Radio amateur examination extended readings

4x4 Adventures
The Essentials:
Malaysian
Radio Amateur Examination RAE
Extended Readings
9th April 2019
Charliechong 黑豹 https://sems.skmm.gov.my/sems/

黑豹
The PUMA
VHF 104.500MHz

Charliechong 黑豹
黑豹
The PUMA
VHF 104.500MHz
https://sems.skmm.gov.my/sems/

Charliechong
The handbook
黑豹

The Puma
Charliechong 黑豹 https://www.facebook.com/puma4x4https://sems.skmm.gov.my/sems/

Charliechong
Zello PTT Walkie Talkie
黑豹 https://play.google.com/store/apps/details?id=com.loudtalks&hl=en_US
Internet Based Walkie Talkie

Charliechong
The Magical Book of Amateur Radio Operator.
https://sems.skmm.gov.my/sems/

Charlie Chong https://sems.skmm.gov.my/sems/

Charliechong
Michio-Kaku
黑豹 https://www.youtube.com/embed/Ih01TpcW8sY

Radio Amateur Examination
Questions &Answers
For Amateur Radio Services In Malaysia
https://www.skmm.gov.my/skmmgovmy/files/attachments/Guideline_Amateur_Radio_Service_2012.pdfCharliechong 黑豹

4x4 Adventures
The Essentials:
Malaysian
Numbers to Remember
9th April 2019

Charliechong
About Amateur Radio
Amateur radio service is defined in the Communications and
Multimedia (Spectrum) Regulations 2000 as “a radio
communications service (covering both terrestrial and satellite) in which
a station is used for the purpose of self training, intercommunication
and technical investigations carried out by authorized persons who are
interested in radio technique solely with a personal aim and without any
pecuniary interest”.
黑豹 https://www.skmm.gov.my/skmmgovmy/files/attachments/Guideline_Amateur_Radio_Service_2012.pdf

Charliechong
If your ASAA application is approved, SKMM will issue a call sign with
“9W” or “9M” prefix depending on your eligible operating class. This call
sign is unique to amateur radio operator. You must use it on the air to
legally identify your amateur station during any and all radio
communication. The entry level to obtain the ASAA (or in general it’s
call as the Amateur License) is ASAA Class B (“9W” prefix). You must
operate on Class B for at least one year before eligible to upgrade
your license to Class A (“9M” prefix).

Charliechong
CMA98
Spectrum Plan and Frequency Allocations
In Malaysia, SKMM has the overall responsibility for managing radio
frequency spectrum under the Communication and Multimedia Act
1998 (CMA98). Among other responsibilities of the SKMM include the
task of developing a spectrum plan in respect of all or any part of the
spectrum. TheCMA98, as the main legislation which regulates the
communications and multimedia industries, also sets out the national
policy objectives for the development of the communications industries.

Charliechong
Standard Radio System Plan (SRSP)
SKMM has also developed a series of documents that is part of the
spectrum plan to provide guidance on efficient spectrum usage namely
Standard Radio System Plan (SRSP). It is designed to provide
information on the minimum requirements in the use of the frequency
band as described in the Spectrum Plan. It provides information on
technical characteristics of radio systems, channelling of frequencies
and coordination initiatives.
For example the SRSP “MCMC SRSP 536 AS” states the equirements
for the utilization of the frequency band 144 MHz to 148 MHz for
Amateur Service in Malaysia.

Charliechong
Amateur Station Apparatus Assignment ASAA
All amateur radio operators in Malaysia must be licensed by getting the
ASAA from SKMM. You need to obtain an ASAA to operate an amateur
radio station. The ASAA authorized the holder to participate and
operate the amateur radio station.
There are 3 types of ASAA under Amateur Radio category:
a) Amateur Station Apparatus Assignment (Class A);
b) Amateur Station Apparatus Assignment (Class B); and
c) Amateur Repeater Station

Charliechong
Eligibility for ASAA Application
To be eligible for ASAA application, applicant must meet the following
conditions.
a) Over 14 years of age for ASAA Class B and 18 years and above
for ASAA Class A. Applicants under 21 years will be required to
present consent from their parent, guardian or any other approved
person who shall be responsible for the observance of the
conditions of the applicants to countersigned their application.

Charliechong
Fee for Apparatus Assignment Amateur Station
The fees for the ASAA are tabled as below.

Charliechong
Examination fee
The fee for the examinations are as followed.

Charliechong
The RAE
The RAE comprises 100 objective questions with four optional answers.
Candidates are given three hours to answer all questions. The question
is in bi-language i.e. English and “Bahasa Melayu”. Passing mark for
the RAE is 50%. No marks are deducted for a wrong answer. The
structure of the question is as shown in the following table.

Charliechong
Operating the Amateur Stations
The amateur radio operators shall adhere to the following.
Emergency
b) The word “BREAK” should never be used to join a conversation in
the progress.
c) Only use of word “BREAK” or even better “BREAK BREAK BREAK”
in emergency of life-threatening situation. Better is to say ”BREAK
BREAK BREAK with emergency traffic”
d) The radio operator should immediately introduce his/her identity by
transmitting his/her call sign after calling “BREAK”. All other stations
must release the frequency immediately and be on stand-by to
assist if necessary.

Charliechong
Operating the Amateur Stations
The amateur radio operators shall adhere to the following.
k) When operating amateur radio station through amateur radio
repeater station, the order of priority shall be as below.

Charliechong
Interference
Please ensure that the radio transmission does not cause interference
to any other radio services.
Regulation 15 (1) of the Communications and Multimedia (Technical
Standards) Regulations 2000 states that no person shall intentionally
design, install, operate, maintain or modify any communications
equipment in a manner is likely to cause interference with, impairment,
or malfunction of, or harm to any communications equipment or any
other equipment.
Regulation 15 (2) of the regulation denotes that a person who
contravenes this regulation commits an offence and shall, on
conviction, be liable to a fine not exceeding three hundred thousand
ringgit (RM 300,000.00) or to imprisonment for a term of not exceeding
three years or to both.

Charliechong
Signal Reports

Charliechong
Examination RAE
I. Regulation and Approval Condition
Knowledge on:
c) The scope of ITU Radio Regulation.
i) The number of regions and which region Malaysia belongs to; (3)
ii) The prefixes of the “call sign” allocated to Malaysia; and (9W/9M)
iii) The definition of Amateur Service.

Charliechong
Examination RAE
d) Basic understanding on relevant provision under the Acts which are
applicable to the amateur radio services specifically. You must have
basic
knowledge on:
i) The Communications and Multimedia Act 1998;
ii) The Communications and Multimedia (Technical Standards)
Regulations 2000;
iii) The Communications and Multimedia (Spectrum) Regulations 2000;
iv) The Malaysian Communications and Multimedia Commission
(SKMM) as the regulatory authority for amateur radio in Malaysia;
v) The Apparatus Assignment for amateur radio operation such as
qualifications requirement, fees, assignment classes and other
related;
vi) The frequencies allocations, AA conditions (terms, provisions and
limitations) and frequency bands, power level, class of emission
code and types of transmission; and
vii) Nature of Amateur Service and Amateur Satellite Service.

Charliechong
Class B privilege

Charliechong
Number
My answer: -)
The correct answer: a)

Charliechong
T8A08
What is the approximate bandwidth of a single sideband
voice signal?
A. 1 kHz
B. 3 kHz
C. 6 kHz
D. 15 kHz
黑豹 https://www.arrl.org/files/file/Get%20Licensed/HRLM%202nd/QPOOL-study%20guide-2nd-ed.pdf

Charliechong
T8A09
What is the approximate bandwidth of a VHF repeater FM
phone signal?
A. Less than 500 Hz
B. About 150 kHz
C. Between 5 and 15 kHz
D. Between 50 and 125 kHz

Charliechong
T8A10
What is the typical bandwidth of analog fast-scan TV
transmissions on the 70 cm band?
A. More than 10 MHz
B. About 6 MHz
C. About 3 MHz
D. About 1 MHz

Charliechong
T8A11
What is the approximate maximum bandwidth required to
transmit a CW signal?
A. 2.4 kHz
B. 150 Hz
C. 1000 Hz
D. 15 kHz

Fast Scan TV
≈6 MHzVHF-FM
5 ~15 kHzSSB
3 kHz
Charliechong 黑豹 https://www.arrl.org/files/file/Get%20Licensed/HRLM%202nd/QPOOL-study%20guide-2nd-ed.pdf
CW
150kHz
Band Width

Band Width
Fast Scan TV
≈6 MHz
VHF-FM
5 ~15 kHz
SSB
3 kHzCW
150kHz
Band Frequency
LF 0.03-0.3MHz
MF 0.3-3MHz
HF 3-30MHz
VHF 30-300MHz
UHF 300-3000MHz

Charliechong
Q153. The standard frequency offset (split) for 2 meter
repeaters in Malaysia is
a) Plus 600kHz c) minus 5 MHz
b) minus 600kHz d) plus5 MHZ
Q193. The standard frequency offset (split) for 70 cm
repeaters in Malaysia is
a) plus 600kHz c) minus 500kHz
b) minus 5 MHz d) plus 5MHz

Charliechong
Repeater Offset
UHF
minus 5 MHz
VHF-FM
minus 600kHz
SSB
-CW
-

Charliechong
Q146. The standard tone use for amateur repeaters in
Malaysia is
a) 203.5 MHz c) 103.5 Hz
b) 203.5 Hz d) 250.3 Hz
My answer: a) The correct answer: a)

Charliechong
T4B09) Which of the following is an appropriate receive
filter bandwidth to select in order to minimize noise and
interference for SSB reception?
A. 500 Hz
B. 1000 Hz
C. 2400 Hz
D. 5000 Hz
My answer: -)
The correct answer: c)

Charliechong
T4B10) Which of the following is an appropriate receive
filter bandwidth to select in order to minimize noise and
interference for CW reception?
A. 500 Hz
B. 1000 Hz
C. 2400 Hz
D. 5000 Hz
My answer: -)

Charliechong
T4B09
Which of the following is an appropriate receive filter to
select in order to minimize noise and interference for SSB
reception?
A. 500 Hz
B. 1000 Hz
C. 2400 Hz
D. 5000 Hz
2400Hz= 0.0024MHz
HF: 3MHz- 30MHz
Class B privilege for HF
: 28MHz- 29.7MHz
0.0024MHz

Charliechong
T4B10
Which of the following is an appropriate receive filter to
select in order to minimize noise and interference for CW
reception?
A. 500 Hz
B. 1000 Hz
C. 2400 Hz
D. 5000 Hz

Charliechong
What is the nominal voltage of a fully charged nickel-
cadmium cell?
A. 1.0 volts
B. 1.2 volts
C. 1.5 volts
D. 2.2 volts

Charliechong
T2A01
What is the most common repeater frequency offset in the 2
meter band?
A. Plus 500 kHz
B. Plus or minus 600 kHz
C. Minus 500 kHz
D. Only plus 600 kHz

Charliechong
T2A03
What is a common repeater frequency offset in the 70 cm
band?
A. Plus or minus 5 MHz
B. Plus or minus 600 kHz
C. Minus 600 kHz
D. Plus 600 kHz

Charliechong
T0A01
Which is a commonly accepted value for the lowest voltage
that can cause a dangerous electric shock?
A. 12 volts
B. 30 volts
C. 120 volts
D. 300 volts

Charliechong
Q39. The capacitor value best suited for filtering the output
of 12 volt 1 amp DC power supply is;
a) 100 pF c) 10 nF
b) 100 nF d) 10,000 uF
C = Q/V
C =
It
V
C =
1t
12
=
1x 0.01
12
106 = 833μF#
t = half cycle time for 50Hz DC (10ms)
My answer: d).
The correct answer is d).
Read more:
https://www.electronics-notes.com/articles/electronic_components/capacitors/capacitor-uses.php
黑豹 https://www.youtube.coam/embed/J9HsLWmtBnE

Charliechong
Q83. In the event of a national disaster which of the
following bands can be used by non-amateurs in the
disaster area in accordance with the Licensing conditions?
a) 144-146 MHz c) 29.0-29.7 MHz b) 146-148MHz d) none of these My answer: ?)

Charliechong
Q127. The total capacitance of two or more capacitors in
series Is
a) always less than that of the smallest capacitor
b) always greater than that of the largest capacitor
c) found by adding each of the capacitances together
d) found by adding the capacitances together and dividing by their total number
My answer: a) The correct answer: a)
黑豹 https://www.facebook.com/puma4x4

Charliechong
Capacitor Calculation
黑豹 https://keisan.casio.com/exec/system/1258035746

Charliechong
Capacitor in series always less than that of the smallest
capacitor

Charliechong
Inductor Calculation

Charliechong
Calculates the total inductance of two coils in series and
parallel.

Charliechong
Q146. The standard tone use for amateur repeaters in
Malaysia is
a) 203.5 MHz c) 103.5 Hz b) 203.5 Hz d) 250.3 Hz
Q181. The 'calling frequency' for 2 meter band is: a) V40-
145.550MHz c) V40-145.500MHz b) V40 - 145.300 MHZ d) V40- 145.200 MHZ

4x4 Adventures
The Essentials:
Malaysian
Unfamiliar Q&A
10th April 2019

Charliechong
 RIT- Receiver Increment Tuning
 XIT- Transmitter Increment Tuning
 Clarifier
黑豹 http://www.amateur-radio-wiki.net/index.php?title=Operating_procedures

Charliechong
RIT
RIT : Receiver Incremental Tuning is the ability to shift the receive frequency of a
transceiver away from the transmit frequency by a small amount. Used in SSB
transmissions, it was very useful in older rigs that had frequency stability problems
and in current systems using some homebrew transceivers or separate transmitters
and receivers. RIT can also be used to deliberately transmit and receive on different
frequencies. This is known as "working split", with the difference in frequencies usually
3 kHz to 10 kHz.
XIT
XIT : Xmitter Incremental Tuning is the ability to shift the transmit frequency of a
transceiver away from the receive frequency by a small amount. Used in SSB
transmissions, it was very useful in older rigs that had frequency stability problems
and in current systems using some homebrew transceivers or separate transmitters
and receivers. XIT can also be used to deliberately transmit and receive on different
frequencies. This is known as "working split", with the difference in frequencies usually
3 kHz to 10 kHz.
黑豹 http://www.amateur-radio-wiki.net/index.php?title=Operating_procedures

Charliechong
Which of the following controls could be used if the voice
pitch of a single-sideband signal seems too high or low?
A. The AGC or limiter
B. The bandwidth selection
C. The tone squelch
D. The receiver RIT or clarifier

Charliechong 黑豹 https://www.reddit.com/r/amateurradio/comments/a0by11/clarifier_vs_split_tuning/
Clarifier= RIT/XIT?
Clarifier vs. Split Tuning
I'm just learning to use my FT-450D mainly been spending time on digital modes and
listening to SSB. I'm just wondering what the difference between using your clarifier vs.
split tuning. Clarifier adjusts your receive frequency while keeping your transmit at the
same spot from what I understand. Doesn't enabling split and using A/B do the same
thing but allow for more offset? Or is it just two tools that can be used to solve similar
problems? 'Clarifier' (also known as receiver incremental tuning, or RIT, on some
radios) performs a slight adjustment on the tuned receive frequency...say, 14265KHz,
+/- 500Hz (or, above and below a frequency by a half KHz.) This is commonly used to
make fine adjustments to the receive only....this is largely cosmetic.
Split is something completely different. There, one can transmit on one frequency, and
receive on another. This is commonly used when a station (say, a DXpedition station)
is working a pile-up. The DXpedition station will have a set transmit frequency, and
tune a 3-5KHz range, some number of KHz away, to pick out stations they can
actually understand. Or, perhaps they have transmitting privileges in one ITU zone,
but are looking for contacts in another Zone. The DXpedition can transmit on a freq on
which they are authorized, but listen for stations in the range which those stations are
authorized to transmit.

Charliechong
Clarifier
.
黑豹 https://ham.stackexchange.com/questions/1467/how-is-clarifier-control-helpful

Charliechong
T4A05
What type of filter should be connected to a TV receiver as
the first step in trying to prevent RF overload from a nearby
2 meter transmitter?
A. Low-pass filter
B. High-pass filter
C. Band-pass filter
D. Band-reject filter

Charliechong
T3A09
Which of the following is a common effect of “skip” reflections between the Earth and
the ionosphere?
A. The sidebands become reversed at each reflection
B. The polarization of the original signal is randomized
C. The apparent frequency of the received signal is shifted by a random amount
D. Signals at frequencies above 30 MHz become stronger with each reflection
My answer: -)
The correct answer: b)

Charliechong
CTCS- Continuous Tone-Coded Squelch System
In telecommunications, Continuous Tone-Coded Squelch System or CTCSS is one
type of circuit that is used to reduce the annoyance of listening to other users on a
shared two-way radio communications channel. (See squelch.) It is sometimes
referred to as tone squelch. It does this by adding a low frequency audio tone to the
voice. Where more than one group of users is on the same radio frequency (called co-
channel users), CTCSS circuitry mutes those users who are using a different CTCSS
tone or no CTCSS. It is sometimes incorrectly referred to as a sub-channel because
no additional channels are created. All users with different CTCSS tones on the same
channel are still transmitting on the identical radio frequency, and their transmissions
interfere with each other, however the interference is masked under most (but not all)
conditions. The CTCSS feature also does not offer any security.
A receiver with just a carrier or noise squelch unmutes for any sufficiently strong signal;
in CTCSS mode it unmutes only when the signal also carries the correct sub-audible
audio tone. The tones are not actually below the range of human hearing, but are
poorly reproduced by most communications-grade speakers and in any event are
usually filtered out before being sent to the speaker or headphone. CTCSS can be
regarded as a form of in-band signaling.

Charliechong
Noise Blanker
In the design of radio receivers, a noise blanker is a circuit intended to reduce the
effect of certain kinds of radio noise on a received signal.
A noise blanker is a common feature on broadcast shortwave receivers or
communications receivers and some types of two-way radio transceivers. The noise
blanker is only effective on impulse-type noise such as from lightning or from
automotive ignition systems, and cannot improve performance on wideband
continuous background noise, or interfering signals on the same frequency. In cases
where there are strong signals on frequencies near to the desired frequency, a noise
blanker circuit may be ineffective and may reduce the quality of the received signal.

Charliechong
Noise Blanker
A Citizen's Band transceiver equipped with a noise blanker for the receiver, controlled
by a button on the front panel (2nd from left)

Charliechong
T8D01
Which of the following is an example of a digital
communications method?
A. Packet
B. PSK31
C. MFSK
D. All of these choices are correct

Charliechong
MFSK
Multiple frequency-shift keying (MFSK) is a variation of frequency-shift keying (FSK)
that uses more than two frequencies. MFSK is a form of M-ary orthogonal modulation,
where each symbol consists of one element from an alphabet of orthogonal
waveforms. M, the size of the alphabet, is usually a power of two so that each symbol
represents log2M bits.
M is usually between 2 and 64
Error Correction is generally also used

Charliechong 黑豹
PSK31
PSK31 or "Phase Shift Keying, 31 Baud",
also BPSK31 and QPSK31, is a popular
computer-sound card-generated
radioteletype mode, used primarily by
amateur radio operators to conduct real-
time keyboard-to-keyboard chat, most often
using frequencies in the high frequency
amateur radio bands (near-shortwave).
PSK31 is distinguished from other digital
modes in that it is specifically tuned to have
a data rate close to typing speed, and has
an extremely narrow bandwidth, allowing
many conversations in the same bandwidth
as a single voice channel. This narrow
bandwidth also concentrates the RF energy
in a very narrow space thus allowing
relatively low-power equipment (25 watts)
to communicate globally using the same
skywave propagation used by shortwave
radio stations.
https://en.wikipedia.org/wiki/PSK31

Charliechong
Packet Radio
Packet radio is a form of packet switching technology used to transmit digital data via
wireless communications. Packet radio uses the same concepts of data transmission
using datagrams that are fundamental to communications on the Internet, as opposed
to older techniques used by dedicated or switched circuits. Packet radio can be used
over long distances without the need for a physical connection between stations.
Packet radio can also be used for mobile communications.
Packet radio is a digital radio communications mode. Earlier digital modes were
telegraphy (using Morse code), teleprinter (using Baudot code) and facsimile.
Packet radio is a particular digital mode of Amateur Radio ("Ham" Radio)
communications which corresponds to computer telecommunications. The telephone
modem is replaced by a "magic" box called a terminal node controller (TNC); the
telephone is replaced by an amateur radio transceiver, and the phone system is
replaced by the "free" amateur radio waves. Packet radio takes any data stream sent
from a computer and sends that via radio to another amateur radio station similarly
equipped. Packet radio is so named because it sends the data in small bursts, or
packets.
黑豹 https://www.tapr.org/pr_intro.html

Charliechong
Packet Radio
黑豹 https://www.tapr.org/pr_intro.html

Charliechong
T8C10
How do you select a specific IRLP node when using a
portable transceiver?
A. Choose a specific CTCSS tone
B. Choose the correct DSC tone
C. Access the repeater autopatch
D. Use the keypad to transmit the IRLP node ID

Charliechong
IRLP
The Internet Radio Linking Project, also called IRLP, is a closed-source project that
links amateur radio stations around the world by using Voice over IP (VoIP). Each
gateway consists of a dedicated computer running custom software that is connected
to both a radio and the Internet. This arrangement forms what is known as an IRLP
Node. Since all end users communicate using a radio as opposed to using a computer
directly, IRLP has adopted the motto "Keeping the Radio in Amateur Radio".
Amateur radio (or ham) operators within radio range of a local node are able to use
DTMF tone generators to initiate a node-to-node connection with any other available
node in the world. Each node has a unique 4 digit node number in the range of 1000–
8999. A real-time searchable list of all nodes worldwide (including their current status)
is available anytime by viewing the IRLP Network at a Glance. As of February 2019,
there are over 1,500 active nodes.

Charliechong
T2B04
Which of the following common problems might cause you
to be able to hear but not access a repeater even when
transmitting with the proper offset?
A. The repeater receiver requires audio tone burst for access
B. The repeater receiver requires a CTCSS tone for access
C. The repeater receiver may require a DCS tone sequence for access
D. All of these choices are correct

Charliechong
DTMF
Dual-tone multi-frequency signaling (DTMF) is a
telecommunication signaling system using the
voice-frequency band over telephone lines
between telephone equipment and other
communications devices and switching centers.
DTMF was first developed in the Bell System in
the United States, and became known under the
trademark Touch-Tone for use in push-button
telephones supplied to telephone customers,
starting in 1963. DTMF is standardized as ITU-T
Recommendation Q.23. It is also known in the UK
as MF4.
The Touch-Tone system using a telephone keypad
gradually replaced the use of rotary dial and has
become the industry standard for landline and
mobile service. Other multi-frequency systems are
used for internal signaling within the telephone
network.

Charliechong
Repeater Access:
Tone burst repeater access method.
The first method that was introduced to access repeaters and prevent spurious
activation of them was to use a simple burst of a tone at the beginning of a
transmission. This tone burst lasted for possibly less than half a second and the tone
had to be of a specific frequency.
Often this tone burst was only required for the first transmission, but different
repeaters had different logic and therefore the functionality could be slightly different.
The repeater would have an audio filter that would extract the tone, and only if it was
present would the repeater activate.
The standard frequency generally adopted for this is 1750 Hz in Europe. A margin of
around 25 Hz either way will normally access a repeater although it is wise to maintain
the tone burst frequency more accurately than this.
黑豹 https://www.electronics-notes.com/articles/ham_radio/amateur-repeater/access-ctcss-tone-burst.php

Charliechong
Repeater Access:
CTCSS
CTCSS repeater access method
With the rise in the number of repeaters, channels have to be re-used relatively
frequently. As a result it is sometimes possible for a station to access more than one
repeater at any given time. This is obviously not desirable and a system known as
CTCSS (Continuous Tone Coded Squelch System) has been introduced to
overcome this problem.
CTCSS uses a sub-audible tone transmitted on the signal of the transmitter trying to
access the repeater. The amateur radio repeater has a very sharp filter to detect
whether the exact tone is present. It will also remove it before transmitting the
required audio. Only when the correct CTCSS tone is present will the amateur radio
repeater be enabled and it will allow audio to be re-radiated on the output channel
signal.
repeater.

Charliechong
CTCSS was initially introduced for commercial operators to allow several
commercial radio users to share the same frequency without overhearing the other
users conversations for normal simplex transmissions. It is possible to have several
companies sharing the same frequency but each using their own CTCSS tone, so
the squelch would only open for calls intended for them.
Amateur radio operation picked up on the idea and it has come into use for repeater
operation.
For amateur radio repeater use, a small selection of the tones is used and in some
areas of the globe these are allocated letters to indicate the particular tone. These
letter can sometimes be transmitted in Morse at the end of a repeater transmission,
instead of the “K” often used. In this way any radio amateurs will know which
CTCSS tone to use to access a particular repeater.

Charliechong
Repeater Access:
DCS
CDCSS or Digital Code Squelch (DCS) is a further development of the continuous
tone-coded squelch system or CTCSS that uses a slow-speed, binary data stream
passed as sub-audible data along with the transmission. Motorola calls this Digital
Private Line or DPL. It consists of a 23-bit telegram sent repeatedly on the channel at
134 bits per second along with the voice transmission. This allows for over 100
possible fleet codes to be used. This gives it an advantage over the CTCSS tones in
that there are more possible codes to use; however, it does use more bandwidth and
can be affected by voice tones below 300 Hz if not properly filtered by the radio
circuitry.
黑豹 http://wiki.radioreference.com/index.php/DCS

Charliechong
T7A09
Which of the following devices is most useful for VHF weak-
signal communication?
A. A quarter-wave vertical antenna
B. A multi-mode VHF transceiver
C. An omni-directional antenna
D. A mobile VHF FM transceiver

Charliechong
T1B08
What do the FCC rules mean when an amateur frequency
band is said to be available on a secondary basis?
A. Secondary users of a frequency have equal rights to operate
B. Amateurs are only allowed to use the frequency at night
C. Amateurs may not cause harmful interference to primary users
D. Secondary users are not allowed on amateur bands

Charliechong
T1E01
When must an amateur station have a control operator?
A. Only when the station is transmitting
B. Only when the station is being locally controlled
C. Only when the station is being remotely controlled
D. Only when the station is being automatically controlled

Charliechong
T1E04
What determines the transmitting privileges of an amateur
station?
A. The frequency authorized by the frequency coordinator
B. The class of operator license held by the station licensee
C. The highest class of operator license held by anyone on the premises
D. The class of operator license held by the control operator
My Remarks:
Station Licensee- The owner of the station
Control operator- The one that transmit
See: T1E07
When the control operator is not the station licensee, who is responsible for the proper
operation of the station?
A. All licensed amateurs who are present at the operation
B. Only the station licensee
C. Only the control operator
D. The control operator and the station licensee are equally responsible

Charliechong
T1F02
When using tactical identifiers, how often must your station
transmit the station’s FCC-assigned call sign?
A. Never, the tactical call is sufficient
B. Once during every hour
C. Every ten minutes
D. At the end of every communication

Charliechong
T8A03
Which type of voice modulation is most often used for long-
distance or weak signal contacts on the VHF and UHF
bands?
A. FM
B. AM
C. SSB
D. PM

Charliechong
T8A04
Which type of modulation is most commonly used for VHF
and UHF voice repeaters?
A. AM
B. SSB
C. PSK
D. FM

Charliechong
T7B12
What does the acronym “BER” mean when applied to digital
communications systems?
A. Baud Enhancement Recovery
B. Baud Error Removal
C. Bit Error Rate
D. Bit Exponent Resource

Charliechong
Q189. The resonant frequency of a tuned circuit can be
checked by:
a) a DC Voltmeter b) a DIP Oscillator c) a Digital Frequency Meter d) an Ohm-Meter

Charliechong
Communication and Multimedia Act 1998 (CMA98).
Spectrum Plan and Frequency Allocations
In Malaysia, SKMM has the overall responsibility for managing radio frequency
spectrum under the Communication and Multimedia Act 1998 (CMA98). Among
other responsibilities of the SKMM include the task of developing a spectrum plan
in respect of all or any part of the spectrum. TheCMA98, as the main legislation
which regulates the communications and multimedia industries, also sets out the
national policy objectives for the development of the communications industries.

4x4 Adventures
The Essentials:
Malaysian
Transceiver Block Diagrams
10th April 2019

Electronic oscillator- is an electronic circuit that produces a periodic, oscillating electronic signal, often
a sine wave or a square wave. Oscillators convert direct current (DC) from a power supply to an
alternating current (AC) signal. They are widely used in many electronic devices. Common examples of
signals generated by oscillators include signals broadcast by radio and television transmitters
Single-conversion superheterodyne CW/SSB Receiver

Mixer- In electronics, a mixer, or frequency mixer, is a nonlinear electrical circuit that creates new frequencies
from two signals applied to it. In its most common application, two signals are applied to a mixer, and it
produces new signals at the sum and difference of the original frequencies. Other frequency components may
also be produced in a practical frequency mixer. Mixers are widely used to shift signals from one frequency
range to another, a process known as heterodyning, for convenience in transmission or further signal
processing. For example, a key component of a superheterodyne receiver is a mixer used to move received
signals to a common intermediate frequency. Frequency mixers are also used to modulate a carrier signal in
radio transmitters.

Carrier
signal
Local
oscillator
signal
Mixer- In electronics, a mixer, or frequency mixer, is a nonlinear electrical circuit that creates new frequencies
from two signals applied to it. In its most common application, two signals are applied to a mixer, and it
produces new signals at the sum and difference of the original frequencies. Other frequency components may
also be produced in a practical frequency mixer. Mixers are widely used to shift signals from one frequency
range to another, a process known as heterodyning, for convenience in transmission or further signal
processing. For example, a key component of a superheterodyne receiver is a mixer used to move received
signals to a common intermediate frequency. Frequency mixers are also used to modulate a carrier signal in
radio transmitters.

Intermediate Frequency Amplifier- In communications and electronic engineering, an intermediate
frequency (IF) is a frequency to which a carrier wave is shifted as an intermediate step in transmission
or reception. The intermediate frequency is created by mixing the carrier signal with a local oscillator
signal in a process called heterodyning, resulting in a signal at the difference or beat frequency.
Intermediate frequencies are used in superheterodyne radio receivers, in which an incoming signal is
shifted to an IF for amplification before final detection is done.

Local
oscillator
signal
Carrier
signal
https://www.arrl.org/files/file/Get%20Licensed/HRLM%202nd/QPOOL-study%20guide-2nd-ed.pdfCharliechong 黑豹
Intermediate Frequency Amplifier- In communications and electronic engineering, an intermediate
frequency (IF) is a frequency to which a carrier wave is shifted as an intermediate step in transmission
or reception. The intermediate frequency is created by mixing the carrier signal with a local oscillator
signal in a process called heterodyning, resulting in a signal at the difference or beat frequency.
Intermediate frequencies are used in superheterodyne radio receivers, in which an incoming signal is
shifted to an IF for amplification before final detection is done.

Beat Frequency Oscillator- In a radio receiver, a beat frequency oscillator or BFO is a dedicated oscillator
used to create an audio frequency signal from Morse code radiotelegraphy (CW) transmissions to make them
audible. The signal from the BFO is mixed with the received signal to create a heterodyne or beat frequency
which is heard as a tone in the speaker. BFOs are also used to demodulate single-sideband (SSB) signals,
making them intelligible, by essentially restoring the carrier that was suppressed at the transmitter. BFOs are
sometimes included in communications receivers designed for short wave listeners; they are almost always
fitted to amateur radio station receivers, which often receive CW and SSB signals.

Beat Frequency Oscillator- Since in a superheterodyne receiver the different frequencies of the different
stations are all translated to the same intermediate frequency (IF) by the mixer, modern BFOs which beat with
the IF need only have a constant frequency. There may be a switch to turn off the BFO when it is not needed,
when receiving other types of signals, such as AM or FM. There is also usually a knob on the front panel to
adjust the frequency of the BFO, to change the tone over a small range to suit the operator's preference.

Charliechong 黑豹 https://www.skmm.gov.my/skmmgovmy/files/attachments/Guideline_Amateur_Radio_Service_2012.pdf
FM Receiver
frequency
discriminator
Limiter- In electronics, a limiter is a circuit that allows signals below a specified input power or level to pass
unaffected while attenuating (lowering) the peaks of stronger signals that exceed this threshold. Limiting is a
type of dynamic range compression. Clipping is an extreme version of limiting. Limiting is any process by
which the amplitude of a signal is prevented from exceeding a predetermined value. Limiters are common as
a safety device in live sound and broadcast applications to prevent sudden volume peaks from occurring.
Limiters are also used as protective features in some components of sound reinforcement systems (e.g.,
powered mixing boards and power amplifiers) and in some bass amplifiers, to prevent unwanted distortion or
loudspeaker damage.

FM Receiver
frequency
discriminator
Wide Pass Filter- Wide Band Pass Filter Band pass can be realised by a number of possible circuits. A wide
band pass filter can be formed by simply cascading high pass and low pass section and is generally the
choice for simple to design. To obtain a ± 20 db/decade band pass filter, a first order high pass filter and a
first low pass sections are cascaded, for a ± 40 db/decade band pass filter, second order high pass filter and
second order low pass filter are cascaded and so on for higher orders. In other words, the order of the Band
Pass Filter Circuit depends upon the order of the High pass and Low pass sections
Continue reading at http://www.eeeguide.com/band-pass-filter-circuit/

FM Receiver
frequency
discriminator
Wide Pass Filter- Wide Band Pass Filter Band pass can be realised by a number of possible circuits. A wide
band pass filter can be formed by simply cascading high pass and low pass section and is generally the choice
for simple to design. To obtain a ± 20 db/decade band pass filter, a first order high pass filter and a first low
pass sections are cascaded, for a ± 40 db/decade band pass filter, second order high pass filter and second
order low pass filter are cascaded and so on for higher orders. In other words, the order of the Band Pass Filter
Circuit depends upon the order of the High pass and Low pass sections
Continue reading at http://www.eeeguide.com/band-pass-filter-circuit/

Charliechong
Simple CW transmitter
Oscillator

Charliechong
Good luck Charlie
黑豹 https://www.facebook.com/puma4x4

Charlie Chong/ Fion ZhangCharlie Chong/ Fion Zhang

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