Q

See also Codes and Alphabets

Q
QAM : Quadrature Amplitude Modulation. A method that allows simultaneous frequency and amplitude modulation of a signal.

Q Code Three letter codes used instead of sentences or phrases.

 Q of a circuit The quality factor of a resonant circuit - the ratio of stored power to dissipated power in the Reactance and Resistance of the circuit.

QCWA : Quarter Century Wireless Association, a radioamateur club with local chapters in which membership is offered solely to operators who were first licensed twenty-five or more years ago.

QRM : Man made noise. Can be used to indicate noise interfering with an amateur station or an amateur station interfering with other spectrum users.

QRN : Electromagnetic noise from natural sources interfering with amateur transmissions.

QRP : Low power operations - usually understood to mean power at or below 5 watts. From QRP, a code requesting that a station reduce its transmitted power.

QRPp : Very low power operation - at or below 1 Watt.

QPSK : Quadrature Phase Shift Keying. Also known as Quadraphase Phase Shift Keying. A method of modulating a carrier in digital transmissions by changing its phase four times, with each change being represented by two binary digits.

QSB : Fading (of signals). Used in signal reports eg "your signal is experiencing rapid QSB tonight"

QRSS : Very low speed operation - typically CW below one character per minute, intended for machine-assisted reception under extreme QRP or noisy/weak signal conditions. Bandwidth used is a small fraction of 1 Hz. From QRS, a code requesting "send more slowly".

QSL : Confirmation of receipt of transmission

QTH : Home, home location, station location

Quartz crystal : a crystal of ?silicon dioxide cut to vibrate at a particular frequency when an electric current is applied to it. Used in high stability oscillators