Untitled Flashcards Set

TECHNICAL DATA

Almost every purchase you make, be it a new laptop, cell phone, or vehicle, comes with some kind

literature; the purpose varies, depending on the content. These documents can range from a list of

specifications and parameters for how the equipment will function, to step-by-step procedures for

setting up, operating, and maintaining it, as well as applicable safety and warranty information for

the product. The overall goal for these types of documents is to educate the user about the item

they are about to operate, and to ensure that the device works safely and as intended. This

minimizes, both, unnecessary risk to the user and equipment, while keeping the equipment in peak

operating condition.

There are many similarities between the purpose and content of commercial manuals and the Air

Force Technical Order (AFTO) System. This section will focus on TO structure, to help you

become familiar with navigating and locating the information contained within. More information

regarding the AFTO System can be found in T.O. 00-5-1 AF Technical Order System.

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TO System Scope

By now you should know that Air Force Instructions

(AFIs) establish policies and responsibilities in order to

implement Air Force Policy Directives (AFPD). Whereas

Air Force Technical Orders (TOs) provide instructions for

the operation and maintenance of AF military systems and

end items (Figure 1-1).

Refer to TO 00-5-1 AF Technical Order System, Chapter

1.2 for the scope of the AF TO System.

Use of Technical Orders

Refer to TO 00-5-1 AF Technical Order System, Chapter

1.5 for the use of TOs.

Enhanced Technical Information Management System (ETIMS)

Refer to TO 00-5-1 AF Technical Order System, Chapter 2.2 for the purpose of ETIMS.

Technical Order Distribution Office (TODO)

Refer to TO 00-5-1 AF Technical Order System, Chapter 4 for the purpose of TODOs.

Types of Technical Orders

Most TOs are prepared according to military standards and performance or detail specifications

which prescribe the contents of each TO type. This standardized approach assigns each TO with

a catalog number. These assigned numbers are standard within the designated category. See T.O.

00-5-18 AF Technical Order Numbering System, Appendix C for a complete list of types of TOs.

Refer to TO 00-5-1 AF Technical Order System, Chapter 3 for the types of TOs.

Locally Prepared Workcards/Checklists

Refer to TO 00-5-1 AF Technical Order System, Chapter 3 and TO 00-33A-1001 General

Cyberspace Support Activities Management Procedures and Practice Requirements, Chapter 10

for Locally Prepared Workcards / Checklists

Commercial Off-The-Shelf Manuals

Refer to TO 00-5-1 AF Technical Order System, Chapter 3.10 and TO 00-33A-1001 General

Cyberspace Support Activities Management Procedures and Practice Requirements, Chapter 10

for COTS Manuals.

Multimeter

Purpose

Refer to TO 31-1-141 Testing Equipment, Chapter 2, Para. 2.2.10-11

& 2.3.7 for Non-electronic and electronic multimeters.

A digital multimeter (DMM) is a test tool used to measure two or

more electrical values – mainly voltage (volts), current (amps) and

resistance (ohms). It is a standard diagnostic tool for technicians in

the electrical/electronic field.

Multimeters fall into one of a handful of categories: general purpose

(aka testers), standard, advanced, compact, or wireless. Regardless

of the category, many features of a DMM are standard across the

board.

For the remainder of this section will refer to the Fluke brand multimeters (Figure 1-2). For

additional technical information, utilize the Fluke 87V DMM Commercial Manual.

Capabilities & Limitations

Refer to Fluke 87V DMM Commercial Manual, Pg 43-52 for capabilities and limitations.

Controls & Indicators

Refer to Fluke 87V DMM Commercial Manual, Table(s) 3-5 for controls and indicators.

Figure 1-2. Fluke 87V

Digital Multimeter

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Making Measurements

Refer to Fluke 87V DMM Commercial Manual, Pg 13-30 for making measurements.

As the name indicates, the digital multimeter can perform a number of different measurements.

Using the dial (rotary knob), you can select from the many available options. During the lab, you

will use the DMM to conduct several tests, such as resistance, AC/DC voltages, and continuity,

among others. While many concepts were learned in Electronic Principles, it is important to recall

the symbols in order to select the correct position on the rotary dial for making measurements.

The Fluke 87V DMM Commercial Manual has several tables defining these symbols and explain

the function for each.

There are many other functions that a DMM can perform. As previously mentioned, a DMM is

an instrument that you will use quite often in the RF Transmission Systems career field. The Fluke

80 Series V Multimeter Quick Reference Guide provides a convenient reference for conducting

many common measurements.

For the performance portion of this objective, you will be using the Fluke 80 Series V Multimeter

(Figure 1-2). For additional technical information, utilize the Fluke 87V DMM Commercial

Manual.

Earth Ground Tester

As a deployed RF Transmission Systems technician, you may to

be assigned to a unit in which you will be responsible for setting

up a communications network from scratch. In this environment,

it will be necessary to establish a grounding system and test that

system for proper readings prior to powering on equipment. Earth

ground testers (Figure 1-3) are tools to help maintain equipment

uptime and resolve intermittent electrical problems because of

poor grounding, due to resistance of the earth.

As you know, grounding provides a safe path for the dissipation of

fault currents, lightning strikes, static discharge, and EMI/RFI

signals. An effective grounding system can help protect personnel

from injury or death, as well as protecting equipment and

communications from damage or interference. Your grounding

system will be ineffective if the soil resistivity is too high.

For the remainder of this section will refer to the AEMC 4630

Ground Resistance Tester (Figure 1-3). For additional technical

information, utilize the AEMC 4630 Ground Resistance Tester User Manual.

Soil Resistivity

Refer to the AEMC Understanding Ground Resistance Workbook, Pg. 1 for soil resistivity.

Figure 1-3. AEMC 4630

Ground Resistance Tester

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Capabilities & Limitations

Refer to AEMC 4630 Ground Resistance Tester User Manual, Chapter 3 for capabilities and

limitations.

Controls & Indicators

Refer to AEMC 4630 Ground Resistance Tester User Manual, Chapter 2 for controls and

indicators.

As you will discover, there are several ways to perform an earth ground test. Using an earth ground

tester will aid in determining the appropriate grounding system to install, as well as helping to

maintain those systems that are already in use. Conducting a periodic inspection on a grounding

system will indicate whether the ground resistance has changed over time, causing a need to

modify the installed system.

For the performance portion of this objective, you will be using the AEMC 4630 Ground

Resistance Tester is an example of an earth ground tester. For additional technical information,

utilize the AEMC 4630 Ground Resistance Tester User Manual.

POWER MEASUREMENTS

Power Meter

Purpose

Refer to TO 31-1-141-7 Testing Equipment, Para. 3.2.2.

An RF power meter is a precision instrument designed specifically for measuring RF power. It

measures the actual power dissipated across a terminating load. Most RF power meters use either

thermal or detector sensors to measure the incoming RF energy at the terminating load.

Characteristics

Refer to TO 31-1-141-7 Testing Equipment, Para. 3.2.2.

Power meters have either analog meters or digital readouts that interpret or display the

representation of the signal power. Because the power sensor and meter combined measure power

directly, and the signal terminates at the meter, there are less sources for error, and therefore

generally provide the most accurate method for measuring the total power of an RF signal.

Today’s RF power meters come in many different configurations and cover a range of frequency

and power applications. Power sensors are even being produced with USB connections that can

plug directly into a computer, which acts as the power meter using a software application to

interpret and display the signals from the attached power sensor.

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Power meters are selectable to display power measured in relative decibels, dBm, microwatts,

milliwatts, and watts. They can measure continuous wave (CW), peak power, absolute power,

average power, and relative power. The attached power sensor determines the power meter’s

frequency range and minimum and maximum power handling capabilities.

For the performance portion of this objective, you will be using the Freedom Communication

Technologies R8000C Communications System Analyzer. (Figure 1-11 (Page 1-15)) For

additional technical information, utilize the Freedom Communication Technologies R8000C

Communications System.

Wattmeter and Dummy Load

In the RF Transmissions Systems career field, some of your routine duties may include testing

transmitters and transmission lines to make sure that they are emitting the proper output power.

To conduct these tests, work centers tend to use a combination of a wattmeter and a dummy load.

Wattmeter

An in-line wattmeter is an instrument used to measure the

electric output power level of a circuit. In the field, the

most commonly used in-line wattmeter is the Bird 4391

series (Figure 1-4). It will be mainly referenced

throughout this section. Unlike the previously discussed

RF Power Meter, an in-line wattmeter can be left in the

line for continuous monitoring of either the transmitter

power output or the amount reflected by the antenna.

It is vital to communications that the circuit is operating

at peak performance. Tuning for minimum reflected

power results in a good match of the load (e.g. an antenna)

to the line. Equally important, adjusting the transmitter

for maximum forward power into a matched antenna

capitalizes on the potential of the circuit. These optimum

system adjustments result in a low voltage standing wave

ratio (VSWR). VSWR will be discussed later on in the

course.

Purpose & Function

Refer to T.O. 33A1-7-322-1 Multi-Purpose Thruline Wattmeter RF Power Analyst Model 4391M,

Chapter 1 for purpose and function.

The Bird 4391 series wattmeter is designed to measure peak or average power flow, load match,

and amplitude modulation in 50Ω coaxial transmission lines. It is capable of reading peak

envelope power (PEP) or continuous wave (CW) power in milliwatts, watts, and kilowatts

Figure 1.4. Bird 4391 Series

Thruline Wattmeter

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depending on the plug-in elements utilized. The wattmeter is used in-line, meaning it is connected

in between the transmitter and the antenna or a dummy load.

Capabilities & Limitations

Refer to T.O. 33A1-7-322-1 Multi-Purpose Thruline Wattmeter RF Power Analyst Model 4391M,

Pg. 49 for specifications.

The plug-in elements are selected based on the test being conducted, and the frequency and power

being measured. The plug-in elements are then inserted into the appropriate sockets on the

wattmeter. These elements are used to sample the traveling RF waves, and are pointed according

to the direction by which the RF is moving. The switches on the wattmeter are then positioned to

correspond with the elements and match the range being measured. The keypad is used to select

the mode of operation, depending on the type of test being conducted.

Controls & Indicators

Refer to T.O. 33A1-7-322-1 Multi-Purpose Thruline Wattmeter RF Power Analyst Model 4391M,

Chapter 2 and 3 for theory of operation and installation.

For the performance portion of this objective, you will be using the Bird 4391M Thruline

Wattmeter. (Figure 1-4) For additional technical information, utilize T.O. 33A1-7-322-1 Multi-

Purpose Thruline Wattmeter RF Power Analyst Model 4391M.

Dummy Load

When testing or troubleshooting any transceiver or

transmission line, it is not always possible to use an

operational antenna or line. Mission requirements may

not allow for those assets to be occupied for that purpose,

so you’ll need a way to simulate those components;

dummy loads serve that purpose.

Purpose & Function

Refer to the Termaline Coaxial Load Resistor Bird 8000

Series Operating Instructions, Chapter 1 for purpose and

function, and TO 31-1-141-7 Testing Equipment,

Para.12.5.1.1

The dummy load (Figure 1-5) is a device which is designed to dissipate undesirable excess power

(e.g. RF) or to serve as a terminating load. They are often used in conjunction with test equipment

(e.g. wattmeter) as part of a measuring setup, allowing you to troubleshoot without fear of

radiation.

Figure 1-5. Termaline Coaxial

Load Resistor Bird 8000

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Characteristics

Refer to Termaline Coaxial Load Resistor Bird 8000 Series Operating Instructions, Pg. 3 for

specifications, and TO 31-1-141-7 Testing Equipment, Para.12.5.2.1.

A dummy load is used to absorb power without creating or causing reflections, providing an ideal

method of locating circuit difficulties or defective circuit components. A typical dummy load uses

a mixture of sand and aquadag to absorb power, and enclosed inside a heat sink exterior. The

exterior often consists of black-painted cooling fins to provide maximum heat transfer or

dissipation. Depending on the required power to be measured, dummy loads can vary greatly in

size.

A dummy load is useful for the following purposes:

 As a substitute antenna.

 The ability to tune RF transmitters under non-radiating conditions.

 Making routine tests and adjustments.

 As a substitute for any circuit loading element.

 To measure, with a suitable indicating device (e.g. a wattmeter), the power output of any

coaxially transmitted RF signal within their rating.

 To determine the cause of an undesirable standing wave ratio (SWR) along a transmission

line.

For the performance portion of this objective, you will be using the Termaline Coaxial Load

Resistor Bird 8000. (Figure 1-5). For additional technical information, utilize the Termaline

Coaxial Load Resistor Bird 8000 Series Operating Instructions.

FREQUENCY MEASUREMENTS

Because of the critical nature of such measurements, frequency measuring equipment and devices

make up a distinct class of test equipment; particularly those used to determine radio frequencies.

The requirement of precise calibration is extremely important in all frequency measuring work.

One of the most accurate means for measuring frequency is by using a counter, which will be

discussed in this section.

Frequency Counter

Purpose

Refer to TO 31-1-141-7 Testing Equipment, Para. 4.4.2.1.

Frequency counters are test instruments used in many applications within the RF field to accurately

measure the frequency of signals. They are commonly used as bench test equipment. These

counters and counter timers are widely used with electronics to measure the frequency of repetitive

signals. Additionally, counters are used for measuring the time between edges on digital signals,

counting the number of times a signal passes a give voltage (trigger) point in a given time (Figure

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1-6). Some frequency counters will have trigger points that can be set, but most automatically set

the trigger, often around the zero crossing point.

Characteristics

Refer to TO 31-1-141-7 Testing Equipment, Para.

4.4.2.1.1.

To break it down, if the time of the frequency counter is

set to count at every second (e.g. a gate time of one

second) and the waveform crosses the trigger point a

hundred times, there will be one hundred repetitions

(cycles) of the waveform every second; in other words, its

frequency is 100 Hz. This would be referred to as cycles

per second (cps). Frequency is calculated using the

equation below:

frequency =

trigger level crossings

time in seconds

To ensure the best accuracy, quartz crystal oscillators (XO) are used to provide a stable frequency

in order to deliver a precise timing reference. XOs are also utilized in every-day electronics such

as, wristwatches, clocks, computers, and cellphones.

Frequency counters come in variety of formats, depending on the intended purpose. For example,

the bench frequency counter is most commonly used; like the one being used in this course.

Another may be handheld for ease of use during field testing. There are even some multimeters

that have a frequency counting function embedded.

For the performance portion of this objective, you will be using the Freedom Communication

Technologies R8000C Communications System Analyzer. See Figure 1-11 (Page 1-15). For

additional technical information, utilize the Freedom Communication Technologies R8000C

Communications System.

WAVEFORM MEASUREMENTS

In the RF Transmission Systems career field, it is likely that you will be responsible for

establishing and maintaining circuits, whether they are wired or wireless. Additionally, you may

find yourself troubleshooting the components within those circuits (e.g. transmitters, receivers,

antennas, etc.). Depending on the job, you may need to use two common equipment items that

look similar but operate very differently; the oscilloscope and spectrum analyzer. Though the

focus of this section is the latter, it is important to compare the two.

Oscilloscope

Figure 1-6 Frequency

Counter Concept

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Purpose

Refer to TO 31-1-141-7 Testing Equipment, Para. 5.1.1.

One of the most common test equipment items used in the

communications and electronics world is the oscilloscope.

It displays signals in what is known as the time domain

(i.e., amplitude against time). (Figure 1-7) It allows many

waveforms to be displayed and the performance of

circuits, modules and equipment to be analyzed. The

oscilloscope displays the amplitude of waveforms on the

vertical axis against time on the horizontal axis.

Controls & Indicators

Refer to TO 31-1-141-7 Testing Equipment, Para. 5.6.

When testing radio frequency circuits and systems, an oscilloscope is very useful. However, it is

oftentimes necessary to analyze spectrum of a signal. Within the spectrum, it is possible to look

at aspects like the location of spurious signals, the width of a signal that has modulation on it,

whether noise is being generated and much more. The frequency domain contains information not

found in the time domain (i.e. signals composed of more than one frequency); therefore, the

spectrum analyzer has certain advantages not available with an oscilloscope.

Spectrum Analyzer

Purpose

Refer to TO 31-1-141-7 Testing Equipment, Para. 5.9.1.

A device with wide capabilities for RF measurements is

the spectrum analyzer. The spectrum analyzer may be

used to display the spectrum of any radio frequency

oscillation within its range. Since the output amplitude

over a very narrow band of frequencies is displayed vertically, and a selected range of frequencies

is displayed horizontally, the complete spectrum may be observed directly.

Characteristics

Refer to TO 31-1-141-7 Testing Equipment, Para. 5.9.1.

When looking at a signal within the frequency domain, the amplitude of the signal is displayed in

the vertical axis and frequency in the horizontal axis. By looking at the amplitudes of signals at

different frequencies it is possible to measure the amplitudes of these signals, find what signals are

present, and the like. (See Figure 1-8)

Figure 1-7. Time

Domain/Oscilloscope Display

Figure 1-8. Frequency Domain /

Spectrum Analyzer

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The display on the screen of a spectrum analyzer is a plot of amplitude versus frequency. Using

this type of display, the presence or absence of signals of interest, their frequencies, frequency

differences, and relative amplitudes, and the nature of their modulation, can be observed.

The spectrum analyzer the ability to aid in observing signal characteristics as well as diagnosing

issues with frequency generating circuits to include:

 Determining pulse width and shape, as well as frequency modulation.

 Checking the frequency difference and/or spectra of two RF signals.

 Observing and measuring sidebands associated with AM and FM signals.

 Determining the presence and measuring the frequency of radio and/or radar signals.

 Locating sources of RF leakage.

 Determining the type of modulation in radio and/or radar signals.

 Checking a transmitter or signal generator for continuous output throughout its tuning

range.

 Measuring noise spectra.

 Checking frequency relationships of multi-frequency transmitters.

 Troubleshooting disturbances caused by electromagnetic interference (EMI).

Controls & Indicators

Refer to TO 31-1-141-7 Testing Equipment, Para. 5.9.2.

For the performance portion of this objective, you will be using the Freedom Communication

Technologies R8000C Communications System Analyzer. See Figure 1-11 (Page 1-15). For

additional technical information, utilize the Freedom Communication Technologies R8000C

Communications System.

SENSITIVITY MEASUREMENTS AND ALIGNMENT

A signal generator is a test device which generates an alternating current signal that is suitable for

test purposes. It is, in effect, a small radio transmitter which can be constructed to generate a signal

of any desired frequency. The generated signal may be modulated or unmodulated, and is used

for the following tests or checks: alignment of tuned circuits, dynamic troubleshooting (e.g. signal

tracing), sensitivity measurements, field-intensity measurements, and approximate frequency

measurements. The signal generator is used principally in the alignment of tuned circuits.

There are two types signal generators, each are classified according to frequency: audio frequency

or radio frequency. The shape of the output waveform permits a further classification of audio-

frequency and radio frequency generators. This section will discuss each of those devices, and

how they are used in the field.

Audio Frequency Generator

Purpose

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Refer to TO 31-1-141-7 Testing Equipment, Para. 9.3.1.

Audio frequency generators, which are sometimes called audio oscillators, are capable of

producing signals whose frequencies range from 20 Hz to 20 kHz. Audio frequency generators

are subdivided into sine-wave and square-wave (pulse) generators.

Characteristics

Reference TO 31-1-141-7 Testing Equipment, Para. 9.3.1.

Tests or measurements made on audio frequency equipment, such as amplifiers, modulators, and

other voice-frequency components, require a source of controlled audio frequencies, with very

little or no harmonic content. The frequency range required generally covers 20 Hz to 20 kHz, as

this is considered the human audio range; however, some audio oscillators have ranges up to 200

kHz.

Many radios are designed to pass audio frequencies between 300 Hz and 3.5 kHz, and suppress

frequencies outside that range. When testing receivers, you may use audio oscillators to modulate

an RF signal, then inject it into a radio’s receiver to determine its ability to demodulate that signal

with minimal noise. Audio oscillators produce audio signals at stable frequencies and amplitudes

for test and maintenance purposes.

Radio Frequency Generator

Purpose

Reference TO 31-1-141-7 Testing Equipment, Para. 9.3.2.

Radio frequency (RF) generators provide practical outputs ranging from 10 kHz to about 10 GHz.

However, no single generator completely covers all of the existing RF ranges. Various RF

generators are available covering specified portions of the RF spectrum; many of these also have

an audio output which is separately available through a front panel jack. RF generators provide

either a pure radio frequency or a radio frequency with amplitude modulation (AM), frequency

modulation (FM), or pulse modulation.

Characteristics

Reference TO 31-1-141-7 Testing Equipment, Para. 9.3.2.

You can use an RF generator to test and troubleshoot transmitters, receivers, antenna systems, or

ground stations. Some applications for the RF generator are:

 Verifying receiver sensitivity and selectivity accuracy.

 Verifying transmission or percent of modulation within designated frequency ranges by

comparing transmitter outputs with RF signal generator outputs.

 Aligning telemetry receivers by injecting the system with range-standard modulated RF.

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 Checking transmission lines and antenna systems for proper operation.

For the performance portion of this objective, you will be using the Freedom Communication

Technologies R8000C Communications System Analyzer. (Figure 1-11 (Page 1-15)). For

additional technical information, utilize the Freedom Communication Technologies R8000C

Communications System.

ACCESSORY EQUIPMENT

Audio Analyzer

Purpose

Reference TO 31-1-141-7 Testing Equipment, Para. 12.23.1.

Audio analyzers are multifunctional equipment used in audio frequency amplifier measurements.

This type of test equipment usually contains circuitry for an AC electronic voltmeter, a dual-

frequency audio oscillator, a wattmeter, and either a harmonic or intermodulation distortion filter.

Characteristics

Reference TO 31-1-141-7 Testing Equipment, Para. 12.23.2.

The various functions of an audio analyzer are selected by means of a function switch. The AC

electronic voltmeter can be selected for individual use as a voltmeter to measure various signal

amplitudes, or it may be transferred into compensation networks to measure power dissipation in

terms of signal voltage. During the process of measuring

intermodulation distortion, the electronic voltmeter must be used

to measure signal voltage output levels of both audio frequency

oscillators, and transferred to two different circuit positions

within the filter circuits.

One of the advantages of an audio analyzer is the reduction in the

number of test leads required to monitor and check an amplifier.

A reduction in the number of test leads reduces the chances of

making mistakes involved in changing leads to measure different

electrical characteristics. Reducing the number of

interconnecting test leads also decreases the chances of unwanted

signal coupling through stray capacitance effects.

Distortion (Figure 1-9) is any change in a signal that alters the

basic waveform or the relationship between various frequency

components; it is usually a degradation of the signal. Audio

analyzers measure the accuracy of an electronic circuit at reproducing a wave and can be used to

test the noise though a receiver.

Figure 1-9. Distortion

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For the performance portion of this objective, you will be using the Freedom Communication

Technologies R8000C Communications System Analyzer. See Figure 1-11 (Page 1-15). For

additional technical information, utilize the Freedom Communication Technologies R8000C

Communications System.

Bit Error Rate Test Set

Purpose

Bit Error Rate (BER) is a measure of telecommunication signal integrity

based on the quantity or percentage of transmitted bits that are received

incorrectly. Essentially, the more incorrect bits, the greater the impact on

signal quality. Bit error rate is an effective indicator of full end-to-end

performance because it encompasses the receiver and transmitter as well

as the media between them.

How BERT works

When data is transmitted over a data link, there is a possibility of errors

being introduced into the system. If errors are introduced into the data,

then the integrity of the system may be compromised. As a result, it is

necessary to assess the performance of the system, and bit error rate

testing (BERT) provides an ideal way in which this can be achieved.

Bit error rate testing (BERT) can be used over wired (e.g. Ethernet, fiber optic, etc.) and wireless

(e.g. cellular) networks, or any other system used to transmit data. To perform a bit error rate test,

a pre-defined data stream is sent through a network link input, then the output of the link at the

receiving end is analyzed to assess the number of errors detected versus the number of bits

transmitted over a given time frame.

A Pseudorandom Binary Sequence (PRBS) can be used to create a data transmission pattern likely

to cause errors by producing a wide range of bit patterns. This acceleration of induced errors is

useful for reducing the BER test time but can only be utilized on lines which are out-of-service.

Whether you are verifying the performance of your own network or performing service activation

for a customer or client, BERT is an effective way to ensure overall network integrity.

How BER is Calculated

The bit error rate is calculated by dividing the quantity of bits received in error by the total number

of bits transmitted within the same time period. A result of 10-9 is generally considered an

acceptable bit error rate for telecommunications, while 10-13 is a more appropriate minimum BER

for data transmissions. If enough confidence in the rate is established, it can also be expressed as

a probability of errors (Pe) occurring in the future.

BER =

Bit Errors Rx′d

# of Bits Tx′d

Figure 1-10. HST-

3000 Handheld

Service Tester

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An effective bit error rate tester can perform service activation testing for several key performance

indicators (KPIs) such as, packet loss, latency, and jitter. These KPIs will be discussed in the

Internet Protocol (IP) Fundamentals module.

The Importance of BERT

With the bandwidth and performance demands on Ethernet networks increasing daily, BERT has

become essential for quantifying bit error rate in optical fiber communication channels and

establishing confidence in high-speed data services. Bit Error Rate Testing critical to ensure

communication systems perform at optimal levels.

The BERT is a quick and easy method for determining the quality of a network connection or

channel. The BERT set comes in all sizes, shapes, and different capabilities. It may be a small,

dedicated, handheld unit or a large laptop computer-type unit that can perform frequency response,

protocol analysis, and other tests. Figure 1-10 shows an example of a BERT set.

The performance portion of this objective will be accomplished during a later Module.

RADIO TEST SET

Purpose

Refer to R8000 Series Communications System Analyzer

Operator’s Manual, Para. 2.1.

A radio test set, often referred to as a communications

system analyzer or monitor (CSA/CSM), supports a

variety of radio communications systems. It has

numerous functions to test radio equipment. This

section highlights a few of its operational capabilities

most likely used in the average work center in the RF

Transmission Systems career field. There are a variety

of radio test sets on the market today. Throughout this

section will be referring to the Freedom Communication Technologies R8000C Communications

System Analyzer (Figure 1-11).

Characteristics

Refer to R8000 Series Communications System Analyzer Operator’s Manual, Para. 2.2.

CSA/CSMs are integrated test instrument primarily designed for testing mobile radio

communication equipment. Many of the embedded features include much of the components you

have already learned about; but rather than individual items, they are conveniently packed into a

single transportable device. Some of the testing capabilities include:

Figure 1-11. Freedom

Communication Technologies

R8000C Communications System

Analyzer

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 RF Generator – Produces a transmission with defined parameters. Signal will be

modulated at the level and frequency set.

 Audio Generator – Provides a source of modulation for the transmitter under test.

 Tones Generator – Modulates transmitters of systems using tone calling to test tone

recognition circuits.

 RF Power Meter – Measure the mean/average output power level of the transmitter.

 Modulation Meter – Measures modulation depth or deviation level and provides a

demodulated output signal.

 RF Counter – Obtains the mean RF frequency of the transmitter output.

 Audio Frequency (AF) Counter – Measures the frequency of the demodulated signal.

Checks the sensitivity of the receiver functions.

 Audio Frequency (AF) Voltmeter – Measure the level of the demodulated signal from

the receiver.

 Distortion Meter – Obtains a signal to noise ratio, Signal, Noise and Distortion (SINAD),

and distortion percentages.

 Spectrum Analyzer – Used to study the sidebands and any harmonics produced by the

transmitter.

 Oscilloscope – Views and measures the demodulated signal or other waveforms.

The Communications Service Monitor allows you to test many functions of a radio and other RF

circuits. You may not use all of the features at once, but you need to know what you have available

to you. When you get to your first duty station, you may have similar, equipment in your shop in

order to perform troubleshooting and PMIs on your systems.

Controls & Indicators

Refer to the R8000 Series Communications System Analyzer Operator’s Manual, Para. 2.3.

For the performance portion of this objective, you will be using the Freedom Communication

Technologies R8000C Communications System Analyzer. See Figure 1-11. For additional

technical information, utilize the Freedom Communication Technologies R8000C

Communications System Analyzer Operator’s Manual. Ensure that you familiarize yourself with the device's features and settings to maximize its capabilities during testing.