Operating instructions
16 ChoosingaHamRadio
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 an-
tenna
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