Download Tech License Study Guide PowerPoint

W5YL Ham Cram
• Technician Class Amateur Radio
License Course.
• Presented by: Thibodaux Amateur
Radio Club
• Instructor: Richard Barrett N5OEQ
• www.w5yl.org
Early 5YL QSL card circa 1921
The Thibodaux Amateur Radio Club was established in 1920.
Introductions
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State your name and a little about yourself.
Why are you taking this course?
What do you know about ham radio?
What expectations do you have for yourself
and your instructors?
Expectations
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Class will start and end on time.
Instructor will be prepared to teach.
Students are expected to be prepared to learn.
Ham radio is not a spectator sport, active
participation during class discussions is vital to
success in obtaining your Technician Class
License (ticket).
Course Outline
Week
Week 1
Week 1
Week 1
Week 1
Week 1
Week 1
Week 1
Week 1
Week 2
Week 2
Week 2
Week 2
Week 2
Start
Slide
1
20
64
87
113
135
149
162
179
203
217
226
244
End
Slide
19
63
86
112
134
148
161
178
202
216
225
243
259
Chapter
Chapter 1
Chapter 2
Chapter 2
Chapter 2
Chapter 3
Chapter 3
Chapter 3
Chapter 4
Chapter 4
Chapter 4
Chapter 5
Chapter 6
Chapter 7
Topic
Introduction
Basic Electricity
Signals
Antennas, Feedlines, and Propagation
Transmitters, Receivers, and Transceivers
Operating a Station -- Repeaters and Digital
Practical Antennas
Antenna Supports
Making a Contact
Special Modes
Licensing Regulations
Operating Regulations
Electrical and RF Safety
Let’s Get Started
• Our goal during this class is for each of you
to achieve the Technician Class Amateur
Radio License!
– The license will authorize you to operate an
Amateur Radio (Ham Radio) transmitter.
What can you do with a
Technician Class License?
Authorizations
Frequency Limits
HF Range
300
Band 
Freq( MHz )
80 meters
3.525-3.600 MHz: CW Only
40 meters
7.025-7.125 MHz: CW Only
15 meters
21.025-21.200 MHz: CW Only
10 meters
28.000-28.500 MHz: CW, Phone
(Some limits)
VHF Range
6 meters
50 – 54 MHz all modes and power
2 meters
144.1-- 148.0 MHz all modes and power
1.25 meters
222 – 225 MHz (Some limits)
UHF Range
70 cm
420 – 450 MHz all modes and power
33 cm
902 – 928 MHz all modes and power
13 cm
2300 – 2450 MHz (Some limits)
What can you do with a
Technician Class License?
• Emission Privileges:
What can you do with a
Technician Class License?
• Power limits.
• Use the minimum power required to get the job
done.
• Up to 1500 watts peak envelope power (PEP).
– Will generally require an external amplifier to achieve
these power levels.
• Some special cases where power is restricted.
Primary and Secondary
Allocations
• Some authorized amateur
frequencies are shared.
– Primary Users.
– Secondary Users.
Band ‘Plan’
•
Frequency privileges for different classes of Amateur Radio licenses.
Amateur Radio Internationally
• International Telecommunication Union
(ITU).
– Regions 1, 2 and 3.
• CONUS hams are in Region 2.
• Reciprocal operating authorizations.
• There are times when there are
restrictions on certain countries that we
can contact.
Call Signs
• US call signs begin
with: K, N, W, and
A.
• US call sign
districts: 0-9
Call Signs
• Portable – operating away from primary
station location.
• If in the different call sign district add:
– “portable 6” if voice.
– /6 if Morse code or digital.
– Not required, just nice to do.
• If recent upgrade add “AG” or “AE.”
Special Call Signs
• Club and special event call signs.
• Vanity call signs.
Steps to Obtaining Your
Ticket
• Study the material in the Ham Radio License
Manual.
• Review the questions in the back of the book
• Take interactive practice exams.
• Pass a proctored 35-question multiple choice test.
– Questions pulled directly from the question
pool.
– Need to answer 26 questions correctly.
• No Morse code is required.
What is Amateur Radio?
• Amateur (or Ham) Radio is a personal radio
service authorized by the Federal Communications
Commission (FCC).
– To encourage the advancement of the art and science of
radio.
– To promote the development of an emergency
communication capability to assist communities when
needed.
– To develop a pool of trained radio operators.
– To promote international good will by connecting private
citizens in countries around the globe.
• Through ham radio, you will become an
ambassador for your community and your country.
What Do Hams Do?
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Communicate
Participate
Experiment
Build
Compete
Serve their
communities
• Life-long learning
What Makes Ham Radio
Different?
• There are many unlicensed radio services
available.
• Ham radio is authorized:
– Less restrictions.
– More frequencies (channels or bands to utilize).
– More power (to improve range and quality).
– More ways to communicate.
– It’s free to operate your radio.
With More Privileges Comes
More Responsibility
• Because ham radios are much more capable and
have the potential of interfering with other radio
services.
• Because ham radios have unlimited reach. They
easily reach around the globe and into space.
• FCC authorization is required to ensure the
operator is qualified to operate the ham radio
safely, appropriately and within the rules and
regulation – that is why you are here.
So Let’s Begin Your Ham
Radio Journey
• We have touched briefly on what
ham radio is.
• Here is where we get into the ‘nitty
gritty’ of how radios actually work.
• Don’t let the technical ‘jargon’ scare
you. We all had to learn it too.
• If you have questions, ASK! It’s how
we all learned this stuff, so ASK!
Technician License Course
Radio and Electronics
Fundamentals
Equipment Definitions
Basic Station Organization
• Station Equipment
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Receiver
Transmitter
Antenna
Power Supply
• Accessory Station Equipment
• Repeaters
What Happens During Radio
Communication?
• Transmitting (sending a signal):
– Information (voice, data, video,
commands, etc.) is converted to
electronic form.
– The information in electronic form is
attached or embedded on a radio wave
(a carrier).
– The radio wave is sent out from the
station antenna into space.
What Happens During Radio
Communication?
• Receiving end:
– The radio wave (carrier) with the information is
intercepted by the receiving station antenna.
– The receiver extracts the information from the
carrier wave.
– The information is then presented to the user in
a format that can be understood (sound,
picture, words on a computer screen, response
to a command).
What Happens During Radio
Communication?
• This sounds pretty simple, but it in reality
is pretty complex.
• This complexity is one thing that makes
ham radio fun…learning all about how
radios work.
• Don’t be intimidated. You will be required
to only know the basics, but you can learn
as much about the “art and science” of
radio as you want.
The Basic Radio Station
The Receiver and Controls
• Main tuning dial for received
frequency (or channel) selection.
• Frequency display.
• Volume control.
• Other accessory controls for mode
(kind of information to process),
filters (to mitigate interference), etc.
The Transmitter and
Controls
• Main tuning dial for transmitted
frequency (or channel) selection.
• Frequency display.
• Power control (transmitted signal
strength).
• Other accessory controls for mode
(kind of information to process), etc.
The Transceiver
• You will notice that many of the controls of
the transmitter and receiver are the same.
• Most modern transmitters and receivers
are combined in one unit – called a
transceiver.
– Saves space
– Cost less
• Many common electronic circuits are
shared in the transceiver.
Transceiver Controls
• Some are physical knobs that you
manually adjust.
• Some are controlled by computer
and you control the settings with
keypad entries that program a
computer in the transceiver.
Antenna
• The antenna exposes your station to the world.
– Facilitates the radiation of your signal into space
(electromagnetic radiation).
– Intercepts someone else’s signal.
• Most times the transmitting and receiving antenna
are the same antenna.
• Connected to your station by a connecting wire
called a feed line.
Transmit/Receive (TR)
Switch
• If the station antenna is shared between
the transmitter and receiver, the TR
switch allows the antenna to be switched
to the transmitter when sending and to
the receiver when receiving.
– In a transceiver, this TR switch is inside the
unit and requires no attention by the operator.
Power Supply
• Your radio station needs some sort
of power to operate.
– Battery
– Household current converted to proper
voltage
– Alternative sources
Power Supply
• Most modern radios operate on 12 volts
direct current (dc).
– A power supply converts household
current to the type of current and the
correct voltage to operate your station.
– Could be internal, might be external.
• You are probably familiar with common
“wall-wart” power supplies.
Basic Station Accessories
• Human interface
accessories:
– Microphones
– Speakers
– Earphones
– Computer
– Morse code key
– TV camera
– Etc.
• Station performance
accessories:
– Antenna tuner
– SWR meter
(antenna match
checker)
– Amplifier
– Antenna rotator
(turning antenna)
– Filters
– Etc.
Accessory Equipment
Special Stations You Will Use
(Repeaters)
• Repeaters are automated stations located
at high places that receive and then
retransmit your signal – simultaneously.
– Dramatically improves range.
• The basic components of a repeater are
the same as your station: receiver,
transmitter, antenna and power supply.
Repeaters
• But, repeaters are transmitting and
receiving at the same time using the same
antenna.
• This requires a very high quality and
specialized filter to prevent the
transmitted signal from overpowering the
receiver.
• This specialized filter is called a duplexer.
Repeater
Technician License Course
Radio and Electronics
Fundamentals
Basic Electricity
Fundamentals of Electricity
• When dealing with electricity, what we are
referring to is the flow of electrons through a
conductor.
– Electrons are negatively charged atomic
particles.
• The opposite charge is the positive charge
– A conductor is a material that allows electrons
to move with relative freedom within the
material.
Fundamentals of Electricity
• In electronics and radio, we control
the flow of electrons to make things
happen.
• You need to have a basic
understanding of how and why we
control the flow of electrons so that
you can better operate your radio.
Basic Characteristics of
Electricity
• There are three characteristics to
electricity:
– Voltage
– Current
– Resistance
• All three must be present for
electrons to flow.
Basic Characteristics of
Electricity
• The flow of water through a hose is a
good analogy to understand the three
characteristics of electricity and how
they are related.
Characteristics of Electricity
are Inter-related
• Voltage, current and resistance must
be present to have current flow.
• Just like water flowing through a
hose, changes in voltage, current
and resistance affect each other.
• That effect is mathematically
expressed in Ohm’s Law.
Ohm’s Law
• E is voltage
– Units - volts
• I is current
– Units - amperes
• R is resistance
– Units - ohms
• R = E/I
• I = E/R
• E=IxR
Moving Electrons Doing
Something Useful
• Any time energy is expended to do
something, work is performed.
• When moving electrons do some
work, power is consumed.
• Power is measured in the units of
Watts.
Power Formula
• Power is defined as the amount of
current that is being pushed through
a conductor or device to do work.
–P=ExI
– E = P/I
– I = P/E
Two Basic Kinds of Current
• When current flows in only one direction,
it is called direct current (dc).
– Batteries are a common source of dc.
– Most electronic devices are powered by
dc.
• When current flows alternatively in one
direction then in the opposite direction, it
is called alternating current (ac).
– Your household current is ac.
The Electric Circuit:
An Electronic Roadmap
• For current to flow, there must be a path
from one side of the source of the current
to the other side of the source – this path
is called a circuit.
– There must be a hose (conductive path)
through which the water (current) can
flow.
• The following are some vocabulary words
that help describe an electronic circuit.
Series Circuits
• Series circuits provide one and only
one path for current flow.
Parallel Circuits
• Parallel circuits provide alternative
paths for current flow.
Short and Open Circuits
• When there is an unintentional current
path that bypasses areas of the circuit –
this is a short circuit condition.
• When the current path is broken so that
there is a gap that the electrons cannot
jump – this is an open circuit condition.
Electronics – Controlling the
Flow of Current
• To make an electronic device (like a
radio) do something useful (like a
receiver), we need to control and
manipulate the flow of current.
• There are a number of different
electronic components that we use
to do this.
The Resistor
• The function of the
resistor is to
restrict (limit) the
flow of current
through it.
• Circuit Symbol
The Capacitor
• The function of the
capacitor is to
temporarily store
electric current.
– Like a very
temporary storage
battery.
– Stores energy in an
electrostatic field.
• Circuit Symbol
The Inductor
• The function of the
inductor is to
temporarily store
electric current.
– Is basically a coil
of wire.
– Stores energy in a
magnetic field.
• Circuit Symbol
The Transistor
• The function of the
transistor is to
variably control the
flow of current.
– Much like an
electronically
controlled valve.
– An analogy, the
faucet in your sink.
• Circuit Symbol
The Integrated Circuit
• The integrated circuit
is a collection of
components
contained in one
device that
accomplishes a
specific task.
– Acts like a “blackbox”
• Circuit Symbol
Protective Components –
Intentional Open Circuits
• Fuses and circuit
• Circuit Symbol
breakers are designed
to interrupt the flow of
current if the current
becomes uncontrolled.
– Fuses blow – one time
protection.
– Circuit breakers trip –
can be reset and
reused.
Other Circuit Symbols
Putting It All Together in a
Circuit Diagram
Dealing with Very Big and Very
Small Numeric Values
• In electronics we deal with
incredibly large and incredibly small
numbers.
• The international metric system
allows for short hand for dealing
with the range of values.
Metric Units
Technician License Course
Radio and Electronics
Fundamentals
Signals and Waves
Radio Waves are AC
• You have already learned that in an
alternating current (ac) the electrons flow in
one direction one moment and then the
opposite direction the next moment.
• Radio waves (electromagnetic radiation) are
ac waves.
• Radio waves are used to carry the
information you want to convey to someone
else.
Wave Vocabulary
• Before we study radio
waves, we need to
learn some wave
vocabulary.
– Amplitude
– Frequency
– Period
– Wavelength
– Harmonics
How Radio Waves Travel
1. Moving electrons in the antenna create a
magnetic field.
2. This changing magnetic field creates an
electric field.
3. Then back and forth between magnetic
and electric fields from point A to point B.
Wavelength
• The distance a radio
wave travels during
one cycle.
– One complete change
between magnetic and
electric fields.
Finding Where You are on the
Radio Dial
• There are two ways to tell someone where
to meet you on the radio dial (spectrum).
– Band
– Frequency
Radio Frequency (RF) Spectrum
• The RF spectrum is the range of wave
frequencies which will leave an antenna and
travel through space.
• The RF spectrum is divided into segments
of frequencies that basically have unique
behavior.
Radio Frequency (RF)
Spectrum
So, Where Am I?
• Back to how to tell where you are in
the spectrum.
• Bands identify the segment of the
spectrum where you will operate.
– Wavelength is used to identify the band.
• Frequencies identify specifically
where you are within the band.
Another Use for Frequency
and Wavelength
• For the station antenna to efficiently send the
radio wave out into space, the antenna must be
designed for the specific operating frequency.
– The antenna length needs to closely match the
wavelength of the frequency to be used.
– Any mismatch between antenna length and
frequency wavelength will result in radio
frequency energy being reflected back to the
transmitter, not going (being emitted) into
space.
Antennas are Part Capacitor –
Part Inductor – Part Resistor
• Antennas actually have characteristics of
capacitor, inductor and resistor
electronic components.
• Capacitors and inductors, because they
store energy in fields, react differently to
ac than dc.
– Special kind of resistance to the flow of
ac – called reactance.
Resonance
• Because capacitors and inductors
store energy in different ways, the
stored energy can actually cancel
each other under the right
conditions.
– Capacitors – electric field
– Inductors – magnetic field
• Cancelled current = no reactance,
just leaving resistance.
Resonant Antenna
• If an antenna is designed correctly,
the capacitive reactance cancels
the inductive reactance.
• Theoretically, the resulting
reactance is zero.
– Leaving only resistance – meaning minimum
impediment to the flow of the radio frequency
currents flowing in the antenna and sending
the radio wave into space.
Adding Information Modulation
• Now that we know where we are in the RF
spectrum and are sending a radio wave into
space.
• When we imprint some information on the radio
wave, we modulate the wave.
– Turn the wave on and off
– Voice AM and FM
– Data
• Different modulation techniques are called modes.
Morse Code – On and Off
Amplitude Modulation (AM)
• In AM, the
amplitude of the
carrier wave is
modified in step
with the waveform
of the information
(voice).
Characteristics of Voice AM
AM signals consist of
three components:
– Carrier
– Lower sideband
– Upper sideband
• Voice bandwidth is
from 300 Hz to 3 kHz.
• AM bandwidth is twice
the voice bandwidth.
Characteristics of Voice
• Sound waves that
make up your voice are
a complex mixture of
multiple frequencies.
• When this complex
mixture is embedded
on a carrier, two
sidebands are created
that are mirror images.
Single Sideband Modulation
(SSB)
• Since voice is made up
of identical mirror image
sidebands:
• We can improve
efficiency of
transmission by
transmitting only one
sideband and then
reconstruct the missing
sideband at the receiver.
Frequency Modulation (FM)
• Instead of varying amplitude,
if we vary the frequency in
step with the information
waveform – FM is produced.
• FM signals are much more
resistant to the effects of
noise but require more
bandwidth.
• FM bandwidth (for voice) is
between 5 and 15 kHz.
Transmitting Data
• Data is made up of binary bits 1 and 0.
– On and off states
• Modems translate the data into a format capable
modulating a carrier wave.
• A terminal node controller (TNC) is a specialized
modem used in ham radio.
– There are many more kinds of modems
developed as data transmission technology
advances.
Basic Data Transmission
Setup
Technician License Course
Radio and Electronics
Fundamentals
Antennas, Feed lines, and
Propagation
The Antenna System
• Antenna: Facilitates the sending of
your signal to some distant station.
• Feed line: Connects your station to
the antenna.
• Test and matching equipment: Allows
you to monitor antenna performance.
The Antenna (Some
Vocabulary)
• Driven element: Where the transmitted energy
enters the antenna.
• Polarization: The direction of the electric field
relative to the surface of the earth.
– Same as the physical direction
• Vertical
• Horizontal
• Circular
The Antenna (Some
Vocabulary)
• Omni-directional – radiates in all
directions.
• Directional beam – focuses radiation in
specific directions.
• Gain – apparent increase in power in a
particular direction because energy is
focused in that direction.
– Measured in decibels (dB)
Antenna Radiation Patterns
• Radiation patterns are a
way of visualizing
antenna performance.
• The further the line is
away from the center of
the graph, the stronger
the signal at that point.
Impedance – AC Resistance
• A quick review of a previous concept:
impedance.
– Antennas include characteristics of
capacitors, inductors and resistors
• The combined response of these
component parts to alternating currents
(radio waves) is called Impedance.
Antenna Impedance
• Antennas have a characteristic impedance.
• Expressed in ohms – common value 50 ohms.
• Depends on:
– Antenna design
– Height above the ground
– Distance from surrounding obstacles
– Frequency of operation
– A million other factors
Antenna versus Feed Line
• For efficient transfer of energy from
the transmitter to the feed line and
from the feed line to the antenna, the
various impedances need to match.
• When there is mismatch of
impedances, things may still work,
but not as effectively as they could.
Feed Line types
• The purpose of the feed line is to get energy from
your station to the antenna.
• Basic feed line types.
– Coaxial cable (coax).
– Open-wire or ladder line.
• Each has a characteristic impedance, each has
its unique application.
Coax
• Most common feed
line.
• Easy to use.
• Matches impedance
of modern radio
equipment (50 ohms).
• Some loss of signal
depending on coax
quality (cost).
Open-Wire/Ladder Line
• Not common today
except in special
applications.
• Difficult to use.
• Need an antenna tuner
to make impedance
match – but this allows a
lot of flexibility.
• Theoretically has very
low loss.
Test and Matching
Equipment
• Proper impedance matching is
important enough to deserve some
simple test equipment as you
develop your station repertoire.
• Basic test equipment: SWR meter.
• Matching equipment: Antenna tuner.
Standing Wave Ratio (SWR)
• If the antenna and feed line
impedances are not perfectly
matched, some RF energy is not
radiated into space and is returned
(reflected) back to the source.
– Something has to happen to this reflected
energy – generally converted into heat or
unwanted radio energy (bad).
SWR Meter
• The SWR meter is inserted in the feed line
and indicates the mismatch that exists at
that point.
• You make adjustments to the antenna to
minimize the reflected energy (minimum
SWR).
Nothing is Perfect
• Although the goal is to get 100% of your radio energy
radiated into space, that is virtually impossible.
• What is an acceptable level of loss (reflected power or
SWR?)
– 1:1 is perfect.
– 2:1 should be the max you should accept (as a
general rule).
• Modern radios will start lowering transmitter
output power automatically when SWR is above
2:1.
– 3:1 is when you need to do something to reduce
SWR.
Antenna Tuner
• One way to make antenna matching adjustments
is to use an antenna tuner.
• Antenna tuners are impedance transformers
(they actually do not tune the antenna).
– When used appropriately they are effective.
– When used inappropriately all they do is make
a bad antenna look good to the
transmitter…the antenna is still bad.
How to use an Antenna
Tuner
• Monitor the SWR
meter.
• Make adjustments on
the tuner until the
minimum SWR is
achieved.
– The impedance of the
antenna is transformed
to more closely match
the impedance of the
transmitter.
Radio Wave Propagation:
Getting from Point A to Point B
• Radio waves propagate by many
mechanisms.
– The science of wave propagation has
many facets.
• We will discuss three basic ways:
– Line of sight
– Ground wave
– Sky-wave
Line-of-Sight
• If a source of radio energy can been
seen by the receiver, then the radio
energy will travel in a straight line
from transmitter to receiver.
– There is some attenuation of the signal
as the radio wave travels
• This is the primary propagation
mode for VHF and UHF signals.
VHF and UHF Propagation
• VHF & UHF propagation is principally line of
sight.
• Range is slightly better than visual line of sight.
• UHF signals may work better inside buildings
because of the shorter wavelength.
• Buildings may block line of sight, but reflections
may help get past obstructions.
• Reflections from a transmitter that is moving
cause multi-path which results in rapid fading of
signal – known as picket fencing.
Ground Wave
• Some radio frequency ranges (lower
HF frequencies) will hug the earth’s
surface as they travel
• These waves will travel beyond the
range of line-of-sight
• A few hundred miles
Ionosphere
• Radiation from the
Sun momentarily will
strip electrons away
from the parent atom
in the upper reaches
of the atmosphere.
– Creates ions
• The region where
ionization occurs is
called the ionosphere.
Levels of the Ionosphere
• Density of the atmosphere
affects:
– The intensity of the
radiation that can
penetrate to that level.
– The amount of
ionization that occurs.
– How quickly the
electrons recombine
with the nucleus.
The Ionosphere – An RF
Mirror
• The ionized layers of the atmosphere
actually act as an RF mirror that reflect
certain frequencies back to earth.
• Sky-wave propagation is responsible for
most long-range, over the horizon
communication.
• Reflection depends on frequency and
angle of incidence.
Sunspot Cycle
• The level of ionization depends on the
radiation intensity of the Sun.
• Radiation from the Sun is connected to
the number of sunspots on the Sun’s
surface.
– High number of sunspots, high ionizing
radiation emitted from the Sun.
• Sunspot activity follows an 11-year cycle.
Technician License Course
Operating Station Equipment
Transmitters, Receivers and
Transceivers
Generalized Transceiver
Categories
•
•
•
•
•
Single Band
Dual Band
Multi-mode
Multi-band
Hand-held (HT)
VHF or UHF FM
VHF/UHFFM
VHF/UHF
HF and VHF/UHF
Single Band Transceiver
• Probably the most common starter rig.
• Operates from 12 volts dc, requires
external power supply.
• Requires an external antenna.
• Can be operated mobile or as a base
station.
• Limited to frequency modulation (FM) and
either 2 meters or 70 cm bands.
• Up to approximately 50 watts output.
Dual Band Transceiver
• Same as the single band transceiver but
includes additional band(s).
• Most common are 2 m and 70 cm bands.
• Could be tri-bander.
• Depending on antenna connectors, might
require separate coax for each band or a
duplexer for single coax.
Multi-Mode Transceiver
• Can be single or dual band.
• Main difference is that these rigs can
operate on all major modes SSB/AM/FM,
CW, Data, RTTY etc.
• More features add complexity and cost.
• Most flexible of the rigs that will allow you
to explore new modes as you gain
experience.
Multi-Band Transceiver
• Covers all bands – can be limited to HF or
can be HF/VHF/UHF.
• Also covers all modes.
• Frequently 100 watts on HF, some power
limitations on high bands (50 watts).
• Larger units have internal power supplies,
smaller units require external power (12 V).
Hand-held (HT) Transceiver
•
•
•
•
Small hand-held FM units.
Can be single band or dual band.
Limited power (usually 5 watts or less).
Includes power (battery) and antenna in
one package.
• An attractive first starter rig – but make
sure it is what you want.
Side-by-Side
Single Band
Dual Band
Multi-mode
Multi-band
HT
Freq Agility
Limited
Medium
Medium
Full
Limited
Functionality
Limited
Limited
Full
Full
Limited
Ease of Use
Easy
Medium
Medium
Difficult
Easy
Programming
Easy
Easy
Medium
Challenging
Easy/Medium
Power
Low
Low
Medium
High
Low
Cost
Low
Modest
High
High
Low
Rig Vocabulary
• We will now go through some jargon and
vocabulary specific to the functions and
controls of a transmitter and receiver.
– This is a way to discuss how to operate
a transceiver.
• These controls, though separate, are
combined in a transceiver.
Transmitter Controls and
Functions
• Main tuning dial (both TX and RX):
– Controls the frequency selection via the
Variable Frequency Oscillator (VFO).
– Could be an actual dial or key pad or
programmed channels.
– Variable frequency step size (tuning
rate, resolution).
– Could have more than one VFO (control
more that one frequency at a time).
Transmitter Controls and
Functions
• Mode selector (both TX and RX multimode rigs).
– AM/FM/SSB (LSB or USB)
– CW
– Data (RTTY)
• Could be automatic based on
recognized band plan.
Transmitter Controls and
Functions
• Microphone controls
– Gain
• How loudly you need to talk to be heard.
– Speech Compressor or Speech Processor
• Compacting your speech into a narrow frequency
range to enhance “punch.”
– Too much gain or compression can cause
problems.
• Splatter
• Over-deviation
• Over-modulation
Transmitter Controls and
Functions
• Automatic Level Control (ALC).
– Automatically limits transmitter drive
(output level) to prevent problems
associated with too much gain or
compression.
• Also can control external power
amplifier operation.
Transmitter Controls and
Functions
• Transmitter on/off
– Push-to-Talk (PTT)
– Voice-Operated Transmission (VOX)
• VOX Gain
• VOX Delay
• Anti-VOX
– Key jack
Transmitter Controls and
Functions
• Microphones (Mic)
– Hand mics
– Desk mics
• Preamplified desk mikes
– Speaker-mics
– Headsets or boom-sets
– Internal mikes
• Speak across the mic, not into the mic.
Transmitter Controls and
Functions
• Morse Keys
– Straight
– Semi-automatic (Bug)
– Electronic keyer, paddle
•
Receiver Controls and
Functions
AF Gain or Volume
– Controls the audio level to the speaker or
headphones.
• RF Gain
– Controls the strength of radio signal
entering the receiver.
– Used to limit (attenuate) very strong local
signals.
– Usually operated in the full-open position.
Receiver Controls and
Functions
• Automatic Gain Control (AGC)
– Automatically limits the incoming signals
during signal (voice) peaks.
• Prevents peaks from capturing the receiver and
limiting reception of lower level portions of the
incoming signal.
– Fast setting for CW.
– Slow settings for SSB and AM.
– Not used in FM because of the type of signal
used in FM.
Receiver Controls and
Functions
• Squelch
– Turns off audio to speaker when signal is
not present.
• Used in FM primarily
– Open – allows very weak signals to pass
through (along with noise).
– Tight – allows only the strongest signals to
pass through.
• Advance the squelch control until the noise
just disappears.
Receiver Controls and
Functions
• Filters
– Band-pass filter
• Used to narrow the width of signal that is passed.
• Can attenuate adjacent interference.
– Notch filter
• Very narrow filter that can be moved over an
interfering signal to attenuate it.
– Noise blanker or limiter
• Limits signal spikes that are frequently associated
with random naturally generated noise.
Receiver Controls and
Functions
• Reception and Transmission Meter.
– In transmit, indicates output power or ALC or
other functions as selected by switch setting.
• In receive - indicates signal strength.
– In “S” units S1 through S9 – S9 is strongest.
– Also have dB over S9 to cover very strong
signals.
Receiver Controls and
Functions
• Receivers can be limited to ham
bands or can cover other parts of
the spectrum.
• General coverage receivers cover a
wide area of the spectrum and can
be used for shortwave listening
(SWL).
Technician License Course
Operating Station Equipment
Repeater Operation and Data
Modes
What is a Repeater?
• Specialized transmitter/receiver
interconnected by computer controller.
• Generally located at a high place.
• Receives your signal and simultaneously
retransmits your signal on a different
frequency.
• Dramatically extends line-of-sight range.
– If both users can see the repeater site.
A Little Vocabulary First
• Simplex
– Transmitting and receiving on the same
frequency.
– Each user takes turns to transmit.
– Is the preferred method if it works.
A Little Vocabulary First
• Duplex
– Transmitting on one frequency while
simultaneously listening on a different
frequency.
– Repeaters use duplex.
– Output frequency – the frequency the
repeater transmits on and you listen to.
– Input frequency – the frequency the
repeater listens to and you transmit on.
Things to Know to Use a
Repeater
• Output frequency.
• Frequency split.
– and therefore the input frequency.
• Repeater access tones (if any).
Repeater Output Frequency
• Repeaters are frequently identified by their
output frequency.
– “Meet you on the 443.50 machine.”
• Here the specific frequency is used.
– “Let’s go to 94.”
• Here an abbreviation for a standard repeater channel
is used meaning 146.94 MHz.
– “How about the NARL repeater?”
• Here the repeater is referenced by the sponsoring
club name.
Repeater Frequency Split
• The split, shifts, or
offset frequencies are
standardized to help
facilitate repeater
use.
• There are + and –
shifts depending on
the plan.
• Different bands have
different standardized
amounts of shift.
Repeater Access Tones
• Sometimes multiple repeaters can be
accessed at the same time
unintentionally.
• To preclude unintentional access, some
repeaters require a special subaudible
tone to be present before the repeater
controller will recognize the signal as a
valid signal and turn on the repeater.
• These tones are called by various names
(depending on equipment manufacturer).
– CTCSS
– PL
– Privacy codes or tones
Repeater Access Tones
• Access tones are usually published along
with repeater frequencies.
• Could also be announced when the
repeater identifies.
– “PL is 123.0”
• Tones are generally programmed into the
radio along with frequency and offset.
Repeater Controller
• Computer that controls the repeater operation.
– Station identification (Morse code or
synthesized voice).
• Same ID requirements as you have.
– Time-out protection.
• Sometimes called the alligator.
• Protects against continuous transmission in
the event of a stuck PTT or long winded
hams.
– Courtesy tone – repeater time-out timer reset.
Data Modes
• Connecting computers via ham radio.
– Some systems use radio to connect to
Internet gateways.
• The bulk of the work is done by
specialized modems or computer
software/sound card.
– Terminal Node Controller (TNC).
– Multiple Protocol Controller (MPC).
TNC – MPC
• Provide digital interface between
computer and radio.
– Package the data into proper format.
– Convert digital data into audio tones
representing 1s and 0s of digital data.
– Send/receive tones to transceiver.
– Control the transceiver.
Data Station Setup
Technician License Course
Operating Station Equipment
Practical Antennas
The Dipole
• Most basic antenna.
– Two conductive, equal length parts.
– Feed line connected in the middle.
• Total length is ½ wavelength (1/2 l ).
• Length (in feet) = 468 / Frequency (in MHz).
The Dipole
The Ground-Plane
• Simply a dipole that is oriented
perpendicular (vertical to the Earth’s
surface).
• One half of the dipole is replaced by the
ground-plane.
– Earth
– Car roof or trunk lid or other metal surface.
– Radial wires.
• Length (in feet) = 234 / Frequency (in MHz).
The Ground-Plane
Loop Antennas – Dipole
Variations
• Quad
• Delta
• Horizontal
Directional (Beam)
Antennas
• Beam antennas focus or direct RF energy
in a desired direction.
– Gain
– An apparent increase in power in the
desired direction (both transmit and
receive).
• Yagi (rod-like elements – TV antennas).
• Quad (square wire loop elements).
Directional (Beam)
Antennas
Directional (Beam)
Antennas
• All beam antennas have parts called
elements.
– Driven element connected to the radio
by the feed line.
– Reflector element is on the back side.
– Director element is on the front side
toward the desired direction.
Coax Feed Lines
•
•
•
•
•
RG-58
RG-8
RG-213
RG-174
Hardline
Coax Connectors
•
•
•
•
SO-239/PL259
BNC
N
SMA
Feed Line Devices
•
•
•
•
•
•
Balun
Duplexer
Antenna switches
SWR meter
Antenna analyzer
Antenna tuners
Antenna Supports
• Trees.
• Towers or masts.
• Covenants and
antenna
restrictions must
be considered.
Technician License Course
Operating Station
Equipment
Power Supplies and Batteries
Handheld Transceivers
RF Interference (RFI)
Power Supplies
• Most modern radio equipment runs from 12
volts dc.
• Household current is 120 volts ac.
• Power supplies convert 120 volts ac to 12
volts dc.
– 13.8 volts dc is the common voltage you will see.
– This is the charging voltage for motorized
vehicles.
Power Supply Ratings
Voltage and Current
• Continuous duty – how much current can
be supplied over the long term.
• Intermittent duty – how much surge
current can be supplied over the short
term.
• Regulation – how well the power supply
can handle rapid current changes.
Types of Power Supplies
• Linear:
–
–
–
–
Transformers
Heavy (physically)
Heavy duty current
Expensive
• Switching:
–
–
–
–
Electronics instead of transformers
Light weight and small
Not as robust
Less expensive
Inverters and Generators
• Inverters convert dc into ac.
– Square, triangle, sine-wave inverters.
• Generators create ac.
– Gas powered.
– Various voltage and current ratings.
– Special precautions.
Batteries
• Create current through a chemical reaction.
– Made up of individual cells (approximately 1.5
volts per cell) connected in series or parallel.
• Battery types.
– Disposable.
– Rechargeable.
– Storage.
• Power capabilities rated in Ampere-hours.
– Amps X time.
Battery Charging
• Some batteries can be recharged, some cannot.
• Use the proper charger for the battery being
charged.
• Batteries will wear out over time.
• Best if batteries are maintained fully charged.
– Over-charging will cause heating and could
damage the battery.
• Some batteries (lead-acid) will release toxic
fumes during charging so require ventilation.
Handheld Transceivers
• Single, dual and multi-band versions (with
increasing cost and complexity).
– Some have expanded receiver coverage
(wide-band receive).
• Very portable and self-contained.
– Internal microphone and speaker.
– Rubber duck antenna.
– Battery powered.
Nice to have handheld
accessories
•
•
•
•
•
Extra battery packs.
Drop-in, fast charger.
Extended antenna.
External microphone and speaker.
Headset.
Radio Frequency Interference
(RFI)
• Unwanted, unintentional signals
from some electronic device that
interferes with radio wave reception.
• You can prevent creating RFI by
operating your transmitting
equipment properly.
• Filters
RFI Mitigation
– Filters attenuate (reduce) interfering
signals – but do not totally eliminate
them.
• High-pass –generally on the receive
side.
• Low-pass – generally on the transmit
side.
• Band-pass – used within most radio
equipment.
Types of RFI
• Direct detection – offending signals get
into the electronics circuits to cause
interference.
• Overload – strong signal that overwhelms
the weaker, wanted signal.
• Harmonics – even multiples of the
offending signal that coincide with the
wanted signal.
Cable TV Interference
• Usually the result of broken shielding
somewhere in the cable.
– Loose connections.
– Broken connections.
– Corroded connections.
• Usually solved by proper cable maintenance by
cable supplier.
– If the subscriber is a legitimate subscriber.
Noise Sources
• Electrical arcs (motors, thermostats,
electric fences, neon signs).
• Power lines.
• Motor vehicle ignitions.
• Motor vehicle alternators.
• Switching power supplies.
• Computers, networks, and TV sets.
Dealing with RFI
• Make sure you operate your
equipment properly.
• Eliminate interference in your own
home first.
Dealing with RFI
• Take interference complaints seriously.
• Make sure that you’re really not the cause
(demonstrate that you don’t interfere
within your own home).
• Offer to help eliminate the RFI, even if you
are not at fault.
• Consult ARRL RFI Resources for help and
assistance.
What the Rules Say
• RFI from and to unlicensed devices is the
responsibility of the users of such
devices
• Bottom line – If your station is operating
properly, you are protected against
interference complaints
• BUT – Be a good neighbor because they
may (probably) not be familiar with Part
15 rules and regulations
Technician License Course
Communicating with other hams
Making Contact
The Typical Telephone
Conversation
• Greeting.
• Identify who is participating.
• Exchange information, generally
taking turns.
• Salutations.
• End the conversation.
The Typical Ham Contact
(QSO)
• Greeting.
• Identify who is participating.
• Exchange information, generally
taking turns.
• Salutations.
• End the conversation.
Radio Manners
• Speak clearly and distinctly.
• Giant party line-topics accordingly.
• Shared use of frequencies.
Radio Manners
• Signal Reports
• Power level
• Location
• RST
– Readability (1-5)
– Strength (1-9)
– Tone (CW only 1-9)
– “Your RST is 58”
Radio Manners
• Ham radio is self-regulated.
– ARRL Official Observers.
• Logging
• QSL’s
– Awards Program
Band Plans
• A band plan is a way of organizing
the use of radio frequencies.
– Formal and legal plan.
– Informal – gentleman's agreement.
Operating Dos and Don’ts
•
•
•
•
•
•
Use of CQ versus “monitoring.”
Use of phonetics.
Taking turns and breaking-in.
Station identification.
Using repeaters.
Using simplex.
Repeater/Digital/Internet
•
•
•
•
Echolink
IRLP
WinLink
D-Star
Communicating with other
Amateurs
Nets and Emergency
Communications
Nets
• Net is short for “Network.”
– Evolved over the years of radio to share
and exchange information in an
organized and efficient way with
accuracy.
• Social Nets.
• Traffic Nets.
• Emergency and Public Service Nets.
Traffic Nets
• Traffic refers to formal messages
that are relayed via ham radio.
• Formal structure to ensure accuracy
– National Traffic System (NTS).
– Procedures.
– Accountability.
Emergency and Public Service Nets
• Public Service Nets – training for
emergency nets.
– Training for ham operators as well as supported
emergency managers.
• Emergency Nets.
Net Structure
• Net Control Station (NCS).
– Traffic cop that controls the flow of information.
• Check-in and check-out procedures.
• Communications discipline vital.
– Learn and follow procedures.
– Speak only when directed, and only to whom directed.
– Follow through with your commitments.
Supporting Emergency Operations
• One of the pivotal reasons for the existence
of Amateur Radio.
• You will be licensed communicators.
– Get involved and use what you have learned.
• Know where you fit in the overall
emergency management team.
EMCOMM Tips
• Don’t become part of the problem.
• You are a communicator, not a decision or policy
maker.
• Don’t give out unauthorized information.
• Know your abilities and limitations-keep yourself
safe.
• Follow radio discipline and net procedures.
• Protect personal information-ham radio
communications is a ‘party line.”
EMCOMM Training
• If you are going to participate in
EMCOMM: get training.
• Actively participate in EMCOMM
activities.
– Nets.
– Public service activities.
– Attend community meetings and get involved
in your community.
• Take EMCOMM courses.
– ARRL EMCOMM Courses 1, 2, and 3.
– NIMS and FEMA courses.
EMCOMM Organizations
• Radio Amateur Civil Emergency
Service (RACES).
– Supports civil emergencies.
– National in scope.
• Amateur Radio Emergency Service
(ARES).
– Local and regional in scope.
– Supports non-governmental agencies.
Emergency Declarations
• FCC may declare a Temporary State of
Communications Emergency.
– Includes details of conditions and rules to be
followed.
– Specifics communicated through web sites
and ARRL bulletins, the NTS, and on-the-air.
– Avoid operating on restricted frequencies
unless engaged in relief efforts.
Making and Answering Distress
Calls
•
•
•
•
•
•
•
Rule number one – speak in plain language!
Mayday (voice); SOS (Morse code) are flags
Identify
Give location
State the situation
Describe assistance required
Provide other important information
Tactical Communications
• Tactical Call Signs.
– Facilitate communications.
– Location or function specific.
– Transcends operator changes.
• FCC ID rules still apply.
Emergency Equipment
• “Go-kits”
– Portable ham radio equipment.
– Emergency power sources.
– Personal survival supplies and
equipment.
Physical Safety
• Mobile Installations.
– Secure all equipment.
– Location, location, location.
• Antenna installation.
– Clear of trees and power lines.
– If it falls it won’t hit anyone or cross
power lines.
• Tower climbing considerations.
Technician License Course
Communicating with other
hams
Special Modes and Techniques
Common Awards
• DXCC
– Contacting 100 different countries
and/or entities.
• WAS
– Contacting 50 states.
• VUCC
– Contacting 100 grid squares on
VHF/UHF.
Special Events
• Special Event stations are set up to
commemorate some significant local
event.
• Usually stations are demonstration
stations set up for public display.
• Commemorative certificates are
awarded for contacting the stations.
Contests
•
•
•
•
Field Day
Sweep Stakes
QSO Parties
CQ DX Contest
• Contest Corral
Amateur Satellites
• OSCAR
– Orbiting Satellites Carrying Amateur
Radio.
• Modes
– FM
– Analog (SSB and CW)
– Digital
• International Space Station.
What satellite contacts sound
like
(left-click to hear the satellites)
• FM contact
• SSB contact
• ISS contact
Digital Techniques
• Radio Teletype (RTTY).
– Single letters sent as they are typed.
• AMTOR and PACTOR.
– Small grouping of letters sent with error
correction.
• Packet and Packet Networks.
– Groups (packets) of collected data sent with
error correction and automatic forwarding.
• PSK31.
– Different modulation technique.
•
•
•
•
•
What Digital sounds like
(left-click to hear the
modes)
RTTY
AMTOR
PACTOR
PACKET
PSK31
Digital Mode Modulation
Techniques
• Digital means two states: ON and OFF.
– Digital code is a sequence of ON and OFF
states or 1’s and 0’s.
– The letter “A” is 0100 0001 (65 decimal).
• When two audio tones are used to represent the
ON and OFF states it is called Frequency Shift
Keying (FSK).
• When changing phase states are used to
represent ON and OFF states it is calls Phase Shift
Keying (PSK).
APRS
• Automatic Position Reporting
System (APRS).
• Packet based Global Positioning
System (GPS) position reporting.
– Uses a packet-like digipeater system to
create an APRS network (also Internet
connected).
Other Special Modes
(left-click to hear SSTV)
• Video
– Slow Scan TV (SSTV).
• Sending snap-shot
pictures.
– Amateur TV (ATV).
• Similar to
commercial TV
imagery.
• What SSTV sounds like:
Other Special Modes
• Meteor Scatter.
– Reflecting radio signals off of the
ionized trail left by meteors.
• Moonbounce.
– Reflecting radio signals off the surface
of the moon.
Technician License Course
Licensing Regulations
Licensing Authority
• Federal Communications Commission
– Located in Gettysburg, PA.
• Amateur Radio operations covered by
FCC rules published in Part 97 of Title 47
– Code of Federal Regulations.
– Use Part 97 for short
Why is There Ham Radio?
1.
2.
3.
4.
5.
Providing emergency communication capability.
Advancement of the art and science of radio.
Advance communication and technical skills of
radio.
Provide a trained reservoir of operators,
technicians, and electronics experts.
Promote and enhance international goodwill.
Some Definitions
• Amateur Service – no pecuniary interest
(private and personal, non commercial).
• Amateur Operator – the person holding
authorization (license) to operate an
Amateur Radio station.
• Amateur Station – equipment capable of
transmitting on frequencies authorized
for Amateur Service.
The Amateur License
• No age limit or citizenship restrictions.
– One exception – foreign representatives.
• License actually contains two parts.
– Operator License.
– Station License (the Call Sign).
• Three levels of operator privileges: Technician,
General, Amateur Extra.
Examinations
• Preparation
– Study the content.
– Question Pool.
• Taking the exam
– Proctored exam.
– Multiple choice.
– What the fee pays for.
• Volunteer Examiners (VEs).
• Volunteer Examiner Coordinators (VECs).
License Term and Renewal
• The license is free and good for 10 years.
– Renewable within 90 days of the
expiration date.
• Some personal identification information
is required.
– Tax ID (Social Security number).
– Current Mailing Address.
– Federal Registration Number (FRN).
Responsibilities of
Licensure
• Prevent unauthorized operation of your
station.
• Provide personal information as required
– keep a current mailing address on file.
• Make your station available for FCC
inspection upon request.
FCC ULS Web Site
• www.wireless.fcc.gov/uls
– Register for on-line access to your
license information.
– Make changes to your address and
other information.
– Renew your license.
– Search for other station information.
Technician License Course
Operating Regulations
Most Important Information
• Control operator responsibilities.
– The FCC’s primary concern is that
transmissions are made only under the
control of a licensed operator.
• Control operator – the licensed amateur
responsible for making sure
transmissions comply with FCC rules.
Control Operator
• Must have a valid FCC issued Amateur Radio
license.
• Station must operate within the authorization
of the control operator’s license.
• Control operator must be present at the
control point of the station (the on-off switch)
or remotely connected by a control link.
Guest Operations
• Non-licensed people can use a ham radio
but only when a control operator is
present.
– The control operator is solely
responsible for station operation.
• Licensed guests can use the ham radio.
– In this case, both the control operator
and the guest ham are responsible for
station operation.
Station Identification (ID)
• Normal ID.
– Say your call sign every ten minutes
during and at the end of the contact
(QSO).
• Use of Tactical Call Signs.
– Does not substitute for proper station
ID.
• Ham Guests.
ID Rules Apply
• Repeaters must also ID using the same 10
minute rule.
– Can be voice or CW (at 20 WPM or
less).
• Satellites and ISS have special rules.
• Special event calls.
– Normal club call or control operator call
given once per hour.
Interference
• QRN
– Natural interference (thunderstorms).
– Man-made (appliances and power lines).
• QRM
– Interference from nearby signals.
– Other hams or other users of the
frequencies.
• Control operators should prevent interfering
with other users of the frequencies.
Preventing Interference
• Use common sense and courtesy.
• Keep equipment in proper operating
order.
• No one owns a frequency; be a good
neighbor and share.
• Yield to special operations and
special circumstances.
Interference
• Harmful
– Interference that is disruptive but not intentional.
– Deal with it as best you can and help others avoid
harmful interference.
• Willful
– Intentionally causing interference.
– This becomes a legal and law enforcement issue.
– This is rare and there are procedures to deal with this
(ARRL Official Observers can help).
Third-Party
Communications
• Third-party means that a non-ham is
involved in communication via ham radio.
– Could be actually speaking on the air.
– Could be passing a message on behalf of the
non-ham.
• Two situations – different rules.
– Within the US.
– Communication that crosses international
borders.
Third-Party within US
• No special rules.
• Just make sure the message is noncommercial in nature.
Third-Party Across Borders
• Make sure that third-party agreement exists.
– Check for current third-party agreements from
FCC sources if in doubt.
– You might be surprised at the countries that
we do not have third-party agreements with.
• During station identification say both stations’
call signs.
Remote and Automatic
Control
• Some stations, repeaters and beacons
operate without the control operator
physically present at the control point.
• These stations must still comply with
control operator stipulations.
– Local.
– Remote.
– Automatic.
Prohibited Transmissions
• Unidentified transmissions .
– (not giving your call sign)
• False or deceptive signals.
– (using someone else’s call sign)
• False distress or emergency signals.
– (fake calls for help)
• Obscene or indecent speech.
– (up to interpretation)
• Music.
No Business
Communications
• You can not make a profit through
the use of transmissions made via
ham radio.
• The exception is teachers using ham
radio in their classrooms.
No Encrypted
Transmissions
• Encryption involves encoding information
for transmission that must be decoded
upon reception to interpret the
information.
• This is okay if:
– Coding is open source.
– Intention is not to hide the message or
deceive.
No Broadcasting
• Broadcasting is sending one-way transmissions
with no expectation of getting a response.
– News
– Music
• Exceptions:
– Code practice.
– Ham radio related bulletins.
– Re-transmission of ISS communications.
Special Circumstances
• Ham communication is generally intended
for hams.
• Emergencies and critical situations
create special circumstances.
• Special commemorative events may
qualify as special circumstances.
• Normal rules return when the situation
returns to normal.
Technician License Course
Electrical and RF Safety
Electrical Safety
• Avoiding contact is the most effective way
of practicing electrical safety.
• Most modern radio equipment uses
currents that are not as dangerous as
older equipment but precautions still must
be taken.
Electrical Injuries
• Shocks.
• Burns.
• Even small
currents can
cause problems.
Mitigating Electrical
Hazards
• TURN OFF POWER WHEN WORKING INSIDE
EQUIPMENT!!!!!!
• MAKE SURE EQUIPMENT IS PROPERLY
GROUNDED AND CIRCUIT PROTECTED!!!!!
• If power is required:
–
–
–
–
–
Remove jewelry.
Avoid unintentional touching of circuitry.
Never bypass safety interlocks.
Capacitors hold a charge even when power is off.
Storage batteries are dangerous when shorted.
Responding to Electrical
Injury
• REMOVE POWER!
– Have ON/OFF switches and circuit
breakers clearly marked.
• Call for help.
• Learn CPR and first aid.
Electrical Grounding and Circuit
Protection (in the home)
• Make sure your home is “up to code.”
• Most ham equipment does not require
special wiring or circuits.
– Use 3-wire power cords.
– Use circuit breakers, circuit breaker
outlets, or Ground Fault Interrupter
(GFI) circuit breakers.
– Use proper fuse or circuit breaker size.
– Don’t overload single outlets.
Electrical Grounding and
Circuit Protection (in the car)
• Car batteries hold lots of energy –
shorting a battery could cause a fire.
• Special requirements for safe car wiring:
– Fuse both positive and negative leads.
– Connect radio’s negative lead to where the
battery ground connection is made.
– Use grommets or protective sleeves to
prevent wire chafing.
– Don’t assume all metal in the car is grounded;
modern cars are as much plastic as metal.
RF Safety
• Proper Grounding.
• Important not only for protection of
equipment and people, any wires
connected to the radio potentially
becomes part of the antenna and can
radiate RF where it is not intended.
Lightning Safety
• Antennas are not struck any more
frequently than trees or tall structures.
• Ground all antennas.
• Use lightning arrestors.
• Disconnect antenna cables and power
cords during storms.
• Disconnect telephone lines from
computer modems.
RF Exposure
• Exposure to high levels of RF can cause
problems.
• If equipment is operated properly, RF
exposure is minimal and not dangerous.
• Problem is RF energy can heat body
tissues.
– Heating depends on the RF intensity
and frequency.
RF Intensity
• Power Density
– Actual transmitter power.
• Higher power, higher risk.
– Antenna gain and proximity.
• Beam antennas focus available energy.
• Being physically close or standing in the beam
direction increases risk.
– Mode duty cycle.
• The more time the power output is at high level, the
higher the risk.
Antenna Proximity
• Controlled Environment.
– You know where people are standing in
relation to your antenna and you can do
something about it.
– More power is allowed because you can make
adjustments if needed.
• Uncontrolled Environment.
– You have no idea, or have no control of people
near your antenna.
– Less power is allowed because you have to
assume the worse case scenario.
Mode Duty Cycle
• The more time the
transmitted power
is at high levels,
the greater the
duty cycle, and the
greater the
exposure risk.
RF Exposure and
Frequency
• When body parts act like antennas, those
parts absorb RF energy at certain
frequencies (wavelengths) more
efficiently and increase risk.
• RF exposure risk varies with frequency.
– More caution is dictated at some
frequencies more than other
frequencies.
RF Exposure and
Frequency
Physical Safety
• Mobile Installations.
– Secure all equipment.
– Location, location, location.
• Antenna installation.
– Clear of trees and power lines.
– If it falls it won’t hit anyone or cross
power lines.
• Tower climbing considerations.
W5YL THIBODAUX AMATEUR RADIO CLUB
TECHNICIAN LICENSE CLASS.
This concludes the Technician Class Amateur Radio License
course. If you have any questions after the class, please see
the instructor, or any of the other Amateur Radio operators in
the room. They are designated by the tags stating their
names and call signs.
Thank you all for participating. Now lets get Communicating!