Text preview for : TKR-750k.pdf part of Kenwood TKR-750 Service Manual VHF FM Repeater (2001) - Type K, K2, E - (5.859Kb) 3 Part File - pag. 69



Back to : vhf_fm_repeater.part1.rar | Home

VHF FM REPEATER

TKR-750
SERVICE MANUAL
© 2001-1 PRINTED IN JAPAN B51-8556-00 (N) 1435
Knob (DC source) (K29-9106-04) Panel (Outer) (A62-0840-03) Knob (VOL) (K29-5389-03)

Panel assy (A62-0934-03)

Key top (K29-5460-02)

Modular jack (E08-0543-05)

CONTENTS
GENERAL .................................................. 2 SYSTEM SET-UP ...................................... 2 OPERATING FEATURES .......................... 3 REALIGNMENT ....................................... 11 INSTALLATION ....................................... 13 MODIFICATION ....................................... 15 DISASSEMBLY FOR REPAIR ................. 16 CIRCUIT DESCRIPTION .......................... 17 SEMICONDUCTOR DATA ...................... 23 DESCRIPTION OF COMPONENTS ........ 25 PARTS LIST ............................................. 27 EXPLODED VIEW .................................... 37 PACKING ................................................. 39 ADJUSTMENT ........................................ 40 TERMINAL FUNCTION ........................... WIRING .................................................... PC BOARD VIEWS RX PLL/VCO (X58-4780-10) ................ TX PLL/VCO (X58-4790-10) ................ DISPLAY UNIT (X54-3330-20) ............ FINAL UNIT (X45-3620-XX) ................ TX-RX UNIT (X57-6260-XX) (A/2) ...... TX-RX UNIT (X57-6260-XX) (B/2) ...... SCHEMATIC DIAGRAM .......................... BLOCK DIAGRAM ................................... KES-4 (EXTERNAL SPEAKER) ............... SPECIFICATIONS .................................... 47 51 53 54 55 59 65 71 77 89 92 93

TKR-750
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.

PERSONNEL SAFETY
The following precautions are recommended for personnel safety : · DO NOT transmit until all RF connectors are verified secure and any open connectors are properly terminated. · SHUT OFF and DO NOT operate this equipment near electrical blasting caps or in an explosive atmosphere. · This equipment should be serviced by a qualified technician only.

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.

SERVICE
This radio is designed for easy servicing. Refer to the schematic diagrams, printed circuit board views, and alignment procedures contained in this manual.

SYSTEM SET-UP
Merchandise received Choose the type of transceiver Frequency range (MHz) TX/RX 146~174 TX/RX 136~150 RF power 50W 50W Type K,E K2

See page 11. Repeater A personal computer (IBM PC or compatible), programming interface (KPG-46), programming & setup and programming software (KPG-66D) are required for programming. DC power supply or duplexer? NO YES

Installation in the optional space

External speaker? NO

YES

KES-4 installation

Delivery

2

TKR-750
OPERATING FEATURES
1. Controls and Functions
1-1. Front Panel
1 2 3 4 5

9

8

7

6

1 Speaker 2 CH/STATUS Display
Two, 7-segment digits display the channel number or status.

7 Programmable Function keys
Press these keys to activate their programmable functions.
PF1 key (left side) PF2 key PF3 key PF4 key PF5 key PF6 key (right side) Default : None (No function) Default : Repeat disable/enable Default : TX disable/enable Default : Take over Default : Monitor on/off Default : Channel up

3 VOLUME control
Rotate to adjust the volume.

4 DC source switch 5 Dc source indicator
Lights green when DC source is applied from the DC 13.6V jack (DC 13.2V jack on E type versions). Lights red when DC source is applied from the BACK UP battery terminal.

8 BUSY indicator
Lights green while a signal is being received.

6 MIC jack
Connect a microphone to this 8-pin modular jack.

9 TX indicator
Lights red while transmitting.

1-2. Rear Panel
1 2 8 3 4 9

7

6

5

1 TX OUT jack
Connect a TX antenna or a duplexer to this receptacle.

5 DC 13.6V (K type) / DC 13.2V (E type) jack
Connect a 13.6 V (K type) or 13.2 V (E type) DC power supply to this jack.

2 CONTROL I/O jack
Connect an external programming device or repeater controller to this DB-25 interface.

6 BACKUP battery terminal 7 TEST/SPKR jack
Test input/output jack. Connect an external speaker to this jack.

3 FUSE
Insert 15 A blade fuses into these fuse holders.

4 RX IN jack
Connect a RX antenna or a duplexer to this BNC receptacle.

8 Cooling fan 9 Optional space
For external DC power supply, or duplexer, etc.

3

TKR-750
OPERATING FEATURES
2. Two 7-segment LED displays
· Channel display (1~16) : While operating normally in user mode. · "E2" is displayed when the channel data is not written.

· When the displayed channel is contained in scan sequence, the right side decimal point is displayed.

· "E3" is displayed when PLL is unlocked. Receiver PLL unlocked = flashing BUSY LED. Transmitter PLL unlocked = flashing TX LED.

· When the displayed channel is the priority channel, the left side decimal point is displayed.

· "E4" is displayed when PTT is attempted on a channel number that has no frequency data programmed.

· "SC" is displayed while in scan mode. · "PC" is displayed while in PC mode.

· "PG" is displayed while in firmware programming mode. 2 decimal points displayed = 115,200bps 1 decimal point displayed = 57,600bps No decimal = 38,400bps

· "E1" is displayed when FPU data is not written.

4

TKR-750
OPERATING FEATURES
3. Programmable Functions
TKR-750 contains many Programmable Functions tabled below.
Programmable Function AUX Out 1~5 Off AUX I/O 1~6 Off AUX Out 1~5 On AUX I/O 1~6 On AUX Out 1~5 On/Off AUX I/O 1~6 On/Off Channel 1~16 Channel Down Channel Up CW ID On CW Message 1~8 On Display Off Display On Display On/Off Description AUX Out 1 to 5 ports become deactivated, respectively. AUX I/O 1 to 6 ports become deactivated, respectively. AUX Out 1 to 5 ports become activated, respectively. AUX I/O 1 to 6 ports become activated, respectively. AUX Out 1 to 5 ports are toggled between its active and inactive states, respectively. AUX I/O 1 to 6 ports are toggled between its active and inactive states, respectively. Directly select Channel 1 to 16, respectively. The channel decrements by one. The channel increments by one. The CW ID is transmitted. The CW Message 1 to 8 is transmitted, respectively. All panel LEDs are turned off except the Power LED. All panel LEDs become active as normal status indicators on the repeater. All panel LEDs, with the exception of the Power LED, are toggled between off and their normal status on the repeater. Hold Time Enable Hold Time Disable Hold Time Disable/Enable Local Tx Disable Local Tx Enable Local Tx Disable/Enable Monitor Off Monitor On Monitor On/Off Monitor Momentary Multi Table Sub Multi Table Main Multi Table Main/Sub QT/DQT Dec Disable QT/DQT Dec Enable QT/DQT Dec Disable/Enable QT/DQT Enc Disable QT/DQT Enc Enable QT/DQT Enc Disable/Enable Repeat Disable Repeat Enable Repeat Disable/Enable Reset DC Power Save Off DC Power Save On DC Power Save On/Off The Parameter of Repeat Hold Time is enabled. The Parameter of Repeat Hold Time is disabled. The Parameter of Repeat Hold Time is toggled between disabled and enabled. The local mic's PTT is disabled. The local mic's PTT is enabled. The local mic's PTT is toggled between disabled and enabled. The QT/DQT decoder is disabled. The QT/DQT decoder is enabled. The QT/DQT decoder is toggled between disabled and enabled. The QT/DQT decoder is momentarily disabled. Multi Table No. Select Signalling changes to the Multi Table Sub. Multi Table No. Select Signalling changes to the Multi Table Main. Multi Table No. Select Signalling changes between Multi Table Sub and Multi Table Main. Disables the QT/DQT decode operation. Enables the QT/DQT decode operation. Toggles between disabling and enabling the QT/DQT decode operation. Disables the QT/DQT encode operation. Enables the QT/DQT encode operation. Toggles between disabling and enabling the QT/DQT encode operation. Disables repeater operation. Enables repeater operation. Toggles between disabling and enabling repeater operation. Resets to default condition set up by FPU. Activates DC Power Save Mode Off. Activates DC Power Save Mode On. Toggles between DC Power Save Mode On and Off.

5

TKR-750
OPERATING FEATURES
Programmable Function Scan Off Scan On Scan On/Off Scrambler Off Scrambler On Scrambler On/Off Squelch Off Squelch On Squelch On/Off Squelch Momentary Take Over On/Off Test Tone Off Test Tone On Test Tone On/Off TOT Disable TOT Enable TOT Disable/Enable TX Disable TX Enable TX Disable/Enable Inhibits scanning. Starts scanning. Scanning is toggled between being enabled or inhibited. Disables an installed optional voice scrambler board. Enables an installed optional voice scrambler board. Toggles between enabling and disabling an installed optional voice scrambler board. The Squelch unmutes. The Squelch mutes. The receiver's squelch toggles between muted and unmuted. The Squelch momentarily unmutes. Toggles between disabling and enabling remote wireline control. The Test Tone is inhibited. The Test Tone is enabled. Toggles between enabling and inhibiting the Test Tone. The Time Out Timer is disabled. The Time Out Timer is enabled. The Time Out Timer is toggled between disabled and enabled. The transmitter is inhibited. The transmitter is enabled (normal). Toggles between transmitter inhibited and transmitter enabled (normal). Description

The following Programmable Functions are output functions used to tell the condition of the TKR-750 to an external device. The output functions can be assigned to only AUX Outputs as follows.
Programmable Function COR (Carrier Operate Relay) TOR (Tone Operate Relay) RX Unlock TX Unlock Power Supply Lower Limit Description This function becomes valid if an RF carrier is present. This function becomes valid if an RF carrier and the specified QT/DQT are present. This alarm function becomes valid if the RX PLL circuitry becomes unlocked. This alarm function becomes valid if the TX PLL circuitry become unlocked. This alarm function becomes valid if the DC power supply voltage becomes less than the preset point. The preset point is selected in the range of 10.6V to 13.6V. TXS (TX Sense) Selectable This function becomes valid when the transmitter is keyed. AUX Outputs which are set up as Selectable appear in the available Function List for the AUX Input Functions and Key Assignment. This allows AUX Inputs and PF Keys to be used to control AUX Outputs. RX Signal Detect This function becomes valid if the RX signal level becomes less than the preset point. The preset point is selected in the range of ­120dBm to ­95dBm. RF Power Down Detect Fan Status This alarm function becomes valid if the RF Power becomes less than about 10W. This alarm function becomes valid when the Fan is turned on, either by sensing a high temperature condition or by its operating mode being set to Continuous.

6

TKR-750
OPERATING FEATURES
4. Trigger Assignment
The Programmable Functions described above can be assigned to PF keys, AUX input, Save on/off, Start up, and Power supply according to following table. In the last column of the table, when the Programmable Functions is assigned to any PF keys, it expresses that the LED in the PF key turns on either conditions. "Yes" expresses that the trigger is available the Programmable Function. "No" expresses that the trigger is not availabale the Programmable Function.
Trigger Function AUX Out 1~5 (I/O 1~6) Off AUX Out 1~5 (I/O 1~6) On AUX Out 1~5 (I/O 1~6) On/Off Channel 1~16, Up/Down CW ID On CW Message 1~8 On Display Off Display On Display On/Off Hold Time Enable Hold Time Disable Hold Time Disable/Enable Local Tx Disable Local Tx Enable Local Tx Disable/Enable Monitor Off Monitor On Monitor On/Off Monitor Momentary Multi Table Sub Multi Table Main Multi Table Main/Sub QT/DQT Dec Disable QT/DQT Dec Enable QT/DQT Dec Disable/Enable QT/DQT Enc Disable QT/DQT Enc Enable QT/DQT Enc Disable/Enable Repeat Disable Repeat Enable Repeat Disable/Enable Reset DC Power Save Off DC Power Save On DC Power Save On/Off Scan Off No No Yes Yes Yes Yes No No Yes No No Yes No No Yes No No Yes Yes No No Yes No No Yes No No Yes No No Yes Yes No No Yes No PF keys AUX input Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes No Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Save on/off Yes Yes No Yes Yes Yes Yes Yes No Yes Yes No Yes Yes No Yes Yes No No Yes Yes No Yes Yes No Yes Yes No Yes Yes No No No No No Yes Yes Yes No Yes Yes Yes Yes Yes No Yes Yes No Yes Yes No Yes Yes No No Yes Yes No Yes Yes No Yes Yes No Yes Yes No No Yes Yes No Yes Start up Power supply Yes Yes No Yes Yes Yes Yes Yes No Yes Yes No Yes Yes No Yes Yes No No Yes Yes No Yes Yes No Yes Yes No Yes Yes No No Yes Yes No Yes ­ ­ Turns on in ON status. Do not turn on. Turns on while transmitting. Turns on while transmitting. ­ ­ Turns on in ON status. ­ ­ Turns on in Disable status. ­ ­ Turns on in Disable status. ­ ­ Turns on in ON status. Turns on in ON status. ­ ­ Turns on in Sub status. ­ ­ Turns on in Disable status. ­ ­ Turns on in Disable status. ­ ­ Turns on in Disable status. Do not turn on. ­ ­ Do not turn on. ­ Condition of LED in he PF key on

7

TKR-750
OPERATING FEATURES
Trigger Function Scan On Scan On/Off Scrambler Off Scrambler On Scrambler On/Off Squelch Off Squelch On Squelch On/Off Squelch Momentary Take Over On/Off Test Tone Off Test Tone On Test Tone On/Off TOT Disable TOT Enable TOT Disable/Enable TX Disable TX Enable TX Disable/Enable None No Yes No No Yes No No Yes Yes Yes No No Yes No No Yes No No Yes Yes PF keys AUX input Yes Yes Yes Yes Yes Yes Yes Yes No No Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Save on/off Yes No Yes Yes No Yes Yes No No No Yes Yes No Yes Yes No Yes Yes No Yes Yes No Yes Yes No Yes Yes No No No Yes Yes No Yes Yes No Yes Yes No Yes Start up Power supply Yes No Yes Yes No Yes Yes No No No Yes Yes No Yes Yes No Yes Yes No Yes ­ Turns on in ON status. ­ ­ Turns on in ON status. ­ ­ Turns on in OFF status. Turns on in OFF status. Turns on in ON status. ­ ­ Turns on in ON status. ­ ­ Turns on in Disable status. ­ ­ Turns on in Disable status. Do not turn on. Condition of LED in he PF key on

5. Simplex/Duplex Operation
The Simplex/Duplex function is used to specify whether the channel is used as simplex (receiver muted during transmit) or duplex (receiver unmuted during transmit). If the channel has same TX/RX frequency, it can operate only in Simplex mode.

6. Repeater/Base Station Operation
The Repeat function is used to specify whether the channel is used as a repeater or as a base station. A repeater simultaneously and automatically re-transmits its received audio, a duplex base station has independent simultaneous transmit and receive paths, a simplex base station are mutually exclusive transmit and receive paths.

7. Signalling Feature
7-1. Multiple QT/DQT
The TKR-750 can function as a multiple-QT/DQT decode/ encode unit for operation as a community repeater or multiple-QT/DQT base station. Two Multi Tables, called Main and Sub, can be created, each consisting of 16 decode/encode combinations.

The Multi Table function enables the TKR-750 to decode any one of the 16 QT/DQTs pre-programmed into the Multi Table. When receiving a signal (repeater operation), the repeater uses the QT/DQT encode which corresponds to the decoded QT/DQT as set in the Multi Table. In the Multi Table, signalling pair of "No.1" (first column) is defined as "Primary". A receiving signalling (if it is contained within No.1 to No.16) is defined "Current". From No.2 to No.16, signalling pairs that can be changed between "Main Table" and "Sub Table" using AUX I/O Ports 1-4 are assigned as "Multi Table Select" and the Multi Table Main, the Multi Table Sub or the Multi Table Main/Sub function is executed. When AUX I/O Ports 1~4 are set for "Multi Table Select", these are 4 bit Binary Coded Decimal (BCD) inputs .AUX I/O 1 is a least significant bit (LSB), and "1101" input (LSB on the right side) signifies the Table No.2 and "1100" input signifies the Table No.3.

7-2. Encode Tone in Multiple
When Local Microphone PTT or External PTT is active while the repeater is in use or the duplex-base station is receiving, the encode signalling is determined according to Encode Tone in Multiple function. The simplex-base station always transmits the "Primary" encode QT/DQT.

8

TKR-750
OPERATING FEATURES
Current : When any PTT as described above is active while the repeater is in use or the duplex-base station is receiving, the "paired" encode QT/DQT associated with receiving QT/DQT is transmitted. When any PTT is active while the repeater or the duplex-base station is in idle period, the "Primary" encode QT/DQT is transmitted. Primary : When any PTT (provided that the Priority of any PTT is higher than the Priority of Repeat PTT) is active while the repeater is in use, the encode QT/DQT changes "paired" encode QT/DQT to "Primary" while continuing to transmit. When any PTT is active while the repeater is in idle period, the "Primary" encode QT/DQT is transmitted. In the base station, the "Primary" encode QT/DQT is always transmitted regardless of the receiver status. 1) if a RF carrier and a valid QT/DQT is present. The receiving channel number is displayed and the received audio is heard from a speaker. 2) if a RF carrier is present, providing that the Monitor On function is executed. 3) if the Squelch Off function is executed. Scanning stops on the channel being scanned when Squelch Off is executed, the channel number is displayed and the received audio is heard from a speaker. 4) if a local microphone's hook is in off hook status, providing that the Off Hook Scan function is set to Disable. Scanning stops on the Revert channel, but the audio is not heard until a valid signal is received. When the received call is ended, scanning automatically resumes after the period set in Dropout Delay Time function has expired. When the Scan Off function is executed, the TKR-750 inhibits scanning and displays the selected channel.

7-3. QT Reverse Burst Time
During repeat with QT tones, the repeater re-transmits a phase-shifted burst of the QT tone ("reverse burst") when it detects the radio using the repeater has un-keyed and also sent a reverse QT burst (squelch-tail elimination). This mutes a receiving radio's speaker audio before its receiver circuit shuts off causing squelch tail noise in the speaker audio. The TKR-750 can select the time between 140 to 200 ms that the QT reverse burst is sent. Typically this time should not have to be adjusted from the default value. The transmission of the QT reverse burst can be also inhibited if the QT Reverse Burst function is set to "No".

8-2. Scan Sequence
1) Normal Scan : When no Priority channel is set, scanning of ADD channels is done in ascending order. 2) Single Priority Scan : The Priority channel is set as either a fixed channel or a selected channel. When Priority channel is set, Priority channel and non Priority channel are scanned by turns. When scanning stops on the non Priority channel, calls from the Priority channel are still checked at set intervals while scanning is stopped. This operation is called Look Back and the interval period is selected by the Look Back Time function.

7-4. DQT Turn Off Code Time
During repeat with DQT tones, the repeater re-transmits a specific turn-off code when it detects the radio using the repeater has un-keyed and also sent the turn-off code (squelch-tail elimination). This mutes a receiving radio's speaker audio before its receiver circuit shuts off causing squelch tail noise in the speaker audio. The TKR-750 can select the time between 140 to 200ms that the DQT turn-off code is sent. Typically this time should not have to be adjusted from the default value.

8-3. Revert Channel
The Revert channel is a channel that is used to transmit during scanning. The time from the end of transmission on Revert channel to the time scanning automatically resumes is set in Dwell Time function. The Revert channel types are Last Called, Last Used, Selected, Selected + TalkBack, Priority, and Priority + TalkBack. 1) Last Called : The TKR-750 reverts to the channel upon which a call was last received even if scanning has resumed (power on default = selected channel). 2) Last Used (with TalkBack) : The TKR-750 reverts to the channel that was last transmitted on (power on default = selected channel). However, if a call is received on a channel other than the last transmit channel and PTT is pressed before scanning resumes, the transceiver "talks back" on the current receive channel. 3) Selected : The transceiver reverts to the channel set by the function prior to scan initiation. 4) Selected+TalkBack : The TKR-750 reverts to the channel set by the Channel `X' functions or Channel Select function prior to scan initiation. However, if a call is received on a channel other than the selected channel and PTT is pressed before scanning resumes, the transceiver "talks back" on the current receive channel. 5) Priority : The TKR-750 always reverts to the Priority channel.

7-5. Off Hook Decode
The TKR-750 is able to decode QT/DQT regardless whether the local microphone is in the on- or off-hook condition. When the Off Hook Decode function is enabled, the TKR-750 is capable of QT/DQT decode even though the microphone is in the off-hook condition (or a local microphone is not installed).

8. Scan Feature
8-1. Scan Operation
Providing that the TKR-750 contains two or more non-priority ADD channel or one or more non-priority ADD channel and Priority channel, it starts scanning once the Scan On function is executed and displays "SC" on the 7-seg LED. Scanning stops temporarily if any following conditions be come valid.

9

TKR-750
OPERATING FEATURES
6) Priority+TalkBack : The TKR-750 always reverts to the Priority channel. However, if a call is received on a channel other than the Priority channel and PTT is pressed before scanning resumes, the transceiver "talks back" on the current receive channel.

13. Take Over
The Take Over function is used to disable the external wireline control of the repeater. When Take over function is enabled, the external AUX inputs and Outputs, transmit audio inputs and receive audio outputs, External PTT and External Monitor lines are disabled. All AUX Input functions assigned to any AUX Input stay in their current state. However External PTT and External Monitor switch to the "Off" state.

9. CW ID and Message
The TKR-750 contains internal automatic station identifiers. The CW ID (Morse code) is set and transmitted on a per-channel basis. The CW ID is transmitted when the interval period is reached (TX Interval Time function), the channel is changed (CW ID on Channel Change function) or CW ID Onfunction is executed. When CW ID is activated by any functions described above, it is actually sent after the total time of TX Delay Time (not applied to CW ID On function) and CW Modulation Delay Time has expired. TX Delay Time is a period from CW ID is activated to the transmitter is keyed. CW Modulation Delay is a period from the transmitter is keyed to the CW ID tone is sent. The CW ID tone is routed to the Receive Audio (RA) port and a speaker if the Send CW ID to RA function is set to Yes. The TKR-750 contains 8 message banks for CW Message. CW Message 1 to 8 is transmitted on the current channel when the CW Message 1 to 8 On function is activated, respectively.

14. Test Tone
The Test Tone is a single-frequency audio sine wave and is turned On and Off by toggling Test Tone On/Off functions. The transmitter can be modulated without a local microphone by using the test tone. When Test Tone On function is executed and any PTT is activated, the TKR-750 transmits the test tone with mic mute and also routes the test tone to RA port.

15. RF Power
The TKR-750 is able to switch transmission output on a per-channel basis. When the TX High Power function is enabled, the transmission output is set to high power.

10. PTT Priority
A number of keying sources can be used to cause the TKR-750 to transmit. The transmit audio path is switched according to their keying sources and when PTTs is simultaneously activated, the transmit audio path related to the PTT with higher priority is given priority. These are Local Microphone PTT, External PTT, and Repeat PTT.

16. Fan Action
The TKR-750 has a cooling fan. The Fan Action function determines whether the fan is continuously operated or operates in response to high temperatures only.

17. AUX Input and Output
There are 6 programmable AUX I/O Ports 1~6 (pins 20~25) and 3 programmable AUX Input Ports 1~3 (pins 4~6) on the rear 25 pin D-Sub connector (CONTROL I/O) and 5 programmable AUX Output Ports 1~5 (pins 10, 11, 13~15) on the rear 15 pin TEST/SPKR connector. The 6 programmable AUX I/O pins are primarily intended for remote control interfaces. Each AUX I/O Port can be set for AUX Input, AUX Output, remote Channel Select or Multi Table Select types. The AUX Input Port can be set execute a single input function or a set of up to three functions when the port is activated. If the port type for an AUX I/O Ports 1~6 is set for "AUX Input", it will also appear AUX Input window for function programming. The input logic is fixed as active Low. The AUX Output Port can be set execute a single output function. If the port type for an AUX I/O Ports 1~6 is set for "AUX Output", it will also appear AUX Output window for function programming. The output logic of AUX Output can be set as either active High or active Low by the Logic Type function. Active High outputs a High (5V) when the programmed condition becomes valid, active Low outputs a Low (0V) when the condition becomes valid.

11. Time Out Timer
The Time Out Timer function determines the period of time users can continuously transmit. When the selected period expires, the transmission is inhibited.

12. Repeat Hold Time
The Repeat Hold Time (hang timer) function is used to prevent the repeater from being repeatedly keyed and unkeyed in response to short message traffic. When a mobile transceiver unkeys, the repeater's Hold Timer allows the repeater to continue transmitting for a brief period while waiting for a responding end user. If no valid QT/DQT is detected within the Hold Timer period, the transmitter is allowed to unkey. This function determines the period of time that the transmitter is allowed to remain keyed after the loss of a valid QT/DQT received signal.

10

TKR-750
OPERATING FEATURES / REALIGNMENT
18. Channel Select
AUX I/O Ports 1~4 (1 or all 4) can each be set for "Channel Select" providing up to 16 channel selection capability. These are 1 to 4 bit Binary Coded Decimal (BCD) inputs. AUX I/O 1 is a least significant bit (LSB). When all of AUX I/ O Ports 1~4 set to Channel Select, "1110" input (LSB on the right side) signifies the Channel 1 and "1101" input signifies the Channel 2.When the Channel Select function is set to any AUX I/O ports, the Channel `X' function (Channel Up, Channel Down, Channel 1, etc.)can not be set to the AUX Input ports, but can be set to the PF Keys. Normally the channel control is controlled by the Channel Select function. If the Take Over function is executed, the channel control is disabled to be controlled by the Channel Select and enabled to be controlled by the PF Keys.

REALIGNMENT
1. Modes
User mode PC mode PC programming mode PC test mode Firmware Programming mode PC tuning mode

Mode User mode PC mode

Function Use this mode for normal operation. Use this mode to make various settings by means of the FPU through the RS-232C port.

19. DC Power Save
The TKR-750 has the DC Power Save feature. The DC Power Save Mode is activated when the DC Power Save On function is executed. When the DC Power Save Mode is activated, all panel LEDs except the Power LED are turned off, and the audio amplifier and the DSP becomes inactive. When the Display On function is executed while the repeater is in the DC Power Save Mode, all panel LEDs become active as normal status indicators on the repeater, and the audio amplifier and the DSP becomes active. However, when the Save Delay Timer A period expires, all panel LEDs except the Power LED are turned off and the audio amplifier becomes inactive again, and when the Save Delay Timer B period expires, the DSP becomes inactive. When the DC Power Save Mode is turned on or off, up to 3 functions preprogrammed into the Save On function or Save Off function are executed in sequence.

PC programming mode PC test mode

Use to read and write frequency data and other features to and from the repeater. Use to check the repeater using the PC. This feature is included in the FPU.

Firmware programming mode

Use when changing the firmware program of the flash memory.

2. How to Enter Each Mode
Mode User mode PC mode Firmware Programming mode Power on. Received commands from PC. [PF1] key + Power on (one second). Operation

20. Power Supply
The TKR-750 is able to use two Power sources that are called Main and Backup. When the Power source changes from Main to Backup or from Backup to Main, up to 3 functions pre-programmed into the Backup Power function or the Main Power function are executed in sequence.

3. PC Mode
3-1. Preface
The TKR-750 repeater is programmed by using a personal computer, programming interface and KPG-66D software.

21. Start Up
When the TKR-750 is first turned on or is reset, up to 3 functions pre-programmed into the Start Up function are executed in sequence.

3-2. Connection Procedure
1. Connect the TKR-750 to the personal computer with the interface cable. 2. When power is applied, the user mode is entered immediately. When the PC sends a command, the repeater enters the PC mode and displays "PC" on the 7-segment LED. When data is being transmitted to the PC from the repeater, the TX LED flashes. The BUSY LED flashes when data from the PC is being received by the repeater.

22. Optional Board
An optional scrambler board can be installed in the TKR750. Scrambler codes between 1 and 16 are available per channel. If the scrambler board is not to be used (although it is installed), set the parameter to "Off". When any Scrambler code is set up and the Scrambler On function is executed, the scrambler board is activated.

Note :
· The data stored in the personal computer must match the model type, when it is written into the flash memory. · Change the TKR-750 to PC mode, then attach the interface cable.

11

TKR-750
REALIGNMENT
3-3. KPG-46 Description (PC Programming Interface Cable : Option)
The KPG-46 is required to interface the TKR-750 to the computer. It has a circuit in its D-sub connector (25-pin) case that converts the RS-232C logic level to the TTL level. The KPG-46 connects the microphone connector of the TKR-750 to the computer's RS-232C serial port.

4. Firmware Programming Mode
4-1. Preface
The TKR-750 uses flash memory to allow it to be easily upgraded when new features are released in the future.

4-2. Connection Procedure
Connect the TKR-750 to the personal computer (IBM PC or compatible) with the interface cable (KPG-46). (Connection is the same as in the PC mode.)

3-4. Programming Software Description
The KPG-66D programming disk is supplied in 3-1/2" disk format. The software on the disk allows a user to program TKR-750 repeater via the programming interface cable (KPG46).

Notes :
You can only program firmware from the 8-pin microphone connector on the front panel. Using the 25-pin logic interface on the rear panel will not work.

3-5. Programming With IBM PC
Data can be programmed into the flash memory in RS232C format via the microphone connector.
IBM PC

4-3. Programming
1. Start up the programming software (Fpro. exe). 2. Set the communications speed (normally, 115200 bps) and communications port in the configuration item. 3. Set the firmware to be updated by file name item. 4. Turn the TKR-750 power on with the [PF1] key held down. Hold the key down for one second until the 7segment display changes to "P.G.". When "P.G." appears, release your finger from the key. 5. Check the connection between the TKR-750 and the personal computer, and make sure that the TKR-750 is in the program mode. 6. Press write button in the window. A window opens on the display to indicate progress of writing. 7. If writing ends successfully, the TX LED on the TKR-750 lights. 8. If you want to continue programming other TKR-750s, repeat steps 3 to 6.

KPG-46

KPG-66D

TKR-750

Fig. 1

Notes :
This mode cannot entered if the firmware program mode is set to disable in the programming software (KPG-66D).

4-4. Function
If you press the [PF1] key (front panel), both decimal point on the 7-segment display will disappear. The writing speed is 38400 bps (low-speed mode). If you press the [PF1] key again, the right hand decimal points will light. The writing speed is 57600 bps (middle-speed mode).

Note :
Normally, write in the high-speed mode (115200 bps).

12

TKR-750
INSTALLATION
1. External Power Supply Connection (Rear Connectors) : See Page 3
This unit has two external power supply connectors : Main DC and Backup. If an external DC power supply is connected to the main DC connector and a backup battery is connected to the Backup connector at the same time, the DC power supply switches to the battery automatically if power failure occurs. Therefore, the operation of the repeater can be continued. If the battery is used, but both the battery and power supply need not be connected (if an external switch is used or if only a solar battery is used), connect it to the Backup connector, not the Main DC connector. Current consumption can be reduced by approx. 120mA because the relay is not used. If it is installed when the temperature at the repeater site is below freezing, check whether the switch (relay) works properly after installation.
TX-RX unit (B/2) control section Component side

R653

CN604

R742

1

CN606

CN601

CN605

2. Voice Scrambler
It operates only during base operation. The voice is not scrambled when it is repeated.

14

Fig. 1
CN601 1 TXI (MIC signal input) TXO (MIC signal output) RXI (RX audio signal input) AC (Audio control signal output) BC1 (Scramble code output 1) BC2 (Scramble code output 2) BC3 (Scramble code output 3) BC4 (Scramble code output 4) PTI (PTT signal input) CLRC (Clear code for scrambler) DEO (Detection signal output) PTO (PTT signal output) 5C (5V output) GND 14 Voice scrambler

2-1. Modification
1) Remove R742 and R653 on the TX-RX unit (B/2) : control section.

2-2. Connection
1) The functions of pins of CN601 on the TX-RX unit (B/2) : control section are shown in the figure. 2) Join the CN601 connector to the voice scrambler board via the E37-0808-05 connector cable. When the operation is checked in PC test mode after the modification, and the maximum deviation is adjusted, the voice from the local microphone is not modulated. In this case, remove the CN601 12-pin (PTO) cable and connect it to the land of the display unit (X54-333) from the voice scrambler. The voice from the local microphone can be modulated in PC test mode.

Display unit

Fig. 2

Display unit Foil side

PTO

Fig. 3

13

TKR-750
INSTALLATION
3. External Speaker (KES-4)
The TKR-750 has a internal built-in speaker (5W/8), and the external speaker output from the TEST/SPKR connector (15-pin) on the rear of the radio is 4W/4. Use external speaker KES-4.

3-1. Connection for the KES-4 With the TKR-750 s When taking the AF output from the TEST/ SPKR connector (15-pin) on the rear of the radio
The following tools are required for changing the connector.

Fig. 4-1

· Extracting tool
The following extracting tool is recommended : Molex Inc. Order No. : 11-03-0002 1. Remove the connector with jumper from the external speaker connector on the rear panel of the radio. (Fig. 41) Note : Save the jumper, which is required when the radio is used without the external speaker. 2. Remove the terminals with the jumper from the connector housing holes number 9 and 12 using the extracting tool.

Removing the jumper lead (Fig. 4-2)
1) Insert the extracting tool (11-03-0002) into the connector while pushing the jumper lead in the direction of (a). 2) Push the extracting tool into collapse the barbs of the crimp terminal. 3) Pull out the lead while continuing to push the extracting tool in the direction (b). 3. Reinsert the terminal with the black and white stripe lead into hole number 12, and the terminal with the black lead into hole number 6. (Fig. 4-3) 4. Attach the connector to the external speaker connector on the radio.

Fig. 4-2

Note :
Relationship between TEST/SPKR connector (15-pin) connection and speaker output. When pins 9 and 12 are shorted : Built-in internal speaker is used. When pins 9 and 12 are open and output is from pins 6 and 12 : KES-4 is used.

Fig. 4-3

14

TKR-750
MODIFICATION
1. Modification for Sinking the Collector Current Up
Auxiliary output 1 and 2 can each be modified to sink up 600mA of the collector current. The following modification should be installed when Auxiliary output 1 or 2 is used to control external equipment. 1. Remove D625, R755, and R769 for Auxiliary output 1 (D624, R756, and R770 for Auxiliary output 2) on the component side of the control section for TX-RX unit PCB. 2. Install $Q608, $Q612, and $R761 for Auxiliary output 1 ($Q607, $Q611, and $R759 for Auxiliary output 2) on the component side of the control section for TX-RX unit PCB. $Q607, $Q608, $Q611, $Q612 : DTD114EKA $R759, $R761 : 3.9k (RK73GB1J392J) chip resistor. 3. Change R801 for Auxiliary output 1 (R797 for Auxiliary output 2) from 1k (RK73GB1J102J) to 0 (R92-125205). By making this modification, Auxiliary output 1 and 2 can now sink up to 600mA each.

2. DC Source Switch
To prevent the power supply from turning off due to misoperation of the DC source switch on the front panel or accidents (tampering) after installation, the main unit can be kept on regardless of the on/off of the DC source switch on the front panel. Short the PSW land near K1 relay by soldering.

TX-RX unit (A/2) Component side

CF1 WIDE

CF2 NARROW

TX-RX unit (B/2) Component side

PSW

K1

IC602

IC623

R756 $Q607

R770 $Q611 $R769 R769 C681 CN605

Fig. 3

$R759 R755

$Q608 $Q612

Fig. 1
5V Add $R761 ($R759) 3.9k Remove D625 (D624) DA204U Add $Q608 ($Q607) DTD114EKA Remove R755 (R756) 0 Add $Q612 ($Q611) DTD114EKA Remove R769 (R770) 0 TEST/ SPKR 5V

Shift register IC623

Fig. 2

15

TKR-750
MODIFICATION / DISASSEMBLY FOR REPAIR
3. Trickle Charge for Backup Battery
If the external DC power supply is connected to the Main DC connector and a backup battery (12V rechargeable type) is connected to the Backup connector at the same time, the battery can be trickle-charged from the external DC power supply with a maximum current of 0.5A. Short the CHARGE land near R61.

DISASSEMBLY FOR REPAIR
How to Remove the Panel Assy (ABS)
Note : You can remove the panel assembly (ABS) without removing the top panel (A62-0840-03). 1. To remove panel (TX-RX, 2 ), loose 6 screws ( 1 ). 2. To remove panel assembly (Front, 4 ), loose 6 screws ( 3 ). 3. The panel assembly (ABS) is security fastened by 4 tabs ( 5 ) on top and bottom. You can remove the panel assembly by pulling to front while you are pulling up the tabs.

Notes :
1. Make this modification after removing the DC power supply and battery for safety. 2. When the DC power supply is connected after the modification, DC voltage is output to the Backup connector. Be careful during setup. 3. When the backup battery is used for a long time, remove the battery from the repeater and recharge it because the trickle charge is not sufficient for recharging a completely discharged battery.
Final unit (A/2) Component side

CN7 BACKUP (ORANGE) K1

CHARGE

R61

Fig. 4

16

TKR-750
CIRCUIT DESCRIPTION
1. Outline
The TKR-750 is a VHF/FM repeater designed to operate in the frequency range of 136 to 174MHz. The unit consists of receiver, transmitter, phase-locked loop (PLL) frequency synthesizer, and control circuits. The BPF L5/L6/L7 attenuates the unwanted signals, and sends only the necessary signal to the first mixer DBM A1.

2-2. First Mixer
The signal from the BPF is heterodyned with the first local oscillator signal from the PLL frequency synthesizer circuit at the first mixer DBM (A1) to become a 44.85MHz first intermediate frequency (IF) signal. The first IF signal is fed through two monolithic crystal filters (XF2; Wide, XF1; Narrow) to further remove spurious signals.

2. Receiver Circuit
The receiver is double conversion super-heterodyne, designed to operate in the frequency range of 146MHz to 174MHz (K,E) or 136MHz to 150MHz (K2). The receiver circuit located in TX-RX unit (X57-626 A/2) consists of the following : 2-1 front-end circuit, 2-2 first mixer, 2-3 IF amplifier circuit, 2-4 audio amplifier circuit, and 2-5 squelch circuit.

2-3. IF Amplifier
The first IF signal is amplified by Q2 and Q3, and then enters IC9 (FM system IC). The signal is heterodyned again with a second local oscillator signal (44.395MHz) with in IC9 to become a 455kHz second IF signal. The second IF signal is fed through a 455kHz ceramic filter, CF1 (Wide), CF2 (Narrow) to further eliminate unwanted signal, and the quadrature detection circuit FM-detects the signal to produce a base-band signal and output it from pin 11.

2-1. Front-end Circuit
The front-end circuit consists of BPF L2/L3, RF amplifier Q1, and BPF L5/L6/L7. The helical BPF covers frequency ranges 146 to 174MHz (K,E) and 136 to 150MHz (K2), with a passband of 3.0MHz.
TX-RX unit (X57 A/2): TX-RX MCF (Wide) XF2 D2 SW MCF (Narrow) XF1 D1 SW

RX ANT 44.85MHz IF AMP Q2 1st MIX DBM A1 BPF L5,L6,L7 RF AMP Q1 BPF L2,L3

IF AMP Q3

W/N

44.850MHz

W/N LPF

RSSI Q4 SW W/N NOISE DET D5 SQL DET

FM SYSTEM IC IC9 QUD

IF AMP IF AMP Q9 Q8

RX VCO A3 (X58-478) VCO A VCO B

fRX+44.85MHz DET CF1 (Wide) SW D4 SW D3 X1 44.395MHz

CF2 (Narrow) NOISE AMP Q7 455kHz W/N

TX-RX unit (X57 B/2): Control AMP DEI DEO IC608 AINR RD ASQ CPU RSSI IC604 IC614 CODEC LPF AMP IC619 (B/2) IC619 (A/2) RXI RXO AOUTR RA IC621 AM SPM

IC615 DAC

IC622 SW

Q606 MUTE

IC629 AF AMP

INV Q605

INT SP

Fig. 1 Receiver circuit 17

TKR-750
CIRCUIT DESCRIPTION
2-4. Audio Amplifier
The audio amplifier circuit is located in control section of TX-RX unit (X57-626 B/2). The recovered audio signal obtained from IC9 is amplified by IC608, input to the AINR terminal of CODEC IC (IC614), and audio processed by DSP (IC618). The processed audio signal from AOUTR terminal of IC614 is amplified by IC619 (B/2) to a sufficient level, antialiasing filtered by IC619 (A/2). The audio signal goes to an electronic volume (IC615) V3/V4, to the input of multiplexer IC (IC622), and is amplified to drive a loudspeaker by an audio power amplifier (IC629). The 4W audio output can be provided to external 4 ohms speaker through the 15-pin test connector "SPO, SPG" on the rear panel.

3. Transmitter Circuit
The transmitter circuit consists of the following circuits : 3-1 microphone circuit, 3-2 modulation level adjustment circuit, 3-3 driver and final power amplifier circuit, and 3-4 automatic power control circuit.

3-1. Microphone Circuit
The signal from the microphone is passed through AGC circuit located in display unit (X54-333), so that it does not saturate. This circuit consists of IC501, D501, D502, Q501, and Q502. The AGC is operated by controlling the + and ­ side levels of amplitude using the current obtained by positive and negative detection of the amplified audio signal. The audio signal goes to control section of TX-RX unit (X57626 B/2) from display unit (X54-333). The transmit audio signal goes to the input of the multiplexer IC (IC605) for microphone muting. The audio signal is amplified by IC610, input to the AINL terminal of CODEC IC (IC614), and audio processed by DSP (IC618). The processed audio signal from the AOUTL terminal of IC614 is amplified by IC616 (B/2) to a sufficient level, anti-aliasing filtered by IC616 (A/2), and amplified by the summing amplifier IC611 (A/2).

2-5. Squelch Circuit
The output signal from IC9 enters FM IC again, then passed through a band-pass filter. The noise component output from IC9 is amplified by Q7 and rectified by D5 to produce a DC Voltage corresponding to the noise level. The DC voltage is sent to the analog port of the CPU (IC604). IC9 outputs a DC voltage (RSSI) corresponding to the input of the IF amplifier.

3-2. Modulation Level Adjustment Circuit
The output of the summing amplifier IC611 (A/2) is passed to an electronic volume (IC615) for maximum deviation adjustment before being applied to a varactor diode in the voltage controlled oscillator (VCO) A2 located in TX-RX unit (X57-626 A/2).
Display unit (X54 B/2) MIC JACK Display unit (X54 A/2) VR501 IC501(A/2) AMP Q501,502 ATT MI

J601 DET D501,502

TXRX unit (X57 B/2): CONTROL IC605 (A/2) MIC MIS TA SW SW TXI TXO D-SUB TD TDS IC610 AMP AINL IC614 CODEC IC AOUTL IC605 (B/2) SW IC616 (B/2) AMP IC616 (A/2) LPF IC611 (A/2) AMP DAC MB IC615 MO

TAS

Fig. 2 Microphone circuit

18

TKR-750
CIRCUIT DESCRIPTION
3-3. Driver and Final Power Amplifier Circuit
The transmit signal is generated by the TX VCO (A2), amplified by Q11, and sent to final unit (X45-362). This amplified signal is amplified by Q2, Q3, and Q4, and is passed to the FINAL stage. The RF power amplifier consists of MOS FET.
TX-RX unit (X57-626 A/2) STT Q11 MO TX VCO A2 (X58-479) ATT TEMP Q3 Drive AMP IC1 FCT MB BUFF IC1 TCXO X3 16.8MHz Vcont D4 DC AMP SW Q8 POWER ADJ PC REF AMP IC1 REF DET FWD DET D5 Final unit (X45-362 A/2) TX ANT Q2 Drive AMP Q4 Drive AMP Q5 Final AMP CM COUPLER

VR1

Fig. 3

Driver and final power amplifier circuit

3-4. Automatic Power Control, Circuit and Transmitter
The automatic power control (APC) circuit stabilizes the transmitter output power at a pre-determined level, and consists of forward/reflected power detector circuits, and switching transistor Q8. The forward/reflected power detector circuits detects forward RF power and reflected RF power to DC voltage, and consists of a CM coupling type detection circuit formed by a strip line, RF detector D4/D5, and DC amplifier IC1 (A/2). The voltage comparator (IC1 B/2) compares the above detected voltage with a reference voltage, set using the microprocessor and IC6 located in the TX-RX unit. An APC voltage proportional to the difference between the sensed voltage and the reference voltage appears at the output of IC1. This output voltage controls the gate voltage for the drive amplifier Q4 and final amplifier Q5, which keeps the transmitter output power constant.
FAN CN4 FAB FAG X45 A/2 +B Q9 FAS 13 Q6 CK, DT, STB IC2 TK11050M 6 OUT CPU TEMP 17 X57 A/2 IC7 BU4094BCF X57 B/2

IC604

VTH Q602

[Fan operation]
ON

3-5. Fan Action Control Circuit
If fan action is set to "Temperature", the cooling fan is turned ON or OFF according to temperature. If the ambient temperature of the final unit exceeds approx. 40°C, the output from pin 6 of the temperature detection IC2 changes from L to H. This signal is sent to the CPU (IC604) by Q602 in the TX-RX unit B/2 (control section), and the output from pin 13 (FAS) of IC7 in the TX-RX unit A/ 2 controlled by the CPU goes H. This signal turns Q9 in the final unit ON to run the cooling fan. It has a hysteresis of approx. 5°C by IC2. If fan action is set to "Continuous", the fan operates continuously, but Q9 stays ON.
OFF +20°C +30°C +40°C

+50°C

Fig. 4 Fan action control circuit

19

TKR-750
CIRCUIT DESCRIPTION
4. PLL Frequency Synthesizer
The PLL frequency synthesizer circuit consists of the following circuits : 4-1 receiver PLL circuit, 4-2 transmitter PLL circuit, and 4-3 unlocked detector circuit.

4-2. Transmitter PLL
The transmitter PLL circuit is located in VCO unit A2 (X58479) on TX-RX unit (X57-626 A/2), and consists of VCXO X3, VCO's (Q350 and Q351), a single-chip PLL IC IC300, buffer amplifier Q355, and high-frequency amplifier Q302. The VCXO generates 16.8MHz. The frequency stability is within ± 2.0ppm (Temperature range of ­30 to +60°C). The frequency tuning and modulation of the VCXO are done to apply a voltage to pin 1 of the VCXO. The output of the VCXO is applied to pin 8 of the PLL IC through the pin 15 of the VCO. The VCO oscillator frequency is 136.00 to 174.00MHz. Two VCOs cover the two bands : Q350 covers the lower band and Q351 VCO covers the upper band. The oscillator frequency is controlled by applying the VCO control voltage, obtained from the phase comparator to the varactor diodes.

4-1. Receiver PLL
The receiver PLL circuit is located in VCO unit A3 (X58478) on TX-RX unit (X57-626 A/2), and consists of VCXO X2, VCO's (Q350 and Q351), a single-chip PLL IC IC300, buffer amplifier Q355, and high-frequency amplifier Q302. The VCXO generates 16.8MHz. The frequency stability is within ± 2.0ppm (Temperature range of ­30 to +60°C). The frequency tuning of the VCXO is done to apply a voltage to pin 1 of the VCXO. The output of the VCXO is applied to pin 8 of the PLL IC through the pin 7 of the VCO. The first local oscillator is an upper heterodyne local oscillator, and the VCO oscillator frequency is 180.850 to 218.850MHz. Two VCOs cover the two bands : Q350 covers the lower band and Q351 VCO covers the upper band. The oscillator frequency is controlled by applying the VCO control voltage, obtained from the phase comparator to the varactor diodes.

4-3. Unlock Detector Circuit
If a pulse signal appears at the LD pin of IC300, an unlock condition occurs, causing the voltage applied to the pin of the microprocessor to go low. The names of this pin are LDT for TX PLL and LDR for RX PLL. When the microprocessor detects this condition, the transmitter is disabled.
VCO unit (X58-479) Q350 VCO A Q354 Q355 AMP TX-RX unit

VCO unit (X58-478) Q350 VCO A Q354 SW SW Q352 Q355 AMP

TX-RX unit

SW

SW

MO Q352 MO Q353 MO

SW Q353 SRR VCO B Q351 Q300 LPF IC300 PLL-IC Q302 AMP X2 VCXO Q300 LPF STT

SW

MO

VCO B Q351 IC300 PLL-IC Q302 AMP X3 VCXO

CP,DP EPR,LDR µ-com IC604

CP,DP EPT,LDT µ-com IC604

Fig. 5 Receiver PLL

Fig. 6 Transmitter PLL

20

TKR-750
CIRCUIT DESCRIPTION
5. Control Circuit
The control circuit mainly located in the control section of TX-RX unit (X57-626 B/2) consists of the following : 5-1 CPU, 5-2 memory circuit, 5-3 CPU clock shift, 5-4 shift register circuit, 5-5 display circuit, 5-6 DSP circuit, 5-7 base-band circuit, 5-8 RS-232C circuit, and 5-9 power supply circuit.

5-5. Display Circuit
The display circuit (X54-333) contains two 7-segment LEDs D506, D507 (orange : see the operation manual for details of display), D503 (red : transmission), D504 (green : busy), two-color LED D505 (red : backup, green : main DC), LEDs in switches S501 to S506, IC502, IC503, IC504, and IC505 to display this model channels and states. IC502 to IC505 are shift registers which convert serial data from the CPU to parallel data and light LEDs. Q507, Q510, and Q511 are switching transistors which control two-color LED D505. IC506, and IC507 are three-pin power supply ICs which produce power used for the display circuit.
TX-RX unit (X57 B/2): CONTROL IC600 EEPROM IC601 Reset IC X600 14.754 MHz Q600 SW BEAT SHIFT IC603/606 INTERFACE IC X601 16.515 MHz Q600 SW IC614 BEAT SHIFT CODEC IC IC618 DSP IC613 DIVIDER CPU IC604 IC609 FLASH ROM IC620 232C DRIVER IC615 D/A IC IC602/623 Shift Register IC

5-1. CPU
The CPU (IC604) is a 16bit single-chip microcomputer containing a 32k ROM and 3k RAM. This CPU controls the flash ROM, the DSP, the receiver circuit, the transmitter circuit, the control circuit, and the display circuit and transfers data to or from an external device.

5-2. Memory Circuit
IC609 has a flash ROM with a capacity of 2M bits that contains the control program for the CPU, the signal processing program for DSP and data such as channels and operating features. This program can be easily written from an external device. Data such as the operating status are programmed into the EEPROM (IC600).

5-3. CPU Clock Shift
There are the 14.754MHz clock for the CPU (IC604) and the 16.515MHz clock for the DSP (IC618) at the control section of TX-RX unit (X57-626). When these clocks are multiplexed with the reception frequency, they become an internal beat signal. To prevent this, by tuning Q600 and Q604 on the clock frequency is shifted. (Shift on/off can be set through programming.)

5-4. Shift Register Circuit
Serial data is sent to the shift register (IC502 to IC505 located in display unit, IC602, IC623, IC7 located in TX-RX unit) from the CPU (IC604) to control various functions in the unit.

Fig. 7 Control circuit
Display unit (X54-333-20 A/2) PF1~6 KEY1~5

CLK,SOE, STB1 SI SO Shift Reg. 1 BU4094BCFV

CLK,SOE, STB1 SI SO

CLK,SOE, STB1 SI SO

CLK,SOE, STB1 DAT

Shift Reg. 2 BU4094BCFV

Shift Reg. 3 BU4094BCFV

Shift Reg. 4 BU4094BCFV

SW SW

SW SW SW SW

KEY LAMP 1~6

TX

BUSY Main DC/ BACKUP

Fig. 8 Display circuit 21

TKR-750
CIRCUIT DESCRIPTION
5-6. DSP
The DSP circuit filters transmit/receive audio signal and encode/decodes signaling (QT, DQT). This circuit consists of IC618, IC612, IC613, IC614, IC603, IC606, IC608, IC610, IC616, and IC619. The receive signal DET is converted from analog to digital by IC614 with a sampling frequency of 16.128kHz. The digitized audio signal is sent to DSP IC618 to process the signaling signal and audio signal. The processed digital audio signal is fed to CODEC IC614, converted from digital to analog, and the analog signal is output from pin 16 (AOUTR). Then, the audio signal is amplified by IC619 (B/2), passes through the IC619 (A/2) low-pass filter, and goes to an electronic volume IC615. The transmit audio signal coming from IC605 is amplified by IC610, fed to pin 3 (AINL) of CODEC IC614, and converted from analog to digital at a sampling frequency of 16.128kHz. The digitized transmit audio signal is AGC-processed, pre-emphasized and filtered at 300Hz to 3kHz by DSP IC618, and the resulting signal is fed back to CODEC IC614, and converted from digital to analog, and the analog signal is output from pin 15 (AOUTL). The transmit signal from AOUTL is amplified by IC616 (B/2), passes through the IC616 (A/2) low-pass filter, and goes to the IC611 (A/2) summing amplifier. IC613 is a counter IC and the clock required for the CODEC and DSP is generated by dividing the 16.515MHz clock signal produced by DSP IC618. IC603 and IC606 are interface IC between the CPU operated at 5.0V and the DSP operated at 3.3V.

6. DC Power Supply Circuit
6-1. DC Source Switching Relay Circuit
1. The final unit contains a relay (K1) for switching between the Main DC and Backup Battery. If an external power source is connected to the Main DC terminal, the Backup terminal is isolated by the relay. If the Main DC turns OFF due to power failure, it is switched to the Backup terminal by the relay. The CPU monitors which is used, Main DC or Backup Battery. 2. Trickle charge circuit If both Main DC and Backup Battery are connected, trickle charging of 0.5 A max. can be performed from the Main DC power supply to the Battery. (The default is OFF. See the Modification section for information on the modification method.) The battery is charged from the Main DC with D8, D9 and R61. If it exceeds 0.5 A, the charging circuit is turned OFF by D9.
Main DC D8 D9 R61 Land Backup battery 120mA K1 (Relay) Final unit (A/2) TX-RX unit (A/2) TX-RX unit (B/2) R54 +B

5-7. Base-Band Circuit
The base-band circuit switches between the modulation signal to the transmitter circuit, and remote audio and adjusts their levels. This circuit consists of IC605, IC607, IC611, IC615, and IC617. Modulation inputs include local microphone input, lowspeed data (LSD), high-speed data (HSD), external audio input (TA), and external data input (TD), and demodulation outputs include receive audio output (RA), and receive data output (RD). The multiplexer (IC605) changes signals, the electronic volume (IC615) adjusts the level, and the operational amplifier (IC607, IC611, IC617) amplifiers and sums signals.

BUP IC604 CPU

16

Q601

Fig. 9 DC source switching relay circuit 6-2. SB Switching Relay Circuit
1. SB (Switched +B) is supplied through the relay (K1) in the TX-RX unit A/2. When S507 (DC source switch) in the display unit is turned ON, the relay (K1) is turned ON to output SB. 2. If +B exceeds 18V, the relay is forcibly turned OFF by D12 and Q25 to interrupt the power and protect the main unit.
K1 +B R165 D12 R166 SB

5-8. RS-232C Circuit
The RS-232C circuit connects the RS-232C serial port of a personal computer directly to this model to perform FPU operation. The FPU operation can also be performed by connecting a programming cable (KPG-46) to the local microphone on the front panel. But, if the D-sub connector on the rear panel is used, the programming cable is not required. The 232C driver IC (IC620) changes the TTL-232C level. The firmware can only be rewritten with the local microphone on the front panel.

Q25 Q24

Land (PSW)

5-9. Power Supply Circuit
The power supply circuit generates power to operate the CPU, DSP, flash ROM, bi-directional buffer, and base-band circuit. This circuit consists of IC624, IC625, IC626, IC627, IC628, and IC630.

S507

Display unit (Front panel)

22

Fig. 10 SB switching relay circuit

TKR-750
SEMICONDUCTOR DATA
Main CPU : 30622M4-113GP (TX-RX unit IC604)
s Pin Function
Pin No. 1~5 6 7 8 9 10 11 12 13 14 15 16 Name IO5~IO1 BYTE CNVss ENT ENR Reset Xout Vss Xin Vcc NMI BUP I/O I/O ­ ­ O O I ­ ­ ­ ­ ­ I Function Aux I/O No.5~No.1 (Acc D-sub 25 pin) 5V GND TX PLL IC enable RX PLL IC enable Microcomputer reset input 14.7456MHz GND 14.7456MHz 5V Not used Backup battery detect H : Backup, L : Main 17 TEMP I Temperature detect for fan action H : Temp high, L : Temp low 18 EPTT I Acc PTT (Acc D-sub 25 pin) H : Off, L : On 19 20 21 22 23 24 25 26 27 CLK DAT SFT LD1 STB3 LD2 STB4 RS SC O O O O O O O O O Common clock Common data Beat shift H : On, L : Off 73 LDT I 72 LDR I Pin No. 40 41 42 43 44 45 46 47 48 49 50~59 60 61 62 63~70 71 Name HLDA BCLK RD BHE WR STB2 INTx HCS CS0 A19 A18~A9 Vcc A8 Vss A7~A0 EMON I/O ­ O O ­ O O O O O O O ­ O ­ O I Not used Not used Flash ROM WR/DSP HDS1 Not used Flash ROM WR/DSP HDS2 Control shift register STB DSP interrupt DSP HCS Flash ROM CS Not used Flash ROM address bus 5V Flash ROM address bus GND Flash ROM address bus Acc monitor (Acc D-sub 25 pin) H : Off, L : On RX VCO lock detect H : Lock, L : Unlock TX VCO lock detect H : Lock, L : Unlock 74,75 76~78 79~86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 KEY5,KEY4 KEY3~KEY1 D7~D0 FWD RSSI ASQ VLI BATT AI1 AI2 AVss AI3 Vref AVcc STB1 SOE IO6 O I I/O I I I I I I I ­ I ­ ­ O O I/O Key matrix output Key matrix input Flash ROM data bus RF power down level input RSSI level input Squelch level input Volume level input Power supply voltage level input Aux input No.1 (Acc D-sub 25 pin) Aux input No.2 (Acc D-sub 25 pin) GND Aux input No.3 (Acc D-sub 25 pin) 5V 5V Display shift register STB Shift register common OE Aux I/O No.6 (Acc D-sub 25 pin) H : Off, L : On Function

Control D/A converter LD Control shift register STB TX/RX D/A converter LD TX/RX shift register STB DSP reset H : Off, L : On

Squelch control (Acc D-sub 25 pin) H : Inactive, L : Active

28 29 30 31 32 33 34 35 36 37 38 39

PTT TXD1 RXD1 SCLK SDAT TXD0 RXD0 CP DP RDY ALE HOLD

I O I O I/O O I O O I ­ ­

Mic PTT Mic TXD

H : Off, L : On

Mic HOOK/RXD EEPROM clock EEPROM data Acc TXD (Acc D-sub 25 pin) Acc RXD (Acc D-sub 25 pin) PLL IC clock PLL IC data CPU ready input Not used Not used

23

TKR-750
SEMICONDUCTOR DATA
DSP : 320VC5402PGE (TX-RX unit IC618)
s Pin Function
Pin No. 1,2 3 4 5 6 7~11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 Name NC1,NC2 Vss DVDD A0 HD0 A1~A5 NC3 HAS Vss NC4 CVDD HCS HR/W READY PS DS IS R/W MSTRB IOSTRB MSC XF I/O ­ ­ ­ O I/O O ­ I ­ ­ ­ I I I O O O O O O O O Function Not used (No connection) GND VDD for I/O pins (+3.3V) Not used (No connection) HPI data bus Not used (No connection) Not used (No connection) HPI address strobe (Pull up) GND Not used (No connection) VDD for core CPU (+1.8V) HPI chip select HPI read/write Data ready (Pull up) Not used (No connection) Not used (No connection) Not used (No connection) Not used (No connection) Not used (No connection) Not used (No connection) Not used (No connection) CODEC control H : Power down, L : Active 28 29 30 31 32 33 34 35~38 39 40 41 HOLDA IAQ HOLD BIO MP/MC DVDD Vss NC5~NC8 HCNTL0 Vss BCLKR0 ­ ­ I I I ­ ­ ­ I ­ I Not used (No connection) Not used (No connection) Hold (Pull up) Serial data syncronize input Not used (Pull down) VDD for I/O pins (+3.3V) GND Not used (No connection) HPI control 0 GND Receive clock input (SCLK : 516.09375kHz) 42 43 BCLKR1 BFSR0 ­ I Not used (No connection) Frame sync. for receiver input (LRCK : 16.128kHz) 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71~74 75 76 77 78 79 HRDY DVDD Vss HD1 BDX0 BDX1 IACK HBIL NMI INT0 INT1 INT2 INT3 CVDD HD2 Vss NC9~NC12 DVDD Vss CLKMD1 CLKMD2 CLKMD3 ­ ­ ­ I/O O ­ ­ I I I I I I ­ I/O ­ ­ ­ ­ I I I 54 BFSX1 I 50 51 52 53 Vss HINT/TOUT1 CVDD BFSX0 ­ O ­ I 49 BCLKX1 O 45 46 47 48 BDR0 HCNTL1 BDR1 BCLKX0 I I ­ I Pin No. 44 Name BFSR1 I/O I Function Frame sync. for receiver input (LRCK : 16.128kHz) Serial data receive input HPI control 1 Not used (No connection) Transmit clock input (SCLK : 516.09375kHz) Master clock output (MCLK : 4.12875MHz) GND Boot mode select (Pull up) VDD for core CPU (+1.8V) Frame sync. for transmitter input (LRCK : 16.128kHz) Frame sync. for transmitter input (LRCK : 16.128kHz) Not used (No connection) VDD for I/O pins (+3.3V) GND HPI data bus Serial data transmit output Not used (No connection) Not used (No connection) Byte identification (HPI) Not used (Pull up) Command interrupt from host CPU Not used (Pull up) Boot mode select (Pull up) Not used (Pull up) VDD for core CPU (+1.8V) HPI data bus GND Not used (No connection) VDD for I/O pins (+3.3V) GND Clock mode select (Pull down) Clock mode select (Pull up) Clock mode select (Pull down)

24

TKR-750
SEMICONDUCTOR DATA / DESCRIPTION OF COMPONENTS
Pin No. 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99~104 105 106 107~109 110 111 112 113~119 120 121~123 124 125 126 127 128 129 130 131~134 135 136~141 142 143,144 Name NC13 HD3 TOUT0 EMU0 EMU1/OFF TDO TDI TRST TCK TMS NC14 CVDD HPIENA Vss CLKOUT HD4 X1 X2/CLKIN RS D0~D5 A6 Vss A7~A9 NC15 Vss DVDD D6~D12 HD5 D13~D15 HD6 CVDD NC16 HDS1 Vss HDS2 DVDD A10~A13 HD7 A14~A19 CVDD NC17,NC18 I/O ­ I/O ­ I/O I/O O I I I I ­ ­ I ­ O I/O ­ ­ I ­ O ­ O ­ ­ ­ ­ I/O ­ I/O ­ ­ I ­ I ­ O I/O O ­ ­ Function Not used (No connection) HPI data bus Not used (No connection) Emulator 0 (to JTAG connector) Emulator 1 (to JTAG connector) Test data output (to JTAG connector) Test data input (to JTAG connector) Test reset (to JTAG connector) Test clock (to JTAG connector) Test mode select (to JTAG connector) Not used (No connection) VDD for core CPU (+1.8V) Not used (Pull up) GND Not used (No connection) HPI data bus 16.515MHz (System clock) 16.515MHz (System clock) DSP reset input Not used (No connection) Not used (No connection) GND Not used (No connection) Not used (No connection) GND VDD for I/O pins (+3.3V) Not used (No connection) HPI data bus Not used (No connection) HPI data bus VDD for core CPU (+1.8V) Not used (No connection) HPI data strobe 1 (Pull up) GND HPI data strobe 2 (Pull down) VDD for I/O pins (+3.3V) Not used (No connection) HPI data bus Not used (No connection) VDD for core CPU (+1.8V) Not used (No connection)

Final Unit (X45-3620-XX)
Ref No. IC1 IC2 IC3 Q2,3 Q4 Q5 Q7 Q8,9 D1 D2 D3 D4,5 D6 D7 D8 D9 D51,52 Part name IC IC IC Transistor FET FET FET Transistor Diode Zener diode Diode Diode Diode Zener diode Diode Varistor Diode Description DC amplifier Thermostat Voltage regulator RF amplifier TX drive amplifier Final amplifier RF switch DC switch Thermal sensor Voltage reference Surge absorption RF detector Surge absorption Surge protector Reverse current protection Current protector Reverse connection protection

Display Unit (X54-3330-20)
Ref No. IC501 IC502~505 IC506,507 Q501,502 Q504 Q506 Q507 Q508 Q510,511 Q512~514 Q516~519 Q521~525 D501,502 D503~505 D506,507 D508~514 D601,602 D603 Part name MOS IC MOS IC MOS IC Transistor FET Transistor FET Transistor Transistor FET FET FET Diode LED LED Diode Diode Varistor Description MIC amplifier Shift registers Voltage regulator Level controller DC switch DC switch DC switch DC switch DC switch DC switch DC switch DC switch AF detector LED 7 segment Surge absorption Surge absorption Current protector

25

TKR-750
DESCRIPTION OF COMPONENTS
TX-RX Unit (X57-6260-XX)
Ref No. IC1,2 IC3~5 IC6 IC7 IC9 IC10,11 IC600 IC601 IC602 IC603 IC604 IC605 IC606 IC607,608 IC609 IC610,611 IC612 I