Subj : Ham Radio Terms (A) To : All From : Daryl Stout Date : Sun Oct 02 2016 12:06 am From QRZ.Com, the Icom handout, and Part 97 Of The FCC Rules - Ham Radio Glossary - An overview of amateur radio terms. AC Alternating Current ACC Accessory ACSB Amplitude Compandored Sideband modulation Adjacent-channel interface When a receiver is tuned to a specific frequency and interference is received on a nearby frequency. Advanced The next to highest class of U.S. Amateur Radio license. While these are no longer issued, Advanced class licensees may continue to use their privileges, and renew their licenses at the appopriate time. They have all amateur radio privileges, except for 250 kilohertz of spectrum that is reserved for Amateur Extra Class licensees. AF Audio Frequency AFC Audio Frequency Cntrol Automatically compensate frequency drift. AFSK Audio Frequency Shift Keying AGC "Automatic Gain Control"; a circuit in a radio which automatically adjusts the overall gain of the receiver, by optimizing receiver amplifier gain automatically. A-Index Linear index for measuring the disturbance level in the earth's magnetic field. The index is defined over a period of one day (Courtesy of IPS Radio and Space Services, Sydney, Australia). ALC Automatic Limiting Control. Limits RF drive level to power amplifier during transmit to prevent distortion. AM "Amplitude Modulation"; slang often used is "Ancient Modulation" (courtesy of VE3FFK). AMSAT Amateur Satellite. Satellites used for amateur radio communication. AMTOR "Automatic Teleprinting Over Radio"; popular digital mode on HF. It is a form of RTTY (radio teletype). Amateur Extra The highest U.S. amateur radio license class granted by the FCC. It allows full amateur radio privileges on all bands designated to the amateur radio service by the FCC. Amateur operator A person named in an amateur operator/primary/primary license station grant on the ULS consolidated licensee database to be the control operator of an amateur station. Amateur radio services The amateur service, the amateur-satellite service and the radio amateur civil emergency service. Amateur-satellite service A radiocommunication service using stations on Earth satellites for the same purpose as those of the amateur service. Amateur service A radiocommunication service for the purpose of self-training, intercommunication and technical investigations carried out by amateurs, that is, duly authorized persons interested in radio technique solely with a personal aim and without pecuniary interest. Amateur station A station in an amateur radio service consisting of the apparatus necessary for carrying on radiocommunications. ANF Automatic Notch Filter ANL Automatic Noise Limiter. Eliminates impulse and static noise peaks. ANT Antenna Antenna Gain The ratio of the power required at the input of a loss-free reference antenna to the power supplied to the input of the given antenna to produce, in a given direction, the same field strength at the same distance (def. courtesy of Telecom Glossary 2000) Antenna Ground System Term used for an RF reference potential for some types of antennas. Most unbalanced or asymmetrical antennas need a good RF ground. Antenna Impedance The impedance of an antenna at its resonance. Although an antenna's impedenance fluctuates with the frequency of operation, an antenna should be 50 ohms for most transceivers. Antenna Matching When the antenna's impedance at resonance is at optimum performance for your transmitter output circuit. Antenna Party A long-standing tradition among hams where several gather to assist a fellow ham in mounting antennas and/or towers. Often accompanied by malt consumables and lies AFTER the tower and the antennas are up and working...well, the consumables anyway (thanks to WD5CTQ). Antenna Tuner Device used to match an antenna to the output impedance of a transmitter. AOS "Acquisition of Signal" from a satellite; occurs when the satellite becomes "visible" to the antenna as it comes up from the horizon. APC Automatic Power Control Current limiting of power amplifier to prevent damage to finals in high SWR conditions. APRS "Automatic Position Reporting System". An amateur radio digital mode, developed by Bob Bruninga, WB4APR, to transmit position reports, weather reports, and messages between users. Used in conjuction with a GPS and a TNC. ARES Amateur Radio Emergency Service ARRL "American Radio Relay League"; A U.S.-based organization which exists to support Amateur Radio. For more information, please visit http://www.arrl.org on the Internet, or write them at 225 Main Street, Newington, Connecticut 06111. ASCII American National Standard Code For Information Exchange. A seven unit digital code for the transmission of teleprinter data. ATT Attenuator. A network designed to reduce the amplitude of a signal. ATV "Amateur Television"; typically found on the 430 MHz and 1.2 GHz bands; see http://www.hampubs.com/atv.htm for more information (thanks to KG4LXA for the suggested link). Includes Fast Scan and Slow Scan modes. Autopatch Used in repeater operation for telephone interconnect. Automatic control The use of devices and procedures for control of a station when it is transmitting so that compliance with the FCC Rules is achieved without the control operator being present at a control point. Auxiliary station An amateur station, other than in a message forwarding system, that is transmitting communications point-to-point within a system of cooperating amateur stations. Average power Power measured on a standard power meter. AWG "American Wire Gauge"; a system of describing the diameter of wire by which the wire size increases as the gauge number decreases. Posted by VPost v1.7.081019 --- Virtual Advanced Ver 2 for DOS * Origin: The Thunderbolt BBS (801:1/7) þ Synchronet þ The Curmudeon's Place .