132 Glossary TB7100 Installation and Operation Manual
© Tait Electronics Limited December 2005
continuously repeating code word.  When assigning DCS signalling for a 
channel, you specify the three-digit code.
de-emphasis De-emphasis is a filtering process in the receiver that attenuates higher 
frequency audio. It restores pre-emphasised audio to its original relative 
proportions. 
digital signal 
processor
The device in a radio that analyses and processes signals in the digital 
domain. Also known as DSP.
Duplexer A duplexer is a device for connecting one antenna to a transmitter and 
receiver at the same time.
duty cycle Duty cycle is used in relation to the transmitter. It is the proportion of time 
(expressed as a percentage) during which the transmitter is keyed. 
The transmitter can be operated continuously. 
E
economy cycling Economy cycling is the switching between states that occurs when economy 
mode is active and after there is no valid activity on a channel for a 
preprogrammed time (the economy mode timer). Economy cycling consists 
of two states, the receive state and the standby state. The amount of time the 
radio spends in each state is determined by the economy duty cycle.
economy duty cycle The economy duty cycle is the amount of time the radio spends in the 
receive and standby states during economy cycling.
economy mode Economy mode reduces the radio’s power consumption when it is idle. 
When economy mode is active, and there has been no valid activity on a 
channel for the duration of the economy mode timer, the radio begins 
economy cycling.
economy mode 
timer
The economy mode timer sets the time between when valid activity was last 
detected on a channel and the start of economy cycling. 
EIA Electronic Industries Alliance.  Accredited by the American National 
Standards Institute (ANSI) and responsible for developing 
telecommunications and electronics standards in the USA.
EMC Electromagnetic Compatibility. The ability of equipment to operate in its 
electromagnetic environment without creating interference with other 
devices or being susceptible to disturbance in the presence of other 
equipment.
ETSI European Telecommunications Standards Institute.  The non-profit 
organisation responsible for producing European telecommunications 
standards.