Icom IC-F4001, IC-F4002, IC-F4003, IC-F4006, IC-F4008 Service Manual

S-14617XZ-C1
Nov. 2009

UHF TRANSCEIVERS

This service manual describes the latest technical
information for the IC-F4001/IC-F4002/IC-F4003/IC-F4006/

IC-F4008 UHF TRANSCEIVERS at the time of publication.

NEVER connect the transceiver to an AC outlet or to a DC

power supply that uses more than the specified voltage.
This will ruin the transceiver.

DO NOT expose the transceiver to rain, snow or any liquids.

DO NOT reverse the polarities of the power supply when

connecting the transceiver.

DO NOT apply an RF signal of more than 20 dBm (100 mW) to
the antenna connector. This could damage the transceiver’s
front-end.

To upgrade quality, any electrical or mechanical parts
and internal circuits are subject to change without notice
or obligation.

MODEL VERSION

CHANNEL

SPACING

(kHz)

FREQUENCY

RANGE

(MHz)

IC-F4001

USA-11

12.5/25.0

400–470

USA-12

USA-13

IC-F4002

EUR-21

12.5/20.0/25.0EUR-22

EUR-23

UK-01

12.5/25.0

UK-02

UK-03

IC-F4003

EXP-11

EXP-12

EXP-13

EXP-21

EXP-22

EXP-23

EXP-01

EXP-03

EXP-31

AUS-21

AUS-22

AUS-23

IC-F4006

RUS-21

RUS-22

RUS-23

IC-F4008 CHN-31

Be sure to include the following four points when ordering
replacement parts:

1. 10-digit Icom part number

2. Component name

3. Equipment model name and unit name

4. Quantity required

<ORDER EXAMPLE>

1110003491 S.IC TA31136FNG IC-F4001 MAIN UNIT 5 pieces

8820001210 Screw 2438 screw IC-F4003 Top cover 10 pieces

Addresses are provided on the inside back cover for your
convenience.

ORDERING PARTS

1. Make sure that the problem is internal before
disassembling the transceiver.

2. DO NOT open the transceiver until the transceiver is
disconnected from its power source.

3. DO NOT force any of the variable components. Turn
them slowly and smoothly.

4. DO NOT short any circuits or electronic parts. An
insulated tuning tool MUST be used for all adjustments.

5. DO NOT keep power ON for a long time when the
transceiver is defective.

6. DO NOT transmit power into a Standard Signal
Generator or a Sweep Generator.

7. ALWAYS connect a 50 dB to 60 dB attenuator between
the transceiver and a Deviation Meter or Spectrum
Analyzer when using such test equipment.

8. READ the instructions of the test equipment throughly
before connecting it to the transceiver.

REPAIR NOTES

INTRODUCTION CAUTION

(IC-F4001)

Icom, Icom Inc. and the Icom logo are registered trademarks of Icom Incorporated (Japan) in Japan, the United States, the
United Kingdom, Germany, France, Spain, Russia and/or other countries.

TABLE OF CONTENTS

SECTION 1 SPECIFICATIONS

SECTION 2 INSIDE VIEWS

SECTION 3 DISASSEMBLY INSTRUCTION

SECTION 4 CIRCUIT DESCRIPITON

4-1 RECEIVER CIRCUITS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

4-2 TRANSMITTER CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

4-3 FREQUENCY SYNTHESIZER CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

4-4 VOLTAGE BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

4-5 PORT ALLOCATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

SECTION 5 ADJUSTMENT PROCEDURES

5-1 PREPARATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5-2 FREQUENCY ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5

5-3 TRANSMIT ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6

5-4 RECEIVE ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7

SECTION 6 PARTS LIST

SECTION 7 MECHANICAL PARTS

SECTION 8 BOARD LAYOUTS

SECTION 9 BLOCK DIAGRAM

SECTION 10 VOLTAGE DIAGRAM

1 - 1

SECTION 1. SPECIFICATIONS

M GENERAL

• Frequency range : 400–470 MHz

• Number of conventional channels : 16 channels

• Type of emission : [EUR] Wide: 16K0F3E (25.0 kHz)
Middle: 14K0F3E (20.0 kHz)
Narrow: 8K50F3E (12.5 kHz)

Except [EUR] Wide: 16K0F3E (25.0 kHz)

Narrow: 11K0F3E (12.5 kHz)

• Antenna impedance : 50 Ω (Nominal)

• Operating temperature range : –30˚C to +60˚C; –22˚F to +140˚F Except [EUR], [UK]

–25˚C to +55˚C [EUR], [UK]

• Power supply voltage : Specified Icom's battery packs only (7.2 V DC; negative ground)

• Current drain (Approx.) : Receiving 70 mA (stand-by)
330 mA (max. audio)

Transmitting 1.3 A (at 4.0 W)

• Dimensions

(Projections not included)

: With BP-264

58.6 (W)×111.0 (H)×31.0 (D) mm; 2 5/16 (W)×4 3⁄8 (H)×1 7⁄32 (D) in.

With BP-265

58.6 (W)×111.0 (H)×35.5 (D) mm; 2 5/16 (W)×4 3⁄8 (H)×1 13⁄32 (D) in.

• Weight : With BP-264 Approx. 330 g; 11 21/32 oz.

With BP-265 Approx. 270 g; 9 17/32 oz.

• Intermediate frequency : 1st 46.35 MHz

2nd 450 kHz

• Output impedance (Audio) : 8

Ω

• Input impedance (Audio) : 2.2 k

Ω

M TRANSMITTER

• Output power : 4 W

• Modulation : Variable reactance frequency modulation

• Maximum frequency deviation : Narrow ±2.5 kHz

Middle ±4.0 kHz
Wide ±5.0 kHz

• Frequency stability : ±2.5 ppm

• Spurious emissions : 70 dB min. Except [EUR], [UK]

0.25 µW (≤1 GHz), 1.0 µW (>1 GHz) [EUR], [UK]

• Adjacent channel power : Narrow 60 dB min., 66 dB typ.

Middle

70 dB min., 73 dB typ.

Wide 70 dB min., 73 dB typ.

• Audio harmonic distortion : Wide, Middle 1.0% typ. at AF 1 kHz 40 % deviation

Narrow 1.5% typ. at AF 1 kHz 40 % Deviation

• FM hum and Noise

(Except [EUR], [UK])

(Without CCITT FILTER)

: Narrow 34 dB min., 40 dB typ.

Wide 40 dB min., 46 dB typ.

• Residual modulation ([EUR], [UK])

(With CCITT FILTER)

: Narrow 40 dB min.

Middle 43 dB min.
Wide 45 dB min.

• Limitting charact of modulator : 60–100% of max. deviation

1 - 2

M RECEIVER

• Sensitivity : 0.25 µV typ. at 12 dB SINAD Except [EUR], [UK]

–4 dBµV (EMF) typ. at 20 dB SINAD [EUR], [UK]

• Squelch sensitivity (at threshold) : 0.25 µV typ. Except [EUR], [UK]

–4 dBµV (EMF) typ. [EUR], [UK]

• Intermodulation : 70 dB min. 74 dB typ. Except [EUR], [UK]

65 dB min. [EUR], [UK]

• Spurious response : 70 dB min.

• Audio output power : 0.8 W typ. at 5% distortion with 12 Ω (Int. speaker)

0.4 W typ. at 5% distortion with 8 Ω (Ext. speaker)

• Hum and noise (Except [EUR], [UK])

(Without CCITT Filter)

: Narrow 34 dB min. 47 dB typ.

Wide 40 dB min. 52 dB typ.

• Hum and noise (

[

EUR], [UK])

(With CCITT Filter)

: Narrow

40 dB min.

Middle

43 dB min.

Wide

45 dB min.

• Adjacent channel selectivity : Narrow 60 dB min. 65 dB typ.

Middle 70 dB min. 73 dB typ.
Wide 70 dB min. 73 dB typ.

Specifications are measured in accordance with TIA/EIA-603B or EN 300 086

All stated specifications are subject to change without notice or obligation.

2 - 1

SECTION 2. INSIDE VIEWS

LED CTRL
(Q82,Q83)

VCO

• MAIN-A UNIT
(TOP VIEW)

CPU5 LINE REGULATOR
(IC54)

+5V LINE REGULATOR
(Q76)

PLL IC
(IC2)

MIC/AF LINE SW
(IC56)

APC AMP

(IC1)

TCXO

(X2)

TONE FILTER SW
(Q52)

TONE LPF
(IC59)

HPF

(IC58)

MIC GAIN CONTROLLER

(IC62)

2ND IF BPF
(FI2)

2ND IF BPF (

For narrow mode only

)

(FI3)

LPF
(Q51)

BEEP SW
(IC61)

+5V LINE REGULATOR
(Q75)

2 - 2

CLONE BUFFER
(Q81, D51)

TUNED BPF
(D24, D26)

• MAIN-A UNIT
(BOTTOM VIEW)

DRIVE AMP
(Q2)

POWER AMP
(Q1)

PRE-DRIVE AMP
(Q3)

PRE-AMP
(Q4)

RF AMP
(Q22)

RESET IC
(IC53)

EEPROM
(IC52)

AF AMP

(IC55)

IF DEMODULATOR IC

(IC3)

XTAL BPF

(FI1)

AGC CTRL

(Q21)

S5 LINE REGULATOR

(Q71)

RIPPLE FILTER
(Q15)

R5 LINE REGULATOR

(Q72)

1ST IF MIXER

(Q23)

POWER CTRL

(Q63)

CPU

(IC51)

D/A CONVERTER
(IC57)

BUFFER
(IC60)

BUFFER
(Q9)

+5V LINE REGULATOR
(Q74)

3 - 1

SECTION 3. DISASSEMBLY INSTRUCTION

BE CAREFUL to not pull out the speaker wire when

separating the CHASSIS and the FRONT PANEL.

For easy separation of the CHASSIS

Use a suction lifter to lift the bottom of the CHASSIS up.

1. REMOVING THE CHASSIS

1) Remove the ANT connector nut and 2 knobs.

2. REMOVING THE MAIN UNIT

1) Remove the 9 screws and the side plate from the
MAIN UNIT.

2) Unsolder the 2 points shown, and then remove the
MAIN UNIT.

2) Remove 2 screws from the bottom of the CHASSIS.

3) Lift the bottom of the CHASSIS up in the direction
of the arrow.

4)

CAREFULLY lift the chassis out of the FRONT PANEL
and turn it over in order to unplug the speaker wire.

(Continued to the right above)

5) Remove the seals and nuts from the CHASSIS.

ANT CONNECTOR NUT

KNOBS

FRONT PANEL

FRONT PANEL

CHASSIS

SCREWS×2

SPEAKER

WIRE

CHASSIS

FRONT PANEL

TOP SEAL

NUTS×2

SIDE SEAL

CHASSIS

UNSOLDER

Solder
remover

CHASSIS

SCREWS×9

MAIN UNIT

MAIN UNIT

SIDE PLATE

Suction lifter

Suction lifter

• Part name : EA950R-2

• Manufacture : ESCO CO.LTD

4 - 1

• RF CIRCUITS

• 1ST IF CIRCUITS

• 2ND IF CIRCUITS

SECTION 4. CIRCUIT DESCRIPTION

LPF

ANT

SW

D3,D22

RF
AMP

Q22

BPF

D28 D24,D26

BPF

T2

T1

From the TX circuits

To the 1st IF circuits

ANT

LO
SW

D5,D6

Q23

BPF

XTAL

FI1

IF
AMP

Q24

BUFF

Q8

BUFF

Q10

LPF

RX VCO

To the TX circuits

From the RF circuits

To the 2nd IF&demodulator circuits

46.35MHz

1st IF mixer

PLL

IC

IC2
MB15A02

X3

Q26

BPF

X2

TCXO

W/N

SW

Q27,
D33,D34

X1

Discriminator

BPF

CERAMIC

FI2

BPF

CERAMIC

FI3

W/N
SW

D31,D32

D/A

converter

IF IC

From the 1st IF

circuits

To the RX AF circuits

IC3:NJM2591

15.3MHz

45.9MHz

DISC

SQIN

IC57
R2A20178

450kHz

450kHz

NWC

NOIS

4-1 RECEIVER CIRCUITS

RF CIRCUITS

The RX signal from the antenna is passed through the LPF
and antenna SW, then filtered by the 2-staged tuned BPF
to eliminate unwanted out-of-band signal. The filtered RX
signal is amplified by the RF AMP, and filtered by another
2-staged tuned BPF to obtain a good image response, then
applied to the 1st IF circuits.

The tuned BPFs are tuned to the RX frequency by applying
adequate tuning voltages; “T1” and “T2” to the variable
capacitors.

1ST IF CIRCUITS

The RX signal from the RF circuits is applied to the 1st IF
mixer and mixed with the 1st LO signal from the RX VCO,
resulting in the 46.35 MHz 1st IF signal. The 1st IF signal is
filtered by the crystal filter, amplified by the 1st IF AMP, then
applied to the 2nd IF circuits.

2ND IF CIRCUITS AND DEMODULATOR

The signal from the 1st IF circuits is applied to the IF
demodulator IC which contains the 2nd IF mixer, 2nd IF
AMP, FM detector, etc. in its package.

The 1st IF signal is applied to the 2nd IF mixer and mixed
with the 2nd LO signal resulting in the 450 kHz 2nd IF
signal.

The 2nd LO signal is generated by tripling the 15.3 MHz
reference frequency signal oscillated by the reference
frequency oscillator (TCXO).

The converted 2nd IF signal is filtered by the crystal filter/
filters to eliminate unwanted signal, and amplified by the
2nd IF AMP, then demodulated by the detector circuit which
employs a discriminator as the phase shifter.

The demodulated AF signal is applied to the RX AF circuits.

4 - 2

• RX AF CIRCUITS

AF

AM P

IC55 TPA0211DGN

J52

IC62

RX

MUTE

SP1

HPF

IC58

AF

AM P

IC12
TA7368F

HPF

IC58

J53

Int.speaker

Ext.speaker

1
2

LPF

IC58

LPF

IC59

the demodulator

circuits

IC56

AF line SW

CD4066

AFON

AFO

RMUT 1

D/A

converter

IC57
R2A20178

RX AF CIRCUITS

The demodulated AF signal from the IF demodulator
IC is passed through the LPF, HPF which attenuates
frequencies 300 Hz and below. The filtered AF signal is
passed through the AF line SW, HPF which additionally
attenuates frequencies 300 Hz and below, de-emphasis
circuit which provides –6 dB/oct of frequency response.
The de-emphasized AF signal is passed through the AF
SW, LPF which attenuates frequencies 3 kHz and above, is
adjusted in level by the D/A converter. The level-adjusted AF
signal is then applied to the AF power AMP via the AF line
SW.

The amplified AF signal is applied to the internal or external
speaker.

4-2 TRANSMITTER CIRCUITS

TX AF CIRCUITS

The audio signal from the internal or external microphone
(MIC signal) is passed through the MIC gain SW and applied
to the MIC AMP. The amplified MIC signal is passed through
the MIC mute SW, HPF which attenuates frequencies
300 Hz and below. The filtered MIC signal is passed through
the pre-emphasis circuit which provides +6 dB/oct of
frequency response, then they applied to the limiter AMP.

The amplitude-limited MIC signal is passed through the
MIC line SW, and applied to the splatter filter, which
attenuate harmonics in the MIC signal to prevent exceeding
permissible deviation.

The filtered MIC signal is applied to the D/A converter which
adjusts its level (=deviation). The level-adjusted MIC signal
is applied to the TX VCO as the modulation signal.

• TX AF CIRCUITS

AM

limit

P

IC58

MIC

MUTE

IC62

MIC

GAIN

SW

IC62

HPF

IC58

MC51

AM

MIC

P

IC60

LPF

IC58

Splatter

J51

Ext.MIC

Int.MIC

D/A

MOD

To the modulation circuits

IC56

MIC

line

SW

CD4066

IC57

MODULATION CIRCUIT

The modulation signal from the TX AF circuits is applied to
D15 of the TX VCO to frequency-modulate it. The frequency­modulated signal from the TX VCO is buffer-amplified by
two buffers, and applied to the TX AMP circuits via the TX/
RX SW (D5).

• MODULATION CIRCUITS

LO

SW

D5,D6

Q14,D16

FREQUENCY
MODULATION

D15

BUFF

Q8

BUFF

Q10

TX VCO

rom the TX AF circuits

To the TX AMP circuits