Kenwood TK-940 service manual LCD Assy B38-0731-05

Page 40

DESCRIPTION OF COMPONENTS

Ref. No.

Parts No.

UseIFunction

Operation/Condition

 

DTC114Eup

 

---

Q201

M u t i ~ l---l c h

Off when TX.

 

 

 

---

Q202

D1 D2

1

(

DTC144EU

DC swlrch

Onloif bv no~se

1

02CZ18iX.Y)

_ _ - - -

L---

I Voltage reference

 

--A

DSA3Al

1protection

 

 

PeveIse current preventon

 

 

--

 

I

Surqe absorption

 

 

m e x n c e

 

 

 

 

 

 

/

Surae absorution

 

D l 1

I 1SS301

I

Reverse current oreventi011

 

 

 

Surge absorption

 

 

 

 

Voltage reference

 

 

DAN235K

 

RF s w l ~ c h

 

 

HSM88AS

I Larae* inuut urotectioli

D l 9

MI809

 

TWRX switch

 

, D20

MA4P1250

 

TWRX s w ~ t c h

 

D21

MI809

-

TWRX swltch

 

 

 

--

D22

MA77

 

DC swltch

 

D201, 202

DA204K

 

Surge absorption

--

D203

1SS301

 

DC swltch

 

 

k

w h e n 5V or more and OV

or less--

 

I~

On when 5V or more and OV

or less.

 

On when 5V or more and OV or less.

i

---

---

----

On when microphone mute on

PLL/VCO (X58-4170-XX)

-10 :TK-940 -11 :TK-941

 

 

Ref. No.

Parts No.

 

UseIFunction

OperationICondition

IC1

SC370651 F

 

PLL system

Or MC145190F-K

--

 

 

 

 

 

Q1

DTC143EK

 

Lock detect~onswltch

On when PLL unlocked

---

 

2SA1586(Y',GRj

 

Lock detection switch

On when PLL unlocked

Q2

 

---

 

-

 

Buffer amplifier

 

Q3

2SC3356

 

 

 

 

2SK508NViK52)

 

Oscillator

 

 

 

-

Buffer ampllfler

 

 

 

2SC3356

 

 

 

Q53

2SC3356

 

Doubler

 

 

D1

1SS301

 

DC switch

On when PLL unlocked

 

D51, 52

1T363A

 

Vanable dlode

Frequency control

---

 

 

 

 

 

D53

MA360

 

Modulator

 

 

LCD ASSY (B38-0731-05)

 

 

 

 

Ref. No.

Parts No.

 

UseIFunction

OperationICondition

IC1

NJM78L05UA

 

Voltage regulator --

5V

 

IC2

75308BGK740BE9

 

M~croprocessor

--

--

ED1

638-0722-05

 

LCD

 

 

Image 40
Contents $@$, ~\, !? .- $LU~CO .i@&4170-XX FX-R%~?ONIT1x57-4590-XXI BIZTesting GeneralDC Power and wiring Installation Planning Control Stations 5-1. Antenna systemAntenna RadioSystem SET-UP Operating Features Front Panel Displays and Indicators System display Scan indicatorDelete 1 indicator Busy indicatorDetails of Features Time-Out Timer TEL ID Codes TEL ModeSystemIGroup Revert Last call revertFree System Ringback System SearchTranspond Preferred System RevertDelay tone Auto TELAudible User Feedback Tones Proceed toneTransmit disable receive-only channels Call indicator, alert toneConventional System Operation Talk-aroundHorn Alert Non-continuousContinuous System Scan Type Fix system scanData Program Mode Transceiver ProgrammingIr 4-1.lntroduction KPG-4 Description Optional PC programming interface cableClone Mode Figure Dealer modeDescription of Each Modes System keyPanel Tuning Mode Volume keyGroup key Scan keyInstalling the Signaling Unit KDD-4 Dtmf Option KDD-4assemblyInstallation Installing the KDD-4 in the transceiverAccessory Connection Cable KCT-19 Option Jumper setup chartsMonireset ON-HOOK OFF-HOOK JU2 JU3 JUJ Mute UrimuteTerminal function GNDConnecting the KCT-18 to the transceiver R5 and R6 setup chartIgnition Sense Cable KCT-18 Option Modifying the transceiverConnection procedure External SpeakerKES-3 Option KES-4 OptionFitting the Control Panel Upside Down Page Page Page Page RF unit If unitMCF ANT AMP If System -AMPSP PLL MIC AMPAudio amplifier unit Squelch circuit Microphone amplifier PLL Buff IRF AMPVcxo DET InvswControl unit PLL data output Power supply circuitHorn control LCD Assembly Power switch circuitCPU Tone generatorBlock diagram Terminal connection diagramTerminal connection diagram Terminal function Eeprom AT24C02NlOS12.7 TX-RX Unit IC201Test DEC DINMicroprocessor 78312AGF3563BE TX-RX Unit IC209 Microprocessor 75308BGK740BE9 LCD Assy IC2 Output a CLKTEST2 TEST1 NJM78L05UA EepromDTA114EU--DC DTA114YULCD Assy B38-0731-05 Cc4riq Rating wattageTK-940/941 KusaTapttte Screw A T Head T a P T T I E Sciiewpannel Screw SET Insulating Tube ANT Cable Speaker 16 QHM 1W MicrqphqnbY4U Icpqwer Modulej .. Drive TX-RXW w w W W 1 W l I P C X E D C UuupiU U P F U P FR c Hesbnatuh ES $j Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Pattern Page Foil side IC20E Dtci 14EU DTCI44EU Page Page Component side PC Board View ~ o h ~ o n esident Page TX-RX Unit TX-RX Section X57 4590 XX A/2 11 TK A1 PLL O w m o d +4- aLIE- - aIz23z= Page Ccrl--------ASSYDISPLAY S~ECTION838 Eqqzj

TK-940 specifications

The Kenwood TK-940 is a highly regarded mobile two-way radio that has earned a reputation for its ruggedness, reliability, and excellent communication capabilities. Designed for professionals in various sectors such as public safety, transportation, and construction, the TK-940 incorporates advanced technologies to meet the demanding needs of users in the field.

One of the standout features of the TK-940 is its robust design, which complies with military specifications for durability. Its construction allows it to withstand harsh environmental conditions, making it suitable for outdoor and challenging work environments. The radio is also equipped with a water-resistant casing, ensuring that it can function reliably even in wet conditions.

The TK-940 operates in the VHF frequency range, providing wide coverage and strong signal penetration. With a power output of up to 110 watts, users can achieve long-range communication, essential for coordinating activities over large areas. The radio supports both analog and digital modes, allowing seamless integration into various communication systems while maintaining high audio clarity.

Another significant feature of the TK-940 is its enhanced audio quality. The radio is equipped with Kenwood's advanced noise cancellation technology, which minimizes background noise and ensures clear voice communication even in noisy environments. The audio output is powerful and adjustable, catering to individual user preferences.

Moreover, the TK-940 supports a variety of signaling options, includingDTMF, MDC-1200, and 2-Tone/5-Tone signaling, facilitating efficient communication. These signaling features enhance interoperability with other communication devices and systems, allowing users to communicate seamlessly with teams or dispatch centers.

Kenwood has also incorporated user-friendly functionalities into the TK-940. It boasts an intuitive user interface with programmable buttons, enabling quick access to essential features. The large, backlit display provides clear visibility and is easy to read in various lighting conditions.

The TK-940 is designed with safety in mind, featuring emergency alerts and lone worker protection, ensuring users can communicate their status in critical situations. Overall, the Kenwood TK-940 is a powerful and versatile mobile radio that combines durability, advanced technology, and user-friendly features, making it an ideal choice for professionals who require reliable communication in the field.