6SIGNAlINGQuiet Talk (QT)/ Digital Quiet Talk (DQT): Your dealer mayhave programmed QT or DQT signaling on your transceiverchannels. QT and DQT signals allow you to ignore (not hear)calls from other parties who are using the same channel.MDC-1200: MDC-200 is a data system using AudioFrequency Shift Keying (AFSK).oPTIoNAl SIGNAlINGYour dealer may also program several types of optionalsignaling for your transceiver channels.2-tone Signaling: 2-tone Signaling opens the squelch onlywhen your transceiver receives a call containing matching 2tones.DTMF Signaling: DTMF Signaling opens the squelch onlywhen the transceiver receives a call containing a matchingDTMF code.FleetSync Signaling: Refer to “SELCALL (SELECTIVECALLING)” on page 7.oPErATor SElECTABlE ToNE (oST)You can change the preset encode and decode tones for theselected channel. Up to 0 OST pairs can be pre-programmedby your dealer.1 Select your desired channel.2 Press the key programmed as [Operator Selectable Tone(OST)] to enter OST Select Mode.• “OST” and the current OST number appear.3 Press or C> to select the desired OST table number.4 Use the transceiver the same as in a regular call; press thePTT switch to transmit and release it to receive.5 To exit OST mode and return to the preset encode anddecode tones, press S.