8StunThis function is used when a transceiver is stolen or lost. When the transceiverreceives a call containing a stun code, the transceiver becomes disabled. Thestun code is cancelled when the transceiver receives a call with a revive code.• “St” appears on the display while the transceiver is stunned.SIGNALINGQuiet tAlk (Qt)/ digitAl Quiet tAlk (dQt)Your dealer may have programmed QT or DQT signaling on your transceiverchannels. A QT tone/ DQT code is a sub-audible tone/code which allows you toignore (not hear) calls from other parties who are using the same channel.optionAl SignAlingYour dealer may also program several types of optional signaling for yourtransceiver channels.2-tone Signaling: 2-tone Signaling opens the squelch only when yourtransceiver receives a call containing matching 2 tones.DTMF Signaling: DTMF Signaling opens the squelch only when the transceiverreceives a call containing a matching DTMF code.FleetSync Signaling: Refer to “Selcall (Selective calling )” on page 9.MDC-1200: MDC-200 is a data system using Audio Frequency Shift Keying(AFSK). Transceivers communicate at a 200 baud rate, using 200 Hz and800 Hz tones.operAtor SelectAble tone (oSt)You can change the preset encode and decode tones for the selected channel.Up to 6 OST pairs can be pre-programmed by your dealer.1 Select your desired channel.2 Press the key programmed as Operator Selectable Tone or press and holdthe microphone key.• “ot” appears on the display, followed by the current OST number.3 Press and C> to select the desired OST number.4 Use the transceiver the same as in a regular call; press the PTT switch totransmit and release it to receive.5 To exit OST mode and return to the preset encode and decode tones, press S.