Activities Involving Ham Radio
Emergency Communication & Response
In instances of crisis and natural disaster, the grid can become a gridlock. We saw it on 9/11 when emergency calls overloaded the networks and we saw it when a blackout swept through North America in 2003. Ham operators were critical in these fragile moments, never more so than when over 1,000 cell sites were incapacitated during Hurricane Katrina in 2005, when cell phones were inoperable, and just as many operators traveled to the Gulf Coast to provide emergency communication assistance.

The amateur radio is cell tower and electricity independent, and batteries can be charged and stored or rejuvenated using solar power. Handheld radios are both portable and sturdy, and repeaters are reachable from states away and have proven significantly more reliable than cell towers. It is for these reasons that emergency-response organizations like the Federal Emergency Management Agency (FEMA) and the Red Cross turn to amateur radio operators when times are dire and communication is otherwise not possible. Hams have a phrase regarding emergency communications, "When All Else Fails." This is a valuable public service.

Contesting
Contesting is a common, shared hobby amongst ham enthusiasts wherein amateur radio organizations (think clubs and magazines) define a set of criteria and participants make as many contacts within these constraints as possible.

The parameters for these events often fall within a specific geographic area, define the mode and band for contact, and require a specific piece of information be obtained from the contact (name, age, etc.). While there is an element of competition, there are no professional contesters and awards are generally limited to a certificate acknowledging the accomplishment.

Ham radio operators are competitive by nature and; in the world of ham radio contesting, participants seek to contact as many stations as possible in as many "entities" as possible. Entities can be countries, US States, CQ or ITU Zones, geographic grids, US National Parks, and many more. In some cases, scores are tabulated in real-time on Internet sites.

The contest sponsor defines the rules about power limits, days of operation, frequency bands, and under what conditions contacting the same station are allowed.

Some contesters establish a presence on a given frequency with the goal of getting every possible benefit from being on the air at a given frequency. This is called "run". Other contesters will tune around various frequencies looking for "multipliers" that will increase their score. This is "search and pounce".

One of the most popular contests is called "Field Day." For many hams, this contest was their first exposure to being on-the-air - even before obtaining a license. The contest is used to promote community outreach, emergency preparedness, technology, and competition. Many field day sites are held in public areas, like a shopping center parking lot. It's always a good time to get out the food and share some good times.

DXing
What started as a gauge for transmission success in the early 1900's grew into a popular hobby by the 1930's and continues to amuse tens of thousands of ham operators today. DXing (said to stand for Distance Unknown) is the practice of conducting two-way communication with remote radio stations from distances that would generally be considered inaudible at a given frequency. There are three main components to the exercise:

1. DXpeditions
For the sake of the contact, ham radio operators collaborate and organize voyages to remote and exotic locations wherein they provide highly sought-after contacts with islands, countries, or grids that would otherwise be unreachable due to location, population, or regulation. They take the gear, electrical generators, and antennas, then transmit around the clock - often making more than 60,000 QSOs (contacts) within a matter of days. DXers also participate in contesting where they attempt to contact as many hams as possible from as many distant places as possible.
2. DX Awards
The Amateur Radio Relay League (ARRL) sponsors a number of awards programs. The DX Century Club (DXCC) is one of these and focuses on rewarding operators for their DXing performance. Operators who have confirmed contacts with more than 100 entities are eligible for one of 16 awards based on the mode and band of contact and; when won, earn a certificate commemorating their success and all the bragging rights that come with it. A contact is confirmed when the destination station sends a QSL card or some alternative, electronic confirmation through an online confirmation system like Logbook of the World (LTOW).

Clubs
Amateur radio clubs are local organizations constructed to promote ham radio. Some are broad, covering a variety of interests, while others focus on a specific niche such as emergency response or DXing. Many host events like contesting weekends or "hamventions" and most are accredited by the ARRL. The most effective method of identifying a club in your area is the ARRL website under "Get Involved."

Hamfests
Hamfests are a combination of a ham radio trade show and a technical flea market. Equipment manufacturers like Icom, Yaesu, Elecraft, Kenwood, Timewave, FlexRadio, and others come to show off their latest gear. Ham radio retailers - or dealers - come and set up a store on-site to enable hams to buy the equipment they see. Hams set up their own tables and sell their own used gear. Hamfests often include forums and presentations aimed to provide new information and educate hams. Licensing exam sessions are proctored to provide an opportunity for hams to upgrade or as a way for unlicensed individuals to take a shot at passing the test.

Transmitter Hunting
Transmitter or "Fox" Hunting is the amateur radio equivalent of geo-caching and is especially popular among high school and college clubs. A designated participant hides one or more radio transmitters within a designated area, then the wider group ventures out in hot pursuit. The nuances of the sport are many, but the primary goal is to identify the location of the transmitter before the rest of the group.

Fox hunting is commonly considered a purely recreational activity but its uses are handy and quite a few. Prime examples include search and rescue operations, the location identification of weather balloons and other scientific devices, and even the tracking down of repeater jammers in situations such as war. Additionally, the practice teaches map reading, equipment operating, triangulation, and orienteering, making it a popular hobby among young groups of hams.

APRS - Automatic Packet Reporting System
I've often heard this referred to as "automatic position reporting system." Based on the AX.25 implementations of packet radio, the "automatic packet reporting system" is used to communicate position information (longitude and latitude) to other ham radio stations. This is used to track everything from vehicles traveling across the country to balloons launched by ham radio operators. Originally implemented with external hardware, many handheld and mobile VHF radios are equipped with a GPS and the software necessary to report position.

Ham Radio Modes of Operating
Methods or "modes" of operating are the ways in which amateur radio operators convey their messages to one another. Examples for travel modes would be plane, train, car, bus, taxi, Uber, Lyft.
For radio they are as follows:

Voice/Sound
Voice communications, also known as "radio telephony" or "phone", can be broken down into the subcategories of analog and digital.

Analog voice is comprised of voice signals detected by microphone and carried across wave signals. The most common forms of voice communication are amplitude modulation (AM), frequency modulation (FM), and single sideband (SSB). Single sideband uses either the upper portion of the AM signal (USB) or the lower portion of the AM signal (LSB).

One of the more popular you may be aware of is frequency modulation, or FM (i.e. your car radio). FM is often used by repeaters spread throughout the local area, which take in a signal and blast it back out at higher power. This allows you to use lower-powered radios and talk across farther distances. FM repeaters are usually good for at most 100 miles of communication due to the way the frequencies propagate through the air.

FM can also be used for making satellite contacts. Groups of amateur radio operators such as AMSAT, launch repeaters into space on satellites. The satellite trajectory is tracked and predicted, and the repeaters can be used to communicate much farther than repeaters on land.

Amateur radio repeaters aren't the only stations in space either, there is a full functioning ham station aboard the International Space Station. It is used not only for contact with schools but also having conversations with other amateurs here on earth. If you have the opportunity to chat with the ISS, make sure you send in for the beautiful QSL card to verify your contact. For more information, check out the ISS Fan Club.

FM isn't the only voice mode, there is also amplitude modulation, AM, and it's cousin, single side band, SSB. Single side band is popular for making longer distance voice contacts (due to its smaller bandwidth) and is popular in the HF range of the the spectrum.

Digital take these voice signals and encodes them into a stream of data before transmitting. At the receiving end, the digital signal is decoded and reproduced as audio that can be understood by the human ear. Much like how a CD/DVD works or how a Youtube video is sent across the internet.

Voice modes are fun, many enjoy the digital modes as you can combine computers and radio. The easiest way to get started with digital modes is to use a special USB sound card to hook up the radio to the computer. This allows computer software to control the transmit receive switch, audio input and audio output. With an applications like HamRadioDeluxe or FLDigi, digital signal processing can be used to modulate and demodulate audio signals into binary data.

The advantage of digital modes over voice modes is their narrow bandwidth. Human voices are much more dynamic and take up a wider area of frequency, compared to a tone produced by a computer. This allows for more efficient radio wave propagation compared to voice modes since the RF power is more concentrated. For example, the typical bandwidth of a SSB voice signal is approximately 3kHz. PSK31 uses phase shift keying, which changes the phase of a carrier signal to represent binary bits with a bandwidth of 31.25 Hz, which is almost 100 times smaller than a voice signal.

The baud rate of PSK31 is approximately 32 bits per second, which seems impossible to use compared to today's internet speeds. However, PSK31 is used to send a stream of characters, nothing more, and equates to approximately 50 words per minute. However there is one flaw with PSK31: no error correction.

Going to the extreme side of binary modes is JT-65, which includes a large amount of error correction making it very useful for less than ideal conditions. JT-65 is much slower compared to PSK31 and allows for the transmission of approximately 13 characters per minute. At first JT-65 may seem painfully slow, but the time passes quickly, and the minutes it takes to make an exchange allows for tension and excitement to build.

Adding to the error correction is time predictability; transmitters and receivers are synchronized around the minute mark. Transmissions start exactly 1 second after the minute and last exactly 48 seconds. Because of the precision of time required, JT-65 requires your computer to be synchronized within 1 second of the official NIST time at all times.

Morse Code
Morse code is a mode of communication also referred to as "Continuous Wave" or "CW". It was developed by the American artist Samuel F. B. Morse in 1836. It is the long and short keying of sound representing the letters of our alphabet. While it has declined in popularity over recent years, it is still considered one of the most efficient means of communication across all bands. The practice was at one time required in order to earn the General and Extra licenses, but the criteria was removed with the development of digital modes in the interest of encouraging more hobbyists to advance their license class.

Digital Modes
With a few exceptions, transmitting digital modes involves using a computer sound-card and software to encode an analog signal and modulate a SSB signal onto a given frequency where it can be decoded by software running on another computer. Essentially, this is "keyboard to keyboard" communications.

There are a number of modes that use this method. They include PSK31, MFSK16, Olivia, Contestia, AFSK (sound-card form of RTTY), JT65, JT9, and FT8.

AFSK is RTTY encoded and decoded by a sound-card. FSK is RTTY encoded by the transmitter or a terminal node controller (TNC). Quite often,a sound-card is still used to decode the FSK signal.