| 1 |
To obtain efficient transfer of power from a transmitter to an antenna, it is important that there is
|
|---|---|
| A | High load impedance |
| B | Low load impedance |
| C | Correct impedance match between transmitter and antenna |
| D | High standing wave ratio |
| 2 |
A coaxial feedline is constructed from:
|
|---|---|
| A | A single conductor |
| B | Two parallel conductors separated by spacers |
| C | Braid and insulation around a central conductor |
| D | Braid and insulation twisted together |
| 3 |
A damaged antenna or feedline attached to the output of a transmitter will present an incorrect load resulting in:
|
|---|---|
| A | The driver stage not delivering power to the final |
| B | The output tuned circuit breaking down |
| C | Excessive heat being produced in the transmitter output stage |
| D | Loss of modulation in the transmitted signal |
| 4 |
A result of mismatch between the power amplifier of a transmitter and the antenna is:
|
|---|---|
| A | Reduced antenna radiation |
| B | Radiation of key clicks |
| C | Lower modulation percentage |
| D | Smaller DC current drain |
| 5 |
The following feeder is the best match to the base of a quarter wave ground plane antenna:
|
|---|---|
| A | 300 ohm balanced feedline |
| B | 50 ohm coaxial cable |
| C | 75 ohm balanced feedline |
| D | 300 ohm coaxial cable |
| 6 |
The designed output impedance of the antenna socket of most modern transmitters is nominally:
|
|---|---|
| A | 25 ohm |
| B | 50 ohm |
| C | 75 ohm |
| D | 100 ohm |
| 7 |
A result of standing waves on a non-resonant transmission line is:
|
|---|---|
| A | Maximum transfer of energy to the antenna from the transmitter |
| B | Perfect impedance match between transmitter and feedline |
| C | Reduced transfer of RF energy to the antenna |
| D | Lack of radiation from the transmission line |
| 8 |
An instrument to check whether RF power in the transmission line is transferred to the antenna is:
|
|---|---|
| A | A standing wave ratio meter |
| B | An antenna tuner |
| C | A dummy load |
| D | A keying monitor |
| 9 |
This commonly available antenna feedline can be buried directly in the ground for some distance without adverse effects:
|
|---|---|
| A | 75 ohm twin-lead |
| B | 300 ohm twin-lead |
| C | 600 ohm open-wire |
| D | Coaxial cable |
| 10 |
If an antenna feedline must pass near grounded metal objects, the following type should be used:
|
|---|---|
| A | 75 ohm twin-lead |
| B | 300 ohm twin-lead |
| C | 600 ohm open-wire |
| D | Coaxial cable |
| 11 |
You are adjusting an antenna matching unit using an SWR bridge. You should adjust for:
|
|---|---|
| A | Maximum reflected power |
| B | Equal reflected and transmitted power |
| C | Minimum reflected power |
| D | Minimum transmitted power |
| 12 |
Peak envelope power (PEP) output is the:
|
|---|---|
| A | Average power output at the crest of the modulating cycle |
| B | Total power contained in each sideband |
| C | Carrier power output |
| D | Transmitter power output on key-up condition |
| 13 |
Your apparatus assignment permits you to:
|
|---|---|
| A | Work citizen band stations |
| B | Establish and operate an earth station in the amateur satellite service |
| C | Service commercial radio equipment over 1 kW output |
| D | Re-wire fixed household electrical supply mains |
| 14 |
A damaged antenna or feedline attached to the output of a transmitter will present an incorrect load resulting in:
|
|---|---|
| A | The driver stage not delivering power to the final |
| B | The output tuned circuit breaking down |
| C | Excessive heat being produced in the transmitter output stage |
| D | Loss of modulation in the transmitted signal |
| 15 |
Losses occurring on a transmission line between a transmitter and antenna result in:
|
|---|---|
| A | Less RF power being radiated |
| B | A SWR of 1:1 |
| C | Reflections occurring in the line |
| D | Improved transfer of RF energy to the antenna |
| 16 |
If the characteristic impedance of a feedline does not match the antenna input impedance then:
|
|---|---|
| A | Standing waves are produced in the feedline |
| B | Heat is produced at the junction |
| C | The SWR drops to 1:1 |
| D | The antenna will not radiate any signal |
| 17 |
An instrument to check whether RF power in the transmission line is transferred to the antenna is:
|
|---|---|
| A | A standing wave ratio meter |
| B | An antenna tuner |
| C | A dummy load |
| D | A keying monitor |
| 18 |
An antenna which transmits equally well in all compass directions is a:
|
|---|---|
| A | Dipole with a reflector only |
| B | Quarter wave grounded vertical |
| C | Dipole with director only |
| D | Half-wave horizontal dipole |
| 19 |
A ground plane antenna emits a:
|
|---|---|
| A | Horizontally polarised wave |
| B | Elliptically polarised wave |
| C | Axially polarised wave |
| D | Vertically polarised wave |
| 20 |
A dummy antenna:
|
|---|---|
| A | Attenuates a signal generator to a desirable level |
| B | Provides more selectivity when a transmitter is being tuned |
| C | Matches an AF generator to the receiver |
| D | Duplicates the characteristics of an antenna without radiating signals |
| 21 |
This property of an antenna broadly defines the range of frequencies to which it will be effective:
|
|---|---|
| A | Bandwidth |
| B | Front-to-back ratio |
| C | Impedance |
| D | Polarisation |
| 22 |
The resonant frequency of an antenna may be increased by:
|
|---|---|
| A | Shortening the radiating element |
| B | Shortening the director element |
| C | Increasing the height of the radiating element |
| D | Shortening the reflector element |
| 23 |
To lower the resonant frequency of an antenna, the operator should:
|
|---|---|
| A | Lengthen the antenna |
| B | Centre feed the antenna with TV ribbon |
| C | Shorten the antenna |
| D | Ground one end |
| 24 |
A half-wave antenna is often called a:
|
|---|---|
| A | Bi-polar |
| B | Yagi |
| C | Dipole |
| D | Beam |
| 25 |
The resonant frequency of a dipole antenna is mainly determined by:
|
|---|---|
| A | Its height above the ground |
| B | Its length |
| C | The output power of the transmitter used |
| D | The length of the transmission line |
| 26 |
A vertical antenna which uses a flat conductive surface at its base is the:
|
|---|---|
| A | Vertical dipole |
| B | Quarter wave ground plane |
| C | Rhombic |
| D | Long wire |
| 27 |
The main characteristic of a vertical antenna is that it:
|
|---|---|
| A | Requires few insulators |
| B | Is very sensitive to signals coming from horizontal aerials |
| C | Receives signals from all points around it equally well |
| D | Is easy to feed with TV ribbon feeder |
| 28 |
A Yagi antenna is said to have a power gain over a dipole antenna for the same frequency band because:
|
|---|---|
| A | It is more expensive than a dipole |
| B | More powerful transmitters can use it |
| C | It concentrates the radiation in one direction |
| D | It can be used for more than one band |
| 29 |
The path radio waves normally follow from a transmitting antenna to a receiving antenna at VHF and higher frequencies is a:
|
|---|---|
| A | Circular path going north or south from the transmitter |
| B | Great circle path |
| C | Straight line |
| D | Bent path via the ionosphere |
| 30 |
An SWR reading of 2.5:1 would indicate:
|
|---|---|
| A | A satisfactory SWR |
| B | That the antenna was not resonant |
| C | That the antenna length must be shortened |
| D | That the antenna system needs adjustment |
| 31 |
The ionosphere is primarily charged by:
|
|---|---|
| A | Your radio transmissions |
| B | Ultraviolet radiation from the sun |
| C | Cosmic radiation |
| D | Ionospheric storms |
| 32 |
The acronym EMC stands for:
|
|---|---|
| A | Electrical and Magnetic compatibility |
| B | Electromagnetic Compatibility |
| C | Engineering Minimum Compatibility |
| D | Electrical Maintenance Compliance |
| 33 |
Amateur radio, TV and Broadcast radio can suffer interference from:
|
|---|---|
| A | High voltage power lines |
| B | The phase of the moon |
| C | Ionospheric ducting |
| D | Trans-equatorial interference |
| 34 |
An antenna is connected via the feeder directly to the transmitter but used on the wrong frequency. This will have the effect of.
|
|---|---|
| A | Reflecting some of the power from the transmitter back along the feeder |
| B | Risking damage to the antenna |
| C | Reducing the SWR on the feeder |
| D | Increasing the signal strength received at a distance from the transmitter. |
| 35 |
An amateur wishes to achieve a greater range on VHF or UHF. Which option is likely to be most successful?
|
|---|---|
| A | Increase the antenna height above surrounding roofs. |
| B | Use a longer feeder to the antenna. |
| C | Use UHF for greatest range. |
| D | Move the antenna onto the ground in the garden. |
| 36 |
The ionosphere is
|
|---|---|
| A | Layers of reflective gasses at heights of 70 to 400km. |
| B | Another name for the air we breathe. |
| C | A type of spherical transmitting antenna. |
| D | A piece of amateur radio test equipment. |
| 37 |
A vertical half wave dipole will radiate
|
|---|---|
| A | Equally in all horizontal directions |
| B | A maximum signal in a vertical direction |
| C | A minimum signal at right-angles to the antenna |
| D | A maximum signal off the ends of the antenna. |
| 38 |
When adjusting an Antenna Matching Unit you should always
|
|---|---|
| A | Adjust for a minimum standing wave ratio |
| B | Adjust for a maximum standing wave ratio |
| C | Turn off the transmitter |
| D | Ensure the antenna is cut for the right wavelength. |
| 39 |
A VHF transmitting antenna should be located
|
|---|---|
| A | Indoors, protected from the rain, wind and sun |
| B | Outdoors, as high as practicable to avoid obstructions |
| C | Close to the transmitter so you can easily adjust it to the correct length |
| D | At ground level to minimise interference. |
| 40 |
Which of the following would NOT help to reduce interference to local TV receivers?
|
|---|---|
| A | Increasing the distance between the antenna and the houses. |
| B | Lengthening the transmitter mains cable. |
| C | Increasing the height of the antenna. |
| D | Using balanced antennas for HF. |
| 41 |
Which statement about radio propagation is correct?
|
|---|---|
| A | At VHF the radio signal can pass through a typical building and the signal strength will not vary much as the receiver is moved around the building. |
| B | The signal strength received from a transmitter on a hilltop will be the same at 1km, 5km 10km from the transmitter provided it is in clear sight. |
| C | Buildings in a town can block VHF radio signals at ground level and better reception will be achieved on a higher floor. |
| D | If a VHF signal is rather weak then switching to UHF with the same power and antenna gains is likely to result in a better signal. |
| 42 |
In a coaxial cable the field
|
|---|---|
| A | Round one conductor is the same as the field round the other |
| B | Round one conductor is equal and opposite to the field round the other |
| C | Exists only between the two conductors and stays inside the cable |
| D | Is present round the cable for a distance of about 10 wavelengths. |
| 43 |
An antenna has a driven element and a reflector. There is probably also a
|
|---|---|
| A | Director |
| B | Radial |
| C | Matching coil |
| D | Ground plane |
| 44 |
What connects your transceiver to your antenna?
|
|---|---|
| A | The power cord |
| B | A ground wire |
| C | A feed line |
| D | A dummy load |
| 45 |
The characteristic impedance of a transmission line is determined by the:
|
|---|---|
| A | Length of the line |
| B | Physical dimensions and relative positions of the conductors |
| C | Frequency at which the line is operated |
| D | Load placed on the line |
| 46 |
What commonly available antenna feed line can be buried directly in the ground for some distance without adverse effects?
|
|---|---|
| A | 300 ohm twin-lead |
| B | 600 ohm open-wire |
| C | 75 ohm twin-lead |
| D | Coaxial cable |
| 47 |
What is a coaxial cable?
|
|---|---|
| A | Two wires side-by-side in a plastic ribbon |
| B | Two wires side-by-side held apart by insulating rods |
| C | Two wires twisted around each other in a spiral |
| D | A center wire inside an insulating material which is covered by a metal sleeve or shield |
| 48 |
What is parallel-conductor feed 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 rods |
| 49 |
What kind of antenna feed line is made of two conductors held apart by insulated rods?
|
|---|---|
| A | Open-conductor ladder line |
| B | Coaxial cable |
| C | Twin lead in a plastic ribbon |
| D | Twisted pair |
| 50 |
What does the term "balun" mean?
|
|---|---|
| A | Balanced unloader |
| B | Balanced to unbalanced |
| C | Balanced un-modulator |
| D | Balanced antenna network |
| 51 |
What is an unbalanced line?
|
|---|---|
| A | Feed line with neither conductor connected to ground |
| B | Feed line with both conductors connected to ground |
| C | Feed line with both conductors connected to each other 4 |
| D | Feed line with one conductor connected to ground |
| 52 |
A balanced transmission line:
|
|---|---|
| A | Is made of two parallel wires |
| B | Has one conductor inside the other |
| C | Carries RF current on one wire only |
| D | Is made of one conductor only |
| 53 |
What device can be installed to feed a balanced antenna with an unbalanced feed line?
|
|---|---|
| A | A triaxial transformer |
| B | A balun |
| C | A wave-trap |
| D | A loading coil |
| 54 |
What is the best antenna feed line to use, if it must be put near grounded metal objects?
|
|---|---|
| A | Ladder-line |
| B | Twisted pair |
| C | Coaxial cable |
| D | Twin lead |
| 55 |
What are some reasons not to use parallel-conductor feed line?
|
|---|---|
| A | You must use an impedance-matching device with your transceiver, and it does not work very well with a high SWR |
| B | It does not work well when tied down to metal objects, and it cannot operate under high power |
| C | It does not work well when tied down to metal objects, and you must use an impedance matching device with your transceiver |
| D | It is difficult to make at home, and it does not work very well with a high SWR |
| 56 |
What does an SWR reading of 1:1 mean?
|
|---|---|
| A | The best impedance match has been attained |
| B | An antenna for another frequency band is probably connected |
| C | No power is going to the antenna |
| D | The SWR meter is broken |
| 57 |
What does an SWR reading of less than 1.5:1 mean?
|
|---|---|
| A | A fairly good impedance match |
| B | An impedance match which is too low |
| C | An impedance mismatch; something may be wrong with the antenna system |
| D | An antenna gain of 1.5 |
| 58 |
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 jumpy reading |
| D | A very low reading |
| 59 |
What does a very high SWR reading mean?
|
|---|---|
| A | The transmitter is putting out more power than normal, showing that it is about to go bad |
| B | The antenna is the wrong length, or there may be an open or shorted connection somewhere in the feed line |
| 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 conditions |
| 60 |
What does standing-wave ratio mean?
|
|---|---|
| A | The ratio of maximum to minimum voltages on a feed line |
| B | The ratio of maximum to minimum inductances on a feed line |
| C | The ratio of maximum to minimum resistances on a feed line |
| D | The ratio of maximum to minimum impedances on a feed line |
| 61 |
If your antenna feed line gets hot when you are transmitting, what might this mean?
|
|---|---|
| A | You should transmit using less power |
| B | The conductors in the feed line are not insulated very well |
| C | The feed line is too long |
| D | The SWR may be too high, or the feed line loss may be high |
| 62 |
The result of the presence of standing waves on a transmission line is:
|
|---|---|
| A | Perfect impedance match between transmitter and feedline |
| B | Maximum transfer of energy to the antenna from the transmitter |
| C | Lack of radiation from the transmission line |
| D | Reduced transfer of RF energy to the antenna |
| 63 |
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 | The angle of radiation is low |
| C | It is easy to match the antenna to the transmitter |
| D | It’s a convenient length on VHF |
| 64 |
How many directly driven elements do most Yagi antennas have?
|
|---|---|
| A | None |
| B | Two |
| C | Three |
| D | One |
| 65 |
A dipole transmitting antenna, placed 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 |
| 66 |
How are VHF signals propagated within the range of the visible horizon?
|
|---|---|
| A | By direct wave |
| B | By sky wave |
| C | By plane wave |
| D | By geometric wave |
| 67 |
A line-of-sight transmission between two stations uses mainly the:
|
|---|---|
| A | Troposphere |
| B | Skip wave |
| C | Ionosphere |
| D | Ground wave |
| 68 |
The distance traveled by ground waves:
|
|---|---|
| A | Depends on the maximum usable frequency |
| B | Is more at higher frequencies |
| C | Is less at higher frequencies |
| D | Is the same for all frequencies |