Trainer

Fibre Optics

LAN-T Trainer

By using a single trainer and a network of two or three PCs, users will gainhands-on experience of a wide range of different network topologies andprotocols, including all the most used ones such as CSMA/CD (Ethernet)and token passing (Arcnet, Token Ring).

The LAN-T consists of a Network Emulator Unit (NEU) with PC plug-in NetworkInterface Units (NIU) and Windows based experiment software.

The software contains a series of experiments in the form of stand-aloneapplications, ‘C’ source code, allowing better understanding of the experimentsand a ‘C’ library to access the NIU. This allows new users to program newexperiments, modify existing experiments and try out various network layersand protocols.

Network Emulator Unit (NEU)schematic

PC 1

PC 3

PC 2

FeaturesAllows experimentation usingthe software provided; sourcecode included for betterunderstanding

Allows programming of allexperiments from scratchusing the library, for morein-depth exposure

Menu driven user interface toexperiments

Comprehensive manualsuitable for both lab instructionas well as self-study

Curriculum CoverageExperiment Level 1 continued

Other possible topics of interest thatcan be implemented by users are:

Star topology - throughputmeasurement

Connection management -2-way handshake

Sliding window - Jumpingwindow

Experiment Level 2Implement & test various protocolson one node by writing code whilethe experiment software is runon the other nodes. The programdevelopment is explained in detailin the manual. Data structures, FSM,Pseudo-code, wherever necessary,are provided. Exercises are givenat the end of each topic.

Experiment Level 3(Projects demonstrating real-world principles)

Projects involving several layersof network software, includingapplication layers, are possible toimplement with LAN-T. Users maybe required to workout and imple-ment the detailed specification.

File Transfer Programme (FTP)bundled with the experimentsoftware

Routing in a mesh WAN

Network management

Remote procedure calls

Talk program

Distributed database

A sample Web

Transmission Line Demonstrator TLD511

FeaturesFully operational antennas

Vivid displays of antennacharacteristics

Convenient size for classroom

Versatile and easy to assemble

Complex concepts made easy

Reconciles theory and practice

FeaturesLarge bright LED display

Built-in step function process

Variable simulated line length

Manual hold facility

Comprehensive instructionmanual

Antenna System Demonstrator ASD512

This system demonstrates the characteristics of transmission lines in a graphicmanner. The system uses a simulated line that effectively displays the highfrequency characteristics of a transmission line at low frequencies so that theycan be easily observed. The line characteristics can be easily adjusted by theoperator. The line is completely symmetrical so that either end may beregarded as an input or an output.The unit features large, bright LEDs, a built-in step function generator and issupplied with a manual.

This is a fully operational Antenna System Demonstrator, working at afrequency of 167.2MHz, giving a half-wave element of approximately 90cm.It has been designed to provide an ideal classroom demonstrator.The system uses a kit of parts to allow many types of antenna to be construc-ted, making the system versatile as a demonstrator of both antenna principlesand practice.The system has two hand-held detectors that show relative magnitudes ofvoltage and current fields around the antenna, and the field strength of theantenna. Practical demonstrations are described in the accompanying manuals,illustrating the principles involved and introducing the student to the basicconcepts of most types of antennas in common use.

Transmission Lines andAntennas

Curriculum CoverageBasic theory of radiation

Radiating and non-radiatingsystems

Feeders

Radiation resistance

Drive point impedance andground resistance

Physical and electrical length

Directional antennas andradiation patterns

Parasitic arrays & antenna gain

Antenna with folded elements

Slot radiators

3-dimensional polar diagrams

Loop antenna

Further Curriculum Coveragenλλλλλ /2 lines1 to 1 impedance transformationsLines with dissimilar lossless terminationsResonance and capacitive detuningReactive line impedance either side of resonance

Curriculum CoveragePropagation of a wave front

Propagation of a sinewave

Effect of wavelength

Attenuation and dispersion

Terminations

Reflection, standing wavesand characteristic impedance

Partial reflection, standingwaves and superposition ofincident and reflected waves

Resonance and the effect ofattenuation

Complete Microstrip Trainer MST532-1

FeaturesLatest Microwave technology

2.4 to 3.4GHz VCO

2 to 4GHz PIN diodemodulator

No ancillary test equipmentrequired

Safe, low power output

Components identifiedwith inscribed referencenumber

Supplied in protective case

This trainer uses high precision components to allow students to investigatemicrostrip technology principles.

The Complete Microstrip System, MST532-1, needs no additional testequipment, having been designed for use with a digital multimeter anda dual dc power supply, which are provided.

A CD and paper manual is supplied and provides users with detailedbackground material, theory and structured assignments, whilst avoidingunnecessary mathematical analysis.

The precision components (18 passive and 3 active) are packaged inbright nickel-plated enclosures and are interconnected using industrystandard SMA couplings.

The components are:

nnnnn Microwave source (VCO) nnnnn Directional coupler (DC)nnnnn Low pass filter (LPF) nnnnn Matched load (ML)nnnnn Wilkinson power divider (PD) nnnnn Rat-race hybrid coupler (RRH)nnnnn Ring resonator (RR) nnnnn Unknown load 1/4λλλλλ & shunt stub (ZT)nnnnn Three-port circulator (CIR) nnnnn PIN diode modulator (PIN)nnnnn MMIC amplifier (AMP) nnnnn dc biasing unit (BL)nnnnn Patch antenna (ANT) nnnnn Crystal detector (D)nnnnn SMA coaxial connector (PPC) nnnnn Coaxial short-circuit termination (SC)nnnnn 50 ohm coaxial termination (MT) nnnnn Coaxial open-circuit termination (OC)nnnnn 20dB attenuator (ATT) nnnnn SMA plug - BNC jack adapter (ADR)plus accessories.

Alternative configurations

The MST532 Microstrip Trainer excludes the digital multimeter and dual dcpower supply.

56-001 MIDE Microstrip, adds the powerful MIDE Microwave Design Software,(see next page) to the MST532-1.

56-100 MIDE Microstrip (without ancillaries), combines the Microstrip Trainerand MIDE software.

Microstrip

Curriculum Coverage

Power source and detectoraction

Action of a 3-port circulator

Insertion loss measurementon a low-pass filter

Measurement of return loss,reflection coefficient andVSWR of a filter, microstripand commercial matchedloads

Matched investigations:reflection coefficient ofunknown resistive load andits matching by 1/4λλλλλgtransformer and shunt stub

Properties of a power dividerand rat-race coupler

Effective dielectric constant/line loss measurement witha ring resonator

dc biasing and MMICamplifier investigations

PIN diode modulator investi-gations

Microwave radio link andantenna investigations

Microwave Trainer 56-200

Features

Impedance, dispersion andloss calculations

Optimisation including eightoptimisers

Yield analysis

Interactive comparison (tuning)capability

Interactive Smith chart

Interactive planar linesanalysis and synthesis

Integrates measured data withsimulations

Interactive help includes alltransmission line designequations

MIDE linear frequency-domaincircuit simulator

The system allows the user to investigate the principles of microwavetransmission systems, such as those used in radar and communications links.It is a precision-made system, which uses standard type WG16(WR90) wave-guide components to illustrate the essential elements within this field of study.It is completely self-contained and allows students to carry-out realistic practicalwork.

The equipment has a modulated solid-state dielectric resonance oscillator(DRO), X-band microwave source, a selection of waveguide components,a console containing a power supply, a demodulation circuit and a meter thatmonitors the detector output.

The trainer is supplied in a dedicated, protective carrying case.MIDE Microwave 56-002 combines the Microwave Trainer 56-200 withMIDE Microwave Design Software (shown below).

MIDE Design Software is a powerful computer-aided engineering program forthe simulation of complex linear microwave and high-frequency analogue circuits.

It is used to determine transmission, reflections, stability and gain of circuits.These may be composed of lumped or distributed components, different linesand passive or active sub-circuits, including elements determined by scattering,admittance or impedance parameters.

MIDE is an ideal tool for microwave technology students to develop designs inproject work.

Microwave

MIDE Microwave Design Software 56-901

Curriculum CoverageIntroduction to microwavewaveguide bench and measure-ment of: (a) source frequency(b) guide wavelengthMeasurement of VoltageStanding Wave Ratio (VSWR)Measurement of diodedetector lawMeasurement of impedanceand impedance matchingMeasurement of radiationdiagram of a horn antennaUse of directional couplersin power transmission andreflection measurementSeries, shunt and hybrid teewaveguide junctionsWaveguide-to-coaxialtransformers

FeaturesStand-alone, low cost systemNo ancillary equipment requiredSimple, robust stands forantennasModulated 10.425GHz solid-state DRO sourceComponents identified withinscribed reference number

AM Radio Systems Trainer AM2961

FeaturesCovers the principles ofAM radio signal generationand reception

Double sideband carrier

Single and Double sidebandwith suppressed carrier

Receiver operating at 500-1600kHz (MW) & 3-4MHz(SW)

One fixed generator frequencyin each band

Switched faults on both boards

The AM circuits operate within the AM broadcast band and the DSB/SSBcircuits operate within the 80m ‘ham band’.The generator output is only a few milliwatts, so the range of transmissionis extremely limited.The receiver has an integral antenna, but may also be used, with the additionof an external antenna, to receive normal broadcast and amateur signals.The principles and techniques of AM with full carrier, double-sidebandsuppressed carrier and single-sideband suppressed carrier transmissionand reception can be easily investigated.

The AM Radio Systems Trainer comprises two open-boards:-AM2961A, AM/DSB/SSB generatorAM2961B, AM/DSB/SSB receiver

Radio

Curriculum CoverageModulation and demodulation

Mixing techniques

Filtering

RF and audio AGC

RF, IF and AF amplification

LC, crystal and VCO oscillators

Single and double sideband

FeaturesCovers the principles of FMradio signal generationandreception

Stereo transmission andreception

Extensive use of monitoringpoints for signal tracing

Switched faults on both boards

FM Stereo Radio Systems Trainer FM2962

The FM Stereo Radio Systems Trainer comprises two open-boards:-FM2962A, stereo generatorFM2962B, stereo receiver

The FM receiver circuits operate over a range of 88-108MHz and the gen-erator provides a fixed output frequency of 100MHz with a 19kHz pilot tone.The generator output is only a few milliwatts, so the range of transmission isextremely limited.The receiver operates on an IF frequency of 10.7MHz in stereo or monomode and may also be used with an external antenna to receive normalbroadcast and amateur signals. Switched faults can be introduced on bothgenerator and receiver units. Fault options include Multiplex, Pilot tone andMute errors; power for tuner, audio and demodulator, forces tuning volts tozero and high-gain AFC loops locking to a signal.

Curriculum Coverage

Familiarisation with FMmultiplex stereo transmissionand reception

Frequency modulation

Stereo multiplex encoding,pre-emphasis, pilot tonesand sub-carriers

FM reception, filtering, limitingand AFC

FM demodulation

Stereo multiplex decoding,de-emphasis and audioamplification

Ordering InformationAncillary

Equipment

Analogue & Digital Telecommunications Workstation 53-004 PC

Amplifiers and Oscillators Workboard 53-210 PC

Tuned Circuits and Filters Workboard 53-220 PC

Modulation and Coding Workboard 53-230 PC

Telephony Training System 58-001 PC

Digital Switching System 58-002 PC

Dual Switching System 58-003 PC

Trunk Network System 58-004 PC

AntennaLab 57-200 PC

AM Radio Systems Trainer AM2961 01-100 P SupplyFM Radio Systems Trainer FM2961 01-100 P Supply

Transmission Line Demonstrator TLD511

Antenna System Demonstrator ASD512

MIDE Microstrip System 56-001

MIDE Microstrip 56-100

Complete Microstrip Trainer MST532-1

Microstrip Trainer MST532

MIDE Microwave 56-002

Microwave Trainer 56-200

MIDE Microwave Design Software 56-901

Fibre Optics Trainer EFO1101

Fibre Optics Power Meter EFO1102

Fibre Optics Monitor EFO1105

Optical Fibre Laboratory System OFSA

Optical Fibre Trainer OFT

LAN-T Trainer LAN-T

Discovery Courseware

Discovery Tools 93-400Discovery Course Manager 93-410

Telecommunications

Feedback Instruments LimitedPark Road, Crowborough, E. Sussex,TN6 2QR, England.Telephone: +44 (0) 1892 653322Fax: +44 (0) 1892 663719E mail: feedback@feedback-group.comWebsite: www.feedback-group.com

Registered in England number 990620.A subsidiary of Feedback plc.

Feedback reserves the right to changethese specifications without notice.

Feedback Incorporated437 Dimmocks Mill Road, Suite 27,Hillsborough, NC 27278, USATelephone: (919) 644 6466Fax: (919) 644 6470E-mail: info@feedback-group.comWebsite: www.feedback-group.com