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VHF FM TRANSCEIVER
TK-272G
© 2000-11 PRINTED IN JAPAN
B51-8560-00(S) 790
SERVICE MANUAL
GENERAL ...................................................................... 2
SYSTEM SET-UP .......................................................... 2
OPERATING FEATURES .............................................. 3
REALIGNMENT ............................................................. 7
DISASSEMBLY FOR REPAIR ..................................... 15
CIRCUIT DESCRIPTION ............................................. 16
SEMICONDUCTOR DATA .......................................... 20
DESCRIPTION OF COMPONENTS ............................ 22
PARTS LIST ................................................................. 23
EXPLODED VIEW ....................................................... 30
PACKING ..................................................................... 31
CONTENTS
Key top (DTMF)
(K29-9043-02)
ADJUSTMENT ............................................................. 32
PC BOARD VIEWS
DISPLAY UNIT (X54-3250-10) ............................... 41
TX-RX UNIT (X57-587X-XX) .................................. 43
SCHEMATIC DIAGRAM .............................................. 49
BLOCK DIAGRAM ....................................................... 53
LEVEL DIAGRAM ........................................................ 55
KNB-14/KNB-15A (Ni-Cd BATTERY) .......................... 56
OPTIONS ..................................................................... 57
SPECIFICATIONS ................................... BACK COVER
Antenna
(KRA-14:Option)
Knob (ENC)
(K29-5331-03)
Knob (VOL)
(K29-5332-03)
Cabinet assy
(A02-3568-23)
Knob (PTT)
(K29-5334-13)
Knob (Side1)
(K29-5333-13)


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TK-272G
2
GENERAL / SYSTEM SET-UP
INTRODUCTION
SCOPE OF THIS MANUAL
This manual is intended for use by experienced technicians
familiar with similar types of commercial grade communications
equipment. It contains all required service information for the
equipment and is current as of the publication date. Changes
which may occur after publication are covered by either Service
Bulletins or Manual Revisions. These are issued as required.
ORDERING REPLACEMENT PARTS
When ordering replacement parts or equipment information,
the full part identification number should be included. This
applies to all parts, components, kits, or 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 personnel
safety:
q
DO NOT transmit until all RF connectors are verified secure
and any open connectors are properly terminated.
q
SHUT OFF and DO NOT operate this equipment near
electrical blasting caps or in an explosive atmosphere.
q
This equipment should be serviced by a qualified technician
only.
SERVICE
This radio is designed for easy servicing. Refer to the
schematic diagrams, printed circuit board views, and alignment
procedures contained within.
SYSTEM SET-UP
Merchandise received
License and frequency allocated by FCC
Choose the type of transceiver
Transceiver programming
Are you using the optional antenna?
A personal computer (IBM PC or compatible), programming
interface (KPG-22), and programming software (KPG-56D)
are required for programming.
(The frequency, TX power HI/LOW, and signalling data are programmed
for the transceiver.)
YES
NO
KRA-14
Helical antenna
(Option)
Delivery
Are you using the speaker microphone?
YES
NO
KMC-17 or KMC-21
Speaker microphone
(Option)
TX/RX 150~174
5.0W
TK-272G K
Frequency range (MHz) RF power
Type
TX/RX 136~150
5.0W
TK-272G K2
Unit
Model &
TX-RX Unit
Display Unit
Frequency range
Remarks
destination
K
X57-5870-11
150~174MHz
IF1 : 49.95MHz
TK-272G
K2
X57-5870-13
X54-3250-10
136~150MHz
LOC : 50.4MHz


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TK-272G
3
OPERATING FEATURES
1. Operation Features
Programmable Auxiliary Functions
Side 1, Side 2,
°,·, 22222,and 33333canbeprogrammed
with the auxiliary functions listed below.
· Channel Down
· Channel Up
· Display Character
· Group Down 2
· Group Up 2
· Home Channel
· Key Lock
· Lamp
· Monitor A (Monitor Unmute­Momentary)
· Monitor B (Monitor Unmute­Toggle)
· Monitor C (Carrier Squelch­Momentary)
· Monitor D (Carrier Squelch­Toggle)
· None
· Operator Sel Tone 1
· Redial
· RF Power Lo
· Scan
· Scan Del/Add
· Talk-Around
· 2-Tone Encode
· Trunking Group Code Select 2
1 Available for K market models only.
2 Available only when using Trunking function.
2. Programmable keys
The functions the FPU programs to the function keys are
described in the following sections.
1) Channel up/down
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.
2) Display character
This key switches the LCD display between the group/
channel number and group/channel name.
3) 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.
Antenna
q
q
q
q
q
e
e
e
e
e
r
r
r
r
r
t
t
t
t
t
y
y
y
y
y
u
u
u
u
u
i
i
i
i
i
o
o
o
o
o
w
w
w
w
w
Microphone
Speaker
The transceiver is shown with the optional KNB-14 battery pack.
q
q
q
q
q Rotary encoder
Your dealer can program the encoder as either Group
Up/Down (only when the trunking board is installed)
or Channel Up/Down (default setting). Rotate to
select a group or channel. Also rotate to adjust the
squelch in Squelch Adjustment mode.
w
w
w
w
w LED indicator
Lights red while transmitting. Lights green while
receiving. Flashes orange while receiving a Code
Squelch or Selective Call code, or a 2-Tone or DTMF
signal that matches the one set up in your transceiver.
Flashes red when the battery power is low while
transmitting.
e
e
e
e
e Power switch/ Volume control
Turn clockwise to switch ON the transceiver. Rotate
to adjust the volume. To switch OFF the transceiver,
turn counterclockwise fully.
r
r
r
r
r PTT (Push-to-Talk) switch
Press this switch, then speak into the microphone to
call a station.
t
t
t
t
t Side 1 key
This is a PF (Programmable Function) key. Press it
to activate its auxiliary function.
y
y
y
y
y Side 2 key
This is a PF (Programmable Function) key. Press it
to activate its auxiliary function.
u
u
u
u
u
°,·,22222,33333keys
These are PF (Programmable Function) keys.
Press each key to activate its auxiliary function.
i
i
i
i
i SP/MIC jacks
Connect an optional speaker/ microphone here.
o
o
o
o
o Display
Note: The PF keys are programmed with default functions:
·
Side 1 key: Lamp
·
Side 2 key: Monitor A
·
°key: Scan
·
· key:
Scan Del/Add
·
2
2
2
2
2 key:
Talk Around
·
3
3
3
3
3 key:
RF Power Lo


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TK-272G
4
The "Add" channel is contained in the scan sequence, the
"Delete" channel is not contained. In the scan mode, this key
switches the channel between delete or add, temporarily.
13) Talk Around
Press this key, the transceiver uses the receive frequency
and tone for transmission.
The operator can call the other party directly (without
repeater). Press this key again, the talk around function
goes off.
14) None
An error operation beep sounds, and no action will occur.
Use this function when the transceiver is required to be
operated more simply.
3. Display
OPERATING FEATURES
4) Home Channel
Press this key once, the channel switches to the pre-
programmed home channel.
5) Key lock
When the KEY LOCK switch is held down for one second
or more, keys other than [PTT], [Side1], [Side2], [VOL],
[POWER], and KEY LOCK are locked.
When 12/16 KEY LOCK is set with the FPU, the DTMF
key is locked and when front-panel KEY LOCK is set, the
DTMF key and the [PF] key are locked.
6) Lamp
This key illuminates the LCD and keys on the front panel.
When the key is pressed, the LED lamp goes on.
When it is released, the lamp goes off after about five
seconds. If any key is pressed while the LED lamp is on,
the lamp is kept on for five seconds.
7) Monitor
Used to release signalling or squelch when operating in
conventional mode. It is also used to reset option signalling.
8) Operator Selectable Tone
This key switches the pre-set decode QT/DQT and encode
QT/DQT to OST (Operator Selectable Tone) tone pair.
Press this key, the transceiver enters OST mode. In this
mode, the display shows "OFF" and the operator can select
one of the OST tone pair using the tuning control. The display
shows "TONE
" and tone pair No. is selected.
Press OST key again, the transceiver exits from OST mode,
and returns to the group/channel mode.
16 tone pairs for OST can be programmed by KPG-56D.
OST is useful to access the repeater with same radio
frequency and different tone (QT/DQT).
9) 2-Tone Encode Select
1 Press the key programmed as 2-tone Encode Select.
· A pre-programmed 2-tone code name appears on the
display.
2 Press the key programmed as Rotary encoder to select
you desired 2-tone code name.
3 Press PTT switch and 2-Tone Encode Select key to transmit
and release them to receive.
10) RF power low
Used to temporarily switch transmission output to low power.
Turning the function on enables:
Hi
Low, LowLow
Key states are backed up, except in the PC mode when
they are reset.
11) Scan
Pressing this key starts scanning. Pressing this key again
stops scanning.
12) Scan Del/Add
This key switches the currently displayed channel between
"Delete" and "Add".
4. Scan Operating
1) Scan types
q
Single Group Scan
You can scan all valid (ADD) channels in the displayed group
that can be selected with the group selector.
Icon
Description
Appears while using Smar Trunk.
Appears when the selected channel is
busy.
Appears when QT, DQT, DTMF, or 2-
Tone decoding is deactivated (by
pressing the Monitor key).
Appears when you receive a Code
Squelch, Selective Call, 2-Tone, or
DTMF Signalling call. Also appears
when you transmit using Code Squelch
or Selective Call.
Appears while scanning.
Appears when using low power on the
selected channel.
Appears when the selected channel is
included in the scanning sequence.
Displays the selected channel, the
squelch level, DTMF digits (when
entering digits, confirming digits, or
making a call), and messages received
via Selective Call.


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TK-272G
5
OPERATING FEATURES
q
Multiple Group Scan
You can scan all valid (ADD) channels in all valid (ADD)
groups.
2) 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 function,
scan starts. The scan icon ("SCN") lights and "SCAN" is
indicated on display.
3) Scan Stop Condition
The scan stops temporarily if the following conditions are
satisfied.
1 The receiving signal matches the signalling code in your
radio that is set by the programming software (KPG-56D).
2 When the Monitor key is depressed.
4) Scan Channel Types
1 Priority channel is the most important channel for scan,
and always detects a signal during scan and when the scan
stops temporarily.
2 Non-priority channels detect a signal during scan. For the
channels that can be selected with the group or channel
selector when the scan does not occur, the "A" icon lights.
5) Priority Channel Setting
A priority channel can be set as follows with the programming
software (KPG-56D).
1 Specify a priority channel as a fixed priority channel.
2 Make a selected channel a priority channel.
Specify the initial channel before the operator changes it.
6) 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 channel
signal is detected at certain intervals.
If a priority channel stops temporarily, it stops until there is
no signal on the priority channel.
7) Revert Channel
The revert channel is used to transmit during scanning and
set by the programming software (KPG-56D).
1 Priority
The transceiver reverts to the priority channel.
2 Priority with 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 the current
channel to answer to the call however revert channel is set
to priority channel.
After resume time, scan re-starts and the transmission
channel returns to the 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
scan.
5 Last used channel
The transceiver reverts to the last used (transmitted)
channel during scan. "Last used" revert channel includes
talkback function.
6 Selected with talkback
The transceiver reverts to the channel before scanning or
the channel that you changed during scan.
8) Scan End
When you reactivate the key programmed to the scan
function during scan mode, scan ends.
The scan icon ("SCN") and "SCAN" or revert channel
(programmable) display goes off.
9) Temporarily Delete/Add
It is possible to delete or add a channel temporarily during
scan. When scan stops on an unnecessary channel, for
example by interference of the other party, press the delete/
add key, then that channel is deleted temporarily and scan will
re-start immediately.
When you would like to add a deleted channel temporarily
to the scan sequence, select the desired (deleted) channel
during scan, and press the delete/add key before scan re-starts.
That channel is added temporarily to the scan sequence.
The temporarily deleted or added channels are returned to
their pre-set delete/add conditions when the transceiver exits
from scan mode.
5. Details of Features
1) Time-out timer
The time-out timer can be programmed in 15 seconds
increments from 15 seconds to 300. If the transmitter 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.
2) PTT ID
PTT ID provides a DTMF ANI to be sent with the PTT button
every time it is used (Begin of TX ID at beginning of
transmission, End of TX ID at end of transmission, or both).
You can program the PTT ID as one of the followings.
Off, BOT (Begin of TX ID), EOT (End of PTT ID), BOTH.
The contents of ID are programmed for each channel.