Radio amateur examination q151 q200

4x4 Adventures
The Essentials:
MALAYSIAN
RADIO AMATUER EXAMINATION
SAMPLE QUESTIONS with Answers.
Q151~Q200
7th April 2019
Charliechong 黑豹 https://sems.skmm.gov.my/sems/

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
Stephen Hawking
黑豹 https://www.youtube.com/embed/5j0XWi1n6Is

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

Charliechong
Q151. If the MARTS 2 meter-net is about to begin on a
frequency which you and another station are using, what
should you do?
a) as a courtesy to the net, move to a different frequency
b) increase your power output to ensure that all net participants can hear you
c) transmit as long as possible on the frequency so that no other stations may use it
d) tum off your radio
My answer: a)
The correct answer: a)
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Charliechong
Q152 When conversing via a VHF or UHF repeater you
should pause between overs for about
a) half a second
b) 3seconds
c) 30 seconds
d) several minutes
My answer: b)
The correct answer: b)
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
My answer: a)

Charliechong
Offset
Offset is the difference between a radio channel's receive and transmit frequencies.
Most commonly it refers to the separation between the input frequency and output
frequency of a repeater or other type of full duplex system. This should not be
confused with the trunking offset required when programming certain types of trunked
radio systems in certain scanner models.
For example, a mobile radio receives on 146.94 and transmits on 146.34 in order to
operate on a repeater.
146.94 - 146.34 = 0.6 (0.6 MHz or 600 kHz)
Since in this case the mobile radio transmit frequency (repeater input) is lower than
the mobile radio receive frequency (repeater output), it is said to have a negative
offset of 600 kHz or -600 kHz.
Certain bands and frequency ranges in the United States have standardized offsets.
黑豹 http://wiki.radioreference.com/index.php/Offset

Standard US Offsets
Band Frequency Range (MHz) Offset Notes
10m Ham (repeater
subband)
29.5-29.7 -100 kHz 1
VHF Low Band 30-50 No standard offset
6m Ham 50-54 -500 kHz or -1 MHz 1
VHF High Band 138-174 No standard offset 2
2m Ham 144-148 +600 kHz or -600 kHz 1
220 MHz 220-222 +1 MHz
1.25m Ham 222-225 -1.6 MHz 1
380 MHz Federal LMR 380-400 +10 MHz
Federal UHF 406.1-420 +9 MHz 3
70cm Ham (repeater
subband)
440-450 +5 MHz or -5 MHz 1
UHF Canadian border area 420-430 +5 MHz
UHF 450-470 +5 MHz
UHF T 470-512 +3 MHz 4
Lower 700 MHz 698-746 +30 MHz 5
Upper 700 MHz 746-806 +30 MHz
800 MHz 806-896 -45 MHz
900 MHz 896-940 -39 MHz 6
33cm Ham 902-928 -12 MHz or -25 MHz 1
23cm Ham 1240-1300 -12 MHz or -20 MHz 1
Charliechong 黑豹 http://wiki.radioreference.com/index.php/Offset

Charliechong
Q154. The radiation pattern below is typical of:
a) a half wave dipole
b) a quarter way,
c) a beam antenna
d) a Marconi antenna
My answer: c)
The correct answer: c)

Charliechong
Q155. The antenna below is representative of:
a) a Yagi c) a dipole
b) a long wire d) a monopole
My answer: b) The correct answer: c)

Charliechong
Q156. AGC stands for.
a) Amplified gain control
b) auxiliary gain cut-off
c). automatic ganging control
d) automatic gain control
My answer: d) The correct answer: d)
Q157. Over driving a power amplifier will:
a) give a high SWR
b) give minimum distortion on receive
c) generate excessive harmonics
d) minimize power output
My answer: a) The correct answer: c)

Charliechong
Q158. A radio wave may follow two or more different paths
during propagation and produce slowly changing phase
differences between signals at the receiver resulting in a
phenomenon called
a) Absorption c) baffling
b) Fading d) skip
My answer: b) The correct answer: b)
Q159. The distance between the transmitter and the nearest
point at which the received signal is received from
ionospheric propagation is known as the
a) skip distance c) radiation distance
b) skip angle d) skip zone
My answer: a) The correct answer: a)

Charliechong
Q160. VHF and UHF bands are frequency used for satellite
communication because
a) Waves at these frequencies travel to & from the satellite relatively unaffected by the
ionosphere
b) The Doppler frequency change caused by satellite motion is much less than at HF
c) Satellites move too fast for HF waves to follow
d) The Doppler effect would cause HF waves to be shifted into the VHF and UHF
bands
My answer: a)

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Charliechong
Q161 A line of sight transmission between two stations uses
mainly the
a) Ionosphere c) troposphere
b) skyways d) ground wave
My answer: d) The correct answer: c)
Q162. When using voice, which of the following modes of
transmissions required the least bandwidth?
a) single sideband
b) amplitude modulation
c) frequency modulation
d) phase modulation
My answer: a)
Tropospheric propagation describes electromagnetic propagation in
relation to the troposphere. The service area from a VHF or UHF radio
transmitter extends to just beyond the optical horizon, at which point
signals start to rapidly reduce in strength. Viewers living in such a "deep
fringe" reception area will notice that during certain conditions, weak
signals normally masked by noise increase in signal strength to allow
quality reception. Such conditions are related to the current state of the
troposphere.

Charliechong
Q163. Which of the following antenna arrangements is least
likely to radiate harmonics?
a) a dipole fed with coaxial cable
b) a dipole fed with balanced feeder
c) an inverted l-Marconi with vertical feeder
d) a trap dipole
My answer: b)

Charliechong
Balanced Feeder

Charliechong
Trap Dipoles and Parallel Dipoles
For multiband applications, you’ll often find the trap dipole and the parallel dipole.
 Traps are tuned circuits that act somewhat like automatically switched inductors or
capacitors, adding or subtracting from the length of the antenna according to the
frequency of your signal.
 The parallel dipole uses a different approach. In the parallel design, several dipoles
are joined together in the center and fed with the same cable. The dipole that
radiates the RF is the one that presents an impedance that most closely matches
the cable (50 ohms). That matching impedance will change according to the
frequency of the signal. One dipole will offer a 50-ohmmatch on, say, 40 meters,
while another provides the best match on 20 meters.
Obviously, these designs are somewhat more complicated than single-band dipoles,
although many hams do choose to build their own. If you don’t have time or desire to
tackle a trap or parallel dipole, you’ll discover that many QST advertisers sell prebuilt
models.

Charliechong
Parallel Dipole

Charliechong
Trapped Dipole

Charliechong
Q164. To obtain high frequency stability in a transmitter, the
VFO should be:
a) Run from a non-regulated AC supply
b) powered from a regulated DC supply
c) In a plastic box
d) able to change frequency with temperature
My answer: b)

Charliechong
Q165. The process of modulation allows
a) Information to be impressed on to a carrier
b) Information to be removed from a carrier
c) Voice and Morse code to be combined
d) None of these

Charliechong
Q166. In figure N7-2, if block 1 is a transceiver and block 3
is an antenna switch, what is block 2
a) a terminal-node switch
b) an SWR meter
c) a dipole antenna
d) a high-pass filter
My answer: a)
A terminal node controller (TNC) is a device used by
amateur radio operators to participate in AX.25 packet
radio networks. It is similar in function to the Packet
Assembler/Disassemblers used on X.25 networks, with
the addition of a modem to convert baseband digital
signals to audio tones.

Charliechong
Q167. Harmonic frequencies are
a) always lower in the frequency than the fundamental frequency
b) a multiples of the fundamental frequency
c) Any unwanted frequency above the fundamental frequency
d) Any frequency causing TVI
My answer: b)
Q168. Unwanted signals from a radio transmitter which
cause harmful interference to other users are known as
a) Rectified signals
b) Re-radiation signals
c) Reflected signals
d) Harmonic signals and spurious signals

Charliechong
Q169. To reduce the harmonic output from a high frequency
transmitter, the following filter is usually installed at the
transmitter
a) band pass
b) high pass
c) Low pass
d) Active filter
My answer: a) The correct answer: c)
Q170. Define the mode F3E
a) phase-modulated telephony
b) double-sideband telephony
c) single-sideband, suppressed carrier, telephony
d) frequency-modulated telephony

Charliechong
Q171. What is meant by antenna gain
a) the numerical ratio relating the radiated signal strength of an antenna to that of
another antenna
b) the numerical ratio of the signal in the forward direction to the signal In the back
direction
c) the numerical ratio of the amount of power radiated by an antenna compared to
that of transmitter output power
d) the final amplifier gain minus the transmission-line losses (including any phasing
present)
My answer: a)

Charliechong
Stephen Hawking
黑豹 https://www.youtube.com/embed/iJNk79giMbk

Charliechong
Stephen Hawking
黑豹 https://www.youtube.com/embed/wGE4tjATecY

Charliechong
Antenna Gains
黑豹 https://www.youtube.com/embed/wGE4tjATecY
The configuration does not change the total
power of the input power, however the antenna
output in the defined direction has increase with
a gains as compare to the non-configured
standard isotropic antenna.

Charliechong 黑豹 http://www.l-com.com/content/Article.aspx?Type=N&ID=9475
Antenna Gain: A relative measure of an antenna's ability to direct or concentrate
radio frequency energy in a particular direction or pattern. The measurement is
typically measured in dBi (Decibels relative to an isotropic radiator) or in dBd (Decibels
relative to a dipole radiator).
Gains = 10 log10 (
custome antenna
Isotropic antenna
) . Example if the directed signal measured at remote
is twice the isotropic antenna value, the antenna gain will be 10 log10(2) = 3dbi#
Isotropic Radiator: is a theoretical single point in space that radiates energy
equally in every direction similar to the Sun radiating its light. The isotropic radiator
exhibits the same magnitude or properties when measured in all directions. It has no
preferred direction of radiation. It radiates uniformly in all directions over a sphere
centered on the source.

Charliechong
Q173. Why should you wear a hard hat and safety glasses lf
you are on the ground helping someone work on an antenna
tower
a) so you wont hurt if the tower should accidentally fall
b) to keep RF energy away from your head during antenna testing
c) to protect your head from something dropped from the tower
d) so someone passing by wilt know that work is being done on the tower and wilt stay
away
My answer: c) The correct answer: c)

Charliechong
Q174. What safety factors must you consider when using a
bow and arrow or slingshot and weight to shoot an antenna-
support line over a tree
a) You must ensure that the line is strong enough to withstand the shock of shooting
the weight
b) You must ensure that the arrow or weight has a safe flight path if the line breaks
c) you must ensure that the bow and arrow or slingshot is in good working condition
d) all of these choices are correct

Charliechong
Q175. A Class C amplifier operates over:
a) the complete cycle
b) three quarters of a cycle
c) exactly half a cycle
d) less than half a cycle
My answer: b) The correct answer: d)

Charliechong
Amplifier Class by Conduction Angle
黑豹 https://www.electronics-tutorials.ws/amplifier/amplifier-classes.html

Charliechong
Amplifier Classes
Amplifiers are classified into classes according to their construction and operating
characteristics
Not all amplifiers are the same and there is a clear distinction made between the way
their output stages are configured and operate. The main operating characteristics of
an ideal amplifier are linearity, signal gain, efficiency and power output but in real
world amplifiers there is always a trade off between these different characteristics.
Generally, large signal or power amplifiers are used in the output stages of audio
amplifier systems to drive a loudspeaker load. A typical loudspeaker has an
impedance of between 4Ω and 8Ω, thus a power amplifier must be able to supply the
high peak currents required to drive the low impedance speaker.
One method used to distinguish the electrical characteristics of different types of
amplifiers is by “class”, and as such amplifiers are classified according to their circuit
configuration and method of operation. Then Amplifier Classes is the term used to
differentiate between the different amplifier types.

Charliechong
Amplifier Classes represent the amount of the output signal which varies within the
amplifier circuit over one cycle of operation when excited by a sinusoidal input signal.

Charliechong
The classification of amplifiers range from entirely linear operation (for use in high-
fidelity signal amplification) with very low efficiency, to entirely non-linear (where a
faithful signal reproduction is not so important) operation but with a much higher
efficiency, while others are a compromise between the two.
Amplifier classes are mainly lumped into two basic groups. The first are the classically
controlled conduction angle amplifiers forming the more common amplifier classes
of A, B, AB and C, which are defined by the length of their conduction state over some
portion of the output waveform, such that the output stage transistor operation lies
somewhere between being “fully-ON” and “fully-OFF”.
The second set of amplifiers are the newer so-called “switching” amplifier classes of D,
E, F, G, S, T etc, which use digital circuits and pulse width modulation (PWM) to
constantly switch the signal between “fully-ON” and “fully-OFF” driving the output hard
into the transistors saturation and cut-off regions.
The most commonly constructed amplifier classes are those that are used as audio
amplifiers, mainly class A, B, AB and C and to keep things simple, it is these types
of amplifier classes we will look at here in more detail.

Charliechong
Class A Amplifier
Class A Amplifiers are the most common type of amplifier class due mainly to their
simple design. Class A, literally means “the best class” of amplifier due mainly to their
low signal distortion levels and are probably the best sounding of all the amplifier
classes mentioned here. The class A amplifier has the highest linearity over the other
amplifier classes and as such operates in the linear portion of the characteristics curve.
Generally class A amplifiers use the same single transistor (Bipolar, FET, IGBT, etc)
connected in a common emitter configuration for both halves of the waveform with the
transistor always having current flowing through it, even if it has no base signal. This
means that the output stage whether using a Bipolar, MOSFET or IGBT device, is
never driven fully into its cut-off or saturation regions but instead has a base biasing
Q-point in the middle of its load line. Then the transistor never turns “OFF” which is
one of its main disadvantages.

Charliechong
To achieve high linearity and gain, the output stage of a class A amplifier is biased “ON”
(conducting) all the time. Then for an amplifier to be classified as “Class A” the zero
signal idle current in the output stage must be equal to or greater than the maximum
load current (usually a loudspeaker) required to produce the largest output signal.
As a class A amplifier operates in the linear portion of its characteristic curves, the
single output device conducts through a full 360 degrees of the output waveform.
Then the class A amplifier is equivalent to a current source.
Since a class A amplifier operates in the linear region, the transistors base (or gate)
DC biasing voltage should by chosen properly to ensure correct operation and low
distortion. However, as the output device is “ON” at all times, it is constantly carrying
current, which represents a continuous loss of power in the amplifier.

Charliechong
Due to this continuous loss of power class A amplifiers create tremendous amounts of
heat adding to their very low efficiency at around 30%, making them impractical for
high-power amplifications. Also due to the high idling current of the amplifier, the
power supply must be sized accordingly and be well filtered to avoid any amplifier hum
and noise. Therefore, due to the low efficiency and over heating problems of Class A
amplifiers, more efficient amplifier classes have been developed.

Charliechong
Class A Amplifier
Class A Amplifier

Charliechong
Class B Amplifier
Class B amplifiers were invented as a solution to the efficiency and heating problems
associated with the previous class A amplifier. The basic class B amplifier uses two
complimentary transistors either bipolar of FET for each half of the waveform with its
output stage configured in a “push-pull” type arrangement, so that each transistor
device amplifies only half of the output waveform.
In the class B amplifier, there is no DC base bias current as its quiescent current is
zero, so that the dc power is small and therefore its efficiency is much higher than that
of the class A amplifier. However, the price paid for the improvement in the efficiency is
in the linearity of the switching device.

Charliechong
Class B Amplifier

Charliechong
When the input signal goes positive, the positive biased transistor conducts while the
negative transistor is switched “OFF”. Likewise, when the input signal goes negative,
the positive transistor switches “OFF” while the negative biased transistor turns “ON”
and conducts the negative portion of the signal. Thus the transistor conducts only half
of the time, either on positive or negative half cycle of the input signal.
Then we can see that each transistor device of the class B amplifier only conducts
through one half or 180 degrees of the output waveform in strict time alternation, but
as the output stage has devices for both halves of the signal waveform the two halves
are combined together to produce the full linear output waveform.
This push-pull design of amplifier is obviously more efficient than Class A, at about
50%, but the problem with the class B amplifier design is that it can create distortion at
the zero-crossing point of the waveform due to the transistors dead band of input base
voltages from -0.7V to +0.7.

Charliechong
We remember from the Transistor tutorial that it takes a base-emitter voltage of about
0.7 volts to get a bipolar transistor to start conducting. Then in a class B amplifier, the
output transistor is not “biased” to an “ON” state of operation until this voltage is
exceeded.
This means that the part of the waveform which falls within this 0.7 volt window will not
be reproduced accurately making the class B amplifier unsuitable for precision audio
amplifier applications.
To overcome this zero-crossing distortion (also known as Crossover Distortion) class
AB amplifiers were developed.

Charliechong
Class AB Amplifier
As its name suggests, the Class AB Amplifier is a combination of the “Class A” and the
“Class B” type amplifiers we have looked at above. The AB classification of amplifier is
currently one of the most common used types of audio power amplifier design. The
class AB amplifier is a variation of a class B amplifier as described above, except that
both devices are allowed to conduct at the same time around the waveforms
crossover point eliminating the crossover distortion problems of the previous class B
amplifier.
The two transistors have a very small bias voltage, typically at 5 to 10% of the
quiescent current to bias the transistors just above its cut-off point. Then the
conducting device, either bipolar of FET, will be “ON” for more than one half cycle, but
much less than one full cycle of the input signal. Therefore, in a class AB amplifier
design each of the push-pull transistors is conducting for slightly more than the half
cycle of conduction in class B, but much less than the full cycle of conduction of class
A.
In other words, the conduction angle of a class AB amplifier is somewhere between
180oand 360o depending upon the chosen bias point as shown.

Charliechong
Class AB Amplifier

Charliechong
The advantage of this small bias voltage, provided by series diodes or resistors, is that
the crossover distortion created by the class B amplifier characteristics is overcome,
without the inefficiencies of the class A amplifier design. So the class AB amplifier is a
good compromise between class A and class B in terms of efficiency and linearity, with
conversion efficiencies reaching about 50% to 60%.
Class C Amplifier

Charliechong
Class C Amplifier
The Class C Amplifier design has the greatest efficiency but the poorest linearity of the
classes of amplifiers mentioned here. The previous classes, A, B and AB are
considered linear amplifiers, as the output signals amplitude and phase are linearly
related to the input signals amplitude and phase.
However, the class C amplifier is heavily biased so that the output current is zero for
more than one half of an input sinusoidal signal cycle with the transistor idling at its
cut-off point. In other words, the conduction angle for the transistor is significantly less
than 180 degrees, and is generally around the 90 degrees area.
While this form of transistor biasing gives a much improved efficiency of around 80%
to the amplifier, it introduces a very heavy distortion of the output signal. Therefore,
class C amplifiers are not suitable for use as audio amplifiers.

Charliechong
Class C Amplifier

Charliechong
Due to its heavy audio distortion, class C amplifiers are commonly used in high
frequency sine wave oscillators and certain types of radio frequency amplifiers, where
the pulses of current produced at the amplifiers output can be converted to complete
sine waves of a particular frequency by the use of LC resonant circuits in its collector
circuit.

Charliechong
Amplifier Classes Summary
Then we have seen that the quiescent DC operating point (Q-point) of an amplifier
determines the amplifier classification. By setting the position of the Q-point at half
way on the load line of the amplifiers characteristics curve, the amplifier will operate as
a class A amplifier. By moving the Q-point lower down the load line changes the
amplifier into a class AB, B or C amplifier.
Then the class of operation of the amplifier with regards to its DC operating point can
be given as:

Charliechong
Amplifier Classes and Efficiency

Charliechong
As well as audio amplifiers there are a number of high efficiency Amplifier
Classesrelating to switching amplifier designs that use different switching techniques
to reduce power loss and increase efficiency. Some amplifier class designs listed
below use RLC resonators or multiple power-supply voltages to reduce power loss, or
are digital DSP (digital signal processing) type amplifiers which use pulse width
modulation (PWM) switching techniques.

Charliechong
Q176 Which of the following represents over-modulation on
an AM signal?
My answer: d)

Charliechong
Q177. The designation F3E stands for:
a) telegraphy by frequency shift keying
b) telegraphy by on-off keying of a modulating audio frequency
c) frequency modulation by voice
d) facsimile transmission
My answer: c)

Charliechong
Q178. A simple beam is shown below. The names of the
elements in numerical order are:
a) radiator. director. reflector
b) director, radiator. Reflector
c) director reflector, radiator
d) reflector, radiator, director
My answer: d)
The correct answer: d)

Charliechong
Q179. Which of the following represents 100% amplitude
modulation?
My answer: c) The correct answer: b)

Charliechong
Q180. A typical arrangement of equipment is shown below.
The SWR meter should be placed at:
a) A c) C
b) B d) D
My answer: c) The correct answer: a)

Charliechong
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
Q182. Which of the following operating conditions of the
power amplifier stage of a-transmitter is likely to produce
the highest harmonic content in the output waveform?
a) Class C c) Class B
b) Class AB d) Class A
My answer: d) The correct answer: a)
黑豹 https://ham.stackexchange.com/questions/6274/what-is-a-calling-frequency
A calling frequency is a common channel
known to all - this is the channel that anyone
can jump onto and say Hi! Or a specific person
you know may be monitoring this channel, you
can call out to them.

Charliechong
Amplifier Class by Conduction Angle

Charliechong
Classes of Amplifier- #113: Basics of Transistor bias point and
the class of amplifier operation
黑豹 https://www.youtube.com/embed/c6cmkm3UPUI
Adjusting the bias point up till the input
waveform is up all the times, The transistor
will be always in “on” state.

Charliechong
Biasing
Biasing in electronics means establishing predetermined voltages or currents at
various points of an electronic circuit for the purpose of establishing proper operating
conditions in electronic components. Many electronic devices such as diodes,
transistors and vacuum tubes, whose function is processing time-varying (AC) signals
also require a steady (DC) current or voltage to operate correctly — a bias. The AC
signal applied to them is superposed on this DC bias current or voltage. The operating
point of a device, also known as bias point, quiescent point, or Q-point, is the DC
voltage or current at a specified terminal of an active device (a transistor or vacuum
tube) with no input signal applied. A bias circuit is a portion of the device's circuit which
supplies this steady current or voltage.

Charliechong
What is quiescent current?
During the DC biasing of transistor for amplifier, it should be cared that transistor
should be in active region for the whole range of input signal applied to it. A fixed
quiescent point is chosen on V(ce)-I(c) load line curve, so as to get full amplified signal
as of the input. the current Ic (collector current ) at this point is known as quiescent
current and voltage Vce (collector to emitter voltage ) is known as quiescent voltage.

Charliechong
37. Class C Amplifiers
黑豹 https://www.youtube.com/embed/62PdgE07EZ8

Charliechong
Q183. What is a loop antenna?
a) a large circularly-polarised antenna
b) a small coil of wire tightly wound around a toroidal ferrite core
c) several turns of wire wound in the shape of a large open coil
d) any antenna coupled to a feed line through an 'inductive loop of wire
My answer: c)
Q184. What device is used in place of an antenna during
transmitter tests so that no signal is radiated
a) an antenna matcher
b) a dummy load
c) a low-pass titter
d) a decoupling resistor

Charliechong
Q185. What phenomenon has the most effect on radio
communication beyond ground-wave or line-of-sight ranges
a) solar activity
b) lunar tidal effects
c) the F1 region of the ionosphere
d) the F2 region of the ionosphere
Q186. The ionosphere layer mainly responsible for distance
communication at HF is:
a) D c) E
b) F2 d) F1

Charliechong
Q187. To prevent unwanted radiation in the shack, RF
connections between units should be by
a) open wire feeder
b) good quality coaxial cable
c) bell wire
d) mains type cable
My answer: ?) The correct answer: b)
Q188. What is the proper procedure for suppressing
electrical noise in a mobile transceiver
a) apply shielding and filtering where necessary
b) insulate all place sheet metal surfaces from each other
c) apply antistatic spray liberally to all non-metallic surfaces
d) install filter capacitors in series with all DC wiring

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
My answer: c)
Q190. Spurious oscillations may be caused by:
a) self resonance of a carbon resistor
b) self resonance in diode
c) self resonance of an RF choke
d) Damping

Charliechong
DIP Oscillator
Grid dip oscillator (GDO), also called grid dip meter, dip meter, dipmeter, or just dipper,
is a measuring instrument to measure resonant frequency of radio frequency circuits.
It measures the amount of absorption of a high frequency inductively coupled
magnetic field by nearby objects. It is an oscillator whose amplitude changes when
near a resonant circuit which is tuned to the frequency the oscillator generates. At the
heart of the instrument is a tunable LC circuit with a coil that serves as a loose
inductive coupling to the measured LC resonant circuit. Resonance is indicated by a
dip in the meter indicator on the device, usually based on a microammeter.

Charliechong
DIP Oscillator

Charliechong
Q191. The correct order for callsign in a callsign exchange
at the start and end of a transmission is
a) the other callsign followed by your own callsign
b) your callsign followed by the other callsign
c) your own callsign, repeated twice
d) the other callsign, repeated twice

Charliechong
Q192. A signal report of S5 and 9 indicates
a) very low intelligibility but good signal strength
b) perfect intelligibility but very low signal strength
c) perfect intelligibility, high signal strength
d) medium intelligibility and signal strength

Charliechong
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
My answer: ?) The correct answer: b)
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

Charliechong
Q194. The squelch or muting circuitry on a VHF receiver
a) inhibits the audio output unless a station is being received
b) compresses incoming voice signals to make them more intelligible
c) reduces audio burst noise due to lightning emissions
d) reduces the noise on incoming signals
Q195. In a CW contact WX refers to:
a) working conditions b) weather
c) wife d) type of antenna

Charliechong
Appendix 6: Abbreviation used for CW work
Abbreviation Meaning
WUD Would
WX* Weather
X Press
XCVR Receiver
XMTR (TX) Transmitter
XTAL Crystal
XYL* (YF) Wife
YL* Young Lady
73* Regards
88* Love and Kisses
Codes in asterisk (*) are to a limited extend, adopted and accepted in the phone
band.
黑豹 https://www.skmm.gov.my/skmmgovmy/files/attachments/Guideline_Amateur_Radio_Service_2012.pdf

Charliechong
Q196. The priority on usage of any amateur radio repeater is
a) base station to base station
b) portable station to mobile station
c) mobile station to mobile station
d) answer b & c above
Q197. What is the activity known as fox hunting
a) amateurs using receivers and direction-finding techniques attempt to locate a
hidden transmitter
b) amateurs using transmitting equipment and direction- finding techniques attempt to
locate a hidden receiver
c) amateurs helping the government track radio transmitter collars attached to animals
d) amateurs assemble stations using generators and portable antennas to test their
emergency communications skills

Charliechong
Q198. What does a very high SWR reading mean
a) the antenna is not tuned, or there may be an open or shorted connection
somewhere in the feed line
b) the signals coming from the antenna are unusually strong, which means very good
radio conditions
c) the transmitter is putting out more power than normal, showing that it is about to go
bad
d) there is a large amount d solar radiation, which means very poor radio cond~ions
Q199. VOX stands for
a) volume operated extension speaker
b) variable oscillator transmitter
c) voice operated transmit
d) voice operated expander

Charliechong
200. Define Peak Envelope Power
a) means power supplied to an antenna by a radio receiver in a condition of no
modulation
b) means the average power supplied to the antenna transmission lines by a
transmitter during one radiofrequency cycle at the highest crest of the modulation
envelope taken under conditions of normal operation
c) means the average power that is supplied to the antenna transmission lines in a
condition of no modulation
d) means the average power that is supplied to the antenna in a condition where such
power does not create a danger to life

Charliechong
2019/4/8

Charlie Chong/ Fion ZhangCharlie Chong/ Fion Zhang

Radio amateur examination q151 q200

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