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Ham Radio
(See also: Software-Defined Radio)
Amateur radio, also known as ham radio, is an old hobby that has origins as far back as the late 1800's. It was formalized as a hobby in the early 20th century. It is an over-regulated piece of shit, but what isn't nowadays?
Amateur radio operators, known as hams, make contacts all over the world, take part in many different activities that highlight different aspects of the hobby, and operate using a variety of modes. Although the barrier to entry is higher than most other hobbies, ham radio is a hobby with seemingly infinite depth, that can provide a literal lifetime of enjoyment. Hams are always eager to help newcomers get into the hobby.
These days, most hams are fairly old, but many come from highly technical backgrounds, and it isn't uncommon at all to meet a 70-odd-year-old ham who is also an avid Linux user. This is where we're heading, /g/entoomen.
Activities
Local Communication
The VHF and UHF bands are primarily used for local communications, and are accessible to holders of entry-level licenses. You can get on the air with a $50 Baofeng UV-5R handheld, and for some hams, this is enough to thoroughly enjoy ham radio. Many organizations maintain repeaters, which are automatic stations whose purpose is to extend the range of handhelds and mobile stations. Many repeater groups also host VHF/UHF nets, which are structured on-air meetings that amateurs can "call in" to.
Repeaters and nets are an excellent way to meet local hams, and get your feet wet before getting involved in the more complicated and expensive world of HF.
DXing
DXing is the act of operating with the goal of reaching stations in as many foreign countries as possible. Long-distance communication is usually only possible on the HF bands and below, making it out of reach for holders of entry-level licenses. It also involves larger, more complicated, outdoor antennas, and more expensive transceivers. However, many consider DXing to be the most thrilling part of amateur radio, and setting up a station to do it can become a hobby in itself.
Rag-Chewing
Rag-chewing is the act of having long, friendly conversations with other hams on the air. This can pretty much take place on any band, in any mode.
Contesting
Contesting is the act of participating in contests that involve making specific kinds of contacts under specific conditions.
EMCOMM
EMCOMM, or emergency communications, involves participating in emergency preparedness exercises and maintaining emergency radio infrastructure (like repeaters) for when SHTF.
QRP
Operating QRP is when you try to make distant contacts with as little power possible.
Tinkering
Many amateurs enjoy designing and building their own transmitting equipment. In many countries, only the holders of the highest level of amateur license are permitted to design their own equipment, but usually any licensed amateur is allowed to build kits, or professionally-designed projects.
Awards
There are many awards available for hams, from different organizations and for doing different things. The most coveted ham radio award is the DX Century Club (DXCC), awarded by the American Radio Relay League (ARRL) for making confirmed contacts in at least 100 different countries. Although the award comes from the ARRL, you do not need to be an American amateur to get it. Many other awards exist for achieving other feats, and for participating in various contests and special events.
Operating Modes
Phone (voice)
Phone is simple enough: You connect a microphone to a radio and talk into it. Voice is typically modulated using frequency modulation (FM) or single side-band modulation (SSB). SSB requires much lower bandwidth than FM, so it is more common when communicating on HF over long distances. FM is clearer and is more commonly used for local communication on VHF and UHF.
Morse Code (CW)
Morse code, also known as continuous wave (CW) was once required for passing your test. In most countries, it is no longer required, but it remains a good skill to have. It remains popular for its low bandwidth requirement, and how much simpler the equipment is to build. Under conditions where voice and digital modes are unusable, CW can still be used to make contacts over long distances. Like Linux and C on /g/, among hams, proficiency in CW is often accompanied by a (deserved ;) ) superiority complex. Learning CW will greatly increase your enjoyment of amateur radio.
Morse code is easier to learn than you'd think. Once you are proficient, you will no longer hear dits and dahs, but actual letters and words.
Digital
(See also: Software-Defined Radio)
Digital modes are modes that involve digital signals being sent over the radio. Technically, Morse code is a digital mode. More commonly, though, digital refers to connecting a computer to a radio.
The most popular digital mode is FT8, which facilitates communication over very long distances with very low power and very weak signals. Messages can contain up to 13 text characters, and take 15 seconds to send. The most popular software for using FT8 is WSJT-X, which was written by the mode's creators. A lot of people tend to hate FT8 because of how easy it is to make a lot of contacts, and because the software automates almost every step in making a contact. However, it has become the most popular operating mode.
There are also other digital modes, for example packet radio, which involves sending internet packets over the radio, RTTY or radioteletype, and others.
Television
Yes, you can even transmit pictures and video using amateur radio! The most common TV modes are SSTV or slow-scan television, and ATV or amateur television, also known as fast-scan television.
Official Terms and Jargon
Call Signs
Your call sign is how you identify your station on the air, and how you call other stations. Your call sign will be assigned to you by the government when you obtain a license. Each country has a call sign prefix. Usually, states or provinces within a given country will each have unique prefixes based on the country's prefix. The suffix will be unique to you. Most callsigns are five or six characters long, but some may be longer or shorter. In some countries, you can request a specific callsign, although there may be restrictions on certain words, and on using special character sequences like Q codes.
Bands
Bands are groups of frequencies. These are the main bands, specified by the ITU:
| Very low frequency (VLF) | Low frequency (LF) | Medium frequency (MF) | High frequency (HF) | Very high frequency (VHF) | Ultra high frequency (UHF) | Super high frequency (SHF) |
|---|---|---|---|---|---|---|
| 3 to 30 kHz | 30 to 300 kHz | 300 to 3 MHz | 3 to 30 MHz | 30 to 300 MHz | 300 to 3 GHz | 3 to 30 GHz |
It should be noted that a "band" may also be a group of frequencies within the bands specified above, e.g. "20m HF" for HF frequencies in the 14MHz range.
Q Codes
For a full list of Q codes, see Wikipedia.
Q codes are a shorthand system used in amateur radio. They're primarily used when operating CW (Morse code), but some are also commonly used when operating phone (voice).
These are the most common Q codes you'll run into:
| As a question (followed by '?' when sent in Morse code) | As a statement | Notes | |
|---|---|---|---|
| QTH | What is your position? | My position is... | Typically used on voice. Example: "My QTH is New York." |
| QSO | Can you communicate with ____? | I can communicate with ____. | In common usage, a QSO refers to a contact. E.g.: "Thanks for the QSO!", "I made 100 QSOs this weekend". |
| QSL | Can you acknowledge receipt? | I acknowledge receipt. | QSLing is also used to refer to confirming contacts. This is done with physical postcards, called QSL cards, or digitally via sites like Logbook of the World and eQSL. Confirmed contacts can be used as credit for certain awards. E.g.: "Please QSL direct or via bureau", "please QSL via LoTW". |
| QRZ | Who is calling me? | You are being called by... | Typically used on voice. During a "pileup", when multiple stations are trying to call one distant station, the distant station will ask "QRZ?" when he has finished working one station, so that the next station can give his call sign. |
| QRP | Shall I decrease my transmitter power? | Decrease transmitter power. | QRP also refers to the activity of running low-power stations. E.g.: "I'm QRP", "I'm running QRP", "I mainly run QRP". |
| QRS | Shall I send more slowly? | Send more slowly. | Only applicable to CW. |
Some other acronyms and abbreviations used on Morse code:
- "PSE" and "TNX" are used when operating Morse code to say "please" and "thank you", respectively.
- "DE" is used when operating Morse code to say "this is" or "from".
- "SOS" is the official international distress signal. It is very illegal everywhere to transmit SOS when you are not in danger.
- "CQ" means "calling all stations", and is used in all modes.
Jargon
- "73" is used very often in all modes to mean "best regards".
- When operating Morse code, "OM" is a traditional way to address a fellow operator. It stands for "old man".
- "XYL" is used to refer to your wife. It stands for "ex-young lady". "YL", or "young lady", refers to your girlfriend.
- An "Elmer" is someone who has been a mentor to you in the hobby.
Theory
Important Formulas
- Ohm's Law
| Solve For Watts | Amp2 x Ohm | Volt2 / Ohm | Volt x Amp |
| Solve For Volts | Amp x Ohm | √Watt x Ohm | Watt / Amp |
| Solve For Amps | Volt / Ohm | Watt / Volt | √Watt / Ohm |
| Solve For Ohms | Volt2 / Watt | Volt / Amp | Watt / Amp2 |
- The speed of light is a constant 299,792,458 m/s and is represented by c.
- Wavelength is represented in meters as λ.
- Frequency is represented in Hertz (Hz) (seconds to the power of -1) as f.
- c / f = λ
Propagation
Propagation refers to how the radio waves from your antenna travel. Some will travel along the ground, in what is called ground wave propagation. Sky wave propagation, also called ionospheric wave propagation, is when radio waves travel up to the ionosphere and are reflected back to earth. Through sky wave propagation, communication is possible across oceans very easily.
Electronics
In order to pass the exam and set up a station, you should have a basic knowledge of electronics. You should understand series and parallel circuits, as well as the basic electronic components: Resistors, capacitors, diodes, transistors, inductors, and triode tubes.
Antennas
The most important part of your station is your antenna. A bad radio will perform much better on a good antenna than a good radio will perform on a bad antenna. The performance of an antenna is entirely based on physics. Because of this fact, it is possible to build your own antennas that perform just as well as, if not better than, commercially available antennas, and for a fraction of the cost.
Antenna Math
- Loop antennas are full wavelength with one element.
- c / f = Element length
- Dipole antennas are half a wavelength with two elements.
- c / f / 2 = λ / 2 = Element lengths
- Ground plane antennas must be at least a quarter wavelength with one vertical and four radial elements.
- c / f / 4 = λ / 4 = Vertical element length
- c / f / 4 = λ / 4 = Radial element lengths
- 3-element Yagi-Uda antennas are directional antennas consisting of a boom with reflector, driven, and director elements.
- λ * 0.495 = Reflector element length
- λ * 0.473 = Driven element length
- λ * 0.440 = Director element length
- λ * 0.125 = Element separation
Polarization
Polarization basically refers to whether the radio waves' electric lines of force are perpendicular or parallel to the Earth. If they are perpendicular to the Earth, the antenna is called vertically polarized. If they are parallel to the Earth, it is called horizontally polarized. In ground-wave propagation, a vertically polarized antenna will receive signals from other vertically polarized antennas better than a horizontally polarized antenna, and vice-versa. However, in sky-wave propagation, polarization doesn't really matter, because the ionosphere can change the waves' polarization one instant to the next.
Feed Lines
The feed line or transmission line is what will connect your transceiver to your antenna.
- RG6 is common and cheap, but higher resistance at 75 Ohms. You should not use this.
- RG58 is cheap, 50 Ohms, and perfectly acceptable for HF.
- RG8X is slightly more expensive than RG58, but lower loss.
- RG213 is double the price of RG58 and RG8X, but lower attenuation at higher frequencies.
- RG8U is almost identical to RG213 in price and attenuation, but has lower loss per 100ft.
- LMR400 is exceptional at higher frequencies as well as low. If your software radio can do 1GHz-6GHz, this is what you get.
Lightning Protection
If your antenna is outdoors, you should take precaution to prevent yourself and your gear from becoming dead. Metal antenna mounts should be grounded using 10 gauge insulated solid core copper wire. Your coax should have a lightning arrestor between the antenna and your equipment. The arrestor should be mounted near the lightning rod it's grounded to. To prevent moisture ingress, the arrestor and coax connectors should be placed in a plastic electrical box. If you have a wire dipole antenna, you should use ceramic insulators at both ends and guy rope to tie between two points.
Licensing and Regulation
Being an over-regulated piece of shit, in order to fully participate in (transmit) ham radio, you'll need a license, which you get by passing one or more exams. The licensing process varies by country.
Licensing in the U.S.
Amateur radio in the U.S. is regulated by the Federal Communications Commission (FCC). There are three license levels in the U.S.:
- The Technician license is obtained by passing a 35-question test made up of questions from this pool. It grants access to VHF/UHF bands, and some limited privileges on HF bands.
- The General license is obtained by passing a 35-question test made up of questions from this pool. It grants limited operating privileges on all U.S. amateur bands.
- The Amateur Extra license is obtained by passing a 50-question test made up of questions from this pool. It grants full privileges on all U.S. amateur bands.
You will need either an FCC Registration Number or Social Security number in order to take the exam. It is not necessary to register beforehand with the FCC, but it will speed things along if you bring the paperwork. You can find testing locations here.
For a fee of $15 USD you may take one or all three tests in one sitting at no additional charge. If you fail a test, you may spend an additional $15 USD to retake it. Your license is good for 10 years, with a 2 year grace period to renew after expiration without re-testing. You are no longer required to know Morse code for any of these tests.
Some useful links for U.S. amateurs:
The national association for amateur radio in the U.S. is the American Radio Relay League (ARRL).
Licensing in Canada
The Amateur Radio Service in Canada is regulated by Innovation, Science, and Economic Development Canada (ISED, known until 2015 as Industry Canada), in accordance with the Radiocommunication Act.
An Amateur Radio Operator Certificate is required to operate an amateur radio station in Canada. A certificate is issued when an individual obtains a score of 70% or higher on the Amateur Radio Basic Qualification exam. The following are the qualifications available to Canadian amateurs:
- Basic Qualification: Access to all Amateur frequencies above 30MHz. Must obtain a mark of 70% on a 100-question multiple-choice test on theory, practice, and regulations. The question bank is available here.
- Basic with Honours Qualification: Same as Basic, but with access to all Amateur frequencies. Obtained by scoring 80% on the Basic exam.
- Morse Code Qualification: Access to all Amateur frequencies (notice that this one doesn't do anything for you if you passed the basic exam with an 80). Must demonstrate the ability to send and receive Morse code at 5 words per minute. Passing score is 100% (up to 5 mistakes).
- Advanced Qualification: Access to all Amateur frequencies, higher power, ability to set up automatic stations like repeaters, ability to operate remote stations (i.e. over the internet), ability to design and build transmitting equipment. Obtained by scoring 70% on the 50-question, multiple-choice Amateur Radio Advanced Qualification exam. The question bank is available here.
The Basic Qualification must be obtained first in order to be issued an Amateur Radio Operator Certificate and a call sign, but the other qualifications may be obtained in any order.
One difference between Canadian and U.S. regulations is that in Canada, there is no mandatory band plan.
The national association for amateur radio in Canada is Radio Amateurs of Canada (RAC).
Operating in a Foreign Country
The United States and Canada have a reciprocal operating agreement, so Canadian amateurs may operate in the U.S. and vice-versa without any paperwork or permit. Amateurs must follow the regulations of the country they are in, and not exceed the privileges they are licensed for in their home country. U.S. amateurs operating in Canada must identify with their FCC call sign, followed by 'mobile' (voice) or '/' (CW), followed by the call sign prefix of the province they are operating in. For example, "W1AW mobile VE9" in New Brunswick. Likewise, Canadian amateurs must do the same with their ISED call sign when operating in the U.S.
Citizens of CEPT member countries may operate in other CEPT member countries, so long as they have been issued a CEPT permit by their home country. Unlike U.S. amateurs operating in Canada, CEPT-country amateurs must identify with the call sign prefix of the province they are in first, followed by their own call sign, for example "VE9/G5LK"