a class designator which indicates the number of transmitters concurrently used at the station and information about the type of electrical power source being used. The contest portion of Field Day has two purposes. The primary purpose is to test the group's ability to plan operations that can be effective for an entire twenty-four-hour period, including operator endurance and adequate numbers of operators for a shift operation. The secondary portion is to demonstrate the technical proficiency of the station that has been hastily constructed for the purpose; in theory a better station will be capable of emergency operations in dire conditions. Such a station will also be capable of making more contacts during the contest portion of Field Day. Point systems are structured to motivate emergency preparedness activities, such as designating a safety officer for the station or incorporating auxiliary power capabilities. The rules governing this activity are published by the sponsor of the particular Field Day exercise. Promotion of amateur radio Field Day is frequently used to attract significant publicity for amateur radio, and some clubs simultaneously demonstrate technologies including single sideband voice, Morse code, digital modes (such as RTTY, PSK31, and Winlink, among others), and communication via amateur radio satellite. References External links ARRL Field Day Field Day: A Mirror of Amateur Radio History (A history of Field Day in the United States) Field Day Station Locator (Google Maps-based service that shows publicly accessible Field Day operations for June 26–27, 2010) Radio Amateurs of Canada Find a radio club near you to participate in Field Day RSGB SSB Field Day 2019 DARC Field Day Nationwide Simulated Emergency Communications Test ARI Field Day Amateur radio American Radio Relay League