SWR / VSWR
Voltage Standing Wave Ratio
A measure of impedance matching between the transmission line and the antenna. An SWR of 1.0:1 is a perfect match.
CW
Continuous Wave
The transmission of International Morse Code by keying an unmodulated RF carrier wave.
QRP
Low Power Radio Operation
Operating with 5 Watts RF output or less on CW, and 10 Watts PEP or less on SSB.
SSB
Single Sideband
An efficient form of amplitude modulation where the carrier and one of the sidebands are filtered out.
DX
Distance Transmission
Amateur radio communication over long distances, typically between different continents or rare countries.
Balun
Balanced to Unbalanced
An impedance or isolation transformer connecting a balanced antenna (like a dipole) to unbalanced coax.
Yagi-Uda
Directional Beam Antenna
A multi-element directional antenna using a driven element, a reflector, and one or more directors for high forward gain.
Dipole
Half-Wave Wire Antenna
The fundamental resonant antenna measuring approximately 468/f(MHz) in feet, fed at the center.
Maidenhead
QTH Grid Locator
A worldwide coordinate locator system encoding latitude and longitude into 4 or 6 alphanumeric characters.
UTC / Zulu
Coordinated Universal Time
The international astronomical time standard used for all amateur radio logs to avoid time zone ambiguity.
Attenuation
Signal Loss in Transmission
The reduction in signal strength that occurs as radio frequency power passes through coax or filters.
BTRC
Bangladesh Telecom Regulatory Commission
The statutory regulatory authority responsible for administering Amateur Radio licensing exams and callsigns.
ITU
International Telecommunication Union
United Nations specialized agency that coordinates the global shared use of the radio spectrum.
