Ham Radio Glossary
Plain-English definitions of common amateur-radio terms you'll run into as a newcomer.
- 73
- Ham shorthand for "best regards." Operators sign off a contact with "73" (never "73s").
- Elmer
- An experienced ham who mentors newcomers, answering questions and helping them get on the air.
- QSO
- A two-way conversation or contact between operators. "I had a QSO with a station in Ohio."
- QTH
- Your location. "My QTH is Indianapolis." (One of many "Q-codes" borrowed from Morse-code shorthand.)
- QSL
- "I acknowledge / I confirm." Also refers to a QSL card, a postcard mailed to confirm a contact.
- CW
- Continuous Wave, the technical name for Morse code sent by switching a carrier on and off.
- HF
- High Frequency, 3-30 MHz. These bands can travel worldwide by bouncing signals off the ionosphere.
- VHF
- Very High Frequency, 30-300 MHz (includes the popular 2-meter band). Mostly line-of-sight, great for local contacts.
- UHF
- Ultra High Frequency, 300 MHz-3 GHz (includes the 70-centimeter band). Line-of-sight and good at penetrating buildings.
- Simplex
- Talking directly radio-to-radio on a single frequency, with no repeater in between.
- Duplex
- Transmitting and receiving on two different frequencies at once, as repeaters do.
- Offset
- The fixed frequency difference between a repeater's input and output (commonly 600 kHz on 2 meters, 5 MHz on 70 cm).
- Repeater
- An automated station, usually on a tall site, that receives your signal and rebroadcasts it to greatly extend your range.
- PL tone / CTCSS
- A sub-audible tone your radio sends so a repeater knows to open up. CTCSS is the generic name; PL is Motorola's brand for it.
- Net
- A scheduled on-air gathering of operators, run by a moderator, for check-ins, traffic, or a common interest.
- Net Control Station (NCS)
- The operator who runs a net, recognizing stations and keeping the conversation orderly.
- Rag chew
- A long, casual conversation on the air, just chatting rather than a quick exchange.
- DX
- A distant station, often in another country. "Chasing DX" means trying to contact far-away places.
- HT (handheld)
- A Handheld Transceiver, a small walkie-talkie-style radio, usually for VHF/UHF.
- Rig
- Casual term for a radio transceiver of any kind.
- SWR
- Standing Wave Ratio, a measure of how well your antenna matches your radio. Lower (near 1:1) is better; high SWR can damage a transmitter.
- Antenna
- The device that radiates and receives radio signals. A good antenna often matters more than radio power.
- Band
- A range of frequencies set aside for a purpose, referred to by wavelength (e.g., the "2-meter band" or "20-meter band").
- Mode
- The method used to carry information on a signal, such as FM, SSB, CW, or a digital mode.
- FM
- Frequency Modulation, the clear, hiss-free mode most often used on VHF/UHF repeaters and simplex.
- SSB
- Single Sideband, an efficient voice mode favored on HF for long-distance contacts.
- DMR
- Digital Mobile Radio, a digital voice mode that uses "talkgroups" and often links worldwide over the internet.
- D-STAR
- An Icom-originated digital voice and data mode with internet linking for long-distance contacts.
- System Fusion (C4FM)
- Yaesu's digital voice system. C4FM is the underlying signal format; it can also fall back to analog FM.
- APRS
- Automatic Packet Reporting System, a digital mode used to share GPS location, weather, and short messages.
- EchoLink
- Software that links repeaters and individual hams over the internet, letting you reach distant stations from a local radio or computer.
- POTA (Parks on the Air)
- A popular program where operators ("activators") set up and make contacts from designated parks.
- SOTA (Summits on the Air)
- Like POTA, but operators hike to mountain and hill summits to make contacts.
- Field Day
- An annual ARRL event each June where clubs operate from the field to practice emergency communications and have fun.
- ARES
- Amateur Radio Emergency Service, ARRL-sponsored volunteers who provide communications during emergencies.
- RACES
- Radio Amateur Civil Emergency Service, hams operating under the direction of a government emergency-management agency.
- Skywarn
- A National Weather Service program of trained spotters, many of them hams, who report severe weather conditions.
- ARRL
- The American Radio Relay League, the national association for amateur radio in the United States.
- FCC
- The Federal Communications Commission, the U.S. agency that licenses and regulates amateur radio.
- VE (Volunteer Examiner)
- A licensed ham accredited to administer the FCC license exams that newcomers take to get on the air.
- Call sign
- Your unique FCC-issued station identifier (for example, W9XYZ). You must use it to identify on the air.
- Technician / General / Amateur Extra
- The three U.S. license classes, in order. Technician is the entry level; each higher class grants more frequency privileges, especially on HF.
- Identify (ID)
- Stating your call sign on the air, required at least every 10 minutes during a contact and at the end.
- Calling frequency
- A frequency agreed upon for making initial contact; after answering, stations usually move ("QSY") to another frequency to chat.
- 146.520
- The national 2-meter FM simplex calling frequency. A good place to call and listen when you're mobile or testing simplex.
Ready to put these terms to use? See how to get started.