Kenwood Tk 780h1 Owners Manual

							© 2001-5 PRINTED IN JAPAN
B51-8581-00 (
N)
 1370
VHF FM TRANSCEIVER
TK-780/ H
SERVICE MANUAL
GENERAL .................................................................  2
OPERATING FEATURES .........................................  3
REALIGNMENT ......................................................  15
INSTALLATION ......................................................  20
CIRCUIT DESCRIPTION .........................................  28
SEMICONDUCTOR DATA .....................................  33
DESCRIPTION OF COMPONENTS .......................  35
PARTS LIST ............................................................  37
EXPLODED VIEW ..................................................  47
PACKING ................................................................  48
ADJUSTMENT .......................................................  49PC BOARD VIEWS
PLL/VCO (X58-4540-11) : K2,HK2 ....................  57
PLL/VCO (X58-4712-70) : K,HK ........................  58
TX-RX UNIT (X57-6480-XX) (A/2) ...................  59
TX-RX UNIT (X57-6480-XX) (B/2) ....................  65
SCHEMATIC DIAGRAM ........................................  69
BLOCK DIAGRAM ..................................................  77
LEVEL DIAGRAM ...................................................  80
TERMINAL FUNCTION .........................................  82
SPECIFICATIONS ...................................................  83
CONTENTS
Microphone
(T91-0621-05)
Cabinet (Top)
(A01-2165-13)
Panel assy
(A62-0991-03) Key top
(K29-5284-02)
SUPPLEMENT
This service manual applied to products with 30200001 or subsequent serial numbers.
In terms of the products with the serial numbers earier than 30200001, refer to the TK-780/H
service manual as per part No. B51-8461-10. 
						

							2
TK-780/ H
GENERAL
INTRODUCTION
SCOPE OF THIS MANUAL
This manual is intended for use by experienced techni-
cians familiar with similar types of commercial grade com-
munications equipment. It contains all required service infor-
mation for the equipment and is current as of this publica-
tion date. Changes which may occur after publication are
covered by either Service Bulletins or Manual Revisions,
which are issued as required.
ORDERING REPLACEMENT PARTS
When ordering replacement parts or equipment informa-
tion, the full part identification number should be included.
This applies to all parts : components, kits, and chassis. If
the part number is not known, include the chassis or kit
number of which it is a part and a sufficient description of
the required component, for proper identification.
PERSONNEL SAFETY
The following precautions are recommended for person-
nel safety :
• DO NOT transmit if someone is within two feet (0.6
meter) of the antenna.
• DO NOT transmit until all RF connectors are secure and
any open connectors are properly terminated.
• SHUT OFF this equipment when near electrical blasting
caps or while in an explosive atmosphere.
• All equipment should be properly grounded before
power-up for safe operation.
• This equipment should be serviced by only qualified tech-
nicians.
PRE-INSTALLATION CONSIDERNATIONS
1. UNPACKING
Unpack the radio from its shipping container and check
for accessory items. If any item is missing, please contact
KENWOOD immediately.
2. LICENSING REQUIREMENTS
Federal regulations require a station license for each ra-
dio installation (mobile or base) be obtained by the equip-
ment owner. The licensee is responsible for ensuring trans-
mitter power, frequency, and deviation are within the limits
permitted by the station license.
Transmitter adjustments may be performed only by a li-
censed technician holding an FCC first, second or general
class commercial radiotelephone operator’s license. There
is no license required to install or operate the radio.
3. PRE-INSTALLATION CHECKOUT
3-1. Introduction
Each radio is adjusted and tested before shipment. How-
ever, it is recommended that receiver and transmitter opera-
tion be checked for proper operation before installation.
3-2. Testing
The radio should be tested complete with all cabling and
accessories as they will be connected in the final installa-
tion. Transmitter frequency, deviation, and power output
should be checked, as should receiver sensitivity, squelch
operation, and audio output. QT equipment operation
should be verified.
4. PLANNING THE INSTALLATION
4-1. General
Inspect the vehicle and determine how and where the
radio antenna and accessories will be mounted.
Plan cable runs for protection against pinching or crush-
ing wiring, and radio installation to prevent overheating.
4-2. Antenna
The favored location for an antenna is in the center of a
large, flat conductive area, usually at the roof center. The
trunk lid is preferred, bond the trunk lid and vehicle chassis
using ground straps to ensure the lid is at chassis ground.
4-3. Radio
The universal mount bracket allows the radio to be
mounted in a variety of ways. Be sure the mounting surface
is adequate to support the radio’s weight. Allow sufficient
space around the radio for air cooling. Position the radio
close enough to the vehicle operator to permit easy access
to the controls when driving.
4-4. DC Power and wiring
1. This radio may be installed in negative ground electrical
systems only. Reverse polarity will cause the cable fuse
to blow. Check the vehicle ground polarity before installa-
tion to prevent wasted time and effort.
2.You must connect the positive power lead directly to
the positive terminal of the vehicle battery.  Never
connect the lead to any other positive power source,
such as a cigarette lighter jack or fuse terminals.
CAUTION
If DC power is to be controlled by the vehicle ignition
switch, a switching relay should be used to switch the posi-
tive power lead. The vehicle ignition switch then controls
DC to the relay coil.
3.You must also connect the ground lead directly to
the negative terminal of the vehicle battery.
4. The cable provided with the radio is sufficient to handle
the maximum radio current demand. If the cable must be
extended, be sure the additional wire is sufficient for the
current to be carried and length of the added lead. 
						

							3
TK-780 / H
5. INSTALLATION PLANNING – CONTROL STATIONS
5-1. Antenna system
Control station. The antenna system selection depends
on many factors and is beyond the scope of this manual.
Your KENWOOD dealer can help you select an antenna sys-
tem that will best serve your particular needs.
5-2. Radio location
Select a convenient location for your control station radio
which is as close as practical to the antenna cable entry
point. Secondly, use your system’s power supply (which
supplies the voltage and current required for your system).
Make sure sufficient air can flow around the radio and power
supply to allow adequate cooling.
SERVICE
This radio is designed for easy servicing. Refer to the
schematic diagrams, printed circuit board views, and align-
ment procedures contained in this manual.
Note
When you modify your radio as described in system set-
up, take the following precaution.
The rating of pin 7 (SB) of the accessory connector cable
(KCT-19) on the rear of the radio is 13.6V (1A).  Insert a 1A
fuse if you use the SB pin for external equipment.
Accessory connector
cable (KCT-19)
If you do not intend to use the 3.5-mm jack for the exter-
nal speaker, fit the supplied speaker-jack cap (B09-0235-05)
to stop dust and sand getting in.
GENERAL / OPERATING FEATURES
Speaker-jack cap
(B09-0235-05)
1. Operation Features
The TK-780/780H is a VHF FM radio designed to operate
in both trunking format (LTR model) and conventional for-
mat (Conventional model).  The programmable features are
summarized.
Model Trunking format Trunking mode
Conventional format Conventional mode
1-1. Trunking Format
This format can handle up to 32 systems with up to 250
groups in each system.  The transceiver can be used in both
trunked mode and conventional mode.  Systems, groups,
and their functions are programmed.
1-2. Conventional Format
This format can handle up to 250 groups with 250 chan-
nels in each group.  The transceiver can be used only in con-
ventional mode.  Groups, channels, and their functions are
programmed.
2. Transceiver Controls and Indicators (Fig. 1)
2-1. Front Panel Controls
All the keys on the front panel are momentary-type push
buttons.  The functions of these keys are explained below.
•POWER key
Transceiver POWER key.  When the power is switched
off, all the parameters, such as the system and group in
trunking format, and the group and channel in conventional
format, are stored in memory.  When the power is switched
on again, the transceiver returns to the previous conditions.
•SYSTEM UP/DOWN key
(Trunking format, programmable)
•GROUP UP/DOWN key
(Conventional format, programmable)
•SCAN key (Programmable)
•MONITOR key (Programmable)
•A, B, C and D key (Programmable)
•VOLUME UP/DOWN key (Programmable)
•BUSY/TX LED
The BUSY indicator (Green LED) shows that the channel
is in use.  The TX indicator (Red LED) shows that you are
transmitting.
1
3
+
–
7
6 13
15 
						

							4
TK-780/ H
2-2. Programmable Keys
The FPU (KPG-49D) enables programmable keys to se-
lect the following functions.

Conventional format
AUX-A, AUX-B (Only when voice scrambler is not se-
lected), Channel down, Channel up, DTMF ID (BOT), DTMF
ID (EOT), Display character, Emergency (Only foot key),
Function, Group down, Group up, Home channel, Horn alert,
Key lock, Memory (RCL/STO), Memory (RCL), Memory
(STO), Monitor A, Monitor B, Monitor C, Monitor D, Opera-
tor selectable tone, Public address, Redial, Scan, Scan del/
add, Scrambler (Only when voice scrambler is selected),
Talk around, Volume down, Volume up and None.

Trunking format
Auto tel, AUX-A, AUX-B (Only when voice scrambler is
not selected), DTMF ID (BOT), DTMF ID (EOT), Display char-
acter, Emergency (Only foot key), Function, Group down,
Group up, Home group, Horn alert, Key lock, Memory (RCL/
STO), Memory (RCL), Memory (STO), Monitor A, Monitor B,
Monitor C, Monitor D, Public address, Redial, Scan, Scan
del/add, Scan temporary delete, Scrambler (Only when
voice scrambler is selected), System down, System up, TEL
disconnect, Volume down, Volume up and None.
These functions the FPU programs to the function keys
and described in the following sections.
•Auto TEL (Trunking format)
Automatically connects available repeaters that are con-
nected to telephone circuits when operating as LTR system.
The time allocated to search for available repeaters is 60
seconds, after which connection failure occurs, a DTMF
tone is output and the function terminates.
If connection to an available circuit is made, only ID 253,
EOT or hang-up time-out can terminate the function.
•AUX-A
If this key is pressed, “AUX” icon lights on the LCD and
AUX port which is inside of the transceiver turns to the high
level.  If pressed again, the “AUX” icon goes off and the
AUX ports turns to the lower level.
•AUX-B
This function can be programmed when the voice scram-
bler board is not installed.
If this key is pressed, an underscore (“_”) appears at the
extreme right of the LCD and AUX port which is inside of the
transceiver turns to the active level.  If pressed again, the
underscore disappears and the AUX ports turns to the
deactive level.
•Channel up/down (Conventional format)
When the key is pressed each time, the channel number
to be selected is incremented/decremented and repeats if
held for one second or longer.  This key works as the voice
scrambler code selector in the voice scrambler code select
mode.
OPERATING FEATURES
•DTMF ID (BOT)
In conventional mode, if you press this key, a predeter-
mined DTMF ID (Begin of TX) will be sent automatically.
•DTMF ID (EOT)
In conventional mode, if you press this key, a predeter-
mined DTMF ID (End of TX) will be sent automatically.
•Display character
This key switches the LCD display between the system
and group number in trunking format and the group and
channel name in conventional format.
•Emergency
Pressing this key for longer than the programmed “Emer-
gency Key Delay Time” causes the transceiver to enter the
emergency mode.  The transceiver jumps to the pro-
grammed “Emergency system and group in trunking format
and the group and channel in conventional format” and
transmits for the programmed “Active Time”.
The transceiver disables mic mute while transmitting.
After finishing transmission, the transceiver receivers for
the programmed “Interval Time”.  The transceiver mutes
the speaker while receiving.  Following the above sequence,
the transceiver continues to transmit and receive.
•Function
Pressing this key causes the transceiver to display
“FCN”.  Then, pressing a microphone DTMF key causes the
corresponding programmed function to start.  This key may
be convenient when using many functions with the micro-
phone 12-key keypad.
•Group up/down
When the key is pressed each time, the group number to
be selected is incremented/decremented and repeats if held
for one second or longer.
•Home channel (Conventional format)
Press this key once, the channel switches to the pre-pro-
grammed home channel.
•Home group (Trunking format)
Each pressing of the key selects a preset system/group.
•Horn alert
If you are called from the base station using 2-tone/DTMF
while you are away from your transceiver, you will be
alerted by the vehicle horn or some other type of external
alert.  To turn the horn alert function on , press this key.  A
confirmation tone sounds, and the display shows “HA” on
the sub LCD.
If this key is pressed again, the horn alert function is
turned off.
•Key lock
Pressing this key causes the transceiver to accept entry
of only the [Function], [Key lock], [PTT], [Monitor A], [Moni-
tor B], [Monitor C], [Monitor D], and [Emergency] keys. 
						

							5
TK-780 / H
•Message mode
Press this key to enter the message mode. (See “Alpha-
numeric Two-way Paging Function” for details)
•Memory
This key allows DTMF memory data to be recalled; up to
32 memories each with a memory dial of up to 16 digits and
an A/N of up to 10 digits per memory.
•Monitor
Used to release signalling or squelch when operating as a
conventional.  It is also used to reset option signalling.
•Operator selectable tone (Conventional format)
This key switches the pre-set decode QT/DQT and en-
code QT/DQT to OST (Operator Selectable Tone) tone pair.
Press this key, the transceiver enters to OST select
mode.  In this mode, the display shows “OFF” and the op-
erator can select one of the OST tone pair using the group
up/down key.  The display shows “TONE
**” and tone
pair No. 
** is selected.
Press OST key again, the transceiver exits from the OST
select mode, and returns to the group/channel mode with
the handset indicator (
).  The handset indicator () means
that the OST tone pair is selected.  OST tone pair number or
OFF can be memorized for each channel.
16 kinds of tone pair for OST can be programmed by
KPG-49D.  OST is useful to access the repeater with same
radio frequency and different tone (QT/DQT).
•Public address
Public address amplifies the microphone audio, and out-
puts it through a PA speaker.  PA is activated by pressing
this key.  A confirmation tone sounds, and the display shows
“PUBLIC ADRS”.  PA can be activated at anytime (scanning
or non-scanning).
The RADIO continues to scan & receive calls while in PA
mode.  Pressing PTT activates PA, and will override an in-
coming call at anytime; however, no RADIO transmission
takes place.
If this key is pressed again, a confirmation tone will
sound, the display will return to the normal channel or SCAN
display, and the PA function will turn off.
•Redial
If you press this key when the system/group (Trunking
format) or group/channel (Conventional format) is displayed,
the last transmitted DTMF code will appear on the display.
Pressing the PTT switch at this time will transmit the dis-
played DTMF code.
•Scan
Press this key starts scanning.  Pressing this key stops
scanning.
•Scan del/add
1) Trunking format
Used to select whether system scan routines are used
during system scan.  Each pressing of the key (to ON)
toggles between lockout and lock.  The scan routine is
started when on lock.  The DEL indicator flashes when the
system is on lockout.
2) Conventional format
This key switches the currently displayed channel be-
tween “Delete” and “Add”.
The “Add” channel contained in the scan sequence, and
“Delete” channel is not contained.  In the scan mode, this
key switches the channnel delete or add temporarily.
•Scan temporary delete (Trunking format)
This key is temporarily deleted a system being scanned.
If you press this key when scan is stopped (when a call is
being received from another station), the system is tempo-
rarily deleted and scanning restarts.
This key operates even when “Scan Type” is set to “List
Type System Scan”.
•Scrambler
If a scrambler code (1 to 16) has been set in the FPU, an
underscore (“_”) appears at the extreme right of the LCD
display when scrambler is active.  Pressing this key changes
on/off of scramble operation.  Press this key for 2 seconds
to enter scrambler code selection mode.
•Send GPS (Optional)
Pressing this key causes the transceiver to send a single
GPS data. (GPS receiver must be installed.)
•System up/down (Trunking format)
When the key is pressed each time, the system number
to be selected is incremented/decremented and repeats if
held for one second or longer.
•Talk around (Conventional format)
Press this key, the transceiver uses the receive fre-
quency and the tone for transmission.
The operator can call the other party directory (without
repeater).  Press this key again, the talk around function
goes off.
•Telephone disconnect (Trunking format)
Pressing this key ends an RIC connection (disconnects
the telephone line).
•Volume up/down
When the key is pressed, the volume level is increased/
decreased and repeats if held for 200ms or longer.
•None
Sounds error operation beep, and no action will occur.
Use this function when the transceiver is required to be
more simple operated.
OPERATING FEATURES 
						

							6
TK-780/ H
2-3. Front Panel Displays and Indicators
1Sub display
Displays the system, channel and group numbers.  Also
displays various functions, such as TA.
2P (Priority) indicator
The P indicator () appears when a selected channel is
programmed as priority, in conventional operation.
3MON (Monitor) indicator
The MON indicator appears when the button pro-
grammed as MONITOR is pressed.
4SVC (Service) indictor
This icon is not used this transceiver.
5SCN (Scan) indicator
The SCN indicator appears when using scan mode.
6AUX (Auxiliary) indicator
appears when the auxiliary function is activated (ON) by
pressing the AUX-A key.
OPERATING FEATURES
7Handset indicator
The handset indicator () appears when the selected
group is programmed as telephone IDs (Trunking format).
In conventional format, the handset indicator (
) appears
when the OST tone pair is selected.
8MAIL indicator
Flashes when a status message (FleetSync™) is re-
ceived.  Lights when a status message is stored in the stack
memory.
9Alphanumeric display
The twelve-character dot matrix alphanumeric display
shows the system/group numbers.  You can program sys-
tem/group names with up to ten characters in place of these
numbers.  The left display is used as a delete indicator (
)
and the right is used for the selective call (
*) or scrambler
(_) function.  The delete indicator shows the systems
locked out of the scanning sequence.  Selective call and
scrambler are optional functions that can be programmed.
Dispalys received messages when using FleetSync™.
10A,B,C,D key
These keys are programmable function (PF) keys.
MODULAR
MIC JACKMONITORSCAN POWER
BUSY/
TX LEDVOLUME
 UP
VOLUME
DOWN
SYSTEM UP
(Trunking Format)
GROUP UP
(Conventional Format)   
SYSTEM DOWN
(Trunking Format)
GROUP DOWN   
(Conventional Format)    1
23
109
45678
3. Scan Operating
3-1. Trunking Format

System scan
System scan can be selected with the “Scan” key by pro-
gramming the scan feature.  When the “Scan” key is
pressed and the “SCN” mark appears, scan mode in en-
tered.  Scanning starts from the system following the cur-
rently displayed system.  When a call is received, scanning
stops, and the system and group are displayed.
When programming key is touched during scanning, the
scan stops and the revert system or group can be changed.
Scanning resumes one second after the key is released.
There are two types of system scan.
•Fix system scan
All the set systems except locked-out ones are scanned.
If the Del/Add feature is assigned to the programmable key,
it can be controlled from the front panel.
•List type system scan
A scan list can be set for each system.
The list to be scanned can be changed by changing the
display system.
If many systems have been set, the scan speed can be
increased by narrowing the systems to be scanned with
scan lists.
Fig. 1 
						

							7
TK-780 / H

System lockout
The system lockout feature is used to lock systems out
of the scan sequence, and can be selected by programming
in the following two ways;
•Fixed lockout
The system to be locked out is selected by programming.
When a locked system is selected, the Delete (
) indicator
appears on the left of the SYSTEM indicator.  The revert sys-
tem is scanned even if it is locked out.  If there is a locked
system, the Delete (
) indicator flashes during fixed scan-
ning.
•User selectable lockout
If the scan lockout feature is programmed to a key, the
user can lock systems out of the scan sequence with the
key.  To lock a system out of the scan sequence, press the
key when the system is displayed.  The Delete (
) indicator
is displayed on the left of the SYSTEM indicator.
To 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 system
is scanned even if it is locked out.  If there a locked system,
the Delete (
) indicator flashes during fixed scanning.  If all
systems are locked out, the scan stops and only the revert
system is received.

Drop-out delay time (Scan resume time)
If a call is received during scan, the scan stops.  The scan
resume time can be programmed as 0 to 300 seconds in
one-second increments.  The default value is 3 seconds.

Dwell time
The dwell time is the time after transmission ends until
the scan resumes in scan mode.  It can be set 0 to 300 sec-
onds by programming.  The default value is 3 seconds.

System/group revert
System/group revert can be programmed for one of the
following;
•Last called revert
The system or group changes to the revert system or
group when a call is received with the system or group be-
ing scanned.
•Last used revert
If a system/group call is received during scanning and the
PTT button is pressed for transmission and response within
the drop out delay time, the system or group is assigned as
the new revert system or group.
•Selected revert
If the system/group was changed while scanning, the
newly selected system/group.
OPERATING FEATURES
•Selected + Talkback revert
If the system/group was changed while scanning, the
newly selected system/group.  The transceiver “talks back”
on the current receive group.

Scan massage wait
The time for staying with the home repeater that re-
ceives a signal during system scan and monitoring data
messages can be programmed.  If there is no signal from
the home repeater, the system is scanned for about 50ms.
If there is a signal, three data messages are monitored.
Normally, three data messages are monitored for each sys-
tem, and it can be increased in multiples of three data mes-
sages per line to up to eight lines.
If the repeater data message indicates that there is no
call, data monitoring is terminated and the home repeater of
the next system is scanned.

Group scan operation
Group scan can be programmed for each group.  In addi-
tion to the ID codes of the selected group, the ID codes of
the other groups that are permitted for group scan are de-
coded.   (The two fixed ID and block decode codes are al-
ways decoded.)
If, during group scanning, a call is received with one of
the selectable group ID codes for which group scan is en-
abled, the group display indicates the group number that the
call 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 scan
elapses.

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 system
scan) temporarily stops (receiving) in a group that does not
have priority, a look back is performed to the priority group.
Look back is performed according to the look back time A
and B settings.  If a call is received on the priority group,
reception immediately switches to the priority group.
3-2. Conventional Format

Scan types
•Single group scan
You can scan all valid (ADD) channels in the displayed
group that can be selected with the group up/down key.
•Multiple group scan
You can scan all valid (ADD) channels in the all valid
(ADD) group. 
						

							8
TK-780/ H

SCAN start condition
One or more non-priority channels must be added to all
channels that can be scanned.  The transceiver must be in
normal receive mode (PTT off).
When you activate the key programmed to the scan func-
tion, the scan starts.  The scan icon “SCN” lights and “–
SCAN–” or revert channel (programmable) is indicated on
alphanumeric display.

Scan stop condition
The scan stops temporarily if the following conditions are
satisfied.
1) A carrier is detected, then signalling matches on chan-
nels for which receive the signalling is set by the pro-
gramming software.
2) A carrier is detected on the channels for which receiving
signalling is not set by the programming software or
when the monitor (signalling cancel) function is activated.

Scan channel types
1) Priority channel is the most important channel for the
scan, and always detects a signal during scan and when
the scan stops temporarily.
2) Non-priority channels detects a signal during scan.  For
the channels that can be selected with the group or chan-
nel up/down key when the scan does not occur, adds an
indicator “” lights.

Priority channel setting
A priority channel can be set as follows with the program-
ming software (KPG-49D).
1) Specify a priority channel as a fixed priority channel.
2) Make a selected channel, a priority channel.

Scan type according to the priority channel
1) When no priority channel is set : Only the non-priority
channels are scanned.
If a non-priority channel stops temporarily, it stops until
there is no signal on the channel.
2) When priority channel is set : Either priority channel is
scanned.
If a non-priority channel stops temporarily, a priority chan-
nel signal is detected at certain intervals.
If a priority channel stops temporarily, it stops until there
is no signal on the priority channel.

Revert channel
The revert channel is used to transmit during scanning
and set by the programming software (KPG-49D).
1) Priority
The transceiver reverts to the priority channel.2) Priority + talkback
The transceiver reverts to the priority channel.
If you press PTT during a resume timer (dropout delay
time, TX dwell time) or calling, you can transmit on cur-
rent channel to answer to the call however revert channel
is set to priority channel.
After resume time, scan re-starts and transmission chan-
nel is return to priority channel.
3) Selected channel
The transceiver reverts to the channel before scanning or
the channel that you changed during scan.
4) Last called channel
The transceiver reverts to the last called channel during
the scan.
5) Last used channel
The transceiver reverts to the last used (transmitted)
channel during scan.  “Last used” revert channel in-
cludes talkback function.
6) Selected + talkback
The transceiver reverts to the channel before scanning or
the channel that you changed during scan.

Scan end
When you reactivate the key programmed to the scan
function during scan mode, the scan ends.
The scan icon “SCN” and “–SCAN–” or revert channel
(programmable) display goes off.

Temporarily delete/add
It is possible to delete or add channel temporarily during
scan.  When scan stops on unnecessary channel for ex-
ample by interference of the other party, activate the delete/
add function (for example press the key), then that channel
is deleted temporarily and scan re-start immediately.
When you would like to add the deleted channel tempo-
rarily to scan sequence, select the desired (deleted) channel
during scan, activate the delete/add function (for example
press the key) before scan re-start.
That channel is added temporarily to scan sequence.  The
temporary deleted or added channels are returns to pre-set
delete/add, when the transceiver exits from scan mode.
4. Details of Features
4-1. Common Trunking format and Conventional Format

Time-out timer
The time-out timer can be programmed in 15 seconds
increments from 15 seconds to 10 minutes.  If the transmit-
ter is keyed continuously for longer than the programmed
time, the transmitter is disabled and a warning tone sounds
while the PTT button is held down.  The alert tone stops
when the PTT button is released.
OPERATING FEATURES 
						

							9
TK-780 / H

Sub LCD display
You can use 3-digit the display to display the system
number, channel number or group number.  It is useful
when the main (12-digit) display indicates system, group or
channel name or other functions.

Selective call alert LED
You can select whether or not the LED on the transceiver
flashes in an orange color when selective call was occurred.

PTT ID
PTT ID provides a DTMF or MSK (FleetSync™ : Fleet-ID)
ANI to be sent with every time PTT (beginning of transmis-
sion, end of transmission, or both).
You can program PTT ID for each group.  You can pro-
gram a PTT ID as “on” or “off” when “DTMF” is selected
for the PTT ID type.  You can program a PTT ID as “own”,
“sel” or “off” when “MSK” is selected for the PTT ID type.
The contents of ID are programmed for each transceiver.
The timing that the transceiver sends ID is program-
mable.
BOT : DTMF ID (BOT)/MSK ID is sent on beginning of
transmission.
EOT : DTMF ID (EOT)/MSK ID is sent on end of transmis-
sion.
Both : DTMF ID (BOT)/MSK ID is sent on beginning of
transmission and DTMF ID (EOT)/MSK ID is sent on end
of transmission.

Radio password
When the password is set in the transceiver, user can not
use the transceiver unless enter the correct password.
This code can be up to 6 digits from 0 to 9 and input with
the key, and "S" key.

Off hook decode
If the Off hook decode function has been enabled, re-
moving and replacing the microphone on the hook has no
effect for decoding QT/DQT and option signalling.

Timed power off
This function works as “Automatic Power Switch Off”.
Timed power off timer starts from the ignition-off.  After
the timer expires, the radio will automatically turn off.  The
timer will be reset if the ignition is turned on and off.
This function requires ignition-sense.  Connect the igni-
tion-line to the 9-pin connector which is located at the rear of
the radio.
After the timer expires, press the power switch to turn
on the radio.
OPERATING FEATURES

Horn alert
In trunking format, horn alert can be set to on or off for
each group.  If horn alert has been set to YES for a group and
DEC ID/QT/DQT matches, the horn alert, HOR. is turned on
and off.  The group for which the optional signalling is set
works by ANDing the decode ID/QT/DQT with the optional
signalling.
In conventional format, if you are called from the base
station using 2-tone/DTMF while you are away from your
transceiver, you will be alerted by the vehicle horn or some
other type of external alert.  To turn horn alert function on,
press the [Horn Alert] key.
Either continuous or non-continuous operation can be set
by the FPU.  The horn alert port is enabled or disabled as
follows;
Off hook horn alertHook off Hook on
Enable Yes Yes
Disable No Yes

Pulse
The horn alert port, HOR, is turned on and off as follows;
The timing when the fixed LTR ID matches is as follows
(trunking format);

Continuous
Horn alert can be reset by setting an expiration time from
the FPU, pressing the AUX-A key, or setting off hook.

Data TX with QT/DQT
Whether programmed QT/DQT is modulated or not with
a data transmission except for Selcall.  A radio unit can re-
ceive a data message regardless of QT/DQT if the receiving
unit is not scanning.
0.5s 0.5s 0.5s 0.5s 0.5s
HOR
1s 0.5s 1s 
						

							10
TK-780/ H
OPERATING FEATURES
4-2. Trunking Format

Call indicator
The call indicator can be programmed for each group.  In
trunked system, it can be set to respond to a selectable de-
code ID or one of two fixed IDs, except block IDs.  When a
call is received with a selectable decode ID, the call indicator
flashes.  When a call is received with a fixed ID, the call
indicator lights continuously.
On a conventional system, the call indicator can be pro-
grammed to light for each QT or DQT code.  It keeps flash-
ing while a call is being received.  It is turned off by pressing
any front panel key.

Free system ringback
This feature is available only when a telephone intercon-
nected ID code is selected.  If a busy tone sounds when the
PTT button is pressed, the transceiver enters this mode au-
tomatically.
When the PTT button is released, a beep sounds for
400ms to indicate that the mode has been entered.  If the
scan is on, it is resumed (the "SCN" mark goes on).  When
any repeater becomes available, a ringing tone sounds and
this mode ends.
The mode is terminated when the system, group, scan,
PTT, key is changed.

System search
This feature can be programmed to automatically access
other programmed systems when the selected system can-
not be accessed.  If an intercept tone sounds when the PTT
button is pressed after setting the mode, the transceiver
has entered the mode.
If the group ID is a telephone interconnect ID, the trans-
ceiver then attempts to access, in succession, other sys-
tems that have a telephone interconnect ID in the revert
group location.  If the group ID is a dispatch ID, the trans-
ceiver attempts to access other systems that have a dis-
patch ID programmed in the revert group location.
If there is no system to be accessed, an intercept tone
sounds, the mode is terminated, and the transceiver returns
to the first system.  If the access is successful, the mode is
terminated, and the searched system becomes the new se-
lected system (If during scanning, the scan stops).

Transpond
This feature can be programmed to turn on and off for
each group.  If the ID of the group for which transpond is
enabled is received, two data messages (transmit ID and
turn-off code) are automatically transmitted if the PTT but-
ton is not pressed as a response within the time set (0 to
300 seconds in 1-second increments).  If the PTT button is
pressed within the time, the transpond is not preformed.

Transmit inhibit
The transceiver can be programmed with a transmit in-
hibit block of ID codes.  If an ID code within this block is
decoded the preset time before the PTT button is pressed,
transmission is inhibited.  The BUSY indicator lights and a
busy tone sounds until the PTT button is released to indicate
that transmission is not possible (except clear-to talk mode).
Transmission with the group for which the encode ID is
not set is inhibited, and the busy tone is output while the
PTT button is held down, regardless of the clear-to talk set-
ting.

Auto TEL
A telephone interconnect call can be made by simply
pressing the key by assigning this feature to the key.  This
feature accesses the TEL channel of the available system
automatically.
When the key is pressed, a queue tone is output, and the
“AUTO TEL” appears on the alphanumeric display along
with a flashing handset indicator (
) to indicate that this
mode has been entered.  If the TEL ID is set for the revert
system, the TEL channel of that system is accessed.  If all
TEL channels are busy, an attempt is made to access the
TEL channels of another system in which the TEL ID code
has been programmed.  It is repeated for 60 seconds until
the access succeeds.  If the access succeeds, a dial tone
returns from the repeater.  If the key is pressed again when
the queue tone is sounding, this mode is canceled.
If the access fails after 60 seconds, a deny tone is output
and this mode is terminated.  When the talk ends, the revert
system/group returns.  When the scan mode is effective,
the scan resumes.  The Auto TEL feature can be pro-
grammed to turn on or off for each system.

ARQ mode
It affects Trunking mode only.  Automatic Repeat
reQuest (ARQ) mode is a manner to minimize the air traffic
of data communication.  Also, it enables to occupy the
trunking repeater channel fot the data communication pe-
riod.
4-3. Conventional Format

“TOT” pre-alert
The transceiver has “TOT” pre-alert timer.  This param-
eter selects the time at which the transceiver generates
“TOT” pre-alert tone before “TOT” is expired.
“TOT” will be expired when the selected time passes
from a TOT pre-alert tone.

“TOT” re-key time
The transceiver has “TOT” re-key timer.  This timer is the
time you can not transmit after “TOT” exceeded.  After
“TOT” re-key time expired you can transmit again.