Kenwood NXR 710 Service Manual

Page 1

VHF DIGITAL BASE-REPEATER

NXR-710

SERVICE MANUAL

KENWOOD

Kenwood Corporation

© 2009-12 PRINTED IN JAPAN
851-8901-00 (N) 527

From panel Knob (Volume) Knob (Power)
(A62-1 174-03) (K29-5389-03) (K29-9I 06-04)
I

I C)

o@ KENWOOD 000000000 m. @0

o _. Q
Q o
u w: o
i %@ a
O o@ NEXEEIGE @ 0 o Clo ©O C)
Key top Modularjack
(K29-9370-02I (E58-0522-05)
Antenna cable (TX OUTI Blade fuse (15A/32V) Amenna cable (RX IN)
IE30-7528-15) (F054 537-05) (E30-3418-15)
Rear panel Antenna cable (REF INI
(A82-0077-02) (E30-7690-05I

.m. um \ O

0 0 o

o o o
Peg-IE ma ~=u L O

Lead wire with connector

(DSUBZSPI
(E37-1376-05l
Lead wire with connector Modular jack x 2
(ACC15PI (E58-0533-05)
(E37-09I3-05l
GENERAL ................................................................... 2
SYSTEM SET-UP..
REALIGNMENT

OPERATING FEATURES
INSTALLATION .....
MODIFICATION .
DISASSEMBLY FOR REPAIR
CIRCUIT DESCRIPTION ..............
COMPONENTS DESCRIPTION...
PARTS LIST .................................
EXPLODED VIEW.
PACKING ............
ADJUSTMENT ..
TERMINAL FUNCTION ..

commandant-Icon:

This product complies with the RcHS directive for the European market.

CONTENTS

DC cord (Ext DC in)
(E30-3414-05I

PC BOARD
FINAL UNIT (X45-3920-10I .........
CONTROL UNIT (X53-4490-10I ..
DISPLAY UNIT (X54-3580-20I.
TX-RX UNIT (X57-7940-10) .....
RX VCO/PLL UNIT (X58-5070-10) .
TX VCO/PLL UNIT (X58-5080-10I .

INTERCONNECTION DIAGRAM ..........

SCHEMATIC DIAGRAM .

BLOCK DIAGRAM ..........

OPTIONAL ACCESSORIES
KES-5 (EXTERNAL SPEAKER)

SPECIFICATIONS .....

.. BACK COVER

.2:

This product uses Lead Free solder.

Page 2

NXR-71 0

Document Copyrights

Copyright 2009 by Kenwood Corporation. All rights re-
served.

No part of this manual may be reproduced, translated,
distributed, or transmitted in any form or by any means,
electronic, mechanical, photocopying, recording, or other-
wise, for any purpose without the prior written permission
of Kenwood.

Disclaimer

While every precaution has been taken in the preparation
of this manual, Kenwood assumes no responsibility for er-
rors or omissions. Neither is any liability assumed for dam-
ages resulting from the use of the information contained
herein. Kenwood reserves the right to make changes to any
products herein at any time for improvement purposes.

Firmware Copyrights

The title to and ownership of copyrights for firmware
embedded in Kenwood product memories are reserved for
Kenwood Corporation. Any modifying, reverse engineer
ing, copy, reproducing or disclosing on an Internet website
of the firmware is strictly prohibited without prior written
consent of Kenwood Corporation. Furthermore, any resell»
ing, assigning or transferring of the firmware is also strictly
prohibited without embedding the firmware in Kenwood
product memories.

Transceivers containing AMBE+2TM Vocoder:

The AMBE+2TM voice coding technology is embedded
in the firmware under the license of Digital Voice Systems,
Inc.

GENERAL

INTRODUCTION

SCOPE OF THIS MANUAL

This manual is intended for use by experienced techni-
cians familiar with similar types of commercial grade com-
munications equipment. It contains all required service
information for the equipment and is current as of the pub-
lication 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 informa-
tion, 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 re-
quired component for proper identification.

PERSONAL SAFETY

The following precautions are recommended for personal

safety:

. DO NOT transmit if someone is within two feet (0.6 meA
ter) of the antenna.

0 DO NOT transmit until all RF connectors are secure and
any open connectors are properly terminated.

. SHUT OFF this equipment when near electrical blasting
caps or while in an explosive atmosphere.

. All equipment should be properly grounded before powA
erup for safe operation.

0 This equipment should be serviced by only qualified
technicians.

SERVICE

This transceiver is designed for easy servicing. Refer to
the schematic diagrams, printed circuit board views, and
alignment procedures contained within.

Page 15

NXR-71 O

CIRCUIT DESCRIPTION

4-2. Memory circuit

The Memory circuit consists of the MCU (ICZO), the
SRAM (|C9), and the flash memory (lCB).

The flash memory has a capacity of 32Mbit that contains
the transceiver control program for the MCU and stores the
data. It also stores the data for transceiver channels and
operating parameters that are written by the FPU. This pro-
gram can be easily written from external devices.

The SRAM has a capacity of leit that contains work
area and data area.

I Flash memory

Note: The flash memory stores the data that is written by
the FPU, tuning data (Deviation, Squelch, etc), and firm-
ware program.

I SRAM (static memory)

Note: The SRAM has a temporan/ data area and work area.
When the power supply is off, it is backed up by an internal
secondary lithium battery. Therefore, the saved data is not
lost.

4-3. DSP circuit

The DSP circuit consists of a DSP (|C6) and processes
the base band signal. The DSP operates on an external clock
of 18.432MH2 (the same as ICZO). The I/O section operates
at 3.3V and the core section operates at 1.6V. The DSP car-
ries out the following processes:

I Digital processing

0 4Level FSK and Baseband filter processing

0 Vocoder processing between audio codec and modula-
tion/demodulation

0 CAl processing, such as error correction encoding/decodA
ing and interleaving

0 AFC loop control

0 Frame synchronization and Time tracking

0 Data scrambling

I Analog FM processing

0 Pre-emphasis/De-emphasis
OT/DOT encoding/decoding
DTMF encoding/decoding
Compressor/Expander processing
Voice scrambler processing

I Audio or Modulation function

0 Transmit/Receive audio filtering processing
0 Microphone amplifier AGC processing

0 Audio soft mute processing

0 Modulation level processing

0 Squelch Filtering

I Other function

0 Voting tone

CWID

Courtesy tone

Repeater operating
Analog/Digital Mixed mode

4-4. Squelch circuit

The Squelch circuit amplifies the demodulated noise sig-
nal from |C6 after filtering through the EFF circuit. The pro»
cessed digital noise signal is applied to CODEC |C14, and is
converted from digital to analog. The amplified signal is then
converted to a DC signal by the detection circuit. The con-
verted signal is fed back to |C20.

33M 33M 15M 33A
[FRET /FRST
FLASH
lC3 A[0~21], D[0~15],
IRD, NVR, /CSO, /WP
33BU
SRAM A[0~17], D[O~7l,
lCQ IRD, /WR, /C82
MCU
33M 16M lC20
A[0~20], D[0~15], IRD,
NVR, /HRDY, /CS3, /HD52
IDRST /DRST

/MCCSXCN, /MCCSRCN, MCDICN, \

MCDOCN, MCSCKCN

MCSCKAFJMCCSAF, MCDIAF, MCDOAF /

DSP /SYMT|M, /DINT, /DWU P, FSDET, /H|NT ,

(C6
/PCS_DSP
MA|N_CLK

VCTCXO
<- X1 <- BSHIFT
(18t432MHZ)

Buffer
|C16

XTAL_I N

- LDR
/PDN, Squelch <-VREF

LRCLK, DAC
|C14
AMP AMP AMP

SDTI,
|C13(A/2,B/2) Q4 |C15(A/2)

ADC1

BICLK

Fig. 14 Control circuit

4-5. Power supply circuit

The X53449 circuit consists of |C301, |C302, |C303,
|C304, |C305 and |C306.

|C301 is a DC/DC converter that converts 13.6V to 6.0V.
This 13.6V voltage is supplied from TX-RX unit (X51794).

|C302 is connected to [€301 and regulates the voltage
to 5.0V. |C303, |C304, |C305 and |C306 are connected to
|C30l. |C303 and |C306 are 3.3V voltage regulators. |C304
is a 1.5V regulator IC, and |C305 is a 1.6V regulator lC.

CN302 is the connector for the lithium battery. The
lithium battery is used to back up the SRAM and RTC data
when no external DC power source is available.

15

Page 38

NXR-71 O

PACKING

E F

56 Protection bag (H25-O762-O4)
15 DC Cord (E30»3427-35i
74 Line filter (L79-1419-05)
67 Band (J61-0307-05)
\

50 Cushion ((313-1801-04) x 4
51 Cushion (613»1802-04) x 4
/ 55 Protection bag (H25-0747-04)
64 Mounting hardware (J21-8559»04)

710 Pamphlet

Q/ / 711 Pamphlet

10 Instruction manual

/\/ (862-2199-00)

*1

54 Protection bag 8 Front glass
(H25-0029-04) (B10»2635-04)

60 Foot 9 Filter
(J02-0475-05) x 2 (B11-1259-04)

61 Foot (Rubber) 57 Protection bag
(J02-0492-04) x 2 (H25-2328-04)

66 Grommet
(J59-0302-05) x 2

C Pan head machine screw
(N30-4006-48) x 2

H Binding head machine screw
(N35-3006-43) x 5

*2
69 Handle
(K01-0418-15i

712 Packing fixture

*3

2 19 15P plug
(E31-3228-05)

32 Blade fuse
(F05-1537-05)

54 Protection bag
(H25-0029-04)

715 Packing fixture

58 Item carton case
(H52-2334-02)

38 Parts with the exploded numbers larger than 700 are not supplied.

Page 100

NXR-71 O

SPECIFICATIONS

General
Frequency Ranges...
Number of Channels
Channel Spacing
Analog ..
Digital...
PLL Channel Step....
Antenna Impedance
Operating Voltage
Current Drain
Standby...
Receive
Transmit ..
TX Power
50% Duty...
100% Duty.
Operating Temperature Range
~22°F~+140°F (-30°C~+60°C)
Frequency Stability ............................. :1.0ppm
Dimension (W X H X D) (Projections not included)
......... 19.00 X 3.46 X 13.39 inches (482.6 X 88 X 340 mm)
Weight (net) ................................................... 21.4 lbs (9.7kg)

136~174MHZ
.................. 30

12.5/ 15/ 25/ 30kHZ
6.25/7.5/12.5/15kHZ
2.5/ 3.125kHz
............ 509
10.8~15.6V DC

Kenwood Corporation

296773, (shikawaernachi, Hachiojivshi, Tokyo, 1928525 Japan

Kenwood U.S.A. Corporation

P.O. BOX 22745, 2201 East Dominguez Street, Long Beach,
CA 9080175745, U.S.A.

Kenwood Electronics Canada Inc.

6070 Kestrel Road, MlSSlSSaUga, Ontario, Canada LST 158
Kenwood Electronics Deutschland GmbH
Rembmcker Str. 15, 63150 Heusenstamm, Germany
Kenwood Electronics Belgium N.V.
Leuvensesteenweg 248 J, 1800 Vilvoorde, Belgium
Kenwood Electronics France S.A.

L'Etoile Paris Nord 2, 50 Allee des Impressionnistes,

Bp 58416 Villepinte, 95944 Roissy Ch De Gaulle CedeX
Kenwood Electronics UK Limited

0 KENWOOD House, Dwight Road, Watford, Herts.,
70% WD18 9EB United Kingdom

Receiver
Sensitivity
Digital@6.25kHz (3% BER) .. ..
Digital@12.5kHz (3% BER) .. ..0.28uV
Analog (12dB SlNAD) ............................................... 0.28pV
Sensitivity
Analog@ZSkHz .. . 83dB
Analog@12.5kH .77dB
FM Hum & Noise
Analog@ZEkHz .. .55dl3

Analog@12.5kH
lntermodulation Distortion
Spurious Response ........ .90dB
Audio Distortion (EXt. SP). Less than 2.5% at 1000Hz
Audio Output (EXt. SP)....4W (at 49, less than 5% distortion)

. 50dB
. 80dB

Transmitter
RF Power Output ........
Spurious & Harmonics
FM Hum & Noise
Analog@ZSkHz ..
Analog@125kH
Audio Distortion . Less than 1 /0 at 1000Hz
Modulation ........ 6KOF3E, 11KOF3E, 8K30F1 E, 8K30F1 D,
8K30F7W, 4KO0F1 E, 4KOOF1 D,4KOOF7W, 4KO0F2D

Analog measurements made per TlA/EIA 603 and specifica»
tions shown are typical.

KENWOOD reserves the right to change specifications with-
out prior notice or obligation.

Kenwood Electronics Europe B.V.
Amsterdamseweg 37, 1422 AC Uithoorn, The Netherlands
Kenwood Electronics Italia S.p.A.

Via G. Sirtori, 7/9 20129 Milano, ltaly

Kenwood Ibérica, S.A.

Bolivia, 239708020 Barcelona, Spain

Kenwood Electronics Australia Pty. Ltd.

Talavera Business Park Building A, 4 Talavera Road,
North Ryde NSW 2113 Australia

Kenwood Electronics (Hong Kong) Ltd.

Unit 371273724, Level 37, Tower one Metroplaza, 223 Hing Fong Road,
Kwai Fong, N.T., Hong Kong

Kenwood Electronics Singapore Pte Ltd
1 Ang Mo Kio Street 63, Singapore 569110