Glossary of VHF Marine Radio Terminology

By Joe Minick

Bluetooth—A wireless technology that allows communication between Bluetooth-compatible devices. Used for short-range communications,all Bluetooth devices operate on 2.4GHz and range is limited to about 30 feet.

Coaxial Cable—A type of wire that consists of a center wire surrounded by insulation and covered with a grounded shield of braided wire. The shield minimizes electrical and radio frequency interference.

Decibel—Abbreviated as dB, db and DB, the decibel is a logarithmic expression of the ratio between two signal power levels. A decibel is 1/10 of a Bel, a rarely used unit named for Alexander Graham Bell, inventor of the telephone. Because it’s a ratio or comparison between two levels, a decibel may be positive or negative. When a decibel figure is shown with a positive value, it refers to a level that is greater than the base level used for comparison. Conversely, a negative value indicates a lower value when compared with a base level.

FIPS Codes—Federal Information Processing Standard (FIPS) codes are used to program the geographic areas that will sound an alarm when NOAA weather alerts are received by a radio capable of monitoring NOAA weather frequencies. The radio must have SAME weather alert capability to use FIPS codes.

ISM Frequency Band—The international Industrial, Scientific, and Medical (ISM) radio bands were originally created by the International Telecommunication Union for purposes other than communications. While communications devices now operate in these bands, generally speaking, they must be able to tolerate any interference generated by other forms of ISM equipment.

Isotropic Antenna—A theoretically ideal antenna that radiates electromagnetic energy with 100 percent efficiency and equal intensity in all directions. When receiving, it is considered to be equally sensitive in all directions.

SAME—Acronym for a digital encoding system known as Specific Area Message Encoding that allows receivers equipped with the SAME capability to sound an alarm for specific weather conditions that are forecast to exist in a specific geographic area.

SINAD—Acronym for the ratio of desired signal plus noise and distortion to undesired noise and distortion. 12dB SINAD is a standard measurement of FM receiver sensitivity.

UIC—Acronym for U.S.A., International, and Canada that refers to the control or setting for the selection of frequencies used internationally, in Canada, or the United States.

VOX—Acronym for Voice Operated eXchange, which refers to a switch that is activated when the sound of a voice is heard.