Operator's Manual

C-5000 Operator’s Manual
150-041102 REV. A Page 57 of 61
Guard Receiver – Second receiver added to the transceiver to monitor a specific frequency. Some common
“guard” frequencies are 121.5, 243, Marine channel 16, and Marine channel 70. However, this optional
function can also be used to monitor a dispatch channel, or an important tactical frequency. Some Guard
receivers have a single frequency that is set in hardware. Other options, available only in the RT-5000, are a
programmable dual channel receiver and a multi-band P25/Trunking compatible unit.
IF Injection – In a superhetrodyne receiver, high frequency signals are progressively lowered in frequency until
only the audio is left. This is done by multiplying the RF Signal by a sinewave either above or below the RF
carrier. Mathematically this results in an “Intermediate Frequency” (IF) frequency that is the sum and
difference of the two signals. The RT-5000 has the capability of having either High (Above) or Low (Below)
the signal frequency. What this means is if you have a signal interfering with the desired signal, sometimes
the interference can be eliminated by switching either the 2
nd
or 3
rd
injection setting.
Interoperability – The ability for different radio systems to communicate with each other directly. For example,
when one manufacturer’s radio products will communicate with another’s, they are said to be “Interoperable”.
ITM – “Internal Transceiver Module”. This is the module that is physically placed in the Guard Receiver slot in the
RT-5000. This is the part of the radio that can perform P25, encryption, and Motorola Trunking. Each ITM covers
a specific frequency band – 138-174, 403-470, 450-520, and 800 MHz. Up to two ITM’s can be put into one RT-
5000 however one must be below 400 MHz and one above 400 MHz.
KEYMAT – Another name for encryption key.
KVL – Acronym for Key Variable Loader. It is a Motorola product for loading encryption keys into an encryption
capable radio.
Main Receiver – Full function receiver located in every transceiver.
Manual Channel – A special preset channel that allows the operator to manipulate channel information “on the fly”
without going into programming mode. On the C-5000 this special channel is labeled “..M” and is located at
channel 0.
MODE 1 – Operational mode of the C-5000/RT-5000 system where the operator does not know there is a main and
guard located in the transceiver. This simplifies the user interface dramatically. However, only one receiver,
the main or the ITM module in the Guard is in operation at one time so only one channel is monitored.
MODE 2 – Operational mode of the C-5000/RT-5000 system where the main and guard receiver are both
monitoring frequencies at the same time. The user interface is more complex in that the user must select
using the silver “soft” buttons on the C-5000 which channel to display and transmit on.
OTAR – Acronym for “Over The Air Re-key”. Method by which the Encryption Key is transmitted over the radio
channel, hence “over the air”.
P25 – Digital Modulation Standard.
Page – The contents of the display. Sometimes called a screen or view.
PL – Acronym for “Private Line”. Also known as CTCSS or sub-audible tone.
Preset Channel – A channel that has been programmed into the memory of a control head or transceiver.
Private – Another name for encryption.
Repeat – This mode of operation uses a ground or air based repeater to retransmit your signal to another radio.
Transmit and receive frequencies are different.