Subj : Todays New Gear Tip To : All From : Daryl Stout Date : Sat Nov 18 2017 12:05 am HF Glossary All-mode: radio that can operate on AM, SSB, CW, Digital, and FM Attenuate (attenuation): reduce in strength Balun: stands for "balanced-to-unbalanced", provides a transition from parallel wire feed lines or antennas to coaxial feed lines. Beam: antenna with gain primarily in one direction Crystal filter: filters that use quartz crystals to reject unwanted signals in receivers CW (continuous wave): Morse Code dB (decibels): logarithmic method of comparing two signal strengths (power, voltage, current) Data interface: a device for connecting a computer to a radio Digital mode: communication method that exchanges characters instead of voice or Morse Code Dipole: a simple wire antenna 1/2-wavelength long with feed line attached in the middle Directional wattmeter: a wattmeter that can measure power flowing in both directions Emcomm: abbreviation for "emergency communications" Feed line (transmission line): cable used to transfer radio-frequency energy Gain (antenna): antenna's ability to receive or transmit energy in a preferred direction Ground plane: (1) conductive surface that acts as an electrical mirror; (2) an antenna that requires a ground plane to create an electrical image Half-wave: 1/2 wavelength HF: High Frequency (3 MHz to 30 MHz) Impedance: a measure of how easily power can be transferred into a load or through a feed line Keyer: an electronic device that generates Morse code elements. Linear: an amplifier that boosts the power output from a radio without distorting the signal Menu: list of selectable control or configuration functions or options to select from Overload: a signal so strong that circuits begin to operate improperly Paddle: used with a keyer to send Morse code Power supply: device that changes ac power into dc power QRP: very low-power operating (less than 5 watts on CW and 10 watts (peak) on phone) Quarter-wave: 1/4 wavelength Range: distance over which communication can take place Scanning: monitor a range of frequencies or a set of memory channels for activity Screwdriver: a tunable mobile whip, refers to electric screwdriver motors used on early models Selectivity: a receiver's ability to receive only the desired signal and reject all others Sensitivity: a receiver's ability to detect weak signals Signal-to-noise ratio: a comparison of a signal's strength compared to background noise Strong-signal performance: the ability to withstand overload and distortion from strong signal SWR: Standing Wave Ratio, indicates how much power is transferred to a load or antenna VFO: Variable Frequency Oscillator, refers to a radio's continuous tuning mechanism WARC: World Administrative Radio Conference at which frequency allocations are determined Weak-signal: making long-distance SSB and CW contacts with low signal-to-noise ratios Whip: antenna made from a long, thin metal rod ---