Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
92 Cards in this Set
- Front
- Back
|
What could be happening if another operator reports a variable high-pitched whine on the audio from your mobile transmitter? |
The key word in the question is "mobile transmitter" which means a tranciever in your vehicle. The alternator of your vehicle can generate noise that can tag along with the signal transmitted by your radio. Sometimes the whine varies with the RPM of the engine. The best way to prevent this interference is to put filters on the DC power line going to the tranceiver. |
|
|
If your license has expired and is still within the allowable grace period, may you continue to operate a transmitter on amateur service frequencies? |
Once your license is expired, you are no longer permitted to operate a transmitter on the Amateur Radio service. No worries, though, because renewing your license with the FCC through the Universal Licensing System usually only takes a few minutes!
Once the ULS database shows that your license has been renewed, you can go back to operating. To avoid interruption to your amateur radio license privileges, renew your license up to 90 days before it expires. |
|
|
What is the name for the flow of electrons in an electric circuit? |
Current |
|
|
The following results from the fact that skip signals refracted from the ionosphere are elliptically polarized? |
Either vertically or horizontally polarized antennas may be used for transmission or reception |
|
|
What is the approximate bandwidth of a single sideband voice signal? |
Single Sideband is a form of modified Amplutude Modulation (AM). Whereas AM normally uses twice the bandwidth of the original carrier, Single Sideband avoids that issue and also does not waste power on a carrier. The bandwidth used by a single sideband voice signal varries between 300 and 3400 Hz, or .3 to 3.4 kHz. The approximate bandwidth, therefore, is the rough maximum used, which is approximately 3kHz. |
|
|
The following is a way to reduce or eliminate interference by an amateur transmitter to a nearby telephone? |
Put a RF filter on the telephone
Although sometimes a high SWR (Standing Wave Ratio) can cause unwanted radiation near the ground that results in a strong signal appearing at a nearby telephone, the problem is still that the telephone is acting as a receiver. The microphone gain being too high could cause splatter on adjacent frequencies or over-deviation, but can't turn a telephone into a receiver. The only remaining choice is to keep the RF energy from even getting to the telephone by installing and RF filter on the telephone.
|
|
|
What are the frequency limits of the UHF spectrum? |
One thing that often confuses new hams is that the terms "HF," "VHF," and "UHF" actually refer to different parts of the spectrum, with "HF" or "High Frequency" actually referring to frequencies that are the lowest that Amateur Radio Operators use.
The ranges are thus: * UHF (Ultra High Frequency) is from 300MHz to 3000MhzDon't get confused by answer "C" it is in kHz not MHz |
|
|
Which of the following actions might amateur operators take to prevent exposure to RF radiation in excess of FCC-supplied limits? |
RF radiation "radiates" outward from the antenna, therefore, it is the antenna that must be moved. Relocating the transmitter will have no effect, provided the transmitter is connected to the antenna correctly. Increasing the duty cycle would have the reverse effect - it would increase your exposure.
Duty cycle is the ratio of how much time the transceiver spends transmitting to how much it spends receiving; thus, the more you transmit, the higher your duty cycle. |
|
|
What type of circuit controls the amount of voltage from a power supply? |
A regulator, more commonly referred to as a Voltage Regulator, _regulates _the voltage down to a particular point. The amount of current and what voltage the regulator targets depends on the type of regulator and sometimes depends on other components in the circuit. |
|
|
What is used together with an inductor to make a tuned circuit? |
There are two components which have an impedence that changes depending on the frequency of the signal moving through it:capacitors and inductors. Antenna tuners, which match the impedence of antennas that are not properly tuned for a given frequency range so that they can be used there anyway, work with a set of variable capacitors and/or inductors to change the tuning of the circuit. |
|
|
What formula is used to calculate voltage in a circuit? |
Voltage (E) equals current (I) multiplied by resistance (R)
Ohms law involves 3 variables - Voltage (E, for Electromotive force), Resistance (R), and Current (I). In a recent webcast, Gordon West suggested a simple method for remembering their order. He suggests that you think of E as an Eagle, I as an Indian, and R as a Rabbit. Any time E is on the left side, I and R are on the right side; the Indian and the Rabbit are both on the ground, so they go next to each other (multiplication, or E=I*R). If E is on the right side, then the Eagle is always on top (in the air). So Resistance is E/I, because the Eagle is always above the indian. Current (I) is E/R, because the eagle is always above the Rabbit. (Remember that I*R means I multiplied by R) This might help you remember the formulae for Ohms Law.
|
|
|
What name is given to an amateur radio station that is used to connect other amateur stations to the Internet? |
In computer terms a gateway is the name of a device that connects two different networks together; a router is a type of gateway. Thus, a station that connects a packet radio network to the Internet is also a gateway.
A digipeater is a station that receives packets and then retransmits them; it's the only distractor that would make any sense, but it has nothing to do with the Internet, though it is possible for a digipeter to also be a gateway.
Repeaters simultaneously retransmit signals on another frequency and are used for voice operation; beacons transmit some form of information periodically. Neither has anything to do with packet radio. |
|
|
What is a reason to use a properly mounted 5/8 wavelength antenna for VHF or UHF mobile service? |
It offers a lower angle of radiation and more gain than a 1/4 wavelength antenna and usually provides improved coverage |
|
|
What kind of hazard is presented by a conventional 12-volt storage battery? |
Explosive gas can collect if not properly vented.
12 volt storage batteries use lead and sulfuric acid. When the battery is charged, Hydrogen gas is generated. Hydrogen is extremely flammable and in the right combination of oxygen will burn so fast that it explodes. Obviously, the 12 volt battery is not high voltage and it won't generate ozone.
|
|
|
Which of the following is an accepted practice to get the immediate attention of a net control station when reporting an emergency? |
During net operations there are commonly many stations participating and attempting to communicate. It is very important that the priority of your emergency be established immediately, so the first words of your transmission should convey that. "Priority" or "Emergency" should be stated immediately so that there is no confusion about your intent and need. |
|
|
Which of the following establishes grounding requirements for an amateur radio tower or antenna? |
Because the grounding system falls under an electrial installation, it is governed by local electrical codes. Most local codes are based on the National Electrical Code (NEC), so in most cases they will just refer you to the NEC. You should be aware that local codes vary dramatically throughout the United States in terms of who can inspect and approve electrical installations, so it's always a good idea to check with your local code enforcement office to find out what the requirements are. |
|
|
How fast does a radio wave travel through free space? |
All electric, magnetic, and electromagnetic waves travel at the same speed. This includes light waves, radio waves, electrical waves, and magnetic waves. |
|
|
What are the units of impedance? |
Impedance is actually very similar to resistancein many ways -- which makes sense, since impedeand resist are roughly synonymous. Thus it makes sense that they share the same unit --Ohms. |
|
|
The main difference between resistance andimpedance is that |
The main difference between resistance andimpedance is that impedance changes with frequency. Inductors pass direct current (frequency of 0) but have a higher impedance the higher the frequency, since inductors tend to resist changes in current. Capacitors have infinite impedance with DC and the higher the frequency the lower the impedance (capacitors resist changes in voltage). |
|
|
Which of the following is used together with an inductor to make a tuned circuit? |
There are two components which have an impedence that changes depending on the frequency of the signal moving through it:capacitors and inductors.
Antenna tuners, which match the impedence of antennas that are not properly tuned for a given frequency range so that they can be used there anyway, work with a set of variable capacitors and/or inductors to change the tuning of the circuit. |
|
|
What is a disadvantage of air core coaxial cable when compared to foam or solid dielectric types? |
"Air core" coax can have very low loss even at high frequencies, however unlike other dielectrics used in coax, air is very easily displaced by water, should there be any leaks or problems with the coax jacket. |
|
|
When, under normal circumstances, may a Technician Class licensee be the control operator of a station operating in an exclusive Extra Class operator segment of the amateur band |
At no time |
|
|
Which type of conductor is best to use for RF grounding? |
Flat strap - A good RF ground conductor to go from your radio gear to an Earth ground is a Flat strap. The width of the flat strap reduces inductance in the conductor and thus a good ground conductor. |
|
|
What precautions should be taken when measuring high voltages with a voltmeter? |
Ensure that the voltmeter and leads are rated for use at the voltages to be measured Voltmeters have a very high impedance - indeed, the standard for voltmeters used to be 20,000 Ohms/Volt. You want to make sure the voltmeter doesn't affect the circuit that you're measuring, so it has to have a very high impedance. So the choice of low impedance is just wrong. You always hear that things have to be grounded well. But you don't want to be grounding the high voltage through your meter! You might want to measure the difference in voltage between ground and some circuit, but the intention is not to ground the circuit. If you did that, the difference would be zero, and that measure would only obtain for a short while, the length of time it took to blow up your circuit or the meter. |
|
|
What, in general terms, is standing wave ratio (SWR)? |
A measure of how well a load is matched to a transmission line. Standing Wave Ratio is a ratio, but the answer here that lists "ratio" as an option is not it, so don't be fooled. The most efficient transfer of power occurs when the load and the transmission line have the same impedence; in this case, radios are all designed for 50 ohm, so if your feedline and antenna system are not 50 ohm some of the power will get reflected back to the transmitter. The Standing Wave Ratio is the ratio of how much forward power there (the power out of the transmitter) is to how much power is reflected back (or reflected power), but what it actually measures is how well the antenna and feedline (load) are matched in impedence to the transmitter (transmission line). Note that although resistance and impedence are both measured in ohms, they are not the same thing! The primary difference for the purpose of this discussion is that resistance is always the same, but impedence changes with frequency; this is why you may have a very close match (and a good SWR) at one frequency but a very bad match at another. |
|
|
What is a satellite beacon? |
A transmission from a space station that contains information about a satellite. A satellite beacon in Amateur Radio is an intentionally conspicuous device on the space station that is designed to attract attention and pass information about a specific location -- that is, about the satellite. So the actual beacon is the device on the space station that transmits information about the satellite for the information of users on the ground (or wherever)
|
|
|
The following are provided by satellite tracking programs? |
Satellite tracking programs tell you where a satellite is at a given time, including its altitude and where it will be at the start and end of a pass, relative to your location.
The tracking programs even tell you how much to change your transmitter's and receiver's frequency to compensate for the Doppler shift you get when the satellite is coming toward you or moving away from you. |
|
|
What determines the amount of deviation of an FM (as opposed to PM) signal? |
The amplitude of the modulating signal |
|
|
What class of electronic components is capable of using a voltage or current signal to control current flow? |
Transistors |
|
|
What is the definition of duty cycle during the averaging time for RF exposure? |
The percentage of time that a transmitter is transmitting |
|
|
How many microfarads are 1,000,000 picofarads? |
1 microfarad |
|
|
When must the station licensee make the station and its records available for FCC inspection? |
At any time upon request by an FCC representative
Yes, you have protection against unlawful search and seizure; however, part of being a ham radio operator is that your station (not your house, bank records, or little black book) and any of its records can be inspected by an FCC representative at any time. Anyone other than an authorized representative of the FCC has no authority to ask.
|
|
|
How can overload of a non-amateur radio or TV receiver by an amateur signal be reduced or eliminated? |
Block the amateur signal with a filter at the antenna input of the affected receiver
The problem here is that the non-amateur radio is receiving signals in the amateur radio band, so a filter on the amateur transmitter won't help - the signal in the amateur band will still be radiated.
Changing the transmitter from FM to SSB will only change the mode of the interference, and it's likely that it will still be received by the TV receiver.
The bandwidth of the transmitted signal isn't the problem - the problem is that the TV is receiving signals in the amateur radio bands. So the only way to reduce or eliminate the signal is to block the amateur radio signal before it gets into the TV, using a filter at the antenna input of the affected receiver. |
|
|
Which of the following is good procedure when contacting another station in a radio contest? |
Send only the minimum information needed for proper identification and the contest exchange |
|
|
What property of a radio wave is used to describe its polarization? |
The orientation of the electric field
Since there's always a magnetic and electric field to a radio wave, and they're oriented 90 degrees to each other, you could use either magnetic or electric to define polarization, but it's conventional to use the electric field (not the magnetic field, or a ratio). Polarization has nothing to do with the velocity of a radio wave, hence the ratio of velocity to wavelength has nothing to do with polarization. |
|
|
What type of component is often used as an adjustable volume control? |
Potentiometer - A potentiometer (pot) can be configured as a user controlled variable resistor. This change in resistance in turn controls the volume.
|
|
|
What is the characteristic appearance of a cold solder joint? |
A "cold" solder joint results when not all metal surfaces are properly fluxed, brought up to the needed temperature, or if the solder is disturbed during the "plastic phase" as it cools and hardens When this happens, the surface of the solder joint will appear dull or grainy instead of bright and shiny. Inspect every solder joint to ensure that the solder flowed smoothly over all conductors being joined. A small crack in the solder around a large conductor is an indication that it was not heated sufficiently. Remember not to "play" with the solder, just heat up the whole connection until the solder flows freely filling all gaps, then remove the soldering iron and let it cool undisturbed. |
|
|
Which of the following are inputs to a satellite tracking program? |
Keplerian elements are the parameters that define the orbit of a satellite. From these elements, the program can compute the time and bearing of a satellite pass, relative to your position on the earth. The weight of the satellite enters into the equation, but it's the Keplerian data that the tracking program uses. The last observed time of zero Doppler shift would be the time that the satelitte was moving neither toward you or away from you (like when it was overhead, for example). While this might be interesting data, it isn't enough to predict where it will be coming from or going to on its next pass, or at what altitudes. |
|
|
What is the approximate length, in inches, of a 6 meter 1/2-wavelength wire dipole antenna? |
There are many factors that will affect the amount of length needed for the 1/2 wave dipole antenna, such as the physical characteristics of the wire or nearby conductive sources. But the easiest way to solve this problem is to remember that a meter is a little longer than a yard, or approximately 39 inches. To calculate this, half of the 6 meter wavelength would be 3 meters. To convert that to inches, multiply by 39 inches per meter: 3 meters * 39 inches/meter = 117 inches Answer C (112 inches) is the closest to this For those interested in the formula to get the closest answer: To get half-wavelength dipole antenna lengths in feet, divide 468 by the frequency in megahertz: 1. First convert the wavelength to the frequency in megahertz: 300/6 = 50mhz2. Then divide 468 by that number: 468/50 = 9.36 feet. 3. With 12 inches in a foot, you get 9.36*12 = 112.32. Quarter wavelength dipole is the same, but divide 234 by the frequency in megahertz. This is easier to remember (since 234's digits are sequential), so just remember that one and convert up when needed! |
|
|
How much transmitter power should be used on the uplink frequency of an amateur satellite or space station? |
The minimum amount of power needed to complete the contact |
|
|
What is the FCC Part 97 definition of an amateur station? |
A station in the Amateur Radio Service consisting of the apparatus necessary for carrying on radio communications |
|
|
What is the resistance of a circuit in which a current of 3 amperes flows through a resistor connected to 90 volts? |
E = I x R R = E / I = 90 / 3 = 30 ohms R = Resistance (ohms), E - Voltage (volts), I = Current (amperes) |
|
|
What type of radiation are VHF and UHF radio signals? |
No ionizing radiation |
|
|
What is the purpose of the squelch control on a transceiver? |
To mute receiver output noise when no signal is being received - The squelch circuit watches the signal strength detector's output and turns on the signal when it is strong enough. By turning the squelch control up too high you may miss weaker stations. By turning it too low you will hear the "white noise" received continuously or intermittently as the background noise varies. |
|
|
Why is it important to have a low SWR in an antenna system that uses coaxial cable feed line? |
To allow the efficient transfer of power and reduce losses
SWR or Standing Wave Ratio is a measure of how well an antenna system matched to the transmitter and is an indication of efficiency. A low ratio indicates that the transmitted energy is effectively being delivered to the antenna and beyond. A higher number is an indication that something is not matched and that some of the transmitted energy is returning to the transmitter or reflected back. You can understand that if we short out the end of the coax that no energy will be put into the air, also if we leave the connector open and not connected to the antenna that energy is not tranmitted to the air; instead it goes back into the transmitter and is disipated as heat. A very bad SWR can also damage your transmitter.
|
|
|
A very good SWR is |
1.1:1 |
|
|
A good SWR is |
anything less than 1.5:1 |
|
|
The greatest concern for antenna life is |
Weather |
|
|
A high SWR will not neccessarily increase television interference since |
less energy is actually radiated into the air. |
|
|
What brief statement is often transmitted in place of "CQ" to indicate that you are listening on a repeater? |
Your call sign |
|
|
Which of the following is a result of the fact that the amateur service is secondary in some portions of the 70 cm band?
|
U.S. amateurs may find non-amateur stations in the bands, and must avoid interfering with them |
|
|
How would you change a dipole antenna to make it resonant on a higher frequency? |
Antenna length is inversely related to frequency. The higher the frequency, the SHORTER the wavelength. |
|
|
What is a disadvantage of the "rubber duck" antenna supplied with most handheld radio transceivers? |
It does not transmit or receive as effectively as a full-sized antenna.
Smaller antennas use electrical components to maintain resonance on the target frequencies, but having less surface area they don't absorb (or emit) as much power. Therefore they do not transmit or receive as effectively as a regular full-sized antenna. |
|
|
What is probably happening when an ohmmeter, connected across an unpowered circuit, initially indicates a low resistance and then shows increasing resistance with time? |
The circuit contains a large capacitor. |
|
|
What term describes the number of times per second that an alternating current reverses direction? |
Frequency |
|
|
What is the name of a device that combines several semiconductors and other components into one package? |
Integrated circuit |
|
|
Which of the following describes a simple dipole mounted so the conductor is parallel to the Earth's surface? |
A horizontally polarized antenna The orientation of the conductor of an antenna relative to the earth's surface determines it's "polarization". If the polarization of the sending station's antenna does not match the polarization of the receiving station's antenna significant loss in signal can be the result. If the antenna is vertical (perpendicular to the ground) as most antennas are thought to be then it is "vertically polarized" and if it is horizontal (parallel to the ground) then it is "horizontally polarized". |
|
|
For which licenses classes are new licenses currently available from the FCC? |
Technician, General, Amateur Extra |
|
|
What is the formula used to calculate electrical power in a DC circuit? |
Power (P) equals voltage (E) multiplied by current (I) |
|
|
What is the grace period following the expiration of an amateur license within which the license may be renewed? |
2 years
|
|
|
Which emission may be used between 219 and 220 MHz? |
Data |
|
|
What is the source of a high-pitched whine that varies with engine speed in a mobile transceiver's receive audio? |
Alternator. You can filter out the this whine with a 12 Volt power line filter. |
|
|
What is an amateur station control point? |
The location at which the control operator function is performed. This is an important thing to understand; the control point is the location of which the control operator when the station is in use. In some cases this may be the same location as the station (local control) or it could be across some sort of auxiliary link, such as a cross-band repeater, controlling through Echolink or IRLP across the internet from a computer or cellphone, etc. It does not matter where the station is located -- what determines the control point is the location of the control operator. |
|
|
1000 milliwatts |
1 watt |
|
|
What is the national calling frequency for FM simplex operations in the 70 cm band? |
FM Simplex Calling Frequencies: * 10 meters - 29.600 Mhz* 6 meters - 52.525 Mhz * 2 meters - 146.52 Mhz * 1.25 meters - 223.50 Mhz * 70 cm - 446.00 Mhz * 33 cm - 906.50 Mhz * 23 cm - 1294.50 Mhz |
|
|
Which agency regulates and enforces the rules for the Amateur Radio Service in the United States? |
The FCC |
|
|
Who may select a desired call sign under the vanity call sign rules? |
Anyone |
|
|
How much power is being used in a circuit when the applied voltage is 13.8 volts DC and the current is 10 amperes? |
P = I x E = 10 x 13.8 = 138 watts |
|
|
Inserting an inductor in the radiating portion of the antenna to make it electrically longer |
Loading |
|
|
QSY means |
QSY means to change frequency. |
|
|
QSL |
I acknowledge receipt |
|
|
QSL? |
Do you acknowledge? |
|
|
QRX |
Wait |
|
|
QRV |
I am ready to copy |
|
|
QRL |
The frequency is in use |
|
|
QTH |
My location is... |
|
|
Which sideband is normally used for 10 meter HF, VHF and UHF single-sideband communications? |
The Upper Sideband is used for SSB on 10M HF, VHF and UHF bands. |
|
|
What electronic component allows current to flow in only one direction? |
Diode |
|
|
___ generally allows current to flow in either direction but when too much current (or at too high of a voltage) flows across it the "blows" |
Fuse |
|
|
In which direction is the radiation strongest from a half-wave dipole antenna in free space? |
Broadside. The radio waves emit out along the length of the dipole outward, and is strongest at the middle. There is little to no RF energy coming out the ends of the antenna.
The feed line has no effect in the emission of a dipole antenna if properly chocked off by a baluns |
|
|
An ___ radiates equally in all directions. |
isotropic antenna |
|
|
What is the basic unit of capacitance? |
The Farad |
|
|
What is the current flowing through a 24-ohm resistor connected across 240 volts? |
10 Amps E = I x R |
|
|
Power (Watts) = ? |
I x E (Volts X Amps) |
|
|
Which part of the atmosphere enables the propagation of radio signals around the world? |
The Ionosphere |
|
|
Why should you avoid attaching an antenna to a utility pole? |
The antenna could contact high-voltage power wires |
|
|
What might be the problem if you receive a report that your audio signal through the repeater is distorted or unintelligible? |
Your transmitter may be slightly off frequency Your batteries may be running low You could be in a bad location |
|
|
What is the term used to describe an amateur station that is transmitting and receiving on the same frequency? |
Simplex communication |
|
|
Why is it unwise to install a 20-ampere fuse in the place of a 5-ampere fuse? |
Excessive current could cause a fire |
|
|
When the control operator is not the station licensee, who is responsible for the proper operation of the station? |
The control operator and the station licensee are equally responsible |
|
|
How is access to an IRLP node accomplished? |
By using DTMF signals |
|
|
DTMF |
DTMF stands for Dual Tone - Multi Frequencyand it is the basis for your telephone system |
