Operating instructions

OPERATING MANUAL 2945A
46882-311D 3-71
Output level
The required output level of the tone signal can be set using the data entry keys, after
highlighting the legend
by pressing the [Tone Level] key.
The units used to specify the output level will relate to the selected output routeing and, when RF
output is selected, the modulation method. The modulation type is automatically set, to be
appropriate to the level terminator key used (FM for Hz, kHz or MHz; AM for %).
The valid output range for each output option is shown in the following table.
Output type Output range Default
RF AM 0 - 99% 30%
RF FM 0 - 75 kHz 1.5 kHz
Audio 100
µ
V - 4 V 100 mV
Tone selection
The required tone is selected from the table in the lower part of the display. Press the
[Select Tone] key to highlight the legend
. Use the data keys to enter the number of the
required tone, then press the [ENTER] key.
Tone frequency shift
The frequency of the selected tone can be shifted by up to ±10%. Press the [Freq Shift] key to
highlight the legend
. Use the data keys to enter the value of frequency shift
required. Only whole numbers within the above range are valid. Complete the entry with the
[%] key.
Tone ON/OFF control
When the RF CTCSS ENCODER screen or the AF CTCSS ENCODER screen is displayed, the
tone is turned on or off by the orange [ON/OFF] function key.
If the CTCSS tone is ON and the Tx TEST, Rx TEST, Dx TEST or AF TEST mode selected, the
CTCSS tone will continue to be generated.
If the tones out routeing has been set to give RF tones, this is provided by modulation generator 2.
The legend
--CTCSS-- will be displayed against MOD2 FREQ on the RECEIVER TEST or
DUPLEX screens. If is selected, the CTCSS tones can be controlled by repeated presses of
the orange [ON/OFF] function key. If
is selected, the CTCSS tone is still
controlled by the [ON/OFF] key, but if a frequency is entered using the data keys or if the variable
control is adjusted, the CTCSS tone will cease. It can then be re-started only when the
RF
CTCSS ENCODER
screen or the AF CTCSS ENCODER screen is displayed.
If the tones out routeing has been set to give AF tones, this is provided by audio generator 2. The
legend
--CTCSS-- will be displayed against AF2 FREQ on the TRANSMITTER TEST, DUPLEX or
AF TEST screens. If is selected, the CTCSS tones can be controlled by repeated presses of the
orange [ON/OFF] function key. If
is selected, the CTCSS tone is still controlled by
the [ON/OFF] key, but if a frequency is entered using the data keys or if the variable control is
adjusted, the CTCSS tone will cease. It can then be re-started only when the
RF CTCSS
ENCODER
screen or the AF CTCSS ENCODER screen is displayed.
DCS
Overview
Digitally Coded Squelch signalling is a system for addressing mobile radio transceivers from
their base station by transmitting a code unique to the addressed transceiver for the duration of
the transmission. The principles and limitations of the system provide 104 uniquely identifiable
codes for use on any one RF channel.