Operating instructions

LOCAL OPERATION
3-70 46882-311D
Revertive tones
Revertive tones signalling takes various forms. The common factor is that a tone sequence
received by a mobile transceiver or other receiver, will trigger a second sequence to be returned.
The second sequence may be a duplicate of the first or a different sequence. It can be used to
modulate a signal on a reverse channel or on a different channel. For some applications either or
both of the tone sequences may be used as an AF signal.
The routeing of the original tone signal out of the Service Monitor, and the revertive tone signal
into the Service Monitor, is dependent on the settings of the [Tones In] and [Tones Out] keys on
the TONES selection screen. This allows the permutations shown in the following table.
Original tones out Revertive tones in
RF RF
RF AF
AF RF
AF AF
The revertive tones operation is configured by pressing the [Revertv Tones] key. To send a tone
burst, do one of the following:-
• If
TONE BURST has NOT already been selected as the send mode, press the [Send Mode]
key to access the send mode menu, then press the [Tone Burst] key. The tone sequence will
be generated, then after the last tone, the Service Monitor will change to decode mode ready
to decode the revertive tones.
• If
TONE BURST has already been selected as the send mode, press the orange [ON/OFF]
function key. The tone sequence will be generated, then after the last tone, the Service
Monitor will change to decode mode ready to decode the revertive tones.
The encoder screen can be displayed again by pressing the
[Encode] key.
CTCSS
The CTCSS tones system uses a continuous tone at a precise frequency, transmitted below the
audio pass band, to un-squelch the receiver.
Fig. 3-22 RF CTCSS encoder screen and menu
Pressing the [CTCSS] key on the TONES selection screen will display the screen shown in
Fig. 3-22, RF CTCSS encoder screen and menu.
The CTCSS function of the Service Monitor will generate a single AF tone, selected from those
listed on the display.