Kenwood FM Transceiver TK-481 Service Manual

Also see for FM Transceiver TK-481: User manual Instruction manual Specifications Instruction manual Service manual

6TK-480/481 OPERATING FEATURESTo unlock a system, select the system and press the key.The Delete ( ) indicator disappears to indicate that the sys-tem has returned to the scan sequence. The revert systemis scanned even if it is locked out. If there a locked system,the Delete ( ) indicator flashes during fixed scanning. If allsystems are locked out, the scan stops and only the revertsystem is received.3-3. Drop-out delay time (Scan resume time)If a call is received during scan, the scan stops. The scanresume time can be programmed as 0 to 300 seconds inone-second increments. The default value is 3 seconds.3-4. Dwell timeThe dwell time is the time after transmission ends untilthe scan resumes in scan mode. It can be set 0 to 300 sec-onds by programming. The default value is 3 seconds.3-5. System/Group revertSystem/Group revert can be programmed for one of thefollowing; Last called revertThe system or group changes to the revert system orgroup when a call is received with the system or group be-ing scanned. Last used revertIf a system/group call is received during scanning and thePTT button is pressed for transmission and response withinthe drop out delay time, the system or group is assigned asthe new revert system or group. Selected revertIf the system/group was changed while scanning, thenewly selected system/group. Selected + TalkbackIf the system/group was changed while scanning, thenewly selected system/group. The transceiver “talks back”on the current receive group.3-6. Scan message waitThe time for staying with the home repeater that re-ceives a signal during system scan and monitoring datamessages can be programmed. If there is no signal from thehome repeater, the system is scanned for about 50ms. Ifthere is a signal, three data messages are monitored. Nor-mally, three data messages are monitored for each system,and it can be increased in multiples of three data messagesper line to up to eight lines.If the repeater data message indicates that there is nocall, data monitoring is terminated and the home repeater ofthe next system is scanned.3-7. Group scan operationGroup scan can be programmed for each group. In addi-tion to the ID codes of the selected group, the ID codes ofthe other groups that are permitted for group scan are de-coded. (The two fixed ID and block decode codes are alwaysdecoded.)If, during group scanning, a call is received with one ofthe selectable group ID codes for which group scan is en-abled, the group display indicates the group number that thecall came in with. That group then becomes the new se-lected group. Group scan resumes after the specified drop-out delay time or dwell time shared by the system scanelapses.3-8. In Conventional system.If QT or DQT is set for the channel, the channels, includ-ing signalling, are scanned.In case of the priority group is set in conventional sys-tem, if a group scan (including group scan during a systemscan) temporarily stops (receiving) in a group that does nothave priority, a look back is performed to the priority group.Look back is performed according to the look back time Aand B settings. If a call is received on the priority group, re-ception immediately switches to the priority group.4. Details of Features4-1. Time-out timerThe time-out timer can be programmed in 15 secondsincrements from 15 seconds to ten minutes. If the transmit-ter is keyed continuously for longer than the programmedtime, the transmitter is disabled and a warning tone soundswhile the PTT button is held down. The alert tone stopswhen the PTT button is released.4-2. Sub LCDYou can use 3-digit the display to display the systemnumber, channel number or group number. It is useful whenthe main (12-digit) display indicates system, group or chan-nel name or other functions.4-3. Selective Call Alert LEDYou can select whether or not the LED on the transceiverflashes in an orange color when selective call was occurred.4-4. PTT IDPTT ID provides a DTMF ANI or MSK ID to be sent withevery time PTT (connect ID at beginning of transmission,disconnect ID at end of transmission, or both).You can program PTT ID “on” or “off” for each groupchannel (DTMF). The contents of ID are programmed foreach transceiver.The transceiver is capable to have ID. The format isDTMF. The timing that the transceiver sends ID is program-mable.BOT : Connect ID is sent on beginning of transmission.EOT : Disconnect ID is sent on end of transmission.Both : Connect ID is sent on beginning of transmissionand disconnect ID is sent on end of transmission.There is also “PTT ID” setting for each channel.