DESCRIPTION OF COMPONENTS

 

TX-RX UNIT (X57-4590-XX)

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

 

 

 

 

1

'

1

Ref. No.

1

Parts No.

1

Use/Function

 

 

 

OperationlCendition

 

[i~:

1

NJM4558E

---

1

 

 

 

 

(

IC1

1

BU4013BF

/

Power supply circuit loglc control

 

 

 

 

;1;

 

1

 

 

Audio amplifier (Detected output)

 

 

 

 

 

1

NJM78L05UA

 

Voitaqe reuualtor

 

 

 

 

A

 

p --P O 8

 

Voltage regulator

 

 

 

 

 

 

 

 

NJM4558E

 

Act~vef~lter

 

 

 

 

 

 

lC6

 

~ 6 2 3 6 3 ~ ~

 

Level adluster

 

 

 

 

 

 

 

 

 

 

IF system

 

 

 

U4094BCF----. l=L~

 

 

 

 

NJM4558E

 

 

 

 

 

 

 

 

 

NJ~ 4 5

5 ~ t

~

 

 

 

 

 

 

 

 

Aud~opower amplifier

 

 

 

 

 

 

 

 

--

 

 

 

 

 

 

 

 

--

 

----

I

I

IC13

 

NJM2904M

 

Comparator, DC amplifier

 

 

 

-

El

 

 

--

 

-

 

 

--

 

 

 

 

' AT24C02NlOS12.7

 

EEPROM

T , a 7 a c i t y 2-Khit.

 

 

 

 

 

NJM78L05UA

 

Voltage regulator

 

 

 

 

 

I,

I*'

 

 

--

--

 

 

---

 

IC208 TC7S32F

DC swltch

"L"when IC207 access.

 

FAA::~fl'ter

 

 

 

 

 

 

"L" when writlng program or data from external equipment.

 

 

 

 

 

 

 

--

 

1

1

DTA114EU--(DC

I

switch

 

On when power swltch on

 

---

 

---then Q3 turn off

 

DTCll4EU

 

DC swltch

f.-wm=d,

 

a 3

 

 

 

DC switch

 

On when power swltch on.

 

Q4

 

2SA1641 (S,T)

 

DC switch

 

On when power swltch on.

 

Q5

 

DTA114YU

 

DC switch

 

Oh when power switch off, then D22 turn on.

 

 

 

 

 

--

 

RX . OV, TX : 8V

 

Q6, 7

 

2SB1188iQ, R)

 

DC switch

 

 

 

 

 

 

---

 

RX : 8V, TX : OV

 

0 8

 

2SA1362iY)

 

DC switch

 

 

0 9

 

 

 

DC switch

 

On when PLL lock.

 

Q10

 

--DC switch

 

On when PTT switch on.

 

0 1 1

 

DTC114EU

 

 

 

On when RX.

 

Q12

 

DTC114EU

 

DC switch

 

On when TX.

 

 

 

--

 

 

 

On when horn control on.

 

Q13

 

DTC114EU

 

DC s w ~ t c h

 

 

 

 

 

On when horn control on.

 

Q14

 

2SD162415)

 

DC switch-

 

 

 

 

 

 

 

 

Q15

 

2SC4116(GR)-

 

Ripple filter

 

 

 

 

 

 

RX Ist IF amplifier

 

45.0375MHz (TK-9401,39.0375MHz (TK-941)

 

Q16

 

2SC4215(Yi

 

 

 

 

 

-

 

 

 

 

 

 

-

 

Muting switch

 

On when no beep sound at busy.

 

0 17

 

DTA114TU

 

 

 

 

1 RF amplifier

 

 

 

 

Q18

 

2SC4226(R24)

 

 

 

 

 

 

-

 

On when no beep sound at busy.

 

0 1 9

 

DTC144EU---

 

DC switch

 

 

Q20

 

DTC3 14TK

 

Muting switch

 

Off when busy.

--

 

 

3SK241(R)

 

 

 

 

 

 

 

 

 

 

 

 

APC controller.

 

 

 

 

 

 

 

On when PTT switch on.

 

Q26

 

 

 

 

 

 

 

 

Q27

 

DTA114YU

 

 

 

 

 

 

0 2 8

 

 

 

 

 

 

 

 

Q29

 

D T C 1 1 4 G

I

 

1

On when IGN line "H".

 

Q30

 

2SA1586(Y,GR)

DC switch

I

On when modular lack SB terminal shorted.

 

Page 39
Image 39
Kenwood TK-940 service manual NJM78L05UA, Eeprom, DTA114EU--DC, DTA114YU, DTC114EU, DTA114TU, DTC3 14TK

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.