Amateur Radio Info & Exams

Home - About AR - Learning Material - Exams - Clubs - Posters

Amateur Radio Info & Exams - Further permitted activities

This covers some of the additional activities permitted by Amateur Radio.

RDF

Using a directional antenna, such as a short yagi or quad, it is possible to locate signals, be they deliberate interference, a radio with a jammed microphone PTT, noise from arcing electrical equipment, or emergency locator beacons (including those triggered by being thrown into the rubbish).

T-hunts, hidden transmitter hunts, fox-hunts, or RDF (radio direction finding), or Radio-Sport are various names for events which involve locating and walking / running or driving to locate a hidden transmitters. Radio orienteering is a variation. Directional antennas, or systems with 4 vertical antennas which can resolve the direction to the signal are used to determine the direction to the transmitter. Switching attenuators into the antenna feedline can help, especially as you get closer to the transmitter. Reflection from metal buildings, or terrain can make working out the direction more challenging.

There are also several commercial products which use 4 or more antennas to provide a bearing to a signal source; and DIY versions of these.

Contesting

There are a range of contests, which can run from an hour or so, to a month. The big American ones often run over a weekend. Australia VHF-UHF "field day" events go for 24 hours, but allows entries for 8 hours. The Ross Hull Memorial VHF-UHF Memorial Field Day runs for all of January, but only the best 7 or 2 days are used as entries, and the field day can be included.

For VHF field days a system called Maidenhead Locators are used, these being 2 degrees wide, and 1 degree high. For example, QF56 covers Central and Northern Sydney, the Central Coast, and as far west as Jenolan Caves. Rover stations move between grid-squares, as activating multiple gridsquares gets extra points. Perth stations can do this easily, as there is an intersection of 4 in the suburbs; two in the hills, two on the low-lands. It uses WGS-84 as the datum, important perhaps if you are setting up at Cape Banks on Botany Bay, just inside QF55, rather than QF56.

The north-south dimension is 111.12km, this being 60 nautical miles. At the equator the east-west dimension is around 222 km, diminishing to zero at the poles. It is named for the town west of London, on the Elizabeth Line (Crossrail), the site of the meeting at which it was adopted. See: Wikipedia: Maidenhead Locator System and map your gridsquare

They are roughly square over the UK, and have a 1 NM (111.12 km) width 60 degrees north (or south), over Shetland (Scotland); Bergen, Norway; Alaska; and Nunavut & Hudsons Bay in Canada. The boundary of JP50 and JO59 is a 111.12 km line just north of Oslo, Norway. 60° South passes equidistant between Chile and Antarctica. The mathematical reason 2° wide equals 1° high at 60° is: Cosine(60°) = 0.5

Some GPS apps, including HamGPS on Android (free) give these locators, sometimes with extra pairs of letters and numbers, for tighter location (like QF56nh), and more accurate distance calculations, as for some contests, scoring is based on distance. Contacting the same (or other) stations on multiple bands also gets more points.

For HF contests, scores might be based on number of contacts, countries and related entities such as islands contacted, and the number of bands contacts are made on. Some factors are called "multipliers", as they multiply the number of points.

Depending on the nature of the contest (and how serious the station is about a big score), only the minimum information needed for proper identification and the contest exchange should be sent, but some here can be a bit more casual, especially when signals are good.

A few "Downunder" contests are the John Moyle Field Day (mid-March); and the Trans-Tasman Low-Band Challenge (mid-July), covering 160m, 80m, and 40m. The Harry Angel Memorial 80m Sprint goes for 106 minutes on a Saturday evening, to celebrate his 106 year life.

Note that narrower bands, such as 60 metres; and the "WARC" bands, 30, 17, and 12 metres are often avoided in contests.

Some operating events, such as the International Marconi Day, held in late April are not contests.

There are also Awards, for contacting or activating mountain-tops (SOTA), national parks, states, counties, shires, stations at lighthouses or lightships, and gridsquares.

A couple of distractors refer to "spotting". This was a packet radio system which evolved to the Internet, where DXers list the callsign, frequency, and mode of operation of station of interest, termed DX stations. Different contest have different rules re using these, include re "self spotting", where a station publishes there own details online. Web search for "DX cluster".

Internet Linking

Several systems use Voice over Internet Protocol, VoIP to transmit voice via data networks, usually the Internet.

IRLP is the Internet Repeater Linking Project, which uses Linux based PCs, embedded PCs, or Raspberry Pis to link repeaters via the Internet. To access another node, dial its number using a DTMF keypad on your radio. The system managers are insistent that users can only access it from a radio. Read more: irlp.net

When the link is via a simplex radio, rather than a repeater, the term "gateway" is used.

Echolink, allows connections from PCs and Android devices, as well as dialing from a repeater or simplex gateway. See: echolink.org

WIRES-II and WIRES-X are proprietary Yaesu systems, for FM and Fusion (C4FM).

There are a range of linking systems for DMR - Digital Mobile Radio. Incidentally, DMR is a European system, hence the 12.5 kHz channel spacing. It allows two conversations at once on a repeater, using Time Division Multiple Access (TDMA).

Off the exam, NXDN (Next Generation Digital Narrowband, with low bandwidth offering 6.25 kHz channel spacing), also supports linking.

Always wait a few moments after the node connects before calling, and leave a couple of seconds after the other station's over before you transmit. The Internet connection has some "latency" or delay.

Weak-signal data modes

Several WSJT modes, such as JT65 and JT9, are Weak Signal modes named after Joe Taylor, K1JT; as is FT8 and FT4. Some of these are suitable for specific tasks, such as tropospheric scatter, meteor scatter, and bouncing signals of the moon. There are also modes suitable for beacons.

Other data modes

Packet is cited as a digital mode in the exam. It requires good signal strength. It does however include a "check-sum, where calculating on the content of a packet generates a number, which is sent with the data. If the calculation on the received packet gets the same number, then it is likely correct, and an acknowledgement can be sent, allowing the next packet to be sent, if there is one. If there is an error, then ARQ is sent, for a re-transmission.

Phase Shift Keying (PSK) is a system, where, instead of changing frequency, the phase of the signal is changed, by 0° or 90° 180° and 270°. Allowing 4 positions, 2 bits can be sent with one transition.

Allowing 8 positions (multiples of 45°) means 3 bits can be sent.

Smaller shifts, and multiple levels were used with high speed dial-up modems, allowing many bits to be sent in one element. The number of elements per second is called the baud-rate. Those of us who were around in the 1980s may remember 300 baud , which transmitted 1 bit per element, so 300 bps. Faster modems were flogged as 1200 baud, or 2400 baud, but this was a fallacy, they were 600 baud, but with 2, or 4 bits per baud.

IEEE 802.11, or WiFi can be hacked for use on the Ham bands, providing longer range high-rate data transmission, with some participants calling it "Broadband-Hamnet".

Off the exam, Hellschreiber in a system invented by Rudolf Hell in the late 1920s, thus his name and the German word for "writer". It sends the text as a graphical representation, so it can handle almost any language. It has been adapted to Ham radio use.

APRS

APRS stands for the Automatic Packet Reporting System. Unlike other packet systems, it does not require a negotiated connection between stations, as data is just sent out periodically. It does not use requests for retransmission. While positioning data, usually GPS derived, is most often sent, it can also send weather data from a fixed station.

It is useful in public service events, as the position of course sweep vehicles or vessels, searchers, and other operators can be sent, including as a data burst at the end of a voice transmission. Small waterproof (Pelican) cases containing a GPS module, mini TNC, and small transmitter can be clipped to a search team members backpack, so the team can be tracked. As there is no need for the team member to initiate transmission, there is no need for this person to be a ham.

TV

NTSC is the standard North American analogue colour TV format, termed "fast scan" in amateur terms. It has mostly fallen out of use in broadcasting, due to a change to digital TV (ATSC or other digital formats), but remains in use for Ham radio. It stands for National Television System Committee. It is actually the work of the second committee, the first set up to standardise B&W TV, setting it at 525 lines (about 480 visible, as in VGA), 30 frames per second, in two interleaved fields (60 per seconds). Adding colour, using the same scan-rates was done by the second committee, using a colorburst of crystal frequency 3.579545 MHz. These super-common and cheap crystals allow home-brew CW radio nets on this frequency.

A particularly dodgy piece of fake foreign aid was upgrading the broadcasting systems of poor countries using 625 line, 25 frame B&W systems to NTSC, instead of a compatible PAL system (like in Australia). Suddenly the entire populous had to buy US standard TVs just to keep watching, so really it was an aid package for their own industry. Adopting PAL as Australia and much of Europe did would have meant that existing TVs would keep working.

In North America the change was mainly to ATSC, the Advanced Television Systems Committee's standard. Japan adopted its own system, ISDB-T, as has much of Latin America; and Bermuda and Taiwan the global standard DVB-T, as used in Europe and Australia. Cuba is moving to China's DTMB.

Amateur TV outside the US typically uses the scan rates and colour system of the country's (former) analogue TV broadcast system, and/or the current digital TV standard. DVB-S is also sometimes used terrestrially, if cheap surplus modulators are available.

Radio Control

In the US, somewhat uniquely, Amateurs are allowed to send "telecommand" signals to remote-control aircraft, boats, cars, etc, using Ham frequencies. The power limit is 1 watt. As on-air identification is rather tricky half-way through a loop, instead, operators are allowed to affix their name, callsign, and address to the transmitter.

Relevant Questions

Actual exam questions, from the published NCVEC Technician pool.

T8C01 Which of the following methods is used to locate sources of noise interference or jamming? A. Echolocation B. Doppler radar C. Radio direction finding D. Phase locking

This is RDF, or Radio direction finding, answer C.

The recreational and training version of this is "fox-hunting" or T-hunting.

T8C02 Which of these items would be useful for a hidden transmitter hunt? A. Calibrated SWR meter B. A directional antenna C. A calibrated noise bridge D. All of these choices are correct

This is the directional antenna, answer B.

T8C03 What operating activity involves contacting as many stations as possible during a specified period? A. Simulated emergency exercises B. Net operations C. Public service events D. Contesting

This is contesting, answer D.

T8C04 Which of the following is good procedure when contacting another station in a radio contest? A. Sign only the last two letters of your call if there are many other stations calling B. Contact the station twice to be sure that you are in his log C. Send only the minimum information needed for proper identification and the contest exchange D. All these choices are correct

This might be a Maidenhead locator (grid-square), signal report, sequence number, name, postcode, etc. For the VHF contests in VK these are something like QF36bc; 59008, Petra. Some are fairly friendly, and stations may have a a short discussion, if signals are good.

T8C05 What is a grid locator? A. A letter-number designator assigned to a geographic location B. A letter-number designator assigned to an azimuth and elevation C. An instrument for neutralizing a final amplifier D. An instrument for radio direction finding

This is a zone on the earth's surface, a geographic locator, answer A. PF67 or PF67ak are examples.

T8C06 How is over the air access to IRLP nodes accomplished? A. By obtaining a password which is sent via voice to the node B. By using DTMF signals C. By entering the proper Internet password D. By using CTCSS tone codes

Connection is by sending DTMF tones to an IRLP connected repeater, or a simplex IRLP node, answer B.

A marginally improved question. The meaning is: If you can access a local node from your radio, how do you cause it to connect to another node? Dial the node number using DTMF. To connect to a repeater in the Bay of Islands, NZ, transmit, and dial 6767, then de-key and wait for the connection message.

T8C07 What is Voice Over Internet Protocol (VoIP)? A. A set of rules specifying how to identify your station when linked over the internet to another station B. A technique employed to “spot” DX stations via the internet C. A technique for measuring the modulation quality of a transmitter using remote sites monitored via the internet D. A method of delivering voice communications over the internet using digital techniques

In this case Protocol is part of "Internet Protocol", or IP, rather than rules about on-air behaviour or identifying. The term IP, rather than just "Internet" is used in VoIP, as it is possible to use IP over networks other than the Internet. It is the last answer, about the method, D for Delta.

There are remote software defined radios (SDRs) such as KiwiSDR, which do allow you to listen to various things, including to monitor your own station remotely.

T8C08 What is the Internet Radio Linking Project (IRLP)? A. A technique to connect amateur radio systems, such as repeaters, via the internet using Voice Over Internet Protocol (VoIP) B. A system for providing access to websites via amateur radio C. A system for informing amateurs in real time of the frequency of active DX stations D. A technique for measuring signal strength of an amateur transmitter via the internet

It is connecting repeaters and simplex gateways via the Internet, answer A.

T8C09 Which of the following protocols enables an amateur station to transmit through a repeater without using a radio to initiate the transmission? A. IRLP B. D-STAR C. DMR D. EchoLink

Echolink is the only system which allows allows Hams to transmit though a repeater from a PC or Android device, answer D.

If you hear AG6LE connect to your repeater, please say "Hi!".

T8C10 What must be done before you may use the EchoLink system to communicate using a repeater? A. You must complete the required EchoLink training B. You must have purchased a license to use the EchoLink software C. You must be sponsored by a current EchoLink user D. You must register your call sign and provide proof of license

Use must register online, and provide the PDF of the "Official Copy" of your licence, which only you are able to download using your FRN and password, answer D, not a "Reference Copy". Amateurs with their licence printed on FCC "basket-weave" paper may be able to use a scan or photo of this. The organisation has been unlawfully asking for scans of Australian hams' driving licences, so yet another reason to get a US licence, and to use this on the system, as your author does.

T8C11 What name is given to an amateur radio station that is used to connect other amateur stations to the Internet? A. A gateway B. A repeater C. A digipeater D. A beacon

This is a "gateway", answer A. This can be data related, or a simplex voice gateway for IRLP, Echolink, etc.

T8D01 Which of the following is a digital communications mode? A. Packet radio B. IEEE 802.11 C. FT8 D. All of these choices are correct

These are examples of digital modes, FT8 used for weak signals, the "packet-racket" for stronger local ones, answer D.

IEEE 802.11 is a collection of standards relating to WiFi system developed by Australia's CSIRO (the right-wing so-called "Liberals" & Nationals, keep cutting their funding, so need to be booted!). Certain routers can be hacked to work on Ham bands, and to operate at higher power, connected to high-gain antennas.

T8D02 What is a "talkgroup" on a digital repeater? A. A group of operators sharing common interests B. A way for groups of users to share a channel at different times without hearing other users on the channel C. A protocol that increases the signal-to-noise ratio when multiple repeaters are linked together D. A net that meets at a specified time

Talkgroups allow users with different interests to share repeater channels, at different times, answer B.

Remember that the correct answewr fully develops the repeater sharing aspect.

T8D03 What kind of data can be transmitted by APRS? A. GPS position data B. Text messages C. Weather data D. All these choices are correct

While position is a popular use, it can send other data, including text andweather station data, answer D.

T8D04 What type of transmission is indicated by the term "NTSC"? A. A Normal Transmission mode in Static Circuit B. A special mode for satellite uplink C. An analog fast scan color TV signal D. A frame compression scheme for TV signals

This is the standard (fast scan) North American analogue colour TV format, answer C, named for the National Television System Committee.

NTSC is "Never Twice the Same Colour", as it relies on a "Hue" adjustment.

T8D05 Which of the following is an application of APRS? A. Providing real time tactical digital communications in conjunction with a map showing the locations of stations B. Showing automatically the number of packets transmitted via PACTOR during a specific time interval C. Providing voice over internet connection between repeaters D. Providing information on the number of stations signed into a repeater

This is providing location information, with the option to display this on an map on a PC screen, showing the location of stations, answer A.

T8D06 What does the abbreviation "PSK" mean? A. Pulse Shift Keying B. Phase Shift Keying C. Packet Short Keying D. Phased Slide Keying

Phase shift keying, answer B.

T8D07 Which of the following describes DMR? A. A technique for time-multiplexing two digital voice signals on a single 12.5 kHz repeater channel B. An automatic position tracking mode for FM mobiles communicating through repeaters C. An automatic computer logging technique for hands-off logging when communicating while operating a vehicle D. A digital technique for transmitting on two repeater inputs simultaneously for automatic error correction

It is a digital voice mode which can allow a repeater to handle two signals at once in a 12.5 kHz channel, using TDMA, answer A.

T8D08 Which of the following may be included in packet transmissions? A. A check sum which permits error detection B. A header which contains the call sign of the station to which the information is being sent C. Automatic repeat request in case of error D. All of these choices are correct

Using check sums, it is possible for the receiving station to determine that there have been errors, and so it can send back a request for the repetition of the previous packet. The headers also include station callsigns. Thus it is ALL choices, answer D.

T8D09 What is CW? A. A type of electromagnetic propagation B. A digital mode used primarily on 2 meter FM C. A technique for coil winding D. Another name for a Morse code transmission

Continuous Wave is the physical carrier for Morse Code, so the examiner is grasping at answer D.

T8D10 Which of the following operating activities is supported by digital mode software in the WSJT-X software suite? A. Earth-Moon-Earth B. Weak signal propagation beacons C. Meteor scatter D. All these choices are correct

WSJT-X is a comprehensive package which includes modes which support all these activities, answer D.

T8D11 What is an ARQ transmission system? A. A special transmission format limited to video signals B. A system used to encrypt command signals to an amateur radio satellite C. An error correction method in which the receiving station detects errors and sends a request for retransmission D. A method of compressing data using autonomous reiterative Q codes prior to final encoding

This is Automatic Repeat reQuest, where the receive station detects errors, and requests retransmission, answer C.

T8D12 Which of the following best describes an amateur radio mesh network? A. An amateur-radio-based data network using commercial Wi-Fi gear with modified firmware B. A wide-bandwidth digital voice mode employing DRM protocols C. A satellite communications network using modified commercial satellite TV hardware D. An internet linking protocol used to network repeaters

It is the hacked Wi-Fi (IEEE-802.11) based system, answer A.

T8D13 What is FT8? A. A wideband FM voice mode B. A digital mode capable of low signal-to-noise operation C. An eight channel multiplex mode for FM repeaters D. A digital slow scan TV mode with forward error correction and automatic color compensation

It is a digital mode capable of working with signal levels audibly "in the noise", answer B.

Congratulations! You have now reviewed all questions. I would suggest doing some drills on hamtestonline.com, which are available without charge.

It is also time to look at Exams.

Or have a stretch, and head over to my General pages, starting with Regulations: For exams to or on June 30, 2023: General - Regulations, or on or after July 1, 2023: General - Regulations

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

This has taken a fair bit of work to write, so if you have found this useful, there is a "tip jar" below.

You may also want to get a Ham related shirt designed by your author: VK-73

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

Tip Jar: a Jefferson (US$2), A$3 or other amount / currency. Thanks!

Or buy me a coffee: ko-fi.com/ag6le