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Amateur Radio Info & Exams - Operations 1 - Phone operations, Courtesy, and Emergency Communications

Phone (Voice) Operations

Many would say that the main advantage of obtaining a General or Extra callsign is access to phone, or voice, on the MF and HF bands.

Many such operations involve using the ionosphere to bend (refract) signals back to earth. This is "sky-wave" propagation. For longer distances we want to launch our signal at a low angle so it travels a significant distance before being bent back down, to land in another continent, or on the other side of ours. Verticals, high dipoles, and beams are often used. In other cases we want to cover a group of stations over a smaller area, be they club members across a rural area, or stations involved in a search. We do this using low dipoles, or other horizontal antennas, obtaining propagation called NVIS, for Near Vertical Incidence Sky-wave. A local signal can also be received via ground-wave, this being how AM broadcast signals propagate during the daytime. A mixing of NVIS and ground-wave can cause some cancellation.

The mode most often used is currently SSB, or single-sideband. Related to AM, the unnecessary sideband, and the carrier are suppressed (or just not generated). The benefit of SSB is it is narrower than AM, FM or phase modulation.

The "cost" of SSB is that a stable receiver must be used, which can resolve audio without a carrier as a reference, plus a beat frequency oscillator and products detector. The BFO may be activated by the USB or LSB mode switch on ham gear; or there may be a switchable, manually adjusted BFO, which is also used with CW, on better shortwave receivers.

CODEC 2 is a narrow-band digital mode, developed in Australia. This can be run on a Windows or Linux PC, or an overpriced, custom BIOS PC using a Unix derived operating system called OSX; or in a dedicated box called SM1000, to COde and DECode the digital voice (DV). It has greater spectrum efficiency than SSB. It is part of Free DV, and you can download the software from in freedv.org.

In addition to SSB, FM is used on the upper portions of 10 metres, including with repeaters. AM, nicknamed "ancient modulation", is also used for various reasons, on various bands.

Off the exam, but there are Single Sideband Reduced Carrier (SSB-RC) systems, called by the military AME, AM-Equivalent, aka "compatible sideband". Likewise, HCJB (an Ecuadorian callsign, now Reach Beyond Australia) previously experimented with SSB with 20% carrier re-introduction on the higher SW bands, the aim being greater efficiency while hopefully being compatible with low cost AM SW receivers.

Sideband selection

You may remember that on 6 metre, 2 metre, 70 centimetre, and 23 cm and beyond, we use Upper Sideband (USB) for "weak signal" work. This is due to a convention which states that operations above 10 MHz (or 9 MHz, the result is the same) is USB, and below this point is LSB. Thus, operation on 160m, 80m (75m), and 40m are Lower-Sideband (LSB); and on 20m, 17m, 15m, 12m, and 10m are USB. The use of LSB is anachronistic, as commercial, maritime, and aviation users all use USB on all parts of MF and HF, hence 60m being USB. USB is also used in VK on 30m, this being just above 10 MHz. Except 60m, there is no regulation requiring this, and groups such as SPAM might use USB on 80 metres, so as that members using historic commercial radios which use USB only can take part. One TAFE teacher told us that using the inverse sideband was an indication that you did not wish to be disturbed.

Homebrew gear may produce double sideband (DSB-SC), without a carrier, which is compatible with SSB receivers. A simple double-balanced mixer IC or diode "ring modulator" can be used to generate it.

Vestigial sideband (VSB) is / was used in NTSC and PAL TV transmission, to preserve the phase of sync signals with in the signal, and appears as a distractor below.


VOX, is voice-operated switch, X, meaning switch. This means then the radio's circuit, or that in an accessory device triggers transmission in the presence of voice, but it also triggers based on noise, side-conversation with passengers, kids, horns, or reactions to bad drivers, so PTT remains popular. It also may clip the first syllable of an over. Remember, key-up, then talk, then release.

Courtesy & Emergency Communications

Why are these grouped? The G2B group of questions includes the interaction between courteous operations, and that emergency communications have priority.

In normal operation, no one operator, or group, has priority over a particular frequency. That said, if a net has been using a frequency since 1953, it is normal to respect that tradition.

However, emergency traffic has absolute priority. You may be having your chat with a mate, and a station might break in "VE3XYZ requiring assistance", or perhaps with a PAN (Priority) or Mayday (Emergency) call. In this case you need to cease your chat, and provide assistance to the station, whether it is calling road-side assistance, or calling the, ambulance, fire department, VRA, coastal authorities, etc. You may also hear a distress call on ham or other bands, and again, you should reply, and summon whatever help is needed. (Note outside the USA a sheriff is a court official, delivering summonses, etc, not a first responder.)

I am unsure how well the 911 system handles out-of-area calls, it may be necessary to Google the relevant agency. If you are answering the call in Australia from another station in Australia, 000 (triple 0) should be able to put you through to the operator covering, say Tennant Creek in the Northern Territory, even if you are in NSW. Note that if you are, say calling the NSW Ambulance for a ham on a Blue Mountains area repeater, and you are unable to provide a street address, but rather GPS coordinates, or "about 3km along" a named track, you need to tell the Ambulance operator (the person you speak to after the initial Telstra 000 operator) that you need to speak to a supervisor.

Distress and Urgency Signals

The following are prefixed to emergency calls and messages:

DistressLoss of ship / aircraftMAYDAYSOS
UrgencyMedical EmergencyPAN PANXXX
SafetyBad weather, Collision avoidanceSÉCURITÉTTT

SOS indicates the three dits, three dahs, and three dits are run together as one big character. The XXX and TTT are sent as indicudualy characters. X is dah-di-di-dah (the wide, thin, thin, wide pattern reminds me if the shape if an X), and T a single dah.

Avoiding Interference

Sometimes you may be talking to a friend nearby, and a conversation between another two stations becomes louder, due to a change in conditions. It is a good idea to move off frequency, to avoid interfering with them further.

Note that you may find stations operating CW on or near 3.57954 MHz, who are "Crystal locked" so can either not move, or only move a very small amount. Overseas, they may be using AM, DSB, or SSB. This is the old NTSC "color-burst" frequency, and crystals for it are both cheap and plentiful.

Channel spacing

When operating FM, it is fairly easy to move 25 or 30 kHz away from another station, but what about when using CW or SSB?

You may remember that for CW we have mentioned 150 Hz bandwidth, and the use of 500 Hz filters. Thus the answer is that you should move at 150 to 500 Hz away from another CW signal. If you can go further, this is a good idea.

For SSB, assuming use of the same sideband, you should tune at least 3 kHz away.

RACES - the Nuclear Option

RACES stands for "Radio Amateur Civil Emergency Service", and while one version is assisting local and state agencies during more localised events, the "Nuclear Option" involves use of President’s War Emergency Powers, allowing the shut-down of the "Amateur Radio Service", as Ham radio is formally known, and its replacement with the Radio Amateur Civil Emergency Service. This involves putting amateurs who have self-nominated and registered for such service, to work to support the protection of civilians following nuclear strikes on the US, or other war on its territory. Only specific frequencies will be available to RACES, and other ex-ham bands may be taken over for military use. Maybe not in the regulations, but there is also the possibility that government officials will operate in RACES channels.

Not electing petulant males will hopefully avoid the need for this.

In regular RACES you should not hear government officials on Ham frequencies, unless they are also licensed Hams, or are being directly supervised by a Ham, unless there is an immediate threat to life, and a ham radio is the only microphone they have to pick up.

The War Emergency Powers question has been removed, with the one which appears to relate to the less severe situation remaining. Sadly, climatic conditions are driving longer duration, more serious wildfires; more severe flooding, and even more massive snow storms, as hotter oceans means a greater amount of evaporation, and warmer air can transport more moisture.

Distress calls

Amateurs are allowed to use whatever frequency required to communicate the distress message. This may be a repeater channel, a call channel like 146.500 (Aus) or 146.520 MHz (US), an SSB call channel (144.100 MHz, 144.200 MHz, etc, even if you can only do FM here), an HF ham frequency whether or not you currently have privileges there, including if it means interrupting a net in progress. of a non-ham frequency, such as marine calling and distress (156.800 MHz FM, 2182 kHz AM), aviation (civil: 121.500 MHz AM, military: 243.000 MHz AM), various HF USB channels in both services, and things like Australia's Royal Flying Doctor Service, and VKS-737.

In Australia there are a significant number of users in the 3700 to 4000 kHz range, where US versions of Ham gear, such at the FT-857D and FT-897D can transmit. An example is the VKS-737 4WD channel, 3.995 MHz USB (dial frequency) is of potential use, as there are multiple station around the country. Note that while police frequencies may be monitored, especially in the evening when these frequencies work best, SES, VRA and Defence ones may only be monitored during searches and other operations. Missionary Aviation Fellowship are on 3700 kHz USB in the NT, a frequency allocated to Defence elsewhere. Dial (suppressed carrier) frequencies are 1.5 kHz below the centre frequencies listed on the ACMA database.

If travelling in the outback of Australia, you can purchase or rent type-approved HF gear, and satellite 'phones. One HF network operator is VKS-737. Several systems allow telephone calls to be made from these HF radios.

Before calling CQ

Before you call CQ, especially on HF and MF, you should check your operation is in accordance with bandplans for use of the mode, and that is not listed as being for specific operation, such as 6 metre liaison on 10 metres. You should listen for a moment, then either send "QRL? AL5BZ" in Morse (meaning "Are you busy?"), or "Is the frequency in use, AL5BZ". Listen for a moment, as a station in contact with a station you cannot hear may reply they are using the frequency. If you hear nothing, then call "CQ CQ de AL5BZ", or "CQ CQ this is Alpha Lima Five Bravo Zulu".


The normal call is CQ, but if you wish to make a contact outside your own country, call CQ-DX, DX standing for Distance. You can also call something like CQ-ZL, for NZ, or CQ-KH, for Hawaiʻi. DX is not Germany, but one of the prefixes used in the Philippines. The historic (Titanic era) distress call was CQD, replaced with SOS or Mayday.

Some US hams consider that the "lower bank" of Canadian provinces are not DX, but the "upper bank" of territories are.

DX Window

Operators in the "Lower 48", or mainland US should avoid ongoing conversations with each other in the segment 50.1 to 50.125 MHz. This is however voluntary.

Certain sub-bands are set aside to allow contacts with stations overseas, important when other countries have narrower bands than the US. These frequencies thus should only be used if answering a DX station, or to call one. 3776 to 3800 kHz is an example where VK operators can work US Advanced and Extra stations, using SSB.


Sending a series of the letter V - di-di-di-dah - is a test signal in Morse. Thus, you might send "VVV DE NZ2VK".


ALS is Automatic Level Control, a form of audio compression or limiting, designed so that an appropriate signal level goes to air. The idea is to have a decent signal level, without the signal being over-processed. The microphone gain can be adjusted to provide the desired level of ALC activation.

V is also a tasty energy drink, invented in ZL. You may wish to buy me one.

Relevant Questions

These are actual questions from the General exam pool.

Which sideband is most commonly used for voice communications on frequencies of 14 MHz or higher?
A. Upper sideband
B. Lower sideband
C. Vestigial sideband
D. Double sideband

All frequencies above 10 MHz use Upper sideband, answer A, for Alpha.

This applies all the way up, including VHF, UHF, SHF, etc.

Which of the following modes is most commonly used for voice communications on the 160-meter, 75-meter, and 40-meter bands?
A. Upper sideband
B. Lower sideband
C. Vestigial sideband
D. Double sideband

These are the regular bands below 10 MHz, so Lower sideband, answer B for Bravo.

Which of the following is most commonly used for SSB voice communications in the VHF and UHF bands?
A. Upper sideband
B. Lower sideband
C. Vestigial sideband
D. Double sideband

Is 50 greater than 10? Is 432 greater than 10? Yep, so it must be A, USB.

Which mode is most commonly used for voice communications on the 17-meter and 12-meter bands?
A. Upper sideband
B. Lower sideband
C. Vestigial sideband
D. Double sideband

Getting a bit repetitive, it is USB, as these bands are around 18 and 24 MHz, both above 10 MHz, answer A.

Which mode of voice communication is most commonly used on the HF amateur bands
A. Frequency modulation
B. Double sideband
C. Single sideband
D. Phase modulation

Given the number of times upper or lower sideband appears on this page, it just might be Single sideband, answer C.

This allows more users in a band than DSB, AM, or FM.

Which of the following is an advantage when using single sideband as compared to other analog voice modes on the HF amateur bands?
A. Very high fidelity voice modulation
B. Less subject to interference from atmospheric static crashes
C. Ease of tuning on receive and immunity to impulse noise
D. Less bandwidth used and greater power efficiency

SSB uses less bandwidth, and has greater power efficiency, answer D.

AM wastes power in the redundant sideband, and in the carrier, but SSB does need a more sophisticated receiver.

Which of the following statements is true of the single sideband voice mode?
A. Only one sideband and the carrier are transmitted; the other sideband is suppressed
B. Only one sideband is transmitted; the other sideband and carrier are suppressed
C. SSB is the only voice mode that is authorized on the 20-meter, 15-meter, and 10-meter amateur bands
D. SSB is the only voice mode that is authorized on the 160-meter, 75-meter and 40-meter amateur bands

As it says on the label, only one sideband is sent; the redundant sideband and the carrier are suppressed, answer B

What is the recommended way to break in to a phone contact?
A. Say "QRZ" several times, followed by your call sign
B. Say your call sign once
C. Say "Breaker Breaker"
D. Say "CQ" followed by the call sign of either station

This is not the Chook-Band, say YOUR callsign, answer B.

"Chooks" generate "cackle-berries", or eggs, and this is another name for chickens.

Why do most amateur stations use lower sideband on the 160-meter, 75-meter and 40-meter bands?
A. Lower sideband is more efficient than upper sideband at these frequencies
B. Lower sideband is the only sideband legal on these frequency bands
C. Because it is fully compatible with an AM detector
D. It is good amateur practice

It is just an old tradition, still in place, answer D.

Which of the following statements is true of voice VOX operation versus PTT operation?
A. The received signal is more natural sounding
B. It allows "hands free" operation
C. It occupies less bandwidth
D. It provides more power output

VOX allows triggering transmission by speech, meaning "hands free" hamming, but with the risk of other sounds going to air, answer B.

Generally, who should respond to a station in the contiguous 48 states who calls "CQ DX"?
A. Any caller is welcome to respond
B. Only stations in Germany
C. Any stations outside the lower 48 states
D. Only contest stations

This indicates the desire for a long-distance contact, so only stations outside the lower 48 should reply, answer C.

What control is typically adjusted for proper ALC setting on an amateur single sideband transceiver?
A. The RF clipping level
B. Transmit audio or microphone gain
C. Antenna inductance or capacitance
D. Attenuator level

The microphone gain or other control for transmit audio should be adjusted for proper operation of the ALC, answer B.

G2B01 [97.101(b), (c)]
Which of the following is true concerning access to frequencies?
A. Nets always have priority
B. QSOs in progress always have priority
C. Except during emergencies, no amateur station has priority access to any frequency
D. Contest operations must always yield to non-contest use of frequencies

No one has priority on a frequency, except during emergencies, answer C.

That said, courtesy says you should give way to nets, and avoid interfering with ongoing QSOs. Also, contests should avoid interfering with other users.

What is the first thing you should do if you are communicating with another amateur station and hear a station in distress break in?
A. Continue your communication because you were on the frequency first
B. Acknowledge the station in distress and determine what assistance may be needed
C. Change to a different frequency
D. Immediately cease all transmissions

You must acknowledge the station with emergency traffic, and assist them, answer B.

What is good amateur practice if propagation changes during a contact and you notice interference from other stations on the frequency?
A. Tell the interfering stations to change frequency
B. Report the interference to your local Amateur Auxiliary Coordinator
C. Attempt to resolve the interference problem with the other stations in a mutually acceptable manner
D. Increase power to overcome interference

You should try to find a mutually acceptable arrangement, answer C.

If the band is not congested, moving up or down a little should be easy. If you and your contact are local to each other, maybe move to a free repeater, etc.

When selecting a CW transmitting frequency, what minimum separation should be used to minimize interference to stations on adjacent frequencies?
A. 5 to 50 Hz
B. 150 to 500 Hz
C. 1 to 3 kHz
D. 3 to 6 kHz

Depending on the narrowness and quality of filters used, you need to be at least 150 to 500 Hz away from the next station, answer B.

When selecting an SSB transmitting frequency, what minimum separation should be used to minimize interference to stations on adjacent frequencies?
A. 5 to 50 Hz
B. 150 to 500 Hz
C. Approximately 3 kHz
D. Approximately 6 kHz

SSB signals are around 3 kHz wide, so you should tune your dial to be at least this amount above or below the suppressed carrier frequency of the other station, answer C.

G2B06 (A)
What is a practical way to avoid harmful interference on an apparently clear frequency before calling CQ on CW or phone?
A. Send "QRL?" on CW, followed by your call sign; or, if using phone, ask if the frequency is in use, followed by your call sign
B. Listen for 2 minutes before calling CQ
C. Send the letter "V" in Morse code several times and listen for a response or say "test" several times and listen for a response
D. Send "QSY" on CW or if using phone, announce "the frequency is in use", then give your call and listen for a response

Ask if the frequency is in use, via voice, or by sending "QRL?"; and your callsign, answer A.

Which of the following complies with good amateur practice when choosing a frequency on which to initiate a call?
A. Check to see if the channel is assigned to another station
B. Identify your station by transmitting your call sign at least 3 times
C. Follow the voluntary band plan for the operating mode you intend to use
D. All of these choices are correct

Ensure you are using the correct frequency for your mode, answer C.

What is the voluntary band plan restriction for U.S. stations transmitting within the 48 contiguous states in the 50.1 to 50.125 MHz band segment?
A. Only contacts with stations not within the 48 contiguous states
B. Only contacts with other stations within the 48 contiguous states
C. Only digital contacts
D. Only SSTV contacts

This is a sub-band where your should avoid operation between stations in the "lower 48", answer A.

This is the "DX Window". There is plenty of spectrum above this segment for general contacts.

G2B09 [97.407(a)]
Who may be the control operator of an amateur station transmitting in RACES to assist relief operations during a disaster?
A. Only a person holding an FCC issued amateur operator license
B. Only a RACES net control operator
C. A person holding an FCC issued amateur operator license or an appropriate government official
D. Any control operator when normal communication systems are operational

In the local disaster version of RACES at least, only a licensed Amateur may be the control operator, answer A.

G2B10 [97.405(b)]
When is an amateur station allowed to use any means at its disposal to assist another station in distress?
A. Only when transmitting in RACES
B. At any time when transmitting in an organized net
C. At any time during an actual emergency
D. Only on authorized HF frequencies

During an actual emergency, answer C.

G2B11 [97.405]
What frequency should be used to send a distress call?
A. Whichever frequency has the best chance of communicating the distress message
B. Only frequencies authorized for RACES or ARES stations
C. Only frequencies that are within your operating privileges
D. Only frequencies used by police, fire or emergency medical services

It is the frequency where you are most likely to make contact, answer A. These do not have to be within your privileges, or even in the Ham bands, answer A.

On to: Operations 2 - CW, Q-codes & HF Operations

You can find links to lots more on the Learning Material page.

Written by Julian Sortland, VK2YJS & AG6LE, March 2022.

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