Amateur Radio Basic Study Guide Complete.
Amateur Radio Basic Qualifications Manual
amateur radio
basic qualification
Amateur Radio Basic Qualifications Manual
(1) Licensing Requirement (S-4 Act and S-11 Regulations)
(2) Sanctions (S-10)
(1) Presentation of Certificate, Change of Address
(2) Compliance with ITC (S-10)
(3) Obscene Language (S-25)
(4) Confidentiality (S-9 Act and S-32 Regulations)
(1) Frequencies (S-51)
(2) Station Identification (S-57)
(3) Communication Content (S-47)
(4) Bandwidth (S-53)
(5) Power (S-58)
(6) Interference (S-5 Act, S-25 S-56 Regulations)
(7) Measurements (S-61)
(8) Restrictions on the Number of Amateur Radio Stations (S-45)
(9) Equivalency of Certificates (S-44 Regulations)
(10) Emergency Communications (S-SO Regulations)
(11) Operation of Amateur Stations
(12) ITU Regions
(13) Miscellaneous
(1) Emergency Communications
(2) Callsigns
(1) Transceiver
(2) Microphones
(3) Low Pass Filter
(4) Standing Wave Meters
(5) Antenna Switches
(6) Dummy Load
(7) Frequency Counter
(8) Ammeter
(9) Voltmeter
(10) Oscilloscope
Amateur Radio Basic Qualifications Manual
(1) Conductors / Insulators
(2) Electromotive Force (E) / Direct Power (P)
(3) Alternating Current (AC) / Direct Current (DC)
(4) Resistance/Impedance
(1) Capacitors
(2) Inductors (chokes)
(3) Transformers
(4) Vacuum Tubes
(5) Semiconductors
(1) Introduction
(2) Continuous Wave (CW)
(3) Amplitude Modulation
(4) Single Sideband
(5) Frequency Modulation
(6) Power Amplifiers
(1) Introduction
(2) CW and SSB Receivers
(3) FM Receivers
(1) Low Pass Filters
(2) High Pass Filters
(3) Band Pass and Band Reject Filters
(1) Front End Overload
(2) Audio Rectification
(3) Harmonics
(4) Parasitic Oscillations
(5) Intermodulation
(1) Sky Wave
(2) The Sun and the Ionosphere
(3) Ionospheric Layers
(4) Absorption
(5) Attenuation
(6) Fading
(7) Other Atmospheric Effect
(8) Skip Zone
Amateur Radio Basic Qualifications Manual
(1) General Description
(2) Dipoles
(3) Vertical Antennas
(4) Yagis
(5) Quads and Loops
(6) Antenna Measurements
Dummy Loads
(1) Parallel Lines
(2) Coaxial Cable
(3) Baluns
A. Introduction
B. Starting A Conversation On Vhf Fm
A Basic Contact
(1) Variations in Procedure
(2) Looking for Anyone to Contact
(3) Changing to a Different Frequency
(4) Marginal Repeater Reception Conditions
(5) Joining a Conversation in Progress
(6) In an Emergency
C A conversation in Morse code on HT
D Identification
E Simplex, Duplex and Band Plans
F Topics of Discussion and Common Sense
G Checking Into Nets
(1) Contacting another station you just heard
(2) Looking for someone you have not heard
(3) Announcing your presence
H Telephone Patches
I. Standard Phonetic Alphabet
J Common Abbreviations
K Digital Modes
L Industry Canada
Amateur Radio Basic Qualifications Manual
Figure 1 Amateur Radio Station
Figure 2 Conductivity
Figure 3 Power
Figure 4 AC/DC
Figure 5 Resistance
Figure 6. Impedence
Figure 7 Circuit
Figure 8 Ohms Law
Figure 9 Amperes
Figure10 Parallel Resistor
Figure 11 Single Resistor Connected to a 12 V Source
Figure 12 Resistors In Parallel
Figure 13 Resistors in Series
Figure 14 Capacitor in Series
Figure 15 Capacitor in Parallel
Figure 16 Inductors In Series
Figure 17 Inductors in Parallel
Figure 18 Ratio of voltages and currents in the primary and secondary
Figure 19 Diode, Triode, Pentode
Figure 20 Diodes
Figure 21 Bipolars in NPN and PNP polarities
Figure 22 Regulated Power Supply
Figure 23 The effect of filter capacitors on power supply ripple
Figure 24 Carrier Oscillator
Figure 25 CW Transmitter
Amateur Radio Basic Qualifications Manual
Figure 26 Amplitude Modulation
Figure 27 Single Sideband Transmitter
Figure 28 Frequency Modulation Transmitter
Figure 29 Tank Circuit
Figure 30 Single Sideband and CW receiver
Figure 31 Frequency modulated receiver
Figure 32 Ionosphere
Figure 33 Skip zone
Figure 34 Dipole
Figure 35 Marconi
Figure 36 Yagi-Uda parasitic array
Figure 37 Cubical Quad Antenna
Figure 38 Ladder Line
Figure 39 Coax Cable
Amateur Radio Basic Qualifications Manual
The Amateur Radio Service is governed by three pieces of legislation:
 Radiocommunication Act
 Regulations
 International Telecommunications Union Radio Regulations
Extracts from these acts and regulations have been summarized by Communications
Canada in RIC-1, RIC-2, RIC-3 and RIC-9.
Acts differ from regulations. Usually the acts contain general information, while the
regulations are more precise and detailed. The Radiocommunication Act is brief and
lacking in any detail, however the regulations contain the bulk of the rules. The Act dictates
the requirement to obtain a license and the penalties for failing to do so. The regulations
encompass the rules of the hobby, including third party traffic, bandwidth, permitted
frequencies, communications content, power limits and much more. Consequently, while
section B will briefly discuss the Act, the majority of this section will be dedicated to a
detailed description of the regulations.
For the purposes of the exam, the only relevant sections are 4, 9 and 10. These sections set
out the licensing requirement and penalties.
(1) Licensing Requirement (S-4 Act and S-11 Regulations)
The Act states that you may not install, operate, or even possess a device capable of
transmitting electromagnetic waves lower than 3,000 GHz, without being licensed in
accordance with the Act. No reference is made to power limits (i.e. it does not matter how
little power you transmit). If you transmit, or even have equipment capable of transmitting
at a frequency of less than 3,000 GHz, you must be personally certified. The station where
the equipment is physically located must have a station license unless exempt. A legislative
and regulatory circular issued February 1, 1991 by Communications Canada (now Industry
Canada) proposes a number of changes to the General Radio Regulations, Part II
Significant additions include section 6(1), which provides numerous exemptions from the
licensing requirements for communications devices such as cordless phones and cellular
phones. If both you and the station are licensed, an unlicensed individual to use the station,
as long as you remain in control of the station and the individual does not use the station in a
manner exceeding the privileges granted to you. For instance, if you have the basic
certification, the unlicensed individual may not operate the station as if he were an advanced
operator (section 43 of the Regulations).
* Written by Sid Kemp, B. Comm., MSc., LI.B.,Barrister and Solicitor, VE7MT
Amateur Radio Basic Qualifications Manual
You can obtain personal certification after passing the Amateur Operator's Certificate with
Basic Qualification exam. This level has several restrictions placed on it by Section 46 of
the regulations. These restrictions are as follows:
 The Basic Certificate will restrict you to transmitting frequencies above 30 MHz.
 Also with the Basic Qualifications, the transmitter power that your station can emit
is substantially lower than what the Advanced Qualification will allow.
 As a person with the Basic Qualification you may not hold a license for a
repeater or a club station.
 You must use commercially manufactured equipment.
These restrictions are all removed upon obtaining the advanced and 5 wpm Morse code
certification. You should note that there is no minimum age or nationality restrictions;
anyone may obtain an Amateur Certificate upon passing the exam. As well, your
certificate is valid for your lifetime and need not be renewed.
(2) Sanctions (S-10)
The consequences of not having a Amateur Radio Operator's Certificate are set out in
Section 10 of the Act. A maximum fine of $5,000.00, or imprisonment for a period of up
to one year, or both is outlined in the Act. The majority of prosecutions under Section 4.1
of the Act have resulted in fines and the confiscation of the equipment. In R. v. Eles, the
accused was sentenced on April 4, 1990 to three months in jail for operation of a stolen
radio transmitter used to make unauthorized transmissions to pilots to redirect air traffic
at a local airport near Oliver, B.C. In R. v. Johal the accused was convicted under
Section 4.1 of the Act for the unlicensed operation of a radio and for causing interference
with a commercial taxi-cab station. The accused was fined five hundred dollars in
September 1991 and the equipment was confiscated.
The Radio Regulations may be divided into those of general application and those
pertaining to the amateur service. The former applies equally to commercial stations, such
as the CBC and the police, and to amateurs. The latter are tailored and applies only to
(1) Presentation of Certificate, Change of Address
Industry Canada Regulations require they be notified of any change of your radio station
address within thirty days. Duly appointed radio inspectors may require you to present
your radio authorization, or copy thereof, within forty-eight hours.
Amateur Radio Basic Qualifications Manual
(2) Compliance with ITC (S-10)
Radio waves do not respect national boundaries. Consequently, it's necessary to have
agreement amongst most nations on various matters as frequency allocations. This section
should be considered -together with Sections 48 and 49 of the Regulations, which deal
with banned countries and countries for which third party traffic is not permitted.
(a) Third Party Traffic (S-49)
While no definition is provided in the Act, it can be assumed that third party traffic
are messages sent to a non-amateur via an amateur station. The most common
example of this is done by connecting a telephone (with a device called a "phone
patch"), to a radio. The postal and telecommunications authorities in a number of
countries have objected to this practice. It is not necessary for the purposes of this
exam to know which countries permit third party traffic; but for future reference the
list is contained in RIC-3.
Note: You should be aware of the exception contained in Section 49(2) of the
Regulations. Messages from Canadian Forces Affiliate Radio System (CFARS)
stations, or from the United States Military Affiliate Radio System (MARS)
stations, are not considered to be third party traffic.
Obscene Language (S-25)
You may not broadcast superfluous signals, you may not interfere with another station,
and you may not use obscene words or language. What is considered to be obscene is an
unsettled area of law that has troubled Canadian courts for years. Recent decisions
considered the "community standard" when determining whether something was obscene.
This section also governs television and radio stations; the community standard in amateur
radio is arguably much higher and "swearing" would be considered obscene.
Confidentiality (S-9 Act and S-32 Regulations)
Under Section 9 of the Act, a broad prohibition exists which makes illegal the divulgence
of any radiocommunications one hears. Certain exemptions exist to this prohibition. The
wording of Section 9 expressly exempts public broadcasting 2. Section 32 of the
Regulations sets out further exemptions. Most notable is the exemption relating to the
Amateur Radio Service which states that all amateur transmissions may be divulged to
another person. Distress communications are also exempt. If required to do so, you may
also divulge radiocommunications heard to a court or radio inspector. In summation, it is
not an offence to hear any radio communications; any offence lies in divulging or
making use of any radiocommunication heard which is not specifically exempted.
(1) Frequencies (S-51)
The frequencies that amateurs are permitted to transmit on are specified under Section 51
as those set out in Schedule H which are as follows:
(2) With the exemption of public broadcasters, you may tell others what you hear or see on CBC.
Amateur Radio Basic Qualifications Manual
Frequency Band
1.800 to 2.000 MHz
3.500 to 4.000 MHz
7.000 to 7.06MHi
10.100 to 10.150 MHz
14.000 to 14.350 MHz
18.068 to 18.168 MHz
21.000 to 21.450 MHz
24.890 to 24.990 MHz
28.000 to 29.700 MHz
50.000 to 54.000 MHz
144.000 to 148.000 MHz
220.000 to 225.000 MHz
430.000 to 450.000 MHz
902.000 to 928.000 MHz
1.240 to 1.300 GHz
2.300 to 2.450 GHz
3.300 to 3.500 GHz
5.650 to 5.925 GHz
10.000 to 10.500 GHz
24.000 to 24.050 GHz
24.050 to 24.250 GHz
47.000 to 47.200 GHz
75.500 to 76.000 GHz
76.000 to 81.000 GHz
142.000 to 144.000 GHz
144.000 to 149.000 GHz
241.000 to 248.000 GHz
248.000 to 250.000 GHz
B and 5
B and 5
13 and5
B and 5
B and 5
B and 5
B and 5
B and 5
B and 5
6 kHz
6 kHz
6 kHz
I kHz
6 kHz
6 kHz
6 kHz
6 kHz
20 kHz
30 kHz
30 kHz
100 kHz
12 MHz
12 MHz
Not Specified
Not Specified
Not Specified
Not Specified
Not Specified
Not Specified
Not Specified
Not Specified
Not Specified
Not Specified
Not Specified
Not Specified
Not Specified
Not Specified
160 metres
80 metres
40 metres
30 metes
20 metres
17 metres
15 metres
12 metres
10 metres
6 metres
2 metres
1.25 metres
70 centimetres
"B" refers to the Radio Operator's Certificate with Basic Qualification
"5" refers to Morse code 5 words per minute Qualification.
You should study this chart, carefully noting where an amateur radio operator with a
basic qualification may operate (above 30 MHz). As well, you should note the
relationship between frequency and metres and be able to name the frequency and metres
for each band. For example, you should know that the frequency of the 10 metre band is
28 MHz.
Amateur Radio Basic Qualifications Manual
Station Identification (S-57)
You must state your call sign at the beginning and at the end of each exchange of
communication. This does not mean you must identify yourself every time you release
the microphone. "Exchange" implies a much longer period of time. In effect you identify
again when you finish a conversation with a station. However, if you are still talking to
the station after 30 minutes has elapsed from the last time you stated your call sign, then
you are required to identify again at the 30 minute mark. Identification must be in
English or French.
(3) Communication Content (S-47)
You may only communicate with another amateur station (i.e. no talking with the police,
etc.). You cannot develop your own secret code or cipher and use it to communicate with
your friend. As well, you may not play disc jockey. No music and no commercially
recorded material may be retransmitted over an amateur radio. A related section is
Section 62 of the Regulations which makes it clear that you shall not demand nor accept
remuneration (i.e. money) for any communication. This is a hobby and as a consequence
you may not turn it into a commercial venture. There are commercial frequencies available
at a considerably higher fee to dispatch taxicabs.
Bandwidth (S-53)
Section 53 stipulates that the bandwidth of the signal you broadcast must be in accordance
with Schedule II as set out above. Simply put, bandwidth is the portion of the band that your
transmitted signal occupies and thus renders it useless for anyone nearby to share. For the
purposes of the exam you should memorize this Schedule. In general, signals below 25 MHz
shall not exceed 6 kHz bandwidth except for the 10.1-10.15 MHz band which is set at a
maximum of 1 kHz. A bandwidth of 1 kHz effectively restricts the band to CW and other
narrow forms of transmission. On 28.0-29.7 MHz, you are permitted 20 kHz. On 50 MHz and
144 MHz you are permitted a bandwidth 30 kHz. On 220 MHz it jumps up to 100 kHz and on
430 MHz it jumps to 12 MHz for amateur television.
Power (S-58)
This section sets out the maximum power for both amateurs with the Basic Qualification
and Advanced Qualification. Advanced amateurs are allowed more power than the basic
license holders. Transmitter power is expressed in several ways.
Where "Transmitter Power" is expressed as direct current input power, you are permitted
as an amateur with Basic Qualification to use a maximum of 250 watts (Advanced
Qualification, 1 kW) to the anode or collector circuit of the transmitter stage which
supplies radio frequency energy to the antenna.
Where "Transmitter Power" is expressed as radio frequency output power measured
across an impedance matched load, you are permitted as an amateur with Basic
Qualification either 560 watts peak envelope power (Advanced Qualification 2250 watts)
for transmitters producing any type of single sideband emission or 190 watts carrier power
(Advanced Qualification 750 watts) for transmitters producing any other type of emission.
Amateur Radio Basic Qualifications Manual
Interference (S-5 Act, S-25 S-56 Regulations)
Section 5 of the Act specifies that the minister (i.e. Industry Canada employees) may, where
a station is causing harmful interference, order the station to cease transmitting or to modify
its equipment until such time as it can be operated without causing harmful interference.
The key words are "harmful interference". In determining the meaning of these words,
regard should be given to the definition section of the Act. The interference must either
endanger or degrade the use or functioning of safety-related transmitters and receivers (i.e.
police, ambulance, coast guard), or significantly degrade, obstruct, or repeatedly interrupt
the use or functioning of radio apparatus or radio sensitive equipment. This section of the
Act should also be considered together with Section 25 of the Regulations which states that
if you are conducting tests or trials this should be done in such a manner as to preclude
interference with other stations.
These sections do not appear to be directed at interference with your neighbour's TV or
radio, but rather at interference with commercial services. You should note that under
Section 114(1) of the Regulations, an employee of Industry Canada has the authority to
inspect your station.
Section 56 of the Regulations provides that those frequencies in items 13-19 and 21, 24, 26 and
27 of Schedule II may be used by non-amateur users and amateurs may not interfere with them.
Moreover, if an amateur station is interfered with by a non-amateur station, the non-amateur
transmission will take priority. In effect what is happening is that the valuable UHF and
microwave frequencies are now being shared with commercial users, and the commercial
users are taking priority over amateur users.
Measurements (S-61)
This rather archaic section predates modern transceivers and is somewhat out of step with
the current licensing structure. However, for the purposes of this exam you must
understand the requirements of this section. In particular, you should know that your
station must have both a device capable of measuring the transmitted frequency with the
same level of accuracy as a crystal calibrator, and a device capable of preventing and
indicating overmodulation. Section 60 of the Regulations goes on to require that the
frequency stability of the transmitter on frequencies below 148 MHz be equivalent to that
obtained by a crystal-controlled radio. All modem transceivers meet these three
Restrictions on the Number of Amateur Radio Stations (S-45)
Your radio station license authorizes the establishment of a limited number of stations. You
may have one station at the location indicated on the station license, one station at a location
other than the address of the first station, and one mobile station. For example, you could
have a station at your principal residence, secondary station at your summer cottage, and a
third on your yacht. Unfortunately, this is a rather poorly drafted section and as a result is a
bit confusing. Section 45(2) restricts the number of stations operating simultaneously to
two, of which one must be the mobile station. The station at the address named on the
license and the secondary station may not be transmitting at the same time. However,
"station" does not mean "transmitter". In other words, one station may have many
Amateur Radio Basic Qualifications Manual
transmitters operating simultaneously. The limiting factor seems to be the amount of
property (area) that one station can occupy. Industry Canada has arbitrarily set the area to be
the boundaries of the property at the address of the license.
Equivalency of Certificates (S-44 Regulations)
The retirement of certain pre-existing license classifications was necessary upon the
restructuring of the Amateur Radio Service in October of 1990. Prior to October of 1990 there
were three Amateur classifications and several commercial-class licenses. Under the new
licensing structure, Amateurs obtained their Amateur Radio Operator's Certificate or the
Amateur Radio Operator's Advanced Certificate prior to October 1 1990 were now deemed to
hold the Basic, the 12 wpm Morse code and the Advanced levels of Qualification. Holders of
the Digital License were deemed to hold the Basic and Advanced levels of qualification, but
were not upgraded to 12 wpm Morse code.
The mechanics of the retiring old rules is set out in Section 44 of the Regulations. In
particular, Section 44(1) provides that the Radio Operator's First Class Certificate, Radio
Operator's Second Class Certificate, Amateur Radio Operator's Advanced Certificate, and
Amateur Radio Operator's Certificate are deemed to hold the Amateur Radio Operator's
Certificate with Basic, Morse code (12 wpm) and Advanced qualifications. Section 44(2)
deals with the Digital Class and various commercial classifications. In particular,
Radiotelephone Operator's General Certificate (Aeronautical), Radiotelephone Operator's
General Certificate (Maritime), Radiotelephone Operator's General Certificate (Land), and
Amateur Radio Operator's Digi: 1 Certificate are deemed to hold the Amateur Operator's
Certificate with Basic and Advanced qualifications.
Emergency Communications (S-50 Regulations)
One of the justifications for the allocation of such a large portion of valuable radio spectrum
to Amateurs is their claim to be able to provide emergency communications in the event of
disasters such as earthquakes, floods and tornadoes. Section 50 of the Regulations implicitly
recognizes this service and provides an amateur station with the authority to communicate
any message that relates to that emergency on behalf of any person, government, or relief
(11) Operation of Amateur Stations
Section 42 of the Regulations authorizes holders of certain commercial radio certificates as
well as holders of various amateur class certificates to operate an amateur station. The
classes are:
a) Radiocommunication Operator's General Certificate (Maritime);
b) Radio Operator's First Class Certificate;
c) Radio Operator's Second Class Certificate;
d) Radiotelephone Operator's General Certificate (Aeronautical);
e) Radiotelephone Operator's General Certificate (Maritime);
f) Radiotelephone Operator's General Certificate (Land);
g) Amateur Radio Operator's Advanced Certificate;
h) Amateur Radio Operator's Certificate;
i) Amateur Digital Radio Operator's Certificate;
j) Amateur Operator's Certificate with Basic Qualification;
Amateur Radio Basic Qualifications Manual
Valid station license for an amateur station issued to a citizen and resident of
the United States by the government of the United States;
Valid station license issued by the Minister pursuant to paragraph 5.1 (1) of
the General Radio Regulations, Part I.
Some confusion seems to have resulted from this section. This section does not permit
holders of various restricted certificates to operate amateur stations. A related provision is
found under Section 5.1 of the Regulations which provides for the issuance of Amateur
Radio Station Licenses to people who hold the above mentioned certificates.
(12) ITU Regions
For the purposes of frequency coordination and administration the world is broken into zones
and regions by the ITU (International Telecommunications Union). There are three regions as
per the following diagram.
(13) Miscellaneous
Radio controlled models may be operated by amateurs. The use of such models are restricted to
frequencies above 30 MHz (Section 4 of the Regulations). A related provision, Section 59 of the
Regulations, provides that an amateur radio station shall not transmit and unmodulated carrier
below 30 MHz except during brief tests.
Amateur Radio Basic Qualifications Manual
RIC-2 contains a list of Q signals which abbreviate a detailed question or answer. Many of these
are never used. However, for the exam you should familiarize yourself with the following more
commonly used Q Signals which appear in the following table.
Q Code Question
Suggested Mnemonics
Who is calling me?
Can you
communicate with
Are you being
interfered with?
Are you troubled by
Shall I send more
What is your position
in latitude and
longitude (or according
to any other indication)
You are being called by...
I can communicate with ...
direct. (or relay through...)
I am being interfered with.
1. nil,
2. slightly,
3. moderately,
4. severely,
5. extremely.
I am troubled by static.
1. nil,
2. slightly,
3. moderately,
4. severely,
5. extremely.
You are taking a snooZe
when you faintly hear
someone saying your
callsign. You would say
"who is calling me" or
SO, can you
communicate with "SO
and SO"?
Q Radio Man-made
interference or static
Q Radio Natural
interference or static.
Send more slowly (... wpm) Q Radio Slower?
My position is ...
latitude, ... longitude (or
according to any other
Can you acknowledge I can acknowledge receipt.
Will you tell me
Your exact frequency (or
my exact frequency
that of ...) is ... kHz or
(or that of ...)?
Shall I stop sending? _Stop sending.
Shall I increase my
Increase your
transmitter power?
transmitter power.
Shall I decrease my
Decrease your transmitter
transmitter power?
Q The Home
Can you acknowledge
receipt of the QSL
card?you tell me the
exact frequency of my
RiG—hence QRG.
Q Radio Terminate
Shall I Ridiculously
Overload (increase) power?
Shall I Reduce Power?
Amateur Radio Basic Qualifications Manual
Q Code Question
Shall I change
Does my frequency
How is the tone of my
Suggested Mnemonics
Change frequency to...
Your frequency varies.
The tone of your
transmission is
1. good
2. variable
What is the
intelligibility of my
your signal (or those of
signal (or those of
....) is
1. Bad
2. Poor
3. Fair
When will you call me I will4.callGood
you at hours
(on ....5.kHz).
Does my Radio Hold
Radio Intonate.
Radio Klearly.
Will you relay to ....?
I will relay to
Send / Pass.
What is the
strength of my
signal (or those of
The strength of your
signal (or those of ...) is
1. scarcely perceptible
2. weak
3. fairly good
4. good
5. excellent
Signal Amplitude.
Are you ready?
Can you hear me
between your
signals and if so
can I break in on
your transmission?
How many
telegrams have
you my
to send?
I am ready.
I can hear you between
my signals, break in on
my transmission.
Ready and aVailable.
I have ... telegrams
for you (or for ....)
Your signal is fading.
Telegram Count.
Fading is often due to
signals being received
out of phase due to
multipath. You could
relate this as Signals
Amateur Radio Basic Qualifications Manual
(1) Emergency Communications
Several classifications for emergency communications exist. Attached to each classification
is a particular emergency signal to be transmitted by the station in trouble to attract
attention and help. In order of importance they are:
This classification covers situations where there is grave and imminent danger, and
need of immediate assistance. A station in this situation transmits the word "Mayday"
three times and then gives its callsign. This procedure is repeated until a response is
received. Distress ("Mayday") is to be given absolute priority over all other
Situations involving a very urgent message concerning the safety of a person, place,
vehicle, plane, or vessel are considered to be within this classification. The signal is "Pan
Pan" given
three times. Urgency is given priority over all other transmissions except Distress.
This lowest classification of the three involves communications concerning safe
navigation or weather advisories. The signal transmitted is "Security", repeated three
Note: Section 9(1) of the Act makes it an offence under the Act to send any false or
fraudulent distress signal.
(2) Callsigns
Call signs are assigned by the respective governments of each country; however, the actual
prefixes are agreed to by international convention. This international allocation process
makes it easy to identify the location of a station. For example, some of the prefixes
assigned to Canada are "VE", "VA", "VY" and "VO". The Northwest Territories gets VE8;
British Columbia gets VE7 or VA7; Alberta gets VE6; and so on.
Amateur Radio Basic Qualifications Manual
Amateur radio stations vary from the simple to the extremely complicated and expensive.
Chapter two will describe the simple stations with an emphasis on the fundamental
components of the radio station and will conclude with a few comments about safety.
This is the heart of a station. It is a radio which contains both a receiver and a transmitter
and its component parts are discussed in Part In.
(2) Microphones
Microphones are used to convert sound into electrical energy. Several types of microphones
have been used for radio, including carbon, condenser, dynamic and crystal microphones.
Carbon microphones use a mass of carbon pellets behind a diaphragm. As sound waves
compress the carbon pellets, their resistance varies and this causes a variation of the direct
current passing through them. Electret condenser microphones are the most common
microphones and have the highest fidelity. These use a capacitor whose capacitance varies
in accordance with the sound it receives. As the capacitance changes, the voltage between
the two charged plates changes. These microphones require an external voltage for
operation. Dynamic microphones are constructed in a similar manner to a speaker; there is a
winding in the presence of a magnetic field. When sound moves this coil, a voltage is
induced in it. Finally, a crystal microphone uses a piezoelectric crystal. This crystal
produces electricity when it is mechanically stressed. Of the four types, crystal microphones
have the highest impedance.
Sounds are usually considered to be a set of numerous frequency components at various
levels. Human hearing is generally considered to fall in the range of 20 Hz to 20 kHz,
although many people may have a normal range of 50 Hz to 15 kHz. For normal voice
communications, a system with a frequency response of 300 Hz to 3 kHz will transmit
voices with sufficient fidelity for comprehension. Reduction of this bandwidth may make
the message unreadable.
Low Pass Filter
This device is more fully described in Part IV, Interference and Suppression. It is
designed to prevent the passing of high frequencies (greater than 30 MHz) from the
transmitter to the antenna. In theory this item is required; however, in practice it may not
be necessary. Most modern transceivers already contain such a filter, and additional one is
unnecessary unless one believes in both "belts and suspenders".
Amateur Radio Basic Qualifications Manual
(4) Standing Wave Meters
Generally this does two things:
measure the transmitter's output power
indicate how well the antenna is working
The meter will indicate that your coaxial cable has become damaged or if part of your
antenna has fallen down. A high Voltage Standing Wave Ratio (VSWR or SWR) indicates
that there is a poor impedance match between your antenna and the transmission line, and
that a considerable amount of power is being reflected back from the antenna to the
transmitter. If this impedance mismatch is not corrected with some form of impedance
matching device, the incomplete transfer of power from the transmitter to the feed line may
occur. Also, without a impedance matching device an undesirable heating of the final stage
of the transmitter circuit will occur.
Antenna Switches
While not a necessity, these switches allow you to conveniently select one of many
antennas to be used with the transceiver.
Dummy Load
The dummy load should be connected to the antenna switch as one of your antennas. This
device simulates an antenna in all respects except that it does not radiate. It usually has a 50
ohm impedance and it will have a low SWR of 1 to 1. The purpose of this device is to allow
you to tune up or to test and adjust your transceiver without actually transmitting a signal
on the air.
Frequency Counter
This device calculates the frequency by counting the number of times an electronic signal
reverses polarity in a certain time. If this unit was connected (properly and safely) to a
household electrical socket, it would measure 60 cycles per second (60 hertz). In a radio
station the frequency counter would measure radio frequencies in the order of kilohertz and
Electric current is similar to the flow of water through a pipe. To measure the amount of
water flowing through the pipe in a given time you need to cut the pipe. Similarly, an
ammeter measures electric current flow and must be connected in series with a circuit.
In the same way that water at a high elevation flows to a lower elevation, electrons flow
from higher energy potentials to lower energy potentials. Electric energy potential is
voltage, and it is analogous, to the height of water above the ground. To measure voltage,
you need to connect the ends of the voltmeter in parallel to the component (i.e. between
two points).
(10) Oscilloscope
Amateur radio operators may need to know the behavior of electronic signals over time. Like
a seismograph plots on a roll of paper the magnitude of vibrations in the ground during an
earthquake, an oscilloscope plots voltage as a function of time on a video screen. This video
screen is also called a cathode ray tube (CRT).
Amateur Radio Basic Qualifications Manual
Figure 1 Amateur Radio Station
Keep in mind at all times that the equipment employed in an amateur station may contain very
high voltages. These voltages are high enough, with sufficient current, to kill you or anyone
else careless enough to touch the wrong place. Unless you know what you are doing, keep
your fingers and any other conducting material away from the insides of power supplies,
amplifiers and transceivers.
When installing your radio equipment, remember that you must have 110 volt receptacles that
are grounded and equipped to accept three pronged plugs. Do not use extension cords which
do not accept the third prong. The grounding prong is important in the event of an electrical
short between the equipment and the chassis, having the radio grounded through the plug will
keep the chassis from becoming "hot" and electrocuting anyone who touches it.
Yourr station must also have an RF ground. All modern equipment has a grounding post on
the back panel which must be connected to a good ground. This is a copper rod or pipe
approximately 3 metres in length. Pound this into the ground as close to your station as
possible. Then connect a thick copper cable between the ground terminal on the back of the
radio and the pipe.
Amateur Radio Basic Qualifications Manual
Amateur Radio Basic Qualifications Manual
Amateur Radio Basic Qualifications Manual
Amateur Radio Basic Qualifications Manual
Amateur Radio Basic Qualifications Manual
Amateur Radio Basic Qualifications Manual
Amateur Radio Basic Qualifications Manual
Amateur Radio Basic Qualifications Manual
Amateur Radio Basic Qualifications Manual
(b) Transistors
Figure 21 Bipolars in NPN and PNP polarities
Transistors have replaced tubes as the main active component in modem electronics. A
varying input signal at the transistor's control terminal results in a proportionally larger
change in current at the output terminal. Two main sub-c classifications of transistors are
field effect transistors (FETs) and bipolar transistors. J-FET and MOSFET are the two
common types of FETs, each type being available in both N-channel and P-channel
polarities. Similarly, bipolars come in NPN and PNP polarities. The symbols for each
device as well as the names of their terminals are shown in the Figure 1.
Transistors need cooling. Like any resistive device they generate heat when they are in
use. In larger devices 10-100 watts may be dissipated internally as heat. Transistors can
be cooled by bolting a heat sink (finned piece of metal) to the component . Thermal
runaway (failure to maintain a reasonable component temperature) may cause the
component to fail. Thermal runaway occurs when a semiconductor's temperature
increases as its resistance decreases Component heating increases when semiconductor
resistance decreases, the current increases This thermal runaway cycle continues until the
component fails from excessive heat.
(c) Integrated Circuits
Integra ted circuits, or ICs, are composed of hundreds or thousands of microscopic
transistors and other components in one small package . An IC will typically have
between eight and forty pins and will perform a specific function within a circuit "Chips",
as IC's are sometimes called, should be handled with care as they are often susceptible to
damage from static electricity.
Since electronic circuitry uses direct current (DC), but the standard Canadian line supply
(household wall sockets) is 120 volts AC at 60 Hz, a power supply is required to convert
the AC supply to DC. Typically, solid state equipment requires between 5 and 15 volts
DC; high power tube amplifiers require several thousand volts DC. The ideal DC output
voltage from a power supply should be free
Amateur Radio Basic Qualifications Manual
from noise and ripple, and should be regulated to ensure a constant output voltage under a wide
range of current loads or slight fluctuations of the input voltage. There are three main
components in a conventional power supply:
• transformer,
• rectifier and
• filter capacitor
The block diagram shown below illustrates a typical amateur radio power supply with these three
stages (labeled B, C, and D respectively). In some cases the output voltage is regulated by a
Figure 22 Regulated power supply
The transformer alters the input supply AC voltage to a higher or lower AC voltage at the
secondary. This secondary voltage roughly determines the voltage of the power supply output
The transformed AC supply is then rectified by the use of one or more silicon diodes . There are
three standard rectifier diode configurations: half-wave, full-wave, and full-wave bridge
The rectified voltage is still unsuitable for use in electronic circuitry because it isn't constant over
time . The series of peaks and discharges are referred to as ripple. The magnitude of the ripple is
inversely proportional to the capacitance of the filter. To achieve a constant DC Voltage with
minimum ripple, filter capacitors are added to the power supply. During the voltage peaks in the
rectified supply, the capacitors are charged to this peak value. Between the peaks, the capacitors
discharge according to the demands of the circuit until the next peak begins to charge the
Amateur Radio Basic Qualifications Manual
Figure 23 The effect of filter capacitors on power supply ripple.
For safety reasons, the chassis of the power supply is normally grounded to minimize the
chance of electrocution in case the equipment malfunctions. Interlock mechanisms are used
on high voltage power supplies to ensure that potentially lethal voltages are not present
when the cover is removed. Bleeder resistors are connected across the filter capacitors in
the high voltage supplies to speed their discharge once the equipment is shut off. Fuses are
used to protect the equipment in the event of an overload caused by human error,
equipment failure, or act of God.
(1) Introduction
Radio involves the transmission of audio, video, telegraphy, or data information from one
location to another. This information is often referred to as the message signal or baseband
signal. Before it can be transmitted, the signal must be converted to a radio frequency (RF)
signal. This process, called modulation, involves the original information signal and a
continuous, stable, and pure RF sine wave known as the carrier.
The carrier determines what frequency the station transmits on. Modulation will change
either the instantaneous frequency or amplitude of the carrier, so the message can be
extracted when the signal is received by the receiving station.
One Fundamental concept of radio theory is that, even though a pure carrier exists at one
discrete frequency, any modulation of this carrier will produce a signal of finite bandwidth.
Simply put, if useful information is being conveyed with the carrier, then spectrum must be
occupied. Different modulation schemes and different message signals use differing amounts
of bandwidth.
Amateur Radio Basic Qualifications Manual
In the transmission of voice (telephony), the original voice waveform is converted to a
radio frequency (RF) signal by the transmitter. This is achieved through a minimum of
three stages:
RF generator
 modulator
 RF power amplifier
The RF generator or carrier oscillator produces the carrier. The baseband signal is
converted to .a radio frequency signal by the modulator. At this point, the signal is still at a
very low power level (likely in the order of 1 mW) and could be received over only a very
short distance. The RF power amplifier increases the power of the radio frequency signal to
a sufficient level for reliable reception by a distant station.
(2) Continuous Wave (CW)
Figure 24 Carrier Oscillator
The simplest method of modulation is on-off keying (0.0.K.), which is used in the transmission of
Morse code. A simple key switch is fed to a modulator that is controlling the passage of the
carrier through the rest of the transmitter. When the key is pressed, the transmitter sends the
carrier. When the key is released, the transmission stops. Abrupt changes in the amplitude of the
carrier will increase the normal bandwidth of the signal. This causes interference on adjacent
frequencies. Historically this problem was cured by the use of a key click filter between the key
and the transmitter. This filter also helped eliminate sparking of the key contacts. Modem
transceivers are constructed to eliminate the possibility of such a problem. This has rendered key
click filters obsolete.
Amateur Radio Basic Qualifications Manual
Figure 25 CW Transmitter
(3)Amplitude Modulation
A carrier may be changed in amplitude directly by a baseband waveform. This is known
as conventional amplitude modulation. When there is no signal at the input to the
transmitter, a steady carrier is produced at the output of the modulator. When there is an
input signal, the modulator changes the magnitude or envelope of the carrier over time. A
simple representation of amplitude modulation is shown in the diagram below. For
normal operation it is understood that the envelope of the carrier must not reach zero.
This case, called overmodulation, must be avoided to ensure adjacent users are not
interfered with by splatter. An overmodulation indicator should be used on AM
transmitters not having automatic modulation control.
The bandwidth of an AM signal will occupy twice the highest frequency sent to the
modulator. Normal telephone grade voice signals contain frequencies up to 3kHz. This
signal, when modulated using amplitude modulation would occupy 6kHz of bandwidth.
The AM spectrum is made up of two symmetrical sidebands: an upper sideband (USB)
and lower sideband (LSB). Low frequency audio is contained closest to the carrier. The
highest audio frequency components are contained in the part of the sidebands furthest
away from the carrier.
Amateur Radio Basic Qualifications Manual
Figure 26 Amplitude modulation
(4) Single Sideband
Although conventional AM can be recovered at the receiving end through very simple
means, the transmission of such modulation is not power or bandwidth efficient. The carrier
contains a significant amount of the transmitted power, but relays no information. Its sole
use is to simplify receiver design and aid in demodulation. Additionally, both sidebands,
being symmetrical, contain exactly the same information but occupy twice the bandwidth of
the baseband signal.
If the carrier and one sideband can be eliminated, the same message can be
transmitted with much less average power and half the bandwidth. This method of
modulation is called single sideband or SSB.
Although there are several ways of generating SSB, the most common method uses a
balanced modulator and a sideband filter. A block diagram representation of a SSB
transmitter is shown in the figure 2. The RF or carrier oscillator supplies a stable, fixed
frequency to the balanced modulator. The microphone generates an electrical replica of
the operator's voice message. This is amplified to a satisfactory level by the speech
amplifier. The balanced modulator produces a double sideband suppressed carrier
(DSBSC) signal. Simply put, the balanced modulator removes the carrier. A sideband
filter then removes the unwanted sideband. The remaining sideband will be either lower
sideband (LSB) or upper sideband (USB), depending on which sideband mode has been
chosen by the operator.
Amateur Radio Basic Qualifications Manual
Figure 27 Single sideband transmitter
Now that the unwanted sideband has been removed, the signal is converted to the final
output frequency by means of a mixer and a variable frequency oscillator. The VFO
allows the frequency of the transmitter to be easily changed by the operator. The balanced
modulator cannot be changed in frequency. The final signal is then amplified by the linear
amplifier to the desired power level and fed to the antenna.
(5) Frequency Modulation
For local very high frequency (VHF) and ultra high frequency (UHF) communications,
frequency modulation (FM) is used almost universally. It is preferred for its superior noise
immunity, ease of tuning, and high audio quality. Modulation is accomplished by varying
the instantaneous frequency of the carrier directly in accordance with the message signal.
The maximum limit of the instantaneous frequency in either direction is called the
maximum deviation. It is usually +7- 5 kHz for normal two-way radio application. But
maximum deviation may be as high as +7- 12 kHz for cellular radio telephone, and +7- 75
kHz for stereo FM broadcasts. Deviation outside the specified limits will not only cause
interference on adjacent channels but will also cause the received signal to sound
Amateur Radio Basic Qualifications Manual
Figure 28 Frequency modulation transmitter
An FM transmitter involves a number of distinct stages. The microphone signal is first
amplified by the speech amplifier. The modulator then uses the input signal to vary the
carrier frequency between the deviation limits. Since the oscillator is low frequency and since
the modulator has, by design, low deviation, the signal is then multiplied in frequency by the
frequency multiplier to the final transmit frequency. Typically, for 144 MHz transmitters, the
crystal frequency will be 12 MHz, necessitating a multiplication factor of 12 times. The
multiplier also increases the deviation of the signal, necessitating less than 500 Hz deviation
at the modulator. After multiplication, the signal can then be amplified, as before, by an RF
power amplifier.
Determining the occupied bandwidth of an FM signal is more complicated than simply
considering the frequency of the message signal. In fact, one must consider both the
frequency of the message signals and the deviation. It can, however, be approximated using
Carson's rule:
B = ∆ (∆f f m )
∆f= deviation (maximum).
fm = frequency of modulation signal.
(6) Power Amplifiers
Now that the message signal is modulated on a carrier, the RF signal must be amplified to a
sufficiently high level for the receiving station to receive the signal with a suitably low level
of noise. It should be noted mat noise and signal degradation will be present on any realistic
communication system. The quality of the recovered signal will depend on many factors
including mode of emission, transmitter power, receiver quality, antennas and the path over
which the signal travels.
Amateur Radio Basic Qualifications Manual
The signal is first amplified with a driver stage and then with a final power amplifier.
There are several classifications of power amplifiers. The selection depends on the
type of modulation being used.
Figure 29 Tank circuit
For frequency modulation, class C amplifiers are widely used due to their high efficiency.
Since these are non-linear they are not suitable for use with AM or single sideband. Nonlinear amplifiers,
when used with AM or SSB, distort the original signal, producing frequency
components which were not originally present. For single sideband applications class
A amplifiers are used because they exhibit good linearity.
For high power operation, above several hundred watts, tube amplifiers are still widely
used. These amplifiers normally obtain antenna matching and some degree of band pass
filtering by the use of a tank circuit. The tank circuit, sometimes referred to as a pi
network, is shown schematically in the figure 3. The two capacitors are adjusted so the
circuit will resonate at the transmit frequency and provide proper matching to the
Transistorized power amplifiers for HF use do not use tank circuits to provide matching
to the antenna circuit. Instead they use small transformers. Harmonic filtering is
accomplished by a low pass filter connected immediately before the output connector.
This filter is designed to pass the transmit frequency but attenuate frequencies in higher
No amplifiers are perfectly efficient, all of them dissipate or waste power. Of the DC
power supplied to the amplifier stage, approximately half of the power will be
converted to radio frequency, the rest is released as heat. This heat is removed from
the amplifier either by natural convection, or by forced air cooling.
Amateur Radio Basic Qualifications Manual
(1) Introduction
Now that a signal has been created and transmitted, it must be intercepted by an
antenna and fed to a receiver. The RF signal is processed by the receiver to recover
the original message.
Modem receivers typically have six stages:
 a radio frequency (RF) amplifier
 two conversion stages
 two band pass filters
 and a demodulator
Such a receiver is called a double super heterodyne receiver, which means that
the frequency on which the information is carried is converted twice. Conversion
is accomplished with a mixer and a local oscillator. This may seem like a
complicated method, but it is the most cost-effective means. The process of
conversion is used in television video cassette recorders to convert all channels
so that the television receiver can receive them on one channel (i.e. channel 3).
The demodulator converts the RF signal back to the original message signal. If
only one frequency is to be received, the receiver can be designed so that the
demodulator operates directly at the receive frequency. The signal would first be
amplified and then fed through a band pass filter which narrows the spectrum to
that occupied by the incoming signal. Unfortunately, the receiver would not be
tunable to any other frequency as the band pass filter and demodulator are unable
to change frequency.
To receive more than one frequency, it is easiest to convert the desired input
signal to the demodulator frequency (the intermediate frequency or IF). This
single conversion receiver can now be tuned readily and easily to many
As an example, suppose an AM radio receiver has an IF of 455 kHz. In order to
receive a signal of 600 kHz, an oscillator within the conversion stage (the local
oscillator or LO) must produce a frequency 455 kHz below or above 600 kHz. If
we choose 1,055 kHz, the input 600 kHz signal is reproduced at the sum and the
difference of 1055 kHz and 600 kHz, specifically 455 kHz and 1,655 kHz. The
band pass filter selects only the 455 kHz signal, eliminating the others.
Unfortunately, if another signal is present corresponding to 455 kHz plus the local
oscillator frequency of 1,055 kHz, or 1,510 kHz, then this signal will also be
converted to the IF and demodulated. This frequency is known as the image
frequency and is of great concern during the design of conversion type receivers.
This problem can be solved by one or both of two means: by the use of a tunable
preselector or by the use of two IF stages instead of only one. The preselector is a
bandpass filter, centred on the receive frequency, which is inserted before the
conversion stage. It passes the receive frequency but attenuates the image frequency,
plus other interfering signals, as much as possible.
Amateur Radio Basic Qualifications Manual
Sensitivity is a measure of the receiver's ability to detect weak signals. The more
sensitive the receiver is, the better able it is to receive weak signals. Every
receiver has an inherent internal noise that competes with the incoming signal.
The higher the internal noise is, the more difficult it becomes to receive weak
signals. Conversely, the weaker the incoming signal is, the lower the internal
noise must be to maintain a good sounding signal.
Selectivity is a measure of a receiver's ability to reject signals on adjacent
frequencies. The selectivity of the receiver is affected by the characteristics of the
band pass filter. The band pass filter must be chosen to match the bandwidth of the
incoming signal, and at the same time, provide as much attenuation as possible of
unwanted signals outside of the immediate pass band.
The RF amplifier is the input stage after the antenna. It matches the antenna's
impedance to that of the receiver, amplifies the input signal to a usable level, and may
contain a preselector.
The first stage of conversion changes the frequency of the desired signal to an
intermediate frequency (IF), which is then passed through a band pass filter of
fixed frequency. The first IF is then converted to a second IF lower than the first. It
is at this stage, through the use of an IF filter, that the receiver's selectivity is
obtained. After passing through this band pass filter, the signal is fed to the
demodulator, which extracts a replica of the original voice waveform.
Once the signal has been demodulated, the information is passed on to the audio
amplifier. This increases the power level of the audio signal become loud enough to
drive a loudspeaker.
(2) CW and SSB Receivers
The demodulator used for CW or SSB reception is known as a product detector. The
product detector converts the IF signal to audio with the help of the beat frequency
oscillator (BFO). This oscillator operates at a fixed frequency adjacent to the IF. The
BFO signal replaces the carrier, which was removed by the balanced modulator in the
transmitter. The BFO must be adjusted to the correct frequency, otherwise it will
make the received signal sound unnatural.
Amateur Radio Basic Qualifications Manual
Figure 30 Single sideband and CW receiver
The receiver adjusts its gain by an automatic gain control (AGC) circuit. This circuit
maintains a constant audio output for varying RF signal strengths by adjusting the gain of
various stages in the receiver. Additionally, signal strength meter readings are derived from
the AGC.
Single sideband is preferred over AM for long distance (DX) work as many of the problems
associated with severe multipath and frequency dispersion are eliminated. The drawback of
single sideband is that a replica of the removed carrier must by synthesized at the receiving
station in order to recover the information.
(3) FM Receivers
The original message waveform is recovered from an FM signal by means of a
discriminator. This frequency sensitive circuit outputs a signal corresponding directly to the
instantaneous frequency of the received signal. For best receiver performance, the if filter
must be matched correctly to the bandwidth of the incoming signal. Within the IF stage, the
limiter sets the signal to a fixed level immediately before the discriminator. The gain of the
receiver stages is fixed; there is no AGC. A squelch circuit mutes the audio output when
there is no signal, eliminating a constant loud rushing noise that would otherwise be present
Amateur Radio Basic Qualifications Manual
Figure 31 Frequency modulated receiver
A transceiver is a package containing a transmitter and a receiver. Most modem stations use
transceivers. A transceiver greatly simplifies the construction of a two-way station as many
circuits are common to both a transmitter and receiver. When the unit goes into the transm it
mode, the receiver is muted and disconnected from the antenna, but is not disconnected from
the power source. Once the antenna has been connected to the transmitter, the unit begins
Amateur Radio Basic Qualifications Manual
Radio transmissions can cause interference with nearby electronic equipment. Such radio
frequency interference (RFI) can render some equipment completely useless. The
responsibilities for suppression of interference are dealt with in the regulations section. This
section will deal with the causes and solutions of common RFI problems. Because the
equipment most often interfered with belongs the amateur radio enthusiasts, it is important to
be able to correct manufacturing inadequacies in today's consumer electronics. A brief
discussion of filters will be followed by the types of interference and the application of
filters to suppress them.
Filters form the basis of most RF circuits. A filter is a frequency selective circuit which
passes signals of certain frequencies while attenuating others. As filters are able to select
desired frequencies from undesirable frequencies, they are fundamental to suppressing
interference. Typical measures of a filter are its cutoff frequency and its Q. The cutoff
frequency is defined as the frequency at which a signal will be reduced to half the power of
the maximum signal passed. The Q (or quality) of a filter is a measure of how sharp the
filter is. High Q filters are those with a relatively narrow bandwidth, while low Q filters
have a relatively wide bandwidth. A filter's bandwidth is the distance between cutoff points.
The Q is, then, the ratio of the centre frequency to the bandwidth of the filter.
Low Pass Filters
A low pass filter passes low frequencies (including DC) but blocks high frequencies. A
simple inductor has this property, although most filters are made from a combination of
circuit elements. Low pass filters are used to remove excess harmonic energy from a
signal at a transmitter's output. They can also be used on receivers to reduce an
interfering signal which is above the received frequency.
High Pass Filters
A high pass filter passes high frequencies but blocks low frequencies. A simple capacitor
has this property, although most filters are more complicated. They are typically used on
receivers to reduce interference from signals that are lower in frequency (i.e. televisions
being interfered with by HF transmitters).
* Written by Arian Parker, B.A.Sc., M.A.Sc. (Engineering), PE7HEX
Amateur Radio Basic Qualifications Manual
(3) Band Pass and Band Reject Filters
These filters can be used when only a certain frequency range is desired. The band pass
filter can be used on a receiver to eliminate signals above and below the desired frequency.
A band reject filter can be used to remove a specific interfering signal (i.e. a strong FM
signal which is interfering with TV reception). Both of these types of filters can be
assembled from low and high pass filters or be specifically built for the purpose if high Q is
desired. As most interference problems with operation in the VHF amateur bands involve
signals which are in the middle of most TV and radio bands, band pass and band reject
filters are often the best solution.
(1) Front End Overload
Front end overload is the entry, by brute force (exceptionally high signal strength), of a
radio signal into the receiver of a TV or home stereo. Because televisions are usually more
susceptible to interference, most examples will involve the effects on TVs. The solutions,
however, are equally applicable to radio receivers. Front end overload is typically indicated
by a TV's complete loss of picture and sound when the transmitter is on. It is a common
problem with amateur transmission on the 6 metre band as this band is right beside TV
channel 2 (the amateur band was originally designated channel 1). Suppression of this type
of interference involves reducing the interfering signal sufficiently to permit the receiver
front end (TV or stereo) to tune it out. This can be accomplished by moving the receiving
and/or transmitting antenna(s), switching to cable TV (a common solution these days), or
installing a band reject filter on the input of the TV. More than one method may be needed
to completely solve the problem.
(2) Audio Rectification
Audio rectification is the demodulation (rectification) of an RF signal within the audio
circuit of the receiver. It is characterized by the reception of the interfering radio signal
along with the desired program by the receiver (i.e. two signals are discernible in the audio
output). Such interference is independent of the receiver tuning as it enters after the tuning
circuit. It commonly occurs as a result of poor shielding of the receiver circuits and can be
solved by replacing the receiver with a better model, adding shielding to the receiver, or
bypassing the RF that gets into the audio circuit before it is detected. The last method
usually involves adding capacitors across points on the receiver's audio circuit board.
Harmonics are multiples of a transmitted frequency that are produced by exciting a nonlinear circuit element (i.e. diodes, transistors). They are present in any signal which has a
distorted sine wave, which are typically produced by overdriven radio stages. An example is
overmodulation of a transmitter ("flat-topping"). Reducing the microphone gain in this
instance will significantly reduce the harmonic output. Harmonics should be suspected if a
transmitter on a lower frequency causes interference to a frequency which is a multiple of it.
For example, if a transmitter at 29 MHz (10 m band) causes interference to a receiver at 87
MHz (TV channel 6), the probable cause is harmonics (3 x 29 = 87). Harmonic interference
occurs at distinct frequencies.
Amateur Radio Basic Qualifications Manual
Frequencies of Broadcast Television
Channel 2
10 11 12 13
Frequency 54-60 60-66 66-72 76-82 82-88 174- 180- 186- 192- 198- 204- 210180 186 192 198 204 210 216
Harmonics can be produced within transmitters and receivers or outside of both.
Harmonics generated within a transmitter are required by law to be filtered out. This is
accomplished with a low pass filter on the final output of the transmitter (normally
installed internally by the manufacturer). Some older radios use an external circuit
mounted between the transmitter and the antenna. Harmonics within a receiver generally
cause cross modulation or intermod (see section 5 Cross Modulation). Harmonics can,
however, also be generated by a bad connection between two metal surfaces (i.e. gutters,
metal roofing, antennas). The joint can oxidize and form a poor quality diode which, when
excited by a RF field, produces harmonics. These can often be found by keying the
transmitter and then moving suspect metal objects until the interference changes.
Harmonics which are not exactly on the received frequency can be removed with a
selective filter - a band reject, high pass or low pass filter. This will not work if any desired
signal lies within the cutoff region of the filter. Generally, harmonics should be suppressed
at the source. All commercial transceivers are constructed to do this.
Parasitic Oscillations
Parasitic oscillations are similar in effect to harmonics (i.e. a VHF receiver being interfered
with by a HF transmitter), but there is no simple mathematical relationship between the
operating frequency and the interfering frequency. The interference is frequency selective,
but can occur above and below the primary frequency (usually above). The cause is an
additional undesired oscillation of an oscillator or amplifier, which it wasn't designed for.
The circuit functions normally, but the parasitic oscillation occurs simultaneously. Parasitics
are suppressed by adding additional components to the circuit which suppress the undesired
oscillation without affecting the primary function of the circuit (known as neutralization).
Typically this involves a VHF choke (inductor) somewhere close to the active component of
the circuit.
Cross Modulation
Cross modulation is the mixing of two frequencies within a receiver's front end (the first
amplifier or mixer stage) to produce, in addition to the original frequencies, the sum and
difference frequencies:' For instance, if a commercial transmitter at 150 MHz mixed with
an amateur signal at 52 MHz, it could produce interference to an FM broadcast signal at
Amateur Radio Basic Qualifications Manual
98 MHz. Cross modulation should be suspected if there is interference only when both
transmitters are operating. The solution is to remove one or both of the source signals
from the passband of the receiver. A low passband filter with a cutoff frequency at 130
MHz would eliminate the commercial signal (and interference) without degrading the
signals in the FM band.
(6) Intermodulation
Intermodulation is related to cross modulation except that it is caused by signals close to
the receiver input. If two signals are close to one another (i.e. 1 MHz apart) a frequency
difference of 1 MHz will be generated, which can add to one or both of the original
frequencies. This can occur more than once and produce a spectrum of interfering signals
with 1 MHz spacing's. These can interfere with reception. The solution is not as simple as
that for most cross modulation cases because the source of the interfering signals is usually
within the desired passband of the receiver. For fixed frequency operation, the interfering
signal can be reduced with a high Q (narrow bandwidth) filter. Restricting the passband of
the front end of the receiver to only those frequencies that are required will reduce the
Amateur Radio Basic Qualifications Manual
A basic feature of amateur radio is the transmission of signals from point to point without
wires. Radio signals travel from the transmitter antenna to the receiver antenna in various
ways depending on the frequency used. Some frequencies can use the ionosphere to bounce
signals around the world, while other frequencies can be used only for local communication.
Radio waves are the bottom part of the spectrum of electromagnetic radiation, with infrared,
light, ultraviolet, X-rays and cosmic rays at higher frequencies. Radio waves are further
subdivided into different frequency ranges. MF (medium frequency) covers from 0.5 to 3.0
MHz, HF (high frequency, also called shortwave) covers from 3 to 30 MHz, VHF (very high
frequency) covers from 30 to 300 MHz, and UHF (ultra high frequency) covers from 300 to
3,000 MHz. All electromagnetic radiation travels at the same speed, commonly referred to as
the speed of light (c = 3 x 108 metres/second or equivalently 300,000 km/s). Electromagnetic
radiation consists of two waves traveling together (magnetic and electric waves) with the plane
of the waves perpendicular to each other.
The polarization of a radio wave is determined by the direction of the electric field wave. Most
antennas radiate waves that are polarized in the direction of the length of the metal radiating
element. For example, metal whips such as those used on cars are vertically polarized, while most
TV antennas are horizontally polarized. Polarization is important on VHF and higher, but not
very important on HF communications because the many reflections that a skywave undergoes
makes its polarization quite random.
(1) Skywave
Radio waves can travel in several different ways. The simplest to understand are direct waves
which travel in a straight line from transmitter to receiver. Direct waves are the most important
for communication on frequencies above 50 MHz. The signal might be reflected off buildings
and mountains to fill in some shadows, but usually communication is just line of sight. On
lower frequencies, the ionosphere is able to reflect the radio waves (the actual physics are closer
to refraction than simple reflection but reflection is easier to understand). The signal reflected
off the ionosphere is referred to as the skywave or ionospheric wave. The groundwave is the
signal that travels on the surface of the earth and depends on the surface conductivity.
Groundwaves are the main mode of transmission on the MF bands (i.e. AM broadcast band) but
they are not very important for amateur use (except on the only MF amateur band, 160 m). The
groundwave is usually attenuated within 100 kilometres. On VHF and higher frequencies,
variations in atmospheric density can bend the radio waves back down to the earth. This is
referred to as the tropospheric wave.
As the skywave is the primary mode of long distance communication it is usually of the most
interest. A skywave will go farther if it can take longer "hops." For this reason, low angle (<
30°) radiation is best for DX (distance communication) work as it will travel farther before
reflecting back to the earth. Antennas that produce low angle radiation include verticals or
dipoles mounted high (at least half a wavelength) above ground.
* Written by Niall Parker, B.A.Sc., M.A.Sc. (Engineering), VE7HEX
Amateur Radio Basic Qualifications Manual
The Sun and the Ionosphere.
The ionosphere is the upper region of the atmosphere, where the sun's energy charges gas
molecules. The degree of ionization varies with the intensity of the solar radiation. Various
cycles affect the amount of solar radiation, with the obvious ones being daily and yearly
cycles. This means that ionization will be greatest around noon in the summer, and at
minimum just before dawn in winter. In addition, the output of the sun varies over a longer
period of approximately 11 years. During the maximum of the solar sunspot cycle, there is
greater solar activity and hence greater ionization of the ionosphere. A solar peak occurred in
1990, with its corresponding minimum in 1995. Greater solar activity generally results in
better conditions for radio propagation by increasing ionization. However, very intense
activity in the form of geomagnetic storms, triggered by a solar flare, can completely disrupt
the layers of the ionosphere and block communications. This can happen within minutes and
communications can take hours to recover.
Ionospheric Layers
The ionosphere is not a homogeneous region, but consists rather of distinct layers which
have their individual effects on radio propagation. The layers of primary interest to radio
amateurs are the E and F layers. The E layer, the lower of the two, is located at an altitude
of approximately 110 Kilometres. It is in the denser region of the atmosphere where the
ions formed by solar energy recombine quickly. This means the layer is densest at noon and
dissipates quickly when the sun goes down. The F
layer is higher and during the day separates into
F2 320 km
two layers, Fl (225 km) and F2 (320 km). It merges
at night to form a single F layer at approximately
Fl 225 km
280 Kilometres.
E 110 km
The different layers of the ionosphere can reflect
radio waves back down to the earth, which in turn
can reflect the signal back up again. In this fashion,
a signal can "hop" around the world. The bigger the
"hop" the better, because each the signal loses energy Figure 32 Ionosphere
with each "hop". Using higher layers, the radio wave
"hops" farther. Lower angle radiation will go farther before it reflects off the ionosphere. To
achieve the greatest distance communication (DX) choose a frequency that will reflect off the
highest layer possible and use the lowest angle radiation possible. The distance covered in
one "hop" is the skip distance. For destinations beyond the maximum skip distance, the
signal must make multiple hops.
(4) Absorption
In addition to reflecting radio waves, the ionosphere can also absorb them. This absorption is
greater with lower frequencies and denser ionization. There is another layer of the ionosphere
below the E layer (called, surprise, the D layer) which only exists during the day. It will
absorb almost all signals with a frequency lower than 4 MHz (i.e. the 80 and 160 m bands).
Short range communication is still possible using higher angle radiation, which is less
Amateur Radio Basic Qualifications Manual
affected (it travels a shorter distance through the atmosphere). The signal can then reflect off
the E layer to the receiver. The bottom layers (D and E) are responsible for the effect where
one can hear only local AM radio stations during the day. More distant signals can often be
better heard at night.
The attenuation of a signal by the ionosphere is higher at lower frequencies. Higher
frequencies should be used for greater distance coverage. However, if the frequency is too
high, the signal will pass directly into space and not reflect back to earth. While this is
perfect for satellite communications, it is not suitable for HF DX. When trying to work DX
on HF, try to use the highest frequency that will still reflect off the ionosphere. The highest
allowable frequency varies with solar activity and time of day. This frequency is referred
to as the maximum usable frequency (MUF). This can be calculated by various formulas if
given the current solar indices. In the peak of the solar cycle, it can often be over 30 MHz
(on rare occasions up to 50 MHz) and at other times (i.e. during the night) it can drop
below 10 MHz. At the low end of the frequency spectrum, daytime absorption in the D
layer limits the range possible. In addition, atmospheric noise is greater and limits the
lowest usable frequency (LUF). Noise and absorption decreases at night, lowering the LUF
at the same time the MUF is lowered by the decrease in solar excitation of the ionosphere.
This usually means that by picking the right frequency, long distance communication is
possible at any time.
Radio waves can travel over different paths from the transmitter to the receiver. If the path
length varies by a multiple of half of a wavelength of the signal, the two (or more) parts
can partially or completely cancel each other. This causes fading of the received signal
and is called multipath. Various phenomena can cause this. Aircraft, mountains and
ionospheric layers can reflect part of a signal, while another part takes a more direct path.
Fading can also occur when the signal passes through the polar regions. This is called
polar flutter and is caused by a different phenomena. The ionosphere is much more
disorganized in the polar regions because of the interaction of solar energy with the
geomagnetic field. The same phenomenon that causes aurora borealis can cause the
wavering of signals on polar paths.
Other Atmospheric Effects
Other parts of the atmosphere can affect radio propagation, and are often the only way to
extend VHF and higher signals for greater distances than line of sight. The lowest region of
the atmosphere, the troposphere, can scatter VHF signals more than 600 kilometres (i.e.
tropo-scatter). Ducting is a phenomenon where radio waves get trapped by a variation in
the atmosphere.
The radio waves can then travel along by refraction. Ducting usually occurs over water or
other homogeneous surfaces. This is more common at higher frequencies and has
permitted UHF communication over distances greater than 2,500 kilometres.
Sporadic E skip is a seasonal occurrence that usually happens during the summer. A small
region of the E layer becomes more highly charged than usual, permitting the reflection of
Amateur Radio Basic Qualifications Manual
signals as high in frequency as 220 MHz. This highly charged region soon dissipates, and as
a result, sporadic E skip will only occur from a few minutes to a few hours.
An even more exotic mode of communication involves bouncing signals off the ionized
trails of meteors. Meteor scatter communications may last only a few seconds, so it is
feasible only where large numbers of meteors are entering the atmosphere (i.e. during the
Perseid meteor shower in August).
Skip Zone
The area between the limit of maximum range by direct wave or ground wave, and the
minimum skip distance by skywave is the skip zone. Usually you should be concerned
with the maximum possible range. But there are instances when operating close to the
MUF, where you can talk to people thousands of kilometres away, but be unable to talk to
someone only 500 kilometres away. This phenomena is known as the skip zone. This
occurs because the ionosphere can better reflect signals that are at a shallow angle (like
light off a water surface). Those waves approach at a steeper angle, pass directly through,
and are lost into space. The critical angle varies with the degree of ionization and generally
results in larger skip zones at night.
Page 49 Skip Zone
Amateur Radio Basic Qualifications Manual
(1) General Description
The antenna is the part of the radio station that radiates the radio frequency (RF) energy
into space. These generally consists of conductors arranged so that they direct energy in a
desired direction. As antennas involve resonant components, the lower frequency antennas
are generally larger, while the VHF and higher frequency antennas can be quite compact
Antenna Impedance
An antenna represents a load to the transmitter that may have both a reactive and
resistive component (see Resistance/Impedance, page 17). For maximum transfer of
power this impedance must be matched to the transmission line, and it in turn must be
matched to the transmitter output. When an antenna is resonant, it has only a resistive
component. If an antenna is too short (i.e. it is resonant at a higher frequency), it will
have a capacitive reactance component. If it is too long it will have an inductive
reactance. This is usually corrected by adding to or subtracting from the antenna length,
but if the antenna size needs to remain fixed, it can be compensated for by adding a
reactance of the opposite sign (inductive reactance is positive, capacitive reactance is
negative). This is usually done by using a matching network (i.e. transmatch).
Voltage Standing Wave-Ratio (SWR)
When there is a mismatch of impedance between components of an antenna system
(either at the antenna or the transmitter) some of the power will be reflected at the
mismatched joint. This energy travels back down the line and causes a standing
wave. This condition is usually measured with a SWR (Standing Wave Ratio)
bridge. When the system has been matched perfectly (i.e. a 50 ohm line into a 50
ohm antenna) the SWR will be 1 to 1. Most radios will work perfectly with SWRs
under 1.5 to 1. Many tube type transmitters can easily deal with SWRs as high as 4
to 1. The SWR bridge is a good indicator of antenna health, because a bad
connection or broken conductor will usually cause a high S WR. The reflected power
from a damaged antenna can cause transmitter damage by overheating the output
(final) transistor(s) or, if low enough, just reduce the radiated power. Either way, it is
a good idea to monitor the SWR bridge.
(2) Dipoles
The most common type of antenna is the dipole. It is an antenna with two parts or poles. It is
usually a half wave in overall length and is fed in the middle. One pole of the antenna is
connected to one side of the transmission line and the other is connected to the remaining
side, either directly or through a phasing line. As the wavelength for a given frequency is the
speed of light divided by the frequency, one can calculate the desired length of the antenna
for any desired operating frequency. For a simple half-wave dipole the length would simply
be half the calculated wavelength.
Amateur Radio Basic Qualifications Manual
Amateur Radio Basic Qualifications Manual
When making a dipole for HF frequencies, one usually has to reduce the length by 2 percent
to account for capacitive effects at the ends. This is best done after installation because
various factors (i.e. as height from ground and other nearby conducting surfaces, can affect
it). The feedpoint impedance of a half-wave dipole installed about one wavelength or higher
above ground (i.e. in "free space") is 72 ohms. When the ends are lowered (i.e. into an
inverted V) the impedance drops to around 50 ohms. The ends of the antenna should be
insulated as they are high voltage, low current points. The connections of the transmission
line to the antenna should be soldered as the centre of the dipole is a high current, low
voltage- point. -i.e. radiation pattern of a half wave dipole in free space has a minimum off
the ends of the antenna and a maximum perpendicular to it, although this pattern degrades
considerably when the dipole is brought closer to the ground.
A modified version of the simple dipole is a folded dipole (see figure 4). In its most
common form, it has two half-wave conductors joined at the ends. One conductor is broken
and fed in the middle. If the conductor diameters are the same, the feed point impedance
will be 4 times that of a standard dipole, or 300 ohms. A similar dipole with three instead
of two conductors will have an impedance increase of 9 times.
Figure 34 Dipole
Amateur Radio Basic Qualifications Manual
Vertical Antennas
The simplest vertical antenna is the Marconi. This is a quarter wave radiator above a ground
plane. Over a perfect ground it has a feedpoint impedance of 36 ohms. With real grounds
the impedance is usually between 50 and 75 ohms. This makes it a good match for 50 ohm
coax cable, with the shield going to ground. The Marconi is a popular choice for mobile
communications because it is the smallest antenna with reasonable efficiency. It can be
thought of as half of a dipole with the other half appearing as a virtual image in the ground.
A longer antenna can produce even lower radiation angles. However the problems with
longer antennas is that they can become too large at to conduct lower frequencies easily. A
length often used at VHF frequencies is 5/8 of a wavelength. This length has a higher feed
impedance and requires a matching network for most transmission lines. Vertical antennas
need a good, highly conductive ground. If the natural ground is poor, quarter wave radials
can be laid out from the base of the vertical to form a virtual ground. Vertical antennas
provide an Omnidirectional pattern in the horizontal plane, so they receive and transmit
equally well in all directions. Vertical antennas are often used by DX operators as they
produce low angle radiation, which is best for long distances.
Figure 35 Marconi Antenna
Basic elements (either vertical or horizontal) can be combined to form arrays to improve
signal transmission or reception in specific directions,. The most common form of array is
the Yagi-Uda parasitic array (commonly referred to as a Yagi array or beam). It consists of
a driven element, which is either a simple or folded dipole, and a series of parasitic elements
arranged in a plane (see figure 6 below). The elements are called parasitic because they are
not directly driven by the transmitter, but rather absorb energy from the driven element and
re-radiate it. Usually a Yagi will have one reflector behind and one or more directors in
front of the driven element. The reflector will be slightly longer than the driven elements
and the directors will be slightly shorter. In an analogy with a flashlight, the driven element
can be thought of as the light bulb, the reflector as the reflector and the directors as the lens.
The transmitted RF energy is then focused in the forward direction. In order to rotate the
beam, the elements are attached to a boom and in turn to a mast that is connected to a motor
Amateur Radio Basic Qualifications Manual
Figure 36 Yagi-Uda parasitic array
A dipole or a Yagi antenna can be designed to work on more than one band. For HE, the 10,
15 and 20 metre bands are commonly combined in one antenna. Since these antennas work
on three different bands, they are called tribanders. This is accomplished by adding a trap to
the elements of the antenna. A trap is a combination of capacitive and inductive
components, located at a fixed distance on either side of the center of the driven element or
parasitic element. The trap has a high impedence at a specific frequency, in effect blocking
the signal from travelling any farther along the antenna, and making the antenna look much
shorter (electrically) than it really is. On a typical multiband trapped dipole, the 10 metre
traps will be located roughly half way from the center of the dipole to the end on each side.
The 15 metre trap will be farther out, and the full length of the antenna will be used for 20
metres. A triband Yagi will have the same configuration, with traps on the parasitic
elements as well as the driven element. Another common combination in a trapped dipoles
is one covering the 40 and 80 metre bands with a single set of two 40 metre traps.
(5) Quads and Loops
Another way to improve signal transmission and reception in specific directions is to use an
antenna element based on a full wavelength loop of wire. Like a dipole, the maximum gain
will be in the directions perpendicular to the orientation of the loop. Due to the size of the
element, the maximum gain of a single loop in the most favoured direction will be just
slightly greater than that of a dipole.There are two common feedpoints used for this type of
antenna. If the loop of wire is oriented like a diamond, the antenna can be fed at the bottom
of the diamond. This will result in horizontal polarization of the transmitted signal. When
fed at the side of the diamond, vertical polarization will result. Some people prefer to
construct the loop as a square of wire. In a square, feeding it at the center of the bottom of
the loop will result in horizontal polarization, while a feedpoint at the side of the square will
result in vertical polarization. Another variation of the loop uses a triangle (delta loop, after
the shape of the Greek letter delta). In all cases, the characteristic feedpoint impedence is
approximately about 100 ohms. If 50 ohm coax is used to feed the antenna, a 1/4
wavelength length of 75 ohm cable can be used just prior to the feedpoint of the loop. This
will better match the 100 ohm impedence of the loop with the 50 ohm impedence of the
coax. Directional arrays can be built with multiple loops (called two or three element
Amateur Radio Basic Qualifications Manual
cubical quads) as easily as we build arrays of dipoles (Yagis). In a two element quad, we use
only a driven element and a reflector. In a three element quad, there is a central driven
element, a reflector, and a director, all one wavelength in total distance around each loop.
The gain of a two element cubical quad is comparable to that of a three element Yagi. This
is easy to understand qualitatively, since the cubical quad actually has more radiating
surface in the driven element than a Yagi, and the amount of wire in the reflector is also
double that of a dipole (a full wavelength rather than just 1/2 wavelength). The performance
of both cubical quads and Yagis can also be measured in terms of the ratio of the power
radiated in the favoured direction vs the power radiated in the opposite direction. This
parameter is called the "front-to-back ratio". A high front-to-back ratio is useful when trying
to hear a weak signal from one direction while a stronger signal is coming from the opposite
Figure 37 Cubical Quad Antenna
(6) Antenna Measurements
Most antenna measurements are given in decibels (dB). Decibels are a logarithmic scale
where 3 dB corresponds to 2 times the power, 6 dB 4 times and 10 dB 10 times. Important
figures for a beam antenna are forward gain, front-to-side ratio and front-to-back ratio.
Forward gain is often given relative to a simple dipole. For example, if an antenna is said to
have a gain of 10 dB (over a dipole), then the radiated energy would be 10 times stronger in
its maximum direction than a simple dipole. Another comparison standard is the isotropic
antenna or point source. This is a hypothetical antenna that would radiate equally well in all
directions in all planes (unlike a vertical antenna which -radiates equally well only in the
horizontal plane). A dipole has 2.3 dB gain over an isotropic radiator. A front-to-back ratio of
20 dB would mean that the energy off the back of the beam would be one one-hundredth that
of the front. Similar relationships hold for front-to-side ratio.
Amateur Radio Basic Qualifications Manual
Another antenna measurement is the bandwidth or range of frequencies which the antenna
can be used for. High gain antennas usually have a narrower bandwidth than low gain
antennas. Some antennas can only cover a small portion of the band they are used in while
others can cover several bands. Still other antennas are designed to operate on a range of
specific bands but not in between these bands. A simple antenna, which can be used on
two bands, is a half wave dipole for 40 m. It can also be used on 15 m.
(7) Dummy Loads
One piece of equipment that is not really an antenna but is related to one is a dummy load.
A dummy load is a pure resistance that is put in place of an antenna to test a transmitter
without radiating a signal. Commonly referred to as a termination, when placed at the end
of any length of coax it will make the feedline look like an infinite length, provided that the
load is matched in impedance to the line. Most transmitters require an output impedance of
50 ohms, so a dummy load is simply a high power 50 ohm non-inductive resistor. The
resistor can be submerged in oil to improve its power capacity. A dummy load can be used
when locating interference sources and should be placed on the transmitter output when the
transmitter is not in use. This will prevent the transmission of a signal if the radio is
accidentally keyed (see Antenna Switches, page 14).
Transmission lines are the link between the transceiver and the antenna. There are
many different types, but the two types that are most popular on frequencies under 1
GHz are parallel conductor lines, and coaxial cable. Parallel conductor lines consist of
two parallel conductors held at a fixed distance by insulators. This type of transmission
line is balanced. Coaxial cable is the other major type of line and consists of two
concentric conductors, and it is an unbalanced transmission line.
Transmission line loss will reduce the transmitter power that radiates out the antenna.
These losses increase with higher SWR and higher frequency. As most line loss occurs
in the insulators supporting the conductors, lines such as ladder line will have lower
loss than most coax.
An important characteristic of a transmission line is its impedance. It is measured in
ohms and can range from 30 ohms for high power coax 600 - )00 ohms for wide spaced
ladder line. While the units of measure are ohms, impedance can't be measured by
putting the coaxial line in an ohmmeter. The characteristic impedance is not dependent
on the length of the line but rather on its physical arrangement of conductors.
Amateur Radio Basic Qualifications Manual
(1) Parallel Lines
Parallel lines come in various types. Included in this family
are the familiar TV twin lead (which can have solid or foam
insulation) and homemade or commercial ladder line. Ladder
line used to be quite popular because it was inexpensive and had
very low loss at HF frequencies. The disadvantage of ladder line
is that it must be kept away from other conductors, and cannot
be buried or strapped directly to a tower. Also, as the frequency
increases and the line spacing becomes a significant fraction of the
wavelength, the line will radiate some power. Because it is a balanced
line, it can feed a dipole directly without a balun at the antenna.
However, most transceivers now have a 50 ohm unbalanced output and
will require a balun transformer at the transceiver end. The impedance of
these lines varies according to the spacing and diameter of the
conductors. TV twin lead has an impedance of 300 ohms, while
commercial ladder line usually has an impedance of 450 or 600 ohms.
Figure 38 Ladder Line
(2) Coaxial Cable
Coaxial cable consists of coaxial conductors with dielectric
insulation in the gap. The inner conductor carries the signal and
the outer conductor is usually at ground potential. As the outer
conductor completely shields the signal on the inner conductor,
coaxial line can be buried or run close to metal objects with
effects. Coaxial cables come in various sizes, from miniature RG174 to 2 inch and larger hardline. The smaller sizes are for short
distances and low power while the larger sizes have greater power
handling capability as well as lower loss. The ratio of the conductor sizes determines the feedline
impedance. Most amateurs use 50 ohm coaxial while cable TV mainly uses 75 ohm coax. The
dielectric (insulator) used is the main source of power loss. Most coax uses solid polyethylene,
while some types use foamed polyethylene. The foam version has lower loss, while the solid
insulator is more rugged. Hardline has extremely low loss because it has a solid outer conductor
(rather than a wire braid), and the inner conductor supported on either an insulating spiral or
beads so that most of the insulation is air. This type of feedline is harder to work with because it
can't be bent very sharply, and the connectors for it are very expensive.
Amateur Radio Basic Qualifications Manual
(3) Baluns
Baluns are devices that convert from a balanced to an unbalanced line. When a balanced
antenna (such as a dipole) is fed directly with coax, the antenna currents (which are
inherently balanced) will run on the outside of the coax to balance the coax cable currents,
which are inherently unbalanced. This feedline current leads to RF radiation by the line and
the antenna. This can distort the antenna pattern. Also, the RF can travel back down the
shielding to the station and cause metal surfaces to become live with RF. RF shocks, while
not fatal, are unpleasant and should be avoided. To avoid shocks use a balun when
connecting balanced to unbalanced (and vice versa). A balun transformer is a device that
may be found on the back of a TV, connecting the antenna terminals to your cable
television coax. This device is converts from balanced to unbalanced, in addition to
transforming the impedance from 75 to 300 ohms.
Amateur Radio Basic Qualifications Manual
This section differs from the rest in this book in that knowledge of this material is not
essential to successfully pass the amateur radio examination. There are only a small
number of questions that appear in the exam covering this area. It does, however,
contain valuable information on what to do once you have a certificate, a license for
your station, and a microphone in your hand. Listening to amateur radio conversations
is a good way to acquaint yourself with the formal and informal procedures which are
used during an "exchange of communications," as the regulations so cryptically phrase
it. Keep in mind that although there are a great many "good" operators out there, there
are also a number of poor ones (who have acquired the undesirable label "lid"), who
may have (inadvertently) picked up someone else's bad habits. It is the purpose of this
chapter to give you a good start.
Starting a conversation on VHF FM
Your first contact will very likely be with another ham in your immediate area, and
most likely a friend or fellow club member. The examples here assume that your
friend's name is Cam and his call is VE7ACW, and that your name is Doug and your
new call is VE7EWU. First you need to know what frequency Cam normally listens to
and whether or not it is a repeater. Select this frequency on your radio. Each radio is
different in this respect, so you must refer to the vendor manual for your specific radio.
Cam is most likely listening to the UBC club repeater, the frequency is 145.270 MHz.
But to be heard on the repeater output, you must transmit on the input frequency for the
repeater. You must select the proper offset (-600 kHz below 147.000 MHz and +600
kHz above 147.000 MHz is standard in western Canada). You are now set up to listen
to 145.270 MHz, and to transmit on 144.670 MHz (offset -600 kHz) so that everyone
else can hear you on the repeater. If the repeater is busy you may want to try again later
(or if you are really brave, you may join in on the current conversation, more on that
later). Always listen first to ensure that you do not disrupt a conversation in progress. If
you hear no activity for at least one minute, you can assume that the frequency is
available. If it was busy and the stations you heard signed "clear" after their callsigns,
you can assume that the frequency is available if no one else jumps in after 30 seconds
or so.
(1) A Basic Contact
When you call someone, you give their call first, and your call last. When you are ready to
transmit, press the transmit button, and then speak clearly about two inches away from the
Doug: (transmit) "V E 7 A C W, this is VE 7E W U." (unkey)
If the repeater has heard you and is retransmitting your signal, you should hear a squelch
tail (a "kerchunk") as the repeater still transmits for a second or two after you stop
Amateur Radio Basic Qualifications Manual
transmitting. Some repeaters have a courtesy tone (a beep) that indicates that a
transmission is finished. If Cam has heard you, Cam can now reply, and you will hear:
Cam: "V E 7 E W U, V E 7 ,4 C W (beep)"
At this point you have established contact, and may start a conversation:
Doug.• "Hi Cam, this is Doug, and this is the first time I have actually made a contact.
Cam: "Hi Doug, and congratulations on passing the exam and getting your licence.
What kind of radio did you buy? (beep)"
Doug: "It's an ICOM 2SAT, a real neat little radio . . . etc."
When you decide that you have talked enough, it is time to say good-bye, and this
procedure is very similar to the way the contact was started.
Doug: "It's time to go for dinner Cam, so 73s for now and thanks for being my first
contact. (beep)"
Cam: "OK Doug, see you later, and don't forget about the club meeting next week
Doug: 'Don't worry, I'll remember! VE 7A C W, VE 7E W U clear"
Cam: "V E7ACW clear"
Use of the term "clear", which means that you are finished talking, and the frequency is
available for someone else to use.
(2) Variations in Procedure
Of course there are many variations for each of these steps. You don't have to say "this is".
Stating the other station's consign followed by yours is enough. You can use phonetics for
one or more of the callsigns:
"Victor Echo Seven Alpha Charlie Whiskey, Victor Echo Seven Echo Whiskey Uniform. "
If reception conditions are marginal, you may want to repeat the other station's callsign to
be sure that he hears you.
"V E 7 A C W, Victor Echo Seven Alpha Charlie Whiskey, this is VE 7E W U"
You can also repeat your consign, especially when the other station may be having trouble
hearing you. Under marginal conditions, such as when you are far away from the repeater
and your signal activates the repeater but may be scratchy (noisy), callsigns might be
repeated up to a maximum of three times.
Looking for Anyone to Contact
If you just want someone to talk to on VHF FM and are not looking for anyone in
particular, you can give your consign and say "monitoring". This indicates you would like
to start a conversation with someone. "CQ" serves a similar function but is reserved for
contacts made on SSB, CW and on HF or satellites.
* Written by Doug Wirsz, B.Sc., MSc., PhD. (Chemistry), VE7EWU
Amateur Radio Basic Qualifications Manual
Changing to a Different Frequency
Once contact is established, you may want to change frequencies to a repeater with more
reliable coverage of both your areas. In this case you suggest a change in frequency
Doug: "V E 7 A C W, VE 7E W U, QSY to 147.140, up 600"
Cam: "Roger, VE 7A C W, QSY"
The "up 600" is just an optional reminder of the offset of the other repeater, and the
"Roger" is the quickest way to say "yes, I understand, let's do it".
Contact is established on the other repeater just as shown previously.
If the other repeater (147.140) is busy, it is usually understood that you should return to
the previous repeater (145.270) before trying any other frequencies.
Marginal Repeater Reception Conditions
Poor reception due to weak signals is often a problem when you are some distance from
the repeater, or using only a small "rubber duck" antenna. If you don't think you are
reaching the repeater (no courtesy tone or "kerchunk" is heard), try the following:
 use a better antenna (like a quarter wave or a half wave)
 increasing power (from low to high power)
 move the antenna a foot or two in any direction.
You may notice "solid" (strong) copy of the repeater at one position, while only a few
feet away reception is very weak and distorted. This is due to multipath propagation, and
changing your position changes the path. If you are inside a building, going outside or
near a window may help, especially if the building is concrete or steel reinforced.
(6) Joining a Conversation in Progress
If you hear a group talking on a repeater and you would like to join in the conversation,
wait until there is a break between transmissions. To decide when to let your presence be
known, listen for a few minutes, and observe who seems to wait the longest before
transmitting when it is their turn. As soon as the other station has stopped transmitting
and you hear the courtesy tone (wait about a second if there is no courtesy tone), say
your callsign once, and then stop transmitting. The idea is to jump into the space
between transmissions without transmitting on top of someone else. Then be patient. If
you have been heard, the next station to talk may recognize you immediately, and call
you back, or may wait until the end of his transmission to acknowledge your presence. If
there are several people on frequency, it may take a while, but you .would be
acknowledged before everyone has had a second chance to transmit. If you don't hear
any response to your call, don't despair. Your signal into the repeater might be marginal,
or you might have started to transmit just when someone else did even though you tried
Amateur Radio Basic Qualifications Manual
to avoid it. Again, be patient, and try once more with your callsign only (i.e.
"VE7EWU") in an appropriate break. It sometimes takes practice to get the timing right.
A variation you may hear is to yell "break" during a lull. Although this usually works, it
doesn't tell the other stations who you are and is commonly viewed as impolite. More
importantly, it incorrectly conveys the urgency of your desire to talk. The UBC Amateur
Radio Society encourages its members to use their consigns when joining a conversation
in progress, as it indicates that you would like to talk, but are not in immediate need of
the frequency. "Break" is reserved for more urgent situations, and a double break
("Break Break") for emergencies.
(7) In an Emergency
In an emergency, "Break Break" or "Mayday" are generally recognized as a way to get
immediate attention. But be sure that it is an emergency (a life threatening situation), or
you risk being labeled a "lid" in addition to violating the Radio Regulations.
A conversation in Morse code on HF
The following is an example of a typical contact between two Amateur radio stations
using Morse code. Explanatory notes follow the example.
Doug: QRL? DE VE7EWU (note I)
VE7ACW VE7ACW KN (note 3)
VE7ACW KN (note 5)
The conversation continues for as long as desired, with the exchange of any information of
interest to the two parties. If they have met before they would already know their common
interests, but if they have just met they may discuss whatever comes to mind, perhaps
computers, music, travel, or the adventures of student life. At some point one of the two
parties will want to say good-bye, so the contact concludes as follows.
Amateur Radio Basic Qualifications Manual
1) QRL? - is the frequency already in use? It is polite to ask this first in case another
station which you cannot hear (but someone else can) is already on the frequency. If there is
a positive response to this question, try a different frequency.
2) This is a standard 3 by 3 general call for a contact. The call may be made more specific
by alternating CQ with a location.
or: CQ DX CQ DX (DX means a long distance, as in outside North America)
3) In answering a CQ, the callsigns are repeated 3 times to ensure that the correct callsigns
are recorded at both ends.
4) Signal Reports
R - readability on a scale from 1 to 5.
5 = easily heard
4 = heard with a little difficulty
3 = heard with considerable difficulty
2 = heard, but most information lost
1 = barely audible signal
S - strength of the signal in S units from 1 to 9
This is read directly from the signal strength meter on the receiver.
T - tone from 1 to 9
These days a 9 is almost always sent, even if it is not deserved, so this part of
the report has lost its meaning. The original intention was to comment on the
stability and quality of the CW tone, with 9 being a pure tone, and 1 indicating
extreme AC hum or a "whooping" sound indicating an unstable oscillator.
5) Either degrees Fahrenheit or Celsius may be quoted.
6) At the very end of the contact, it is quite common, especially among American
novices, to send "dit dit" ( E E) as a final good-bye.
Amateur Radio Basic Qualifications Manual
ABT - about
ANT - antenna
AR - (didandidandit), end of message
AS - (didandididit), standby
BEAM - directional antenna
COPY - receive information correctly
CQ - general call to contact any station
CUAGN - see you again
CW - continuous wave, more commonly referred to as Morse code
DE - this is
EL - element (on a directional antenna)
FB - fine business, very good
FER - for (quicker to send than the proper spelling)
GL - good luck
GM - good morning
GA - good afternoon
GE - good evening
GN - good night
HI - laughter
HW? or HW? COPY - how do you copy my signal? or - did you copy all the information?
HPE - hope
HR - here
INV VEE, VEE - inverted V antenna
K - (dandidah), waiting for an answer from any station
KN - (dandidandandit), waiting for an answer from only the station called
OM - old man (refers to any male radio operator)
Q## - Q signals (see Part I, section E, Q signals)
R - roger, affirmative, yes
RIG - radio
RST - signal report
SIG - signal
SK - (didididandidah), ending a contact
SLOPER - sloping dipole antenna
TNX, TU - thank you
U, Ult, URS - you, your, yours
WX - weather
XYL - wife
YL - young lady (refers to any female radio operator)
73 - best greetings, good-bye
Note that the abbreviations AR, AS, KN and SK are sent in Morse code as one character
Amateur Radio Basic Qualifications Manual
D. Identification
You are required by law to identify at least every half hour during a conversation. In
practice, people commonly identify every ten or fifteen minutes. Once a solid contact is
established this is quite adequate. Just put your callsign at the end of one of your
transmissions every fifteen minutes or so and everyone should be happy. Remember that
the last consign you give when calling someone MUST be your own.
Doug: " ... so back to you Cam. VE7EFVU."
In a case where several hams are on the same frequency, you will find yourself identifying
more frequently out of necessity. You may indicate who is next to talk by giving their call
and yours at the end of your transmission. This reduces the likelihood of two or more hams
transmitting at the same time, making neither one intelligible. When one ham accidentally
transmits on top of someone else, this is called "doubling".
Doug: ".... YE7ACW , in the group, VE7EWEI."
Simplex, Duplex and Band Plans
All repeaters operate in a duplex mode. This uses two frequencies. You listen on an output
frequency, tuned directly on your radio, and transmit on an input frequency, which is
automatically selected by your radio when you transmit (assuming you have set the proper
offset, + or -).
For shorter distance communications, or to "get away" to a less busy frequency, it is
common to use a simplex frequency, where you transmit and receive on the same
frequency. No repeater is involved, so you hear the other station's signal directly. Of
course, there will be no courtesy tone. You will only hear a squelch tail when the other
station stops transmitting. In fact, you may not hear the other station at all, even if it was
full quieting (a very clear signal) on a repeater. This is because most repeaters are located
on high buildings or mountains, and thus can "see" much farther (remember that 'VHF
propagation is "line of sight") than you can from your lower geographic location. The
other station must be within your radio horizon for you to talk directly on a simplex
The 2 metre band is divided up into different segments allocated to different activities. A
brief chart giving examples for British Columbia is given below, but keep in mind that exact
frequencies within these band segments may differ by region (for example, Ontario uses
15kHz spacing, not 20kHz).
144.000 - 144.100 CW (Morse code)
144.100 - 144.300 USB
144.300 - 144.500 Mode L satellite uplinks (SSB and CW)
144.510 - 144.890 repeater inputs (don't transmit simplex here!)
144.910 - 145.090 packet radio every 20 ktiz
145.110 - 145.490 repeater outputs every 20 kHz (-600 offsets)
Amateur Radio Basic Qualifications Manual
145.510 - 145.690 packet radio duplex digipeater inputs
145.710 - 145.790 simplex every 20 kHz
145.800 - 146.000 Mode B satellite downlinks (don't transmit!)
146.020 - 146.400 repeater inputs (don't transmit simplex here)
146.420 - 146.600 simplex every 20kHz (146.520 FM simplex calling
frequency)146.620 - 147.000 repeater outputs every 20 kHz (-600 offset)
147.020 - 147.380 repeater outputs every 20 kHz (+600 offset)
147.400 - 147.580 simplex every 20 kHz
147.600 - 147.980 repeater inputs (don't transmit simplex here)
Similar plans exist for all other amateur frequencies. You should talk to someone who uses
the other bands and is familiar with them, before transmitting on those bands.
Topics of Discussion and Common Sense
Use your common sense in deciding which topics are appropriate for a conversation on the
amateur radio bands. There are no restrictions on topics, but remember that in addition to
the person you are talking to, there could be many other hams listening, and even more
people with scanners. This does not mean that you should avoid controversial topics, but
keep in mind that a community standard applies, and what is an acceptable topic for a
friend on two metres in Vancouver may not be an acceptable topic for someone on HF in
Luxembourg. In fact you may find considerable variation from one repeater to the next. As
the "community" that commonly uses each frequency may differ, so may their community
standard. It is better to drop a topic than get frustrated with someone on the air. Remember,
it's only a hobby!
Checking Into Nets
A net is a gathering of a large number of hams on a single frequency. A single station acts
as net control (a supervisor), and all stations contact the net control station to check in. This
is an easy way, especially on HF, to find another ham whom you know to be active. The
net control station will commonly go through a roll call where he sequentially lists
different geographic areas and invites stations in those areas to "check in" or announce
their presence by giving their callsign. If the station you want to talk to is heard you may
call "contact" and wait for the net control station to recognize you. You then speak to the
net control station (NOT directly to the other station) and request permission to call the
other station to arrange a meeting on another frequency.
(1) Contacting another station you just heard.
Net Control: "This is VE7FVH, net control. Any stations from Richmond?"
Amateur Radio Basic Qualifications Manual
Wait for a break in the transmissions. Don't transmit on top of someone else! Suppose
again that you (alias Doug (VE7EWU) in this example) would like to contact another
station. The exchange should proceed as follows:
Doug: "Contact."
Net Control: "Go the contact."
Doug: "This is VE7EWU. Could I contact VE7ACW on 145.270?"
Net Control: "VE7ACW, do you copy OSY 145.270? "
VE7ACW: "Roger, QSY 145.270."
Doug: "Thank you net, VE7EFVU, QSY."
(2) Looking for someone you have not heard.
Alternately, when your area is called, you may give your callsign and (in addition)
say "with traffic".
Net Control: "This is VE7FV-1-1: Any stations from Vancouver?"
Doug: "VE7EWU with traffic"
Net Control: "VE7EWU, go with your traffic."
Doug: "Looking for VE7ACW in Richmond"
Net Control: "Is VE7ACW on frequency tonight?"
Net Control: "No copy on VE7ACW Would you like me to list him?"
You have a choice here. You can say "no", which means you don't want to try to
call him again later. In this case you thank the net and may leave. If you say "yes"
the Net Control station will periodically call for your friend, adding his callsign to
the list of callsigns which other people may be looking for. In this case, you should
stay on frequency and listen in case your friend shows up. If you decide not to wait
any longer, then contact the Net Control station and cancel your traffic. DON'T just
disappear, since the Net Control and everyone else on the net are trying to help you
to find your friend.
Doug: "No thanks. 111411 look for him tomorrow. Thank you net. VE7EFFU."
(3 ) Announcing your presence.
Finally, you may want to check into a net just to indicate that you are listening. This
is done by giving your callsign when your area is mentioned. Quite often a friend
may be listening and hoping to contact you if you are on the net, and of course he
will never know if you are listening unless you announce your presence. Some nets
also commonly use the Q signal QRU, which means that you have no traffic. As a
general rule, listen first to see how other stations are checking into the net.
Net Control: "Any Vancouver?"
Doug: "VE7EWU"
Doug: "VE7EWU, QRU."
Doug: "VE7EWU, no traffic."
Amateur Radio Basic Qualifications Manual
7.; As with any amateur radio activity which you are not familiar with, listen for a
while first to get an idea of how things work. Nets can be particularly useful to
listen to since they commonly have announcements relating to amateur radio
from national organizations, local club news and activities, and swap and shops,
which are listings of amateur radio equipment for sale by local hams.
H. Telephone Patches
A phone patch is a device that feeds audio from a radio receiver to a telephone line,
and audio from the telephone line to the microphone input of the radio transmitter.
This allows you to use your radio to talk with someone who is on the telephone.
On HF, phone patches are usually manually operated by a fellow ham who switches
between transmit and receive as you and your friend on the telephone talk.
On VHF automatic phone patches may be heard on certain repeaters in your area, or
even on simplex. These phone patches are activated by transmitting a touch tone
access code. Many clubs install phone patches on their repeaters, and give their club
members the access codes to bring up the phone patch and dial numbers. Many phone
patches can also be found on simplex frequencies. These phone patches are generally
owned by individuals, and as they are connected to a private telephone line, you should
ask permission from the owner of the phone patch before using it, even if someone else
has given you the access codes.
Phone patches differ from radiotelephones (cellular phones) in that you cannot listen
while you are transmitting; you must release the transmit button to hear the other
person. Also, since you are using amateur radio frequencies, you cannot conduct
business through a phone patch. Many hams may use a phone patch on a busy repeater
throughout the day, so you should keep your calls short. Also keep in mind that the
phone company no doubt frowns upon you using your own phone patch rather than
paying for their radiotelephone. The only reason hams are allowed to maintain phone
patches is that during an emergency an amateur radio phone patch may be the only
means of obtaining help. This is a privilege which should not be abused.
Standard Phonetic Alphabet
You will hear many different ways of phonetically spelling out words. Some use country
names. Others use "cute" combinations of words. All of these approaches share a
common feature. They are inefficient, as they may confuse rather than assist the other
station in figuring out what you are saying, especially when reception of your signal is
marginal. There exists a worldwide standard set of 26 words to represent the letters of
the alphabet, with each word selected to be as different from the others as possible. This
helps a message to get through even under the worst reception conditions. If you decide
to use these phonetics, the station listening to you knows to expect only one of 26
Amateur Radio Basic Qualifications Manual
distinct words, and will more easily recognize them. If you choose to use some other set
of phonetics, the station who is trying to hear you must now struggle to determine which
of the 400,000 words in the English language you have arbitrarily chosen to pass your
message. Use the standard phonetic alphabet, and memorize it.
Common Abbreviations
A number of phrases used on the amateur radio bands may at first be unfamiliar to you.
As with any hobby, amateur radio has its own jargon. A number of common
expressions are included below (including two to avoid!).
Okay, I understand.
a poor operator
radio equipment
how copy? How is my signal?
Do you understand/receive?
digipeater a simplex packet radio retransmitter
bye for now.
love and kisses.
a long distance contact for the band in use
calling for a contact (SSB or CW)
monitoring calling for a contact (VHF FM)
two stations transmitted at the same time
Two phrases to AVOID!
use "name" instead
If you want to join an existing conversation, use your own consign.
"break" should be used only in more urgent situations.
Another source of confusion for a new ham is the use of Q signals on voice transmissions.
Q signals serve a useful purpose as internationally recognized abbreviations in Morse code,
but there is really no reason to use them in a voice contact. The UBC Amateur Radio
Society suggests the following preferred phrases, especially on VHF.
Amateur Radio Basic Qualifications Manual
Q Signal Preferred Phrase
(Morse code) (Voice)
low power
going off the air
is there a station calling?
fading or flutter
send a QSL card (can also mean "I understand")
change frequency to ...
Digital Modes
While most familiar forms of radio communication are analog in nature (i.e.
broadcasting, TV, etc.), much of the advancement in radio technology today involves
using digital modes. The simplest digital mode is Morse code (also known as CW for
continuous wave, it is more accurately described as an interrupted carrier). While
some experienced operators can achieve speeds up to 60 words per minute, this is
much slower than more advanced digital modes. The most common of these modes
which are used in amateur radio are radioteletype (RTTY), PSK31, AMTOR (a
variant on RTTY), and packet radio.
RTTY is the oldest of the machine generated digital modes. RTTY works by
encoding characters into a digital code. The most common digital coding scheme
used is Baudot, which uses a number between 0 and 31 to represent the various
letters, digits and punctuation marks. In order to fit more than 32 different characters
into the code, some numbers are used twice, with a special character used to switch
between the two meanings. The number can be represented by a 5 digit binary
number (i.e. 14 = 01110 in binary). To send a character over the radio, each bit
(binary digit) is assigned to one of two tones, and the audio output of each bit in
succession is then fed to the modulator. The two states of a bit (0 and 1) are referred
to as mark and space. The device that produces a tone for each state is called a
modem. In order for the receiving end to be able to decode the character sent, the bits
must be sent at a constant speed. Common speeds used by amateurs are 60 wpm, 67
wpm, 75 wpm, 100 wpm and 132 wpm. The two tones must also maintain a fixed
frequency separation or shift. The most common shift used by amateurs on BF is 170
Hz. While Baudot is the most commonly used code, ASCII, a 7 bit code common in
computer communication can be used.
Amateur Radio Basic Qualifications Manual
PSK31 is the first new digital mode to find popularity on HF in many years. It has
recently gained popularity along with the proliferation of inexpensive computers with
sound cards. Low power and inexpensive equipment with plenty of free software will
get you on the air quickly in this mode.
AMTOR is a form of RTTY that uses error checking to ensure that the data that is
sent is received correctly. The message being sent is broken up into groups of 3
characters each. A checksum is calculated and appended to the group and the
resulting small packet is then transmitted through a modem to the radio. The system
can operate in two modes, A and B. Mode B checks the data but will not ask for a
repeat and is used for establishing a contact (i.e. calling CQ). Mode A uses
Automatic Repeat Request (ARQ) to ask the sending station to resend any packets
that are not received properly once contact is established.
Packet radio is a system similar to AMTOR, but with more powerful error checking
and message handling abilities. The system sends and receives larger packets and
encodes in each the sender and destination addresses. This allows a limited number of
stations to carry on independent conversations without interference. The effective
communication rate will be reduced if many stations are using the same frequency and
excessive packet collisions occur. Packets are assembled and prepared for transmission
by a terminal node controller (TNC). The individual characters are usually encoded in
ASCII and the packet format is usually set to the AX.25 protocol, though other formats
do exist. The assembled packet is then passed to a modem and a radio in the same
fashion as RTTY and AMTOR. Packet radio allows automated message forwarding
throughout the world, but most activity takes place on VHF and higher bands where
the more stable propagation prevails. Large centers of activity in different cities are
then connected to each other either via a series of VHF relay stations, or by larger hops
through HF gateways.
Amateur Radio Basic Qualifications Manual
L. Industry Canada
Regulatory requirements for acquiring an amateur radio license are in flux. The Morse
code requirement for the Advanced license has dropped to five words per minute and
may be dropped entirely in the near future. Anyone wishing to take the exams should
review the latest requirements on the Industry Canada web site. Sample exams may also
be downloaded.
Exams are multiple choice and usually heavy on regulations as compared to the
technical content. They may be administered by your local amateur radio club or
authorized Industry Canada representative. There will often be a minimal fee in the
range of twenty dollars.
G o o d l u c k o n t h e e x a m!
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project