Service manual

June 2003 IPN: M5000-00-105 Glossary G - 7
TCXO
Temperature compensated crystal oscillator
(voltage controlled). The frequency reference
for the RF part of the radio.
test mode
The operating mode of the radio whereby
computer (computer equipment can control
various radio functions by sending controlled)
commands down a serial link to the radio.
traffic channel
The channel used by the radio for the duration
of a call.
transmit mode
The radio has validated a request and
commenced or completed the sequence of
switching out of receive mode. This does not
necessarily imply that RF is being generated.
trunked mode
The mode of operation of the radio whereby
the radio obeys commands on the control
channel and generally operates as proscribed
in MPT1343.
trunking system
The infrastructure comprising repeaters and
radios required to support a number of control
channels and traffic channels.
Two-tone
Also known as Type 99. In-band, two tone
sequential signaling used to control the
muting of a radio. Used for selective calling of
individual units or groups of units. Tait Orca
radios are able to decode Two-tone individual,
group and super group calls.
VCO
Voltage controlled oscillator. The oscillator
that generates either the on-channel signal to
drive the transmitter, or the local oscillator to
mix incoming RF signals to the IF of the radio.
The instantaneous frequency of the VCO is
determined by a combination of the synthesis-
er (PLL) and the modulation signals TCXO-
MOD and VCO-MOD.
VOX
Voice operated transmit.