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ISED - BASIC Radio Amateur > 006 - Feedlines and Antenna Systems > Flashcards

006 - Feedlines and Antenna Systems Flashcards

1
Q

B-006-001-001
What connects your transceiver to your antenna?

(a) A transmission line
(b) The power cord
(c) A ground wire
(d) A dummy load

A

B-006-001-001
What connects your transceiver to your antenna?

(a) A transmission line

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2
Q

B-006-001-002
The characteristic impedance of a transmission line is determined by the:

(a) physical dimensions and relative positions of the conductors
(b) length of the line
(c) frequency at which the line is operated
(d) load placed on the line

A

B-006-001-002
The characteristic impedance of a transmission line is determined by the:

(a) physical dimensions and relative positions of the conductors

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3
Q

B-006-001-003
The characteristic impedance of a 20 metre piece of transmission line is 52 ohms. If 10 metres were cut off, the impedance would be:

(a) 26 ohms
(b) 39 ohms
(c) 13 ohms
(d) 52 ohms

A

B-006-001-003
The characteristic impedance of a 20 metre piece of transmission line is 52 ohms. If 10 metres were cut off, the impedance would be:

(d) 52 ohms

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4
Q

B-006-001-004
The characteristic impedance of a coaxial line:

(a) can be the same for different diameter line
(b) changes significantly with the frequency of the energy it carries
(c) is correct for only one size of line
(d) is greater for larger diameter line

A

B-006-001-004
The characteristic impedance of a coaxial line:

(a) can be the same for different diameter line

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5
Q

B-006-001-005
What commonly available antenna transmission line can be buried directly in the ground for some distance without adverse effects?

(a) 300 ohm twin-lead
(b) Coaxial cable
(c) 600 ohm open-wire line
(d) 75 ohm twin-lead

A

B-006-001-005
What commonly available antenna transmission line can be buried directly in the ground for some distance without adverse effects?

(b) Coaxial cable

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6
Q

B-006-001-006
The characteristic impedance of a transmission line is:

(a) the impedance of a section of the line one wavelength long
(b) equal to the pure resistance which, if connected to the end of the line, will absorb all the power arriving along it
(c) the dynamic impedance of the line at the operating frequency
(d) the ratio of the power supplied to the line to the power delivered to the load

A

B-006-001-006
The characteristic impedance of a transmission line is:

(b) equal to the pure resistance which, if connected to the end of the line, will absorb all the power arriving along it

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7
Q

B-006-001-007
A transmission line differs from an ordinary circuit or network in communications or signalling devices in one very important way. That important aspect is:

(a) capacitive reactance
(b) propagation delay
(c) inductive reactance
(d) resistance

A

B-006-001-007
A transmission line differs from an ordinary circuit or network in communications or signalling devices in one very important way. That important aspect is:

(b) propagation delay

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8
Q

B-006-001-008
The characteristic impedance of a parallel wire transmission line does not depend on the:

(a) radius of the conductors
(b) centre to centre distance between conductors
(c) dielectric
(d) velocity of energy on the line

A

B-006-001-008
The characteristic impedance of a parallel wire transmission line does not depend on the:

(d) velocity of energy on the line

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9
Q

B-006-001-009
If the impedance terminating a transmission line differs significantly from the characteristic impedance of the line, what will be observed at the input of the line?

(a) Some value of impedance influenced by line length
(b) An infinite impedance
(c) A negative impedance
(d) An impedance nearly equal to the characteristic impedance

A

B-006-001-009
If the impedance terminating a transmission line differs significantly from the characteristic impedance of the line, what will be observed at the input of the line?

(a) Some value of impedance influenced by line length

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10
Q

B-006-001-010
What factors determine the characteristic impedance of a parallel-conductor antenna transmission line?

(a) The distance between the centres of the conductors and the radius of the conductors
(b) The distance between the centres of the conductors and the length of the line
(c) The radius of the conductors and the frequency of the signal
(d) The frequency of the signal and the length of the line

A

B-006-001-010
What factors determine the characteristic impedance of a parallel-conductor antenna transmission line?

(a) The distance between the centres of the conductors and the radius of the conductors

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11
Q

B-006-001-011
What factors determine the characteristic impedance of a coaxial antenna transmission line?

(a) The diameter of the shield and the length of the line
(b) The diameter of the shield and the frequency of the signal
(c) The frequency of the signal and the length of the line
(d) The ratio of the diameter of the inner conductor to the diameter of the outer shield

A

B-006-001-011
What factors determine the characteristic impedance of a coaxial antenna transmission line?

(d) The ratio of the diameter of the inner conductor to the diameter of the outer shield

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12
Q

B-006-002-001
What is a coaxial cable?

(a) A center wire inside an insulating material which is covered by a metal sleeve or shield
(b) Two wires side-by-side in a plastic ribbon
(c) Two wires side-by-side held apart by insulating rods
(d) Two wires twisted around each other in a spiral

A

B-006-002-001
What is a coaxial cable?

(a) A center wire inside an insulating material which is covered by a metal sleeve or shield

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13
Q

B-006-002-002
What is parallel-conductor transmission line?

(a) Two wires twisted around each other in a spiral
(b) A center wire inside an insulating material which is covered by a metal sleeve or shield
(c) A metal pipe which is as wide or slightly wider than a wavelength of the signal it carries
(d) Two wires side-by-side held apart by insulating material

A

B-006-002-002
What is parallel-conductor transmission line?

(d) Two wires side-by-side held apart by insulating material

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14
Q

B-006-002-003
What kind of antenna transmission line is made of two conductors held apart by insulated rods?

(a) Coaxial cable
(b) Twin lead in a plastic ribbon
(c) Open wire line
(d) Twisted pair

A

B-006-002-003
What kind of antenna transmission line is made of two conductors held apart by insulated rods?

(c) Open wire line

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15
Q

B-006-002-004
What does the term “balun” mean?

(a) Balanced unloader
(b) Balanced to unbalanced
(c) Balanced unmodulator
(d) Balanced antenna network

A

B-006-002-004
What does the term “balun” mean?

(b) Balanced to unbalanced

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16
Q

B-006-002-005
Where would you install a balun to feed a dipole antenna with 50-ohm coaxial cable?

(a) Between the transmitter and the coaxial cable
(b) Between the antenna and the ground
(c) Between the coaxial cable and the antenna
(d) Between the coaxial cable and the ground

A

B-006-002-005
Where would you install a balun to feed a dipole antenna with 50-ohm coaxial cable?

(c) Between the coaxial cable and the antenna

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17
Q

B-006-002-006
What is an unbalanced line?

(a) Transmission line with neither conductor connected to ground
(b) Transmission line with one conductor connected to ground
(c) Transmission line with both conductors connected to ground
(d) Transmission line with both conductors connected to each other

A

B-006-002-006
What is an unbalanced line?

(b) Transmission line with one conductor connected to ground

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18
Q

B-006-002-007
What device can be installed to feed a balanced antenna with an unbalanced transmission line?

(a) A triaxial transformer
(b) A balun
(c) A wave trap
(d) A loading coil

A

B-006-002-007
What device can be installed to feed a balanced antenna with an unbalanced transmission line?

(b) A balun

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19
Q

B-006-002-008
A flexible coaxial line contains:

(a) four or more conductors running parallel
(b) braided shield conductor and insulation around a central conductor
(c) only one conductor
(d) two parallel conductors separated by spacers

A

B-006-002-008
A flexible coaxial line contains:

(b) braided shield conductor and insulation around a central conductor

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20
Q

B-006-002-009
A balanced transmission line:

(a) has one conductor inside the other
(b) carries RF current on one wire only
(c) is made of two parallel wires
(d) is made of one conductor only

A

B-006-002-009
A balanced transmission line:

(c) is made of two parallel wires

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21
Q

B-006-002-010
A 75 ohm transmission line could be matched to the 300 ohm feed point of an antenna:

(a) with an extra 250 ohm resistor
(b) by using a 4 to 1 trigatron
(c) by using a 4 to 1 impedance transformer
(d) by inserting a diode in one leg of the antenna

A

B-006-002-010
A 75 ohm transmission line could be matched to the 300 ohm feed point of an antenna:

(c) by using a 4 to 1 impedance transformer

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22
Q

B-006-002-011
What kind of antenna transmission line can be constructed using two conductors which are maintained a uniform distance apart using insulated spreaders?

(a) Coaxial cable
(b) 600 ohm open wire line
(c) 75 ohm twin-lead
(d) 300 ohm twin-lead

A

B-006-002-011
What kind of antenna transmission line can be constructed using two conductors which are maintained a uniform distance apart using insulated spreaders?

(b) 600 ohm open wire line

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23
Q

B-006-003-001
Why does coaxial cable make a good antenna transmission line?

(a) It is weatherproof, and its impedance is higher than that of most amateur antennas
(b) It can be used near metal objects, and its impedance is higher than that of most amateur antennas
(c) It is weatherproof, and its impedance matches most amateur antennas
(d) You can make it at home, and its impedance matches most amateur antennas

A

B-006-003-001
Why does coaxial cable make a good antenna transmission line?

(c) It is weatherproof, and its impedance matches most amateur antennas

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24
Q

B-006-003-002
What is the best antenna transmission line to use, if it must be put near grounded metal objects?

(a) Ladder-line
(b) Twisted pair
(c) Twin lead
(d) Coaxial cable

A

B-006-003-002
What is the best antenna transmission line to use, if it must be put near grounded metal objects?

(d) Coaxial cable

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25
Q

B-006-003-003
What are some reasons not to use parallel-conductor transmission line?

(a) It does not work well when tied down to metal objects, and you should use a balun and may have to use an impedance-matching device with your transceiver
(b) You must use an impedance-matching device with your transceiver, and it does not work very well with a high SWR
(c) It does not work well when tied down to metal objects, and it cannot operate under high power
(d) It is difficult to make at home, and it does not work very well with a high SWR

A

B-006-003-003
What are some reasons not to use parallel-conductor transmission line?

(a) It does not work well when tied down to metal objects, and you should use a balun and may have to use an impedance-matching device with your transceiver

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26
Q

B-006-003-004
What common connector type usually joins RG-213 coaxial cable to an HF transceiver?

(a) An F-type cable connector
(b) A banana plug connector
(c) A PL-259 connector
(d) A binding post connector

A

B-006-003-004
What common connector type usually joins RG-213 coaxial cable to an HF transceiver?

(c) A PL-259 connector

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27
Q

B-006-003-005
What common connector usually joins a hand-held transceiver to its antenna?

(a) A PL-259 connector
(b) An F-type cable connector
(c) An SMA connector
(d) A binding post connector

A

B-006-003-005
What common connector usually joins a hand-held transceiver to its antenna?

(c) An SMA connector

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28
Q

B-006-003-006
Which of these common connectors has the lowest loss at UHF?

(a) An F-type cable connector
(b) A type-N connector
(c) A BNC connector
(d) A PL-259 connector

A

B-006-003-006
Which of these common connectors has the lowest loss at UHF?

(b) A type-N connector

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29
Q

B-006-003-007
If you install a 6 metre Yagi on a tower 60 metres (200 ft) from your transmitter, which of the following transmission lines provides the least loss?

(a) RG-174
(b) RG-59
(c) RG-58
(d) RG-213

A

B-006-003-007
If you install a 6 metre Yagi on a tower 60 metres (200 ft) from your transmitter, which of the following transmission lines provides the least loss?

(d) RG-213

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30
Q

B-006-003-008
Why should you regularly clean and tighten all antenna connectors?

(a) To keep them looking nice
(b) To keep them from getting stuck in place
(c) To increase their capacitance
(d) To help keep their contact resistance at a minimum

A

B-006-003-008
Why should you regularly clean and tighten all antenna connectors?

(d) To help keep their contact resistance at a minimum

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31
Q

B-006-003-009
What commonly available antenna transmission line can be buried directly in the ground for some distance without adverse effects?

(a) 75 ohm twin-lead
(b) Coaxial cable
(c) 600 ohm open wire line
(d) 300 ohm twin-lead

A

B-006-003-009
What commonly available antenna transmission line can be buried directly in the ground for some distance without adverse effects?

(b) Coaxial cable

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32
Q

B-006-003-010
When antenna transmission lines must be placed near grounded metal objects, which of the following transmission lines should be used?

(a) Coaxial cable
(b) 300 ohm twin-lead
(c) 600 ohm open wire line
(d) 75 ohm twin-lead

A

B-006-003-010
When antenna transmission lines must be placed near grounded metal objects, which of the following transmission lines should be used?

(a) Coaxial cable

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33
Q

B-006-003-011
TV twin-lead transmission line can be used for a transmission line in an amateur station. The impedance of this line is approximately:

(a) 600 ohms
(b) 50 ohms
(c) 70 ohms
(d) 300 ohms

A

B-006-003-011
TV twin-lead transmission line can be used for a transmission line in an amateur station. The impedance of this line is approximately:

(d) 300 ohms

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34
Q

B-006-004-001
Why should you use only good quality coaxial cable and connectors for a UHF antenna system?

(a) To keep television interference high
(b) To keep RF loss low
(c) To keep the power going to your antenna system from getting too high
(d) To keep the standing wave ratio of your antenna system high

A

B-006-004-001
Why should you use only good quality coaxial cable and connectors for a UHF antenna system?

(b) To keep RF loss low

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35
Q

B-006-004-002
What are some reasons to use parallel-conductor transmission line?

(a) It has low impedance, and will operate with a high SWR
(b) It will operate with a high SWR, and has less loss than coaxial cable
(c) It will operate with a high SWR, and it works well when tied down to metal objects
(d) It has a low impedance, and has less loss than coaxial cable

A

B-006-004-002
What are some reasons to use parallel-conductor transmission line?

(b) It will operate with a high SWR, and has less loss than coaxial cable

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36
Q

B-006-004-003
If your transmitter and antenna are 15 metres (50 ft) apart, but are connected by 60 metres (200 ft) of RG-58 coaxial cable, what should be done to reduce transmission line loss?

(a) Shorten the excess cable so the transmission line is an odd number of wavelengths long
(b) Shorten the excess cable
(c) Roll the excess cable into a coil which is as small as possible
(d) Shorten the excess cable so the transmission line is an even number of wavelengths long

A

B-006-004-003
If your transmitter and antenna are 15 metres (50 ft) apart, but are connected by 60 metres (200 ft) of RG-58 coaxial cable, what should be done to reduce transmission line loss?

(b) Shorten the excess cable

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37
Q

B-006-004-004
As the length of a transmission line is changed, what happens to signal loss?

(a) Signal loss decreases as length increases
(b) Signal loss is the least when the length is the same as the signal’s wavelength
(c) Signal loss increases as length increases
(d) Signal loss is the same for any length of transmission line

A

B-006-004-004
As the length of a transmission line is changed, what happens to signal loss?

(c) Signal loss increases as length increases

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38
Q

B-006-004-005
As the frequency of a signal is changed, what happens to signal loss in a transmission line?

(a) Signal loss increases with decreasing frequency
(b) Signal loss is the least when the signal’s wavelength is the same as the transmission line’s length
(c) Signal loss increases with increasing frequency
(d) Signal loss is the same for any frequency

A

B-006-004-005
As the frequency of a signal is changed, what happens to signal loss in a transmission line?

(c) Signal loss increases with increasing frequency

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39
Q

B-006-004-006
Losses occurring on a transmission line between transmitter and antenna results in:

(a) less RF power being radiated
(b) an SWR reading of 1:1
(c) reflections occurring in the line
(d) the wire radiating RF energy

A

B-006-004-006
Losses occurring on a transmission line between transmitter and antenna results in:

(a) less RF power being radiated

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40
Q

B-006-004-007
The lowest loss transmission line on HF is:

(a) 75 ohm twin-lead
(b) coaxial cable
(c) open wire line
(d) 300 ohm twin-lead

A

B-006-004-007
The lowest loss transmission line on HF is:

(c) open wire line

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41
Q

B-006-004-008
In what values are RF transmission line losses expressed?

(a) Ohms per MHz
(b) dB per unit length
(c) dB per MHz
(d) Ohms per metre

A

B-006-004-008
In what values are RF transmission line losses expressed?

(b) dB per unit length

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42
Q

B-006-004-009
If the length of coaxial transmission line is increased from 20 metres (66 ft) to 40 metres (132 ft), how would this affect the line loss?

(a) It would be reduced by 10%
(b) It would be increased by 10%
(c) It would be increased by 100%
(d) It would be reduced to 50%

A

B-006-004-009
If the length of coaxial transmission line is increased from 20 metres (66 ft) to 40 metres (132 ft), how would this affect the line loss?

(c) It would be increased by 100%

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43
Q

B-006-004-010
If the frequency is increased, how would this affect the loss on a transmission line?

(a) It is independent of frequency
(b) It would increase
(c) It depends on the line length
(d) It would decrease

A

B-006-004-010
If the frequency is increased, how would this affect the loss on a transmission line?

(b) It would increase

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44
Q

B-006-005-001
What does an SWR reading of 1:1 mean?

(a) An antenna for another frequency band is probably connected
(b) No power is going to the antenna
(c) The best impedance match has been attained
(d) The SWR meter is broken

A

B-006-005-001
What does an SWR reading of 1:1 mean?

(c) The best impedance match has been attained

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45
Q

B-006-005-002
What does an SWR reading of less than 1.5:1 mean?

(a) An impedance match which is too low
(b) A fairly good impedance match
(c) A serious impedance mismatch, something may be wrong with the antenna system
(d) An antenna gain of 1.5

A

B-006-005-002
What does an SWR reading of less than 1.5:1 mean?

(b) A fairly good impedance match

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46
Q

B-006-005-003
What kind of SWR reading may mean poor electrical contact between parts of an antenna system?

(a) A negative reading
(b) No reading at all
(c) A very low reading
(d) A jumpy reading

A

B-006-005-003
What kind of SWR reading may mean poor electrical contact between parts of an antenna system?

(d) A jumpy reading

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47
Q

B-006-005-004
What does a very high SWR reading mean?

(a) The antenna is the wrong length for the operating frequency, or the transmission line may be open or short circuited
(b) The transmitter is putting out more power than normal, showing that it is about to go bad
(c) There is a large amount of solar radiation, which means very poor radio conditions
(d) The signals coming from the antenna are unusually strong, which means very good radio condition

A

B-006-005-004
What does a very high SWR reading mean?

(a) The antenna is the wrong length for the operating frequency, or the transmission line may be open or short circuited

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48
Q

B-006-005-005
What does standing-wave ratio mean?

(a) The ratio of maximum to minimum inductances on a transmission line
(b) The ratio of maximum to minimum voltages on a transmission line
(c) The ratio of maximum to minimum resistances on a transmission line
(d) The ratio of maximum to minimum impedances on a transmission line

A

B-006-005-005
What does standing-wave ratio mean?

(b) The ratio of maximum to minimum voltages on a transmission line

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49
Q

B-006-005-006
If your antenna transmission line gets hot when you are transmitting, what might this mean?

(a) You should transmit using less power
(b) The SWR may be too high, or the transmission line loss may be high
(c) The conductors in the transmission line are not insulated very well
(d) The transmission line is too long

A

B-006-005-006
If your antenna transmission line gets hot when you are transmitting, what might this mean?

(b) The SWR may be too high, or the transmission line loss may be high

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50
Q

B-006-005-007
If the characteristic impedance of the transmission line does not match the antenna input impedance then:

(a) standing waves are produced in the transmission line
(b) heat is produced at the junction
(c) the SWR reading falls to 1:1
(d) the antenna will not radiate any signal

A

B-006-005-007
If the characteristic impedance of the transmission line does not match the antenna input impedance then:

(a) standing waves are produced in the transmission line

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51
Q

B-006-005-008
The result of the presence of standing waves on a transmission line is:

(a) perfect impedance match between transmitter and transmission line
(b) reduced transfer of RF energy to the antenna
(c) maximum transfer of energy to the antenna from the transmitter
(d) lack of radiation from the transmission line

A

B-006-005-008
The result of the presence of standing waves on a transmission line is:

(b) reduced transfer of RF energy to the antenna

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52
Q

B-006-005-009
An SWR meter measures the degree of match between transmission line and antenna by:

(a) measuring radiated RF energy
(b) measuring the conductor temperature
(c) inserting a diode in the transmission line
(d) comparing forward and reflected voltage

A

B-006-005-009
An SWR meter measures the degree of match between transmission line and antenna by:

(d) comparing forward and reflected voltage

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53
Q

B-006-005-010
A resonant antenna having a feed point impedance of 200 ohms is connected to a transmission line which has an impedance of 50 ohms. What will the standing wave ratio of this system be?

(a) 6:1
(b) 3:1
(c) 5:1
(d) 4:1

A

B-006-005-010
A resonant antenna having a feed point impedance of 200 ohms is connected to a transmission line which has an impedance of 50 ohms. What will the standing wave ratio of this system be?

(d) 4:1

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54
Q

B-006-005-011
The type of transmission line best suited to operating at a high standing wave ratio is:

(a) 75 ohm twin-lead
(b) 600 ohm open wire line
(c) coaxial line
(d) 300 ohm twin-lead

A

B-006-005-011
The type of transmission line best suited to operating at a high standing wave ratio is:

(b) 600 ohm open wire line

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55
Q

B-006-006-001
What device might allow use of an antenna on a band it was not designed for?

(a) An antenna tuner
(b) An SWR meter
(c) A low pass filter
(d) A high pass filter

A

B-006-006-001
What device might allow use of an antenna on a band it was not designed for?

(a) An antenna tuner

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56
Q

B-006-006-002
What does an antenna tuner do?

(a) It helps a receiver automatically tune in stations that are far away
(b) It switches an antenna system to a transmitter when sending, and to a receiver when listening
(c) It matches a transceiver to a mismatched antenna system
(d) It switches a transceiver between different kinds of antennas connected to one transmission line

A

B-006-006-002
What does an antenna tuner do?

(c) It matches a transceiver to a mismatched antenna system

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57
Q

B-006-006-003
What would you use to connect a coaxial cable of 50 ohms impedance to an antenna of 17 ohms impedance?

(a) An impedance-matching device
(b) An SWR meter
(c) A low pass filter
(d) A terminating resistor

A

B-006-006-003
What would you use to connect a coaxial cable of 50 ohms impedance to an antenna of 17 ohms impedance?

(a) An impedance-matching device

58
Q

B-006-006-004
When will a power source deliver maximum output to the load?

(a) When the impedance of the load is equal to the impedance of the source
(b) When air wound transformers are used instead of iron-core transformers
(c) When the power-supply fuse rating equals the primary winding current
(d) When the load resistance is infinite

A

B-006-006-004
When will a power source deliver maximum output to the load?

(a) When the impedance of the load is equal to the impedance of the source

59
Q

B-006-006-005
What happens when the impedance of an electrical load is equal to the internal impedance of the power source?

(a) The electrical load is shorted
(b) The source delivers maximum power to the load
(c) No current can flow through the circuit
(d) The source delivers minimum power to the load

A

B-006-006-005
What happens when the impedance of an electrical load is equal to the internal impedance of the power source?

(b) The source delivers maximum power to the load

60
Q

B-006-006-006
Why is impedance matching important?

(a) So the load will draw minimum power from the source
(b) To ensure that there is less resistance than reactance in the circuit
(c) To ensure that the resistance and reactance in the circuit are equal
(d) So the source can deliver maximum power to the load

A

B-006-006-006
Why is impedance matching important?

(d) So the source can deliver maximum power to the load

61
Q

B-006-006-007
To obtain efficient power transmission from a transmitter to an antenna requires:

(a) high load impedance
(b) low load resistance
(c) inductive impedance
(d) matching of impedances

A

B-006-006-007
To obtain efficient power transmission from a transmitter to an antenna requires:

(d) matching of impedances

62
Q

B-006-006-008
To obtain efficient transfer of power from a transmitter to an antenna, it is important that there is a:

(a) high load impedance
(b) proper method of balance
(c) matching of impedance
(d) low load resistance

A

B-006-006-008
To obtain efficient transfer of power from a transmitter to an antenna, it is important that there is a:

(c) matching of impedance

63
Q

B-006-006-009
If an antenna is correctly matched to a transmitter, the length of transmission line:

(a) must be a full wavelength long
(b) must be an odd number of quarter-wave
(c) must be an even number of half-waves
(d) will have no effect on the matching

A

B-006-006-009
If an antenna is correctly matched to a transmitter, the length of transmission line:

(d) will have no effect on the matching

64
Q

B-006-006-010
The reason that an RF transmission line should be matched at the transmitter end is to:

(a) ensure that the radiated signal has the intended polarization
(b) transfer the maximum amount of power to the antenna
(c) prevent frequency drift
(d) overcome fading of the transmitted signal

A

B-006-006-010
The reason that an RF transmission line should be matched at the transmitter end is to:

(b) transfer the maximum amount of power to the antenna

65
Q

B-006-006-011
If the centre impedance of a folded dipole is approximately 300 ohms, and you are using RG8U (50 ohms) coaxial lines, what is the ratio required to have the line and the antenna matched?

(a) 2:1
(b) 4:1
(c) 10:1
(d) 6:1

A

B-006-006-011
If the centre impedance of a folded dipole is approximately 300 ohms, and you are using RG8U (50 ohms) coaxial lines, what is the ratio required to have the line and the antenna matched?

(d) 6:1

66
Q

B-006-007-001
What does horizontal wave polarization mean?

(a) The electric and magnetic lines of force of a radio wave are perpendicular to the Earth’s surface
(b) The electric lines of force of a radio wave are parallel to the Earth’s surface
(c) The electric lines of force of a radio wave are perpendicular to the Earth’s surface
(d) The magnetic lines of force of a radio wave are parallel to the Earth’s surface

A

B-006-007-001
What does horizontal wave polarization mean?

(b) The electric lines of force of a radio wave are parallel to the Earth’s surface

67
Q

B-006-007-002
What does vertical wave polarization mean?

(a) The electric lines of force of a radio wave are perpendicular to the Earth’s surface
(b) The magnetic lines of force of a radio wave are perpendicular to the Earth’s surface
(c) The electric and magnetic lines of force of a radio wave are parallel to the Earth’s surface
(d) The electric lines of force of a radio wave are parallel to the Earth’s surface

A

B-006-007-002
What does vertical wave polarization mean?

(a) The electric lines of force of a radio wave are perpendicular to the Earth’s surface

68
Q

B-006-007-003
What electromagnetic wave polarization does a Yagi antenna have when its elements are parallel to the Earth’s surface?

(a) Helical
(b) Horizontal
(c) Vertical
(d) Circular

A

B-006-007-003
What electromagnetic wave polarization does a Yagi antenna have when its elements are parallel to the Earth’s surface?

(b) Horizontal

69
Q

B-006-007-004
What electromagnetic wave polarization does a half-wavelength antenna have when it is perpendicular to the Earth’s surface?

(a) Vertical
(b) Circular
(c) Horizontal
(d) Parabolical

A

B-006-007-004
What electromagnetic wave polarization does a half-wavelength antenna have when it is perpendicular to the Earth’s surface?

(a) Vertical

70
Q

B-006-007-005
Polarization of an antenna is determined by:

(a) the height of the antenna
(b) the type of antenna
(c) the magnetic field
(d) the orientation of the electric field relative to the Earth’s surface

A

B-006-007-005
Polarization of an antenna is determined by:

(d) the orientation of the electric field relative to the Earth’s surface

71
Q

B-006-007-006
An isotropic antenna is:

(a) an infinitely long piece of wire
(b) a dummy load
(c) a hypothetical point source
(d) a half-wave reference dipole

A

B-006-007-006
An isotropic antenna is:

(c) a hypothetical point source

72
Q

B-006-007-007
What is the antenna radiation pattern for an isotropic radiator?

(a) A parabola
(b) A cardioid
(c) A unidirectional cardioid
(d) A sphere

A

B-006-007-007
What is the antenna radiation pattern for an isotropic radiator?

(d) A sphere

73
Q

B-006-007-008
VHF signals from a mobile station using a vertical whip antenna will normally be best received using a:

(a) vertical ground-plane antenna
(b) random length of wire
(c) horizontal ground-plane antenna
(d) horizontal dipole antenna

A

B-006-007-008
VHF signals from a mobile station using a vertical whip antenna will normally be best received using a:

(a) vertical ground-plane antenna

74
Q

B-006-007-009
A dipole antenna will emit a vertically polarized wave if it is:

(a) fed with the correct type of RF
(b) mounted vertically
(c) too near to the ground
(d) parallel with the ground

A

B-006-007-009
A dipole antenna will emit a vertically polarized wave if it is:

(b) mounted vertically

75
Q

B-006-007-010
If an electromagnetic wave leaves an antenna vertically polarized, it will arrive at the receiving antenna, by ground wave:

(a) polarized at right angles to original
(b) horizontally polarized
(c) polarized in any plane
(d) vertically polarized

A

B-006-007-010
If an electromagnetic wave leaves an antenna vertically polarized, it will arrive at the receiving antenna, by ground wave:

(d) vertically polarized

76
Q

B-006-007-011
Compared with a horizontal antenna, a vertical antenna will receive a vertically polarized radio wave:

(a) at weaker strength
(b) at greater strength
(c) without any comparative difference
(d) if the antenna changes the polarization

A

B-006-007-011
Compared with a horizontal antenna, a vertical antenna will receive a vertically polarized radio wave:

(b) at greater strength

77
Q

B-006-008-001
If an antenna is made longer, what happens to its resonant frequency?

(a) It decreases
(b) It increases
(c) It stays the same
(d) It disappears

A

B-006-008-001
If an antenna is made longer, what happens to its resonant frequency?

(a) It decreases

78
Q

B-006-008-002
If an antenna is made shorter, what happens to its resonant frequency?

(a) It stays the same
(b) It increases
(c) It disappears
(d) It decreases

A

B-006-008-002
If an antenna is made shorter, what happens to its resonant frequency?

(b) It increases

79
Q

B-006-008-003
The wavelength for a frequency of 25 MHz is:

(a) 15 metres (49.2 ft)
(b) 12 metres (39.4 ft)
(c) 4 metres (13.1 ft)
(d) 32 metres (105 ft)

A

B-006-008-003
The wavelength for a frequency of 25 MHz is:

(b) 12 metres (39.4 ft)

80
Q

B-006-008-004
The velocity of propagation of radio frequency energy in free space is:

(a) 3000 kilometres per second
(b) 150 kilometres per second
(c) 300 000 kilometres per second
(d) 186 000 kilometres per second

A

B-006-008-004
The velocity of propagation of radio frequency energy in free space is:

(c) 300 000 kilometres per second

81
Q

B-006-008-005
Adding a series inductance to an antenna would:

(a) increase the resonant frequency
(b) have little effect
(c) decrease the resonant frequency
(d) have no change on the resonant frequency

A

B-006-008-005
Adding a series inductance to an antenna would:

(c) decrease the resonant frequency

82
Q

B-006-008-006
The resonant frequency of an antenna may be increased by:

(a) lowering the radiating element
(b) increasing the height of the radiating element
(c) lengthening the radiating element
(d) shortening the radiating element

A

B-006-008-006
The resonant frequency of an antenna may be increased by:

(d) shortening the radiating element

83
Q

B-006-008-007
The speed of a radio wave:

(a) is infinite in space
(b) is always less than half speed of light
(c) varies directly with frequency
(d) is the same as the speed of light

A

B-006-008-007
The speed of a radio wave:

(d) is the same as the speed of light

84
Q

B-006-008-008
At the end of suspended antenna wire, insulators are used. These act to:

(a) limit the electrical length of the antenna
(b) increase the effective antenna length
(c) allow the antenna to be more easily held vertically
(d) prevent any loss of radio waves by the antenna

A

B-006-008-008
At the end of suspended antenna wire, insulators are used. These act to:

(a) limit the electrical length of the antenna

85
Q

B-006-008-009
To lower the resonant frequency of an antenna, the operator should:

(a) shorten it
(b) ground one end
(c) lengthen it
(d) centre feed it with TV ribbon transmission line

A

B-006-008-009
To lower the resonant frequency of an antenna, the operator should:

(c) lengthen it

86
Q

B-006-008-010
One solution to multiband operation with a shortened radiator is the “trap dipole” or trap vertical. These “traps” are actually:

(a) large wire-wound resistors
(b) a coil and capacitor in parallel
(c) coils wrapped around a ferrite rod
(d) hollow metal cans

A

B-006-008-010
One solution to multiband operation with a shortened radiator is the “trap dipole” or trap vertical. These “traps” are actually:

(b) a coil and capacitor in parallel

87
Q

B-006-008-011
The wavelength corresponding to a frequency of 2 MHz is:

(a) 360 m (1181 ft)
(b) 1500 m (4921 ft)
(c) 150 m (492 ft)
(d) 30 m (98 ft)

A

B-006-008-011
The wavelength corresponding to a frequency of 2 MHz is:

(c) 150 m (492 ft)

88
Q

B-006-009-001
What is a parasitic beam antenna?

(a) An antenna where the driven element obtains its radio energy by induction or radiation from director elements
(b) An antenna where some elements obtain their radio energy by induction or radiation from a driven element
(c) An antenna where all elements are driven by direct connection to the transmission line
(d) An antenna where wave traps are used to magnetically couple the elements

A

B-006-009-001
What is a parasitic beam antenna?

(b) An antenna where some elements obtain their radio energy by induction or radiation from a driven element

89
Q

B-006-009-002
How can the bandwidth of a parasitic beam antenna be increased?

(a) Use traps on the elements
(b) Use tapered-diameter elements
(c) Use larger diameter elements
(d) Use closer element spacing

A

B-006-009-002
How can the bandwidth of a parasitic beam antenna be increased?

(c) Use larger diameter elements

90
Q

B-006-009-003
If a parasitic element slightly shorter than a horizontal dipole antenna is placed parallel to the dipole 0.1 wavelength from it and at the same height, what effect will this have on the antenna’s radiation pattern?

(a) A major lobe will develop in the horizontal plane, parallel to the two elements
(b) A major lobe will develop in the vertical plane, away from the ground
(c) The radiation pattern will not be affected
(d) A major lobe will develop in the horizontal plane, from the dipole toward the parasitic element

A

B-006-009-003
If a parasitic element slightly shorter than a horizontal dipole antenna is placed parallel to the dipole 0.1 wavelength from it and at the same height, what effect will this have on the antenna’s radiation pattern?

(d) A major lobe will develop in the horizontal plane, from the dipole toward the parasitic element

91
Q

B-006-009-004
If a parasitic element slightly longer than a horizontal dipole antenna is placed parallel to the dipole 0.1 wavelength from it and at the same height, what effect will this have on the antenna’s radiation pattern?

(a) A major lobe will develop in the horizontal plane, from the parasitic element toward the dipole
(b) A major lobe will develop in the horizontal plane, parallel to the two elements
(c) A major lobe will develop in the vertical plane, away from the ground
(d) The radiation pattern will not be affected

A

B-006-009-004
If a parasitic element slightly longer than a horizontal dipole antenna is placed parallel to the dipole 0.1 wavelength from it and at the same height, what effect will this have on the antenna’s radiation pattern?

(a) A major lobe will develop in the horizontal plane, from the parasitic element toward the dipole

92
Q

B-006-009-005
The property of an antenna, which defines the range of frequencies to which it will respond, is called its:

(a) front-to-back ratio
(b) bandwidth
(c) impedance
(d) polarization

A

B-006-009-005
The property of an antenna, which defines the range of frequencies to which it will respond, is called its:

(b) bandwidth

93
Q

B-006-009-006
Approximately how much gain does a half-wave dipole have over an isotropic radiator?

(a) 1.5 dB
(b) 3.0 dB
(c) 6.0 dB
(d) 2.1 dB

A

B-006-009-006
Approximately how much gain does a half-wave dipole have over an isotropic radiator?

(d) 2.1 dB

94
Q

B-006-009-007
What is meant by antenna gain?

(a) The numerical ratio of the signal in the forward direction to the signal in the back direction
(b) The numerical ratio of the amount of power radiated by an antenna compared to the transmitter output power
(c) The numerical ratio relating the radiated signal strength of an antenna to that of another antenna
(d) The power amplifier gain minus the transmission line losses

A

B-006-009-007
What is meant by antenna gain?

(c) The numerical ratio relating the radiated signal strength of an antenna to that of another antenna

95
Q

B-006-009-008
What is meant by antenna bandwidth?

(a) The frequency range over which the antenna may be expected to perform well
(b) Antenna length divided by the number of elements
(c) The angle between the half-power radiation points
(d) The angle formed between two imaginary lines drawn through the ends of the elements

A

B-006-009-008
What is meant by antenna bandwidth?

(a) The frequency range over which the antenna may be expected to perform well

96
Q

B-006-009-009
In free space, what is the radiation characteristic of a half-wave dipole?

(a) Maximum radiation from the ends, minimum broadside
(b) Minimum radiation from the ends, maximum broadside
(c) Omnidirectional
(d) Maximum radiation at 45 degrees to the plane of the antenna

A

B-006-009-009
In free space, what is the radiation characteristic of a half-wave dipole?

(b) Minimum radiation from the ends, maximum broadside

97
Q

B-006-009-010
The gain of an antenna, especially on VHF and above, is quoted in dBi. The “i” in this expression stands for:

(a) isotropic
(b) ideal
(c) ionosphere
(d) interpolated

A

B-006-009-010
The gain of an antenna, especially on VHF and above, is quoted in dBi. The “i” in this expression stands for:

(a) isotropic

98
Q

B-006-009-011
The front-to-back ratio of a beam antenna is:

(a) the forward power of the major lobe to the power in the backward direction both being measured at the 3 dB points
(b) undefined
(c) the ratio of the forward power at the 3 dB points to the power radiated in the backward direction
(d) the ratio of the maximum forward power in the major lobe to the maximum backward power radiation

A

B-006-009-011
The front-to-back ratio of a beam antenna is:

(d) the ratio of the maximum forward power in the major lobe to the maximum backward power radiation

99
Q

B-006-010-001
How do you calculate the length in metres (feet) of a quarter-wavelength antenna using frequencies below 30MHz?

(a) Divide 468 (1532) by the antenna’s operating frequency in MHz
(b) Divide 71.5 (234) by the antenna’s operating frequency in MHz
(c) Divide 300 (982) by the antenna’s operating frequency in MHz
(d) Divide 150 (491) by the antenna’s operating frequency in MHz

A

B-006-010-001
How do you calculate the length in metres (feet) of a quarter-wavelength antenna using frequencies below 30MHz?

(b) Divide 71.5 (234) by the antenna’s operating frequency in MHz

100
Q

B-006-010-002
If you made a quarter-wavelength vertical antenna for 21.125 MHz, how long would it be?

(a) 3.6 metres (11.8 ft)
(b) 3.36 metres (11.0 ft)
(c) 7.2 metres (23.6 ft)
(d) 6.76 metres (22.2 ft)

A

B-006-010-002
If you made a quarter-wavelength vertical antenna for 21.125 MHz, how long would it be?

(b) 3.36 metres (11.0 ft)

101
Q

B-006-010-003
If you made a half-wavelength vertical antenna for 223 MHz, how long would it be?

(a) 67 cm (26.4 in)
(b) 128 cm (50.4 in)
(c) 105 cm (41.3 in)
(d) 134.6 cm (53 in)

A

B-006-010-003
If you made a half-wavelength vertical antenna for 223 MHz, how long would it be?

(a) 67 cm (26.4 in)

102
Q

B-006-010-004
Why is a 5/8-wavelength vertical antenna better than a 1/4-wavelength vertical antenna for VHF or UHF mobile operations?

(a) A 5/8-wavelength antenna has less corona loss
(b) A 5/8-wavelength antenna is easier to install on a car
(c) A 5/8-wavelength antenna can handle more power
(d) A 5/8-wavelength antenna has more gain

A

B-006-010-004
Why is a 5/8-wavelength vertical antenna better than a 1/4-wavelength vertical antenna for VHF or UHF mobile operations?

(d) A 5/8-wavelength antenna has more gain

103
Q

B-006-010-005
If a magnetic-base whip antenna is placed on the roof of a car, in what direction does it send out radio energy?

(a) It goes out equally well in all horizontal directions
(b) Most of it is aimed high into the sky
(c) Most of it goes equally in two opposite directions
(d) Most of it goes in one direction

A

B-006-010-005
If a magnetic-base whip antenna is placed on the roof of a car, in what direction does it send out radio energy?

(a) It goes out equally well in all horizontal directions

104
Q

B-006-010-006
What is an advantage of downward sloping radials on a ground plane antenna?

(a) It increases the radiation angle
(b) It brings the feed point impedance closer to 300 ohms
(c) It brings the feed point impedance closer to 50 ohms
(d) It lowers the radiation angle

A

B-006-010-006
What is an advantage of downward sloping radials on a ground plane antenna?

(c) It brings the feed point impedance closer to 50 ohms

105
Q

B-006-010-007
What happens to the feed point impedance of a ground-plane antenna when its radials are changed from horizontal to downward-sloping?

(a) It decreases
(b) It increases
(c) It stays the same
(d) It approaches zero

A

B-006-010-007
What happens to the feed point impedance of a ground-plane antenna when its radials are changed from horizontal to downward-sloping?

(b) It increases

106
Q

B-006-010-008
Which of the following transmission lines will give the best match to the base of a quarter-wave ground-plane antenna?

(a) 50 ohms coaxial cable
(b) 300 ohms balanced transmission line
(c) 75 ohms balanced transmission line
(d) 300 ohms coaxial cable

A

B-006-010-008
Which of the following transmission lines will give the best match to the base of a quarter-wave ground-plane antenna?

(a) 50 ohms coaxial cable

107
Q

B-006-010-009
The main characteristic of a vertical antenna is that it will:

(a) be very sensitive to signals coming from horizontal antennas
(b) require few insulators
(c) be easy to feed with TV ribbon transmission line
(d) receive signals equally well from all compass points around it

A

B-006-010-009
The main characteristic of a vertical antenna is that it will:

(d) receive signals equally well from all compass points around it

108
Q

B-006-010-010
Why is a loading coil often used with an HF mobile vertical antenna?

(a) To lower the losses
(b) To tune out capacitive reactance
(c) To lower the Q
(d) To filter out electrical noise

A

B-006-010-010
Why is a loading coil often used with an HF mobile vertical antenna?

(b) To tune out capacitive reactance

109
Q

B-006-010-011
What is the main reason why so many VHF base and mobile antennas are 5/8 of a wavelength?

(a) The angle of radiation is high giving excellent local coverage
(b) It is easy to match the antenna to the transmitter
(c) It’s a convenient length on VHF
(d) The angle of radiation is low

A

B-006-010-011
What is the main reason why so many VHF base and mobile antennas are 5/8 of a wavelength?

(d) The angle of radiation is low

110
Q

B-006-011-001
How many directly driven elements do most Yagi antennas have?

(a) Two
(b) One
(c) Three
(d) None

A

B-006-011-001
How many directly driven elements do most Yagi antennas have?

(b) One

111
Q

B-006-011-002
Approximately how long is the driven element of a Yagi antenna for 14.0 MHz?

(a) 5.21 metres (17 feet)
(b) 10.21 metres (33.5 feet)
(c) 10.67 metres (35 feet)
(d) 20.12 metres (66 feet)

A

B-006-011-002
Approximately how long is the driven element of a Yagi antenna for 14.0 MHz?

(b) 10.21 metres (33.5 feet)

112
Q

B-006-011-003
Approximately how long is the director element of a Yagi antenna for 21.1 MHz?

(a) 5.18 metres (17 feet)
(b) 3.2 metres (10.5 feet)
(c) 12.8 metres (42 feet)
(d) 6.4 metres (21 feet)

A

B-006-011-003
Approximately how long is the director element of a Yagi antenna for 21.1 MHz?

(d) 6.4 metres (21 feet)

113
Q

B-006-011-004
Approximately how long is the reflector element of a Yagi antenna for 28.1 MHz?

(a) 4.88 metres (16 feet)
(b) 10.67 metres (35 feet)
(c) 2.66 metres (8.75 feet)
(d) 5.33 metres (17.5 feet)

A

B-006-011-004
Approximately how long is the reflector element of a Yagi antenna for 28.1 MHz?

(d) 5.33 metres (17.5 feet)

114
Q

B-006-011-005
What is one effect of increasing the boom length and adding directors to a Yagi antenna?

(a) SWR increases
(b) Weight decreases
(c) Gain increases
(d) Wind load decreases

A

B-006-011-005
What is one effect of increasing the boom length and adding directors to a Yagi antenna?

(c) Gain increases

115
Q

B-006-011-006
What are some advantages of a Yagi with wide element spacing?

(a) High gain, lower loss and a low SWR
(b) High front-to-back ratio and lower input resistance
(c) High gain, less critical tuning and wider bandwidth
(d) Shorter boom length, lower weight and wind resistance

A

B-006-011-006
What are some advantages of a Yagi with wide element spacing?

(c) High gain, less critical tuning and wider bandwidth

116
Q

B-006-011-007
Why is a Yagi antenna often used for radiocommunications on the 20-metre band?

(a) It helps reduce interference from other stations off to the side or behind
(b) It provides excellent omnidirectional coverage in the horizontal plane
(c) It is smaller, less expensive and easier to erect than a dipole or vertical antenna
(d) It provides the highest possible angle of radiation for the HF bands

A

B-006-011-007
Why is a Yagi antenna often used for radiocommunications on the 20-metre band?

(a) It helps reduce interference from other stations off to the side or behind

117
Q

B-006-011-008
What does “antenna front-to-back ratio” mean in reference to a Yagi antenna?

(a) The relative position of the driven element with respect to the reflectors and directors
(b) The power radiated in the major radiation lobe compared to the power radiated 90 degrees away from that direction
(c) The number of directors versus the number of reflectors
(d) The power radiated in the major radiation lobe compared to the power radiated in exactly the opposite direction

A

B-006-011-008
What does “antenna front-to-back ratio” mean in reference to a Yagi antenna?

(d) The power radiated in the major radiation lobe compared to the power radiated in exactly the opposite direction

118
Q

B-006-011-009
What is a good way to get maximum performance from a Yagi antenna?

(a) Optimize the lengths and spacing of the elements
(b) Use RG-58 transmission line
(c) Use a reactance bridge to measure the antenna performance from each direction around the antenna
(d) Avoid using towers higher than 9 metres (30 feet) above the ground

A

B-006-011-009
What is a good way to get maximum performance from a Yagi antenna?

(a) Optimize the lengths and spacing of the elements

119
Q

B-006-011-010
The spacing between the elements on a three-element Yagi antenna, representing the best overall choice, is _____ of a wavelength.

(a) 0.10
(b) 0.50
(c) 0.75
(d) 0.20

A

B-006-011-010
The spacing between the elements on a three-element Yagi antenna, representing the best overall choice, is _____ of a wavelength.

(d) 0.20

120
Q

B-006-011-011
If the forward gain of a six-element Yagi is about 10 dBi, what would the gain of two of these antennas be if they were “stacked”?

(a) 13 dBi
(b) 7 dBi
(c) 20 dBi
(d) 10 dBi

A

B-006-011-011
If the forward gain of a six-element Yagi is about 10 dBi, what would the gain of two of these antennas be if they were “stacked”?

(a) 13 dBi

121
Q

B-006-012-001
If you made a half-wavelength dipole antenna for 28.150 MHz, how long would it be?

(a) 10.5 metres (34.37 ft)
(b) 28.55 metres (93.45 ft)
(c) 5.08 metres (16.62 ft)
(d) 10.16 metres (33.26 ft)

A

B-006-012-001
If you made a half-wavelength dipole antenna for 28.150 MHz, how long would it be?

(c) 5.08 metres (16.62 ft)

122
Q

B-006-012-002
What is one disadvantage of a random wire antenna?

(a) You may experience RF feedback in your station
(b) It usually produces vertically polarized radiation
(c) It must be longer than 1 wavelength
(d) You must use an inverted T matching network for multi-band operation

A

B-006-012-002
What is one disadvantage of a random wire antenna?

(a) You may experience RF feedback in your station

123
Q

B-006-012-003
What is the low angle radiation pattern of an ideal half-wavelength dipole HF antenna in free space installed parallel to the Earth?

(a) It is a circle (equal radiation in all directions)
(b) It is a figure-eight, perpendicular to the antenna
(c) It is two smaller lobes on one side of the antenna, and one larger lobe on the other side
(d) It is a figure-eight, off both ends of the antenna

A

B-006-012-003
What is the low angle radiation pattern of an ideal half-wavelength dipole HF antenna in free space installed parallel to the Earth?

(b) It is a figure-eight, perpendicular to the antenna

124
Q

B-006-012-004
The impedances in ohms at the feed point of the dipole and folded dipole in free space are, respectively:

(a) 73 and 150
(b) 73 and 300
(c) 52 and 100
(d) 52 and 200

A

B-006-012-004
The impedances in ohms at the feed point of the dipole and folded dipole in free space are, respectively:

(b) 73 and 300

125
Q

B-006-012-005
A horizontal dipole transmitting antenna, installed at an ideal height so that the ends are pointing North/South, radiates:

(a) mostly to the South and North
(b) mostly to the South
(c) equally in all directions
(d) mostly to the East and West

A

B-006-012-005
A horizontal dipole transmitting antenna, installed at an ideal height so that the ends are pointing North/South, radiates:

(d) mostly to the East and West

126
Q

B-006-012-006
How does the bandwidth of a folded dipole antenna compare with that of a simple dipole antenna?

(a) It is greater
(b) It is essentially the same
(c) It is less than 50%
(d) It is 0.707 times the bandwidth

A

B-006-012-006
How does the bandwidth of a folded dipole antenna compare with that of a simple dipole antenna?

(a) It is greater

127
Q

B-006-012-007
What is a disadvantage of using an antenna equipped with traps?

(a) It may radiate harmonics more readily
(b) It is too sharply directional at lower frequencies
(c) It must be neutralized
(d) It can only be used for one band

A

B-006-012-007
What is a disadvantage of using an antenna equipped with traps?

(a) It may radiate harmonics more readily

128
Q

B-006-012-008
What is an advantage of using a trap antenna?

(a) It has high directivity at the higher frequencies
(b) It has high gain
(c) It minimizes harmonic radiation
(d) It may be used for multi-band operation

A

B-006-012-008
What is an advantage of using a trap antenna?

(d) It may be used for multi-band operation

129
Q

B-006-012-009
If you were to cut a half wave dipole for 3.75 MHz, what would be its approximate length?

(a) 32 meters (105 ft)
(b) 45 meters (145 ft)
(c) 38 meters (125 ft)
(d) 75 meters (245 ft)

A

B-006-012-009
If you were to cut a half wave dipole for 3.75 MHz, what would be its approximate length?

(c) 38 meters (125 ft)

130
Q

B-006-013-001
What is a cubical quad antenna?

(a) A center-fed wire 1/2-electrical wavelength long
(b) Two or more parallel four-sided wire loops, each approximately one-electrical wavelength long
(c) A vertical conductor 1/4-electrical wavelength high, fed at the bottom
(d) Four straight, parallel elements in line with each other, each approximately 1/2-electrical wavelength long

A

B-006-013-001
What is a cubical quad antenna?

(b) Two or more parallel four-sided wire loops, each approximately one-electrical wavelength long

131
Q

B-006-013-002
What is a delta loop antenna?

(a) A large copper ring or wire loop, used in direction finding
(b) An antenna whose elements are each a three sided loop whose total length is approximately one electrical wavelength
(c) An antenna system made of three vertical antennas, arranged in a triangular shape
(d) An antenna made from several triangular coils of wire on an insulating form

A

B-006-013-002
What is a delta loop antenna?

(b) An antenna whose elements are each a three sided loop whose total length is approximately one electrical wavelength

132
Q

B-006-013-003
Approximately how long is each side of a cubical quad antenna driven element for 21.4 MHz?

(a) 0.36 metres (1.17 feet)
(b) 14.33 metres (47 feet)
(c) 143 metres (469 feet)
(d) 3.54 metres (11.7 feet)

A

B-006-013-003
Approximately how long is each side of a cubical quad antenna driven element for 21.4 MHz?

(d) 3.54 metres (11.7 feet)

133
Q

B-006-013-004
Approximately how long is each side of a cubical quad antenna driven element for 14.3 MHz?

(a) 21.43 metres (70.3 feet)
(b) 5.36 metres (17.6 feet)
(c) 53.34 metres (175 feet)
(d) 7.13 metres (23.4 feet)

A

B-006-013-004
Approximately how long is each side of a cubical quad antenna driven element for 14.3 MHz?

(b) 5.36 metres (17.6 feet)

134
Q

B-006-013-005
Approximately how long is each leg of a symmetrical delta loop antenna driven element for 28.7 MHz?

(a) 2.67 metres (8.75 feet)
(b) 7.13 metres (23.4 feet)
(c) 3.32 metres (10.89 feet)
(d) 10.67 metres (35 feet)

A

B-006-013-005
Approximately how long is each leg of a symmetrical delta loop antenna driven element for 28.7 MHz?

(c) 3.32 metres (10.89 feet)

135
Q

B-006-013-006
Which statement about two-element delta loops and quad antennas is true?

(a) They perform very well only at HF
(b) They are effective only when constructed using insulated wire
(c) They compare favourably with a three-element Yagi
(d) They perform poorly above HF

A

B-006-013-006
Which statement about two-element delta loops and quad antennas is true?

(c) They compare favourably with a three-element Yagi

136
Q

B-006-013-007
Compared to a dipole antenna, what are the directional radiation characteristics of a cubical quad antenna?

(a) The quad has more directivity in the horizontal plane but less directivity in the vertical plane
(b) The quad has less directivity in the horizontal plane but more directivity in the vertical plane
(c) The quad has more directivity in both horizontal and vertical planes
(d) The quad has less directivity in both horizontal and vertical planes

A

B-006-013-007
Compared to a dipole antenna, what are the directional radiation characteristics of a cubical quad antenna?

(c) The quad has more directivity in both horizontal and vertical planes

137
Q

B-006-013-008
Moving the feed point of a multi-element quad antenna from a side parallel to the ground to a side perpendicular to the ground will have what effect?

(a) It will change the antenna polarization from vertical to horizontal
(b) It will significantly decrease the antenna feed point impedance
(c) It will change the antenna polarization from horizontal to vertical
(d) It will significantly increase the antenna feed point impedance

A

B-006-013-008
Moving the feed point of a multi-element quad antenna from a side parallel to the ground to a side perpendicular to the ground will have what effect?

(c) It will change the antenna polarization from horizontal to vertical

138
Q

B-006-013-009
What does the term “antenna front-to-back ratio” mean in reference to a delta loop antenna?

(a) The power radiated in the major radiation lobe compared to the power radiated in exactly the opposite direction
(b) The relative position of the driven element with respect to the reflectors and directors
(c) The power radiated in the major radiation lobe compared to the power radiated 90 degrees away from that direction
(d) The number of directors versus the number of reflectors

A

B-006-013-009
What does the term “antenna front-to-back ratio” mean in reference to a delta loop antenna?

(a) The power radiated in the major radiation lobe compared to the power radiated in exactly the opposite direction

139
Q

B-006-013-010
The cubical “quad” or “quad” antenna consists of two or more square loops of wire. The driven element has an approximate overall length of:

(a) three-quarters of a wavelength
(b) two wavelengths
(c) one-half wavelength
(d) one wavelength

A

B-006-013-010
The cubical “quad” or “quad” antenna consists of two or more square loops of wire. The driven element has an approximate overall length of:

(d) one wavelength

140
Q

B-006-013-011
The delta loop antenna consists of two or more triangular structures mounted on a boom. The overall length of the driven element is approximately:

(a) one-quarter of a wavelength
(b) one wavelength
(c) two wavelengths
(d) one-half of a wavelength

A

B-006-013-011
The delta loop antenna consists of two or more triangular structures mounted on a boom. The overall length of the driven element is approximately:

(b) one wavelength

ISED - BASIC Radio Amateur (8 decks)

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