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VHF FM TRANSCEIVER
TK-260G/270G
SERVICE MANUAL
© 1999-9 PRINTED IN JAPAN
B51-8493-00(S) 1425
Antenna
(T90-0679-05):M
Knob (CHANNEL SELECTOR) Knob (ENC)
(K29-5341-03) (K29-5331-03)
Knob (VOL) Knob (VOL)
(K29-5332-03) (K29-5332-03)
Cabinet assy
Cabinet assy
(A02-2391-23)
(A02-2385-23)
Knob (PTT) Knob (PTT)
(K29-5334-13) (K29-5334-13)
Knob (MONI) Knob (MONI)
(K29-5333-13) (K29-5333-13)
Key top (DTMF)
(K29-5330-02)
TK-260G
TK-270G
M market models are shown.
CONTENTS
GENERAL .........................
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TK-260G/270G GENERAL / SYSTEM SET-UP l SHUT OFF and DO NOT operate this equipment near INTRODUCTION electrical blasting caps or in an explosive atmosphere. SCOPE OF THIS MANUAL l This equipment should be serviced by a qualified technician This manual is intended for use by experienced technicians only. 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 SERVICE
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TK-260G/270G OPERATING FEATURES causes an error tone to sound. (When changing a 1. Operation Features channel from high to low power, all channels programmed with high power are changed to low.) • 2-Tone Encode Select: To transmit using a 2-Tone • TK-260G code, press the PTT switch and the 2-Tone Encode Power switch/ Channel selector Select key, then speak into the microphone in your Volume control Rotate to select a normal voice. Turn clockwise to channel (1 ~ 8). Release the PTT switch and 2
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TK-260G/270G OPERATING FEATURES u u u , , 222,333 keys u u 2233 2. Programmable keys • These are PF (Programmable Function) keys. Press The functions the FPU programs to the function keys are each key to activate its auxiliary function. described in the following sections. i i i i i DTMF keypad 1) Channel up/down (TK-270G only) Used for storing and transmitting DTMF numbers. When the key is pressed each time, the channel number to o o o o o SP/MIC jacks be selected is incremented/decremented
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TK-260G/270G OPERATING FEATURES 9) Reverse (REV) (Note: C type only) 3. Display (TK-270G only) When the REV switch is pressed, transmission can be performed with the receive frequency and receive signaling, and reception can be performed with the transmit frequency and transmit signaling. When REV is on, HORN ALERT and PUBLIC ADDRESS do not work. 10) Selectable QT (SEL QT) (TK-270G M types only) Icon Description When the SEL QT switch is pressed, QT frequency can be temporarily changed with the
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TK-260G/270G OPERATING FEATURES 3) Scan Stop Condition 6 Selected with talkback The scan stops temporarily if the following conditions are The transceiver reverts to the channel before scanning or satisfied. the channel that you changed during scan. 1 The receiving signal matches the signalling code in your radio that is set by the programming software (KPG-56D). 8) Scan End 2 When the Monitor key is depressed. When you reactivate the key programmed to the scan function during scan mode, scan en
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TK-260G/270G OPERATING FEATURES 4) Battery Warning 6. Option Signalling (DTMF/2 tone) This transceiver has a battery warning feature. If low voltage Built-in DTMF decoder is available for option signalling. is detected during transmission, the transceiver warns you by Built-in 2-Tone decoder is available for option signalling. a flashing red "LED". When the voltage is detected to be even lower during It is possible to use individual call, group call, DBD (Dead transmission, the transceiver stop
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TK-260G/270G OPERATING FEATURES / REALIGNMENT REALIGNMENT 7. Audible user feedback tones The transceiver outputs various combinations of tones to 1. Modes notify the user of the transceiver operating state. The main User mode tones are listed below The high tone is 1477Hz, the mid tone is 941Hz, and the Panel test mode Panel tuning mode (TK-270G only) low tone is 770Hz. PC mode Data programming • Power on tone mode Firmware This tone is output when the transceiver is turned on. (The programming
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TK-260G/270G REALIGNMENT 4. Checksum Executing this function, "TUNING" appears on the display of TK-270G while calculating the checksum . When the calculation is completed, the display returns to normal and PC displays the checksum of the radio. 5.PC Mode 5-1. Preface The TK-260G/270G transceiver is programmed using a personal computer, a programming interface (KPG-22) and programming software (KPG-56D). The programming software can be used with an IBM PC or compatible. Figure 1 shows the setup
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TK-260G/270G REALIGNMENT 9. If you want to continue programming other TK-260G/ Note: You can clone the programmed data between the 270Gs, repeat steps 5 to 8. tramsceiver listed below. Frequency version must be same. Notes: l To start the Firmware Programmer from KPG-56D, the Slave TK-260G TK-260G TK-760G TK-760G Fpro path must be set up by the KPG-56D Setup. KM K M l This mode cannot be entered if the Firmware Programming TK-270G TK-270G TK-762G TK-762G Master mode is set to Disable in th
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TK-260G/270G REALIGNMENT 8. Self Programming Mode (TK-270G only) Write mode for frequency data and signalling etc. Mainly X57-587X used by the person maintaining the user equipment. Compoent Side 8.1 Self programming mode setting Remove D17 from the TX-RX unit (Figure 3) (K models only). Hold down the [LAMP]+[l ] switches and turn the power switch on. When the self programming mode is entered, [SELF] appears on the display. The mode changes automatically to Model Select Mode and "PORTABLE" is
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TK-260G/270G REALIGNMENT l Flow Chart No. Function Choices Display Remarks Channel Setting Mode 3 TX frequency Step 2.5kHz-1MHz STP_250 Same as RX frequency. STP_1000 Self programming mode Blank ———— 100.0000- T.100.0000 [MON] [MON] 550.0000MHz Channel set mode Channel selection Group selection [3] 4 TX Signaling Same as RX signaling. 5 Option Signaling OFF NONE____ Default [2] [MON] DTMF DTMF____ RX frequency OFF [LAMP] 2-TONE 2TONE___ [LAMP] 6ID 000- ___ID___ Display when an item is selected
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TK-260G/270G REALIGNMENT 8-3. Function Setting Mode No. Function Choices Display Remarks This is a mode for using the panel keys to make function 2 [MONI] Monitor B MON_18 settings without using the FPU, that operate on all channels. Monitor C MON_19 Monitor D MON_20 Pressing the [LAMP] when "SELF" is displayed, sets the RF Power Low MON_21 Function Setting Mode. Scan MON_22 * TK-260G cannot be selected. Select an item set using [3] then change the selection with the encoder. Scan DEL/ADD MON_23
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TK-260G/270G REALIGNMENT No. Function Choices Display Remarks No. Function Choices Display Remarks Optional Feature 4 [ ]TK-270G Group Up KEY2_25 • 8 Power On Tone YES/NO PONT_YES Default:YES only Scrambler KEY2_26 Only when scrambler is set 9 Control Tone YES/NO CNTT_YES Default:YES 5[2]TK-270G No Function KEY3_OFF 10 Warning Tone YES/NO WART_YES Default:YES only Talk Around KEY3_3 Default 11 Time Out Timer OFF,15-300/15s Step TOT_60 Default:60s Display Character KEY3_5 12 TOT OFF,1-10/ TOTP_
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TK-260G/270G REALIGNMENT No. Function Choices Display Remarks When the [ ] switch is pressed while "SELF" is displayed, 34 D Key D Code DKA_D_CD Default the memory is reset. Assignment 1-16/1s DKA_16__ When the memory is reset, mode data and model data are 35 DTMF Code SQ DTMF_OFF Default not reset. Signaling SEL CALL DTMF_SEL The TK-260G cannot reset the memory. 36 Inter Mediaate 0-9,A-D,*,# IMC__#_ Default: # (Can be set only when l Flow Chart Code DTMF signaling = SEL CALL.) Function S
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TK-260G/270G DISASSEMBLY FOR REPAIR Separating the case assembly from the chassis. Separating the chassis from the unit. 1. Remove the two knobs and three round units . z x • TK-260G 2. Remove the two screws . c 1. Remove the twelve small screws , and the three large m 3. Expand the right and left sides of the bottom of the case screws . , assembly, lift the chassis, and remove it from the case 2. Remove the solder from the antenna terminal using a assembly . v soldering iron, then lift the uni
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TK-260G/270G CIRCUIT DESCRIPTION 3) IF Amplifier circuit 1. Frequency configuration The first IF signal is passed through a four-pole monolithic The receiver utilizes double conversion. The first IF is 49.95 crystal filter (XF1) to remove the adjacent channel signal. MHz and the second IF is 450 kHz. The first local oscillator The filtered first IF signal is amplified by the first IF amplifier signal is supplied form the PLL circuit. (Q22) and then applied to the lF system IC (IC4). The IF The P
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TK-260G/270G CIRCUIT DESCRIPTION (3) DTMF (High-speed data) 5) Audio amplifier circuit The DTMF input signal from the IF IC(IC4) is amplified by The demodulated signal from IC4 is amplified by IC16 (2/ 2), high-pass filtered, low-pass filtered, high-pass filtered, IC16(2/2) and goes to IC18, the DTMF decoder. The decoded band-eliminate filtered, and de-emphasized by IC14. information is then processed by the CPU. During The signal then goes through an AF amplifier IC15 (2/2), transmission and st
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TK-260G/270G CIRCUIT DESCRIPTION 3) UNLOCK DETECTOR ANT Q6 IC1 If a pulse signal appears at the LD pin of IC2, an unlock D3 From RF DRIVE ANT T/R SW condition occurs, and the DC voltage obtained form D1, LPF POWER AMP AMP SW (D5) R1, and C6 causes the voltage applied to the microprocessor VDD VGG +B to go low. When the microprocessor detects this condition, R56 the transmitter is disabled, ignoring the push-to-talk switch R57 input signal.(See Fig. 6) R58 IC3 IC3 (1/2) (2/2) APC 5C (IC13) Fig. 8
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TK-260G/270G CIRCUIT DESCRIPTION 3) Low battery warning 6. Control Circuit The battery voltage is monitored by the microprocessor The control circuit consists of a microprocessor (IC13) and (IC13). When the battery voltage falls below the voltage set by its peripheral circuits. It controls the TX-RX unit and transfers the Low Battery Warning adjustment, the LED flashes red to data to and from the display unit. IC13 mainly performs the notify the operator that it is time to replace the battery. I
