Icom IC-r2500, IC-r1500 Service Manual

iC-r1500 iC-r2500

S-14233MZ-C1 Jun. 2006

COMMUNICATIONS RECEIVERS

3%26)#%

-!.5!,

This service manual describes the latest service information for the IC-R1500 and IC-R2500 COMMUNICATIONS RECEIVERS at the time of publication.

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

1. 10-digit Icom parts numbers

2. Component name and informations

3. Equipment model name and unit name

4. Quantity required

1110001811 S.IC TA7S04F IC-R2500 Main-A unit 5 pieces 8810008960 Screw FH M2.6 IC-R2500 Chassis 8 pieces

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

NEVER connect the receiver to an AC outlet or to a DC power supply that uses more than 16 V. Such a connection could cause a fire hazard and/or electric shock.

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

DO NOT reverse the polarities of the power supply when

connecting the receiver.

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

front end.

1. Make sure a problem is internal before disassembling the receiver.

2. DO NOT open the transceiver until the receiver 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 turning tool MUST be used for all adjustments.

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

6. READ the instructions of test equipment thoroughly before connecting equipment to the receiver.

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

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

INTRODUCTION CAUTION

ORDERING PARTS

REPAIR NOTES

MODEL VERSION SYMBOL

IC-R1500 IC-R2500

Europe EUR

U.K. UK

U.S.A. USA

Canada CAN

France FRA

South East Asia SEA

Export

IC-R2500* U.S.A. USA-2

*UT-122 is already installed as DIGITAL UNIT.

(IC-R2500)

(IC-R1500)

EXP EXP-1

SECTION 1 SPECIFICATIONS

SECTION 2 INSIDE VIEWS

SECTION 3 DISASSEMBLY INSTRUCTIONS

SECTION 4 CIRCUIT DESCRIPITON

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

4-2 PLL CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

4-3 DIGITAL MODE OPERATION WITH UT-122 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

4-4 POWER SUPPLY CIRCUITS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

4-5 CPU PORT ALLOCATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7

SECTION 5 ADJUSTMENT PROCEDURES

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

5-2 MAIN-A UNIT ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3

5-3 MAIN-B UNIT ADJUSTMENT (R2500 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5

SECTION 6 PARTS LIST

SECTION 7 MECHANICAL PARTS AND DISASSEMBLY

SECTION 8 SEMICONDUCTOR INFORMATION

SECTION 9 BOARD LAYOUTS

9-1 LOGIC UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1

9-2 MAIN-A UNIT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3

9-3 MAIN-B UNIT (R2500 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-5

9-4 CONTROL UNITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-7

9-4 UT-122 (Optional product; DIGITAL UNIT for [R2500; USA-2]) . . . . . . . . . . . . . . . . . . . . . . . . . 9-7

SECTION 10 BLOCK DIAGRAM

SECTION 11 VOLTAGE DIAGRAM

SECTION 1 SPECIFICATIONS

M GENERAL

• Frequency coverage

A.S.U

010.0 :

2581

–000.

7981

–

000

181

.9923

ecnarF

02.15–002.05

ehtO

• Mode :

• Number of memory channels :

1 4 1 0 :

10.

evoba naht r

: For IC-R2500. Available on Main band only.

Sub band does not cover outside of frequency range; 50 to 1300.000000 MHz.

: Guaranteed: 0.495–3000.000 MHz range only

FM, AM, WFM, USB*1, LSB*1, CW, DV*1,*2, P25*1,*

: For R2500. Available on Main band only.

: For R2500. Available when optional UT-118 is installed.

: For R2500. Available when optional UT-122 is installed, and depending on versions.

2600

0.641

–000.44

–

031

000.042

• Tuning steps : 1 Hz, 10 Hz, 20 Hz, 50 Hz, 100 Hz, 500 Hz, 1 kHz, 2.5 kHz, 5 kHz, 6.25 kHz,

8.33 kHz, 9 kHz, 10 kHz, 12.5 kHz, 15 kHz, 20 kHz, 25 kHz, 30 kHz, 50 kHz, 100 kHz, 125 kHz, 150 kHz, 200 kHz, 500 kHz, 1 MHz, 10 MHz, USER TS

• Operating temperature range : 0°C to +60°C; +32°F to +140°F

* 999999.908–00

999999.668–000.158

000000.0031–000.698

999999.0181–100000.003

* 999999.7681–000.

* 999998.5032

* 999999.1182–000.7532

* 999999.8682–000.3582

* 999997.9013–000.8982

* 999997.4513–000.6313

* 999999

* 999999.92–000010.0 :

0000

999999.701–005.78

0000

00000.044–000.03

000.0

* 999999.9923–0

• Current drain (at 12.0 V DC: approx.) [1500] POWER ON Standby 650 mA

Max. audio Less than 1.2 A *While using controller (R1500): plus 50 mA with above current value.

[1500/2500] POWER OFF PC (USB VBAS-ON) 550 mA typ.

PC (VBAS-OFF) 15 mA typ. Controller (R1500) 15 mA

[2500] single band operation Standby 650 mA

Max. audio Less than 1.2 A

Dualwatch operation Standby 850 mA

Max. audio Less than 1.5 A *While using controller (R2500): plus 110 mA with above current value.

• Frequency stability : ±3 ppm (–10°C to +60°C)

• Power supply requirement : 12 V DC ±15% (Negative ground)

• Current drain (At 12 V DC ; approx.)

• Dimensions (projections not included) :

146(W)×41(H)×206(D) mm; 5 111(W)×40(H)×26.5(D) mm; 4 140(W)×50(H)×27.5(D) mm; 5

• Weight (approx.) : MAIN UNIT 1.2 kg; 2 lb 10 oz (1500)

⁄4(W)×15⁄8(H)×8

⁄8(W)×19⁄16(H)×8

⁄2(W)×131⁄32(H)×1

1.35 kg; 2 lb 15 oz (2500)

CONTROLLER 0.2 kg; 2 lb 7

0.25 kg; 2 lb 8

⁄32 oz (1500)

⁄16 oz (2500)

• Antenna connector : BNC (50 Ω)

⁄8(D) in

⁄32(D) in

1 - 1

M RECEIVER

• Receive system : Triple-conversion superheterodyne and down converter

• Intermediate frequencies : 1st: 266.700 MHz, 2nd: 10.700 MHz, 3rd: 450 kHz (except for WFM mode)

• Sensitivity :

•

(

2 3 5

9.94–000.0

0.0

92–0

;.veD zHk5.3/zHk1

HM999.932–00

9.972–000.042

9.9

HM999.996–000.003

031–000.007

9.9922–100000.0031

2 FW

•

–

3 M

k1(

5.25/zH

00.007

922–100000.00

000.0032

MA )

•

–

4.0

9.41–008.1

;.DOM %03/zHk1(

HM9

999.992–000.0

00.003

–

00.007

•

WC/BSS

01(

1–008.

6–000.05

HM9

97.1–594.0

9.94–000.51

zHM99

9.99

31–000.007

M000.00

z z z

zHM00

HM000.0003

veD zHk

HM000.0031–0

HM999.9

HM000.0003–

HM000.0031–0

)DA

NIS Bd21

0 naht

sseL:zHM999.92–000.8

sseL:zHM

ht sseL:z

eL:

Vµ36.

0 na

Vµ36. Vµ5.0 V

0 naht

µ5.0 naht ss

Vµ5.0 naht sseL:

t sseL

: :zHM99

sse

eL:z

t ss

)DANIS Bd21 ;.

µ36.0 n

µ6.5 na

Vµ81 n

Vµ4.1 naht sseL:zHM999.996–000.0

sseL

:z :z

/S Bd

Vµ8.1 naht sseL

Vµ81 naht Vµ65 naht sseL

Vµ52 naht sseL:z

Vµ5.2 naht sseL Vµ5.2 naht sseL:zHM999.94–000.5

seL:z

Vµ2 naht Vµ2 naht sseL:zHM999.996

µ5.2 naht sseL:z

Vµ5 naht sseL:z

Vµ5.0 naht sseL Vµ5.0 naht sseL:

sseL:zHM99

Vµ4

naht

Vµ5.0

naht sseL:zH

• Selectivity :

)lacipyt( Bd 6–/zHk 8.2 naht eroMMA/WC/BSS

C/BSS

MF/MA

FW/

eroM

t eroMM

zHk 0.6 naht eroMMF/MA/W

–/zHk 51 naht eroMMF/M

Hk0

32 nah

)lacipyt( Bd 6–/ )lacipyt( Bd 6 )

ipyt( Bd 6–/zHk 05

lac

)lacipyt( Bd6–/z

• Audio output power : More than 0.5 W (at 10% distortion with an 8 Ω load)

• Ext. speaker connector : 2-conductor 3.5 (d) mm (

• Packet connector : 2-conductor 3.5 (d) mm (

• Data connector : 3-conductor 2.5 (d) mm (

⁄8″)/8 Ω

⁄8″)

⁄10″)

• IF shift variable range : More than ±1.2 kHz

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

1 - 2

2 - 1

SECTION 2 INSIDE VIEWS

LOGIC UNIT

TOP VIEW

BOTTOM VIEW

+33V regulator IC2: BA6161F D2: 1SS355

VSC/TONE filter (IC2021: LM2904) IC-R2500 only

AF +8V regulator (Q5: 2SB1201, Q8: XP1501)

AF amplifier (IC12: LA4425A)

USB HUB (IC32: USB2502)

USB +3.3V regulator

IC1: S-812C33 Q31: 2SB789 Q32: 2SC4116

VCC line controller Q4: 2SJ377 Q6: DTC144EU

−5V regulator IC8: µPC1553 D6: 1SS272 D8: MA8051

VSC/TONE filter (IC21: LM0904)

AF selecter (IC23: SN74AHC2053)

AF selecter (IC2023: SN74AHC2053) IC-R2500 only

USB audio IC (IC16: PCM2901M)

Electric VR (IC17: SM6451B)

AF amplifier (Q18: 2SC4617)

AF amplifier (Q2018: 2SC4617) IC-R2500 only

CPU5V regulator (IC3: XC6202P502PR)

L5V regulator (IC9: AN78L05)

CPU reset IC (IC35: S-80942)

SP mute switch (Q12: 2SC4213)

CPU (IC18: M30624FGPGP)

DTMF decoder (IC19: BU8872FS)

A+5V regulator (IC6: TA7805)

A+8V regulator (IC7: AN7708)

B+5V regulator (IC2006: TA7805F)

IC-R2500 only

B+8V regulator (IC2007: TA7708SP)

IC-R2500 only

Clock oscillator (X2: CR-818 4.19304 MHz)

(

)

( )

(

)

( )

Down converter circuit

1st VCO circuit

2nd VCO circuit

DDS circuit

RF circuits

• MAIN-A UNIT

Noise blanker amplifier (Q68: 2SK882)

APCO5V regulator (Q77: 2SA1832)

Buffer (Q60: 2SC4617)

AM detecter circuit

WFM IF IC (IC16: LA1145M)

IF IC (FM) (IC24: TA31136)

RSSI meter amplifier (IC25: NJM2904V, D80: 1SS400)

AGC amplifier (Q58: 2SC4617)

2nd IF amplifier (Q66: 3SK131)

2nd mixer (IC19: TA4107F)

1st IF amplifier (Q44: 3SK131)

1st mixer (IC14: SPM5001)

+5V regulator (Q23: UNR9111)

DVCO +5V regulator (Q78: UNR9111)

DPLL 3.3V regulator (IC2: S-812C33AMC)

D3.3V regulator (Q10: UNR9111)

IF IC (Band scope) (IC20: TA31136)

ATT circuits

TOP VIEW

BOTTOM VIEW

SSB decoder (IC23: TA4101F)

DDSREF 8V regulator (D120: DAN222)

DDS REF 8V regulator (Q90: XP4311)

HF 8V regulator (Q25: XP4311)

HF band RF amplifier (Q22: 2SC5226)

PLL 3.3V regulator (IC9: S-812C33AMC)

2 - 2

• MAIN-B UNIT (IC-R2500 only)

• UT-122 (Optinal product; DIGTAL UNIT for [IC-R2500: USA-2])

Noise blanker (Q68: 2SK882)

BAPCO5V regulator (Q77: 2SA1832)

3rd IF filter (FI1: CFWKA450)

Buffer (Q60: 2SC4617)

AM detecter circuit

IF IC (WFM) (IC16: LA1145M)

IF IC (FM) (IC24: TA31136)

AGC amplifier (Q58: 2SC4617)

2nd IF amplifier (Q66: 3SK131)

2nd mixer (IC19: TA4107F)

1st IF amplifier (Q44: 3SK131)

1st mixer (IC14: SPM5001)

+5V regulator (Q23: UNR9111)

ATT circuit

HF filters

1st VCO circuit

2st VCO circuit

TOP VIEW

BOTTOM VIEW

TOP VIEW

BOTTOM VIEW

RSSI meter amplifier (IC25: NJM2904V D80: 1SS400)

PLL 3.3V regulator (IC9: S-812C33AMC)

Clock oscillator (X1: CR-798)

Liner codec (IC9: AK4550VT)

EEPROM (IC17: HN58X2416TI)

CPU (IC12: HD64F2239TE16)

2 - 3

• CONTROL UNIT (R1500)

• CONTROL UNIT (R2500)

Color controller (Q6,Q7: 2SC4116)

Control unit CPU (IC6: HD6433842RB36H)

Reset IC (IC2: S-80945CLMC-G7F)

+5V regurator IC5: TA78L05F D4: MA8062

+8V regurator Q1: 2SC4116 Q3: 2SA1734 D5: MA8068

Color controller (Q6, Q7: 2SC4116)

Control unit CPU (IC6: HD6433842RB36H)

Reset IC (IC2: S-80945CLMC-G7F)

+5V regulator IC5: TA78L05F D4: MA8062

+8V regulator Q1: 2SC4116 Q3: 2SA1734 D5: MA8068

Dimmer

+8V regurator (Q1: 2SC4116)

+5V regurator (IC3: TA78L05F)

Sub CPU (IC4: HD6473847RH)

Reset IC (IC2: S-80945CLMC)

Data comparator (IC1: TA75S01F)

LED drivers (Q6-Q13: 2SC4116)

+8V regurator Q1: 2SC4116 Q3: 2SA1586 D1: MA8091

+5V regurator (IC3: TA78L05F)

Control unit CPU (IC4: HD6473847RH)

Reset IC (IC2: S-80945CLMC)

Data comparator (IC1: TA75S01F, D2: MA8047)

3 - 1

SECTION 3 DISASSEMBLY INSTRUCTIONS

• Removing the top cover and shield covers

q Unscrew 8 screws, A. w Unplug the connectors B and C from the LOGIC unit. e Remove the top cover in the direction of the arrow.

r Remove the shield covers D and E* in the direction of

the arrow.

• Removing the LOGIC unit, MAIN-A unit and MAIN-B* unit

q Unscrew nut F*, G. w Unscrew 6 screws H from the LOGIC unit and remove the LOGIC plate. e Unscrew 6 screws I from the MAIN-A unit and 6 screws J* from the MAIN-B unit*. r Remove the units in the direction of the arrows.

Top cover

LOGIC Unit

Chassis

LOGIC UNIT

LOGIC Plate

MAIN-A UNIT

MAIN-B UNIT

* IC-R2500 only

3 - 2

• CONTROL unit disassembly (R1500)

q Remove 2 knobs A.

w Unscrew 2 screws B, and remove the cover.

e Unscrew 2 screws C, and remove the LCD plate. r Remove the CONTROL unit.

• CONTROL unit disassembly (R2500)

q Remove 6 knobs A.

w Unscrew 4 screws B, and remove the cover. e Remove the plate C, and remove CONTROL unit.



CONTROL UNIT







CONTROL UNIT





SECTION 4 CIRCUIT DESCRIPTION

4-1 RECEIVE CIRCUITS

4-1-1RF CIRCUITS (MAIN-A/-B UNITS)

The MAIN-A UNIT has eight RF circuits and one down converter circuit to provide wide receiving range. The received signals from the antenna connector (CHASSIS; J1) are applied to RF circuits or down converter circuit according to the received frequency, and amplified within the frequency coverage.

IC-R2500 contains MAIN-B UNIT which has 4 RF circuits to provide dulalwatch or diversity capability .

The 0.01–50 MHz signals from the antenna are passed through the attenuator (D1, D3), band switch (D9) and lowpass ﬁ lter (LPF; L20, L26, C54, C60, C68, C72, C81, C88), then applied to one of the RF circuit.

• 0.01–1.8 MHz*

The 0.01–1.8 MHz signals are passed through the band switch (D29), LPF (L48, L52, C134, C148, C171, C173) and another band switch (D56), then applied to the 1st mixer (IC14, pins 4, 5).

<0.01–18 MHz>

D56

• 1.8–15.0 MHz*

The 1.8–15.0 MHz signals are passed through the band switch (D25), LPF (L43, L47, L50, C102, C120, C125, C131, C135, C140), high-pass filter (HPF; L57, L60, L72, C150, C161, C163, C174, C178, C618, C619) and another band switch (D49), and then applied to the RF amplifier (Q22). The amplified signals are then applied to the 1st mixer (IC14, pins 4, 5) via the band switch (D102).

<1.8–15 MHz>

To the 1st mixer (IC14, pins 4, 5)

• 15.0–30 MHz*

The 15.0–30 MHz signals are passed through the band switch (D82), LPF (L46, L49, C116, C118, C124, C130, C136), HPF (L55, L58, C139, C149, C151, C162, C164) and another band switch (D83), and then applied to the RF ampliﬁ er (Q22). The ampliﬁ ed signals are then applied to the 1st mixer (IC14, pins 4, 5) via the band switch (D102).

<15–30 MHz>

To the 1st mixer (IC14, pins 4, 5)

• 30–50 MHz*

The 30–50 MHz signals are passed through the band switch (D30), HPF (L77, L82, C201, C206, C208, C213, C216) and another band switch (D48), and then applied to the RF ampliﬁ er (Q22). The ampliﬁ ed signals are then applied to the 1st mixer (IC14, pins 4, 5) via the band switch (D102).

<30–50 MHz>

To the 1st mixer (IC14, pins 4, 5)

LPF

D102

Q22

amp.

RF amp.

D29

From the LPF

D49D102

HPF

LPF

D30D48

D25

D82D83D102

From the LPF

The 50–1300 MHz signals from the antenna are passed through the anttenuator (D1, D3), band switch (D7) and LPF (L5, C33, C34), then applied to one of the RF circuit.

• 50–150 MHz

The received signals 50–150 MHz are passed through the band switch (D5) and the tunable bandpass ﬁ lter (BPF; D8, D16–D18, D28, D31, L9, L21, L25, L31, L33, C39, C41, C44, C49, C70), and then applied to the RF ampliﬁ er (Q15). The amplified signals are passed through another tunable BPF (D35, D36, L53, L62, L69, L73, C142, C154, C199) and another band switch (D44), and then applied to the 1st mixer (IC14, pins 4, 5).

<50–150 MHz>

To the 1st mixer (IC14, pins 4, 5)

D44

D35, D36

BPF

Q15

amp.

D8, D16–D18

D28, D31

BPF

From the HPF

• 150–350 MHz

The received signals 150–350 MHz are passed through the band switch (D6) and BPF (D32, L10, L12, L34, L37, L39, C40, C42, C45, C50, C82, C114, C117), and applied to the RF amplifier (Q17). The amplified signals are passed through another BPF (D37, L56, L67, L71, C155, C167, C183, C195) and another band switch (D46), and then applied to the 1st mixer (IC14, pins 4, 5).

<150–350 MHz>

To the 1st mixer (IC14, pins 4, 5)

D46

D37

BPF

Q17

RF amp.

D32

BPF

From the HPF

• 350–700 MHz

The received signals 350–700 MHz are passed through the band switch (D14) and BPF (D26, D27, L24, L32, L40, C65, C71, C81, C106), then applied to the RF amplifier (Q16). The ampliﬁ ed signals are passed through another BPF (D38, D39, L54, L64, L74, L78, C144, C172, C211) and another band switch (D47), and then applied to the 1st mixer (IC14, pins 4, 5).

<350–700 MHz>

To the 1st mixer (IC14, pins 4, 5)

D47

D38, D39

BPF

Q16

RF amp.

D26, D27

BPF

D14

From the HPF

• 700–1300 MHz

The received signals 700–1300 MHz are passed through the band switch (D13) and BPF (D19, D23, D33, D34, L22, L27, L36, L36, L41, L44, C66, C77, C119), then applied to the RF amplifier (Q18). The amplified signals are passed through another BPF (D40, D41, L51, L59, L68, L72, C168, C176, C205) and the band switch (D45), and then applied to the 1st mixer (IC14, pins 4, 5).

<700–1300 MHz>

To the 1st mixer (IC14, pins 4, 5)

D45

D40, D41

BPF

Q18

RF amp.

D19, D23

BPF

D13

From the HPF

*MAIN-A UNIT only

4 - 1

• 1300–3300 MHz*

The 1300–3300 MHz signals from the antenna are applied to the down converter circuit where those signals are converted into the lower frequencies.

D42

To the RF circuits (350–1300 MHz)

LPF

LO signals from VCO (Q19, D43)

IC5

amp.

HPF

Q11

Buff

amp.

D15

From the antenna

In FM or AM mode, the 2nd IF signal is passed through the FI5 (band width=50 kHz) via mode switches (D66, D70),

In WFM mode, the 2nd IF signal is passed through the FI6 (band width=230 kHz) via mode switches (D67, D71).

The ﬁ ltered 2nd IF signal is applied to the 2nd IF ampliﬁ er (Q66). The ampliﬁ ed 2nd IF signals are then applied to the 3rd IF and demodulation circuits.

The received signals are applied to the buffer ampliﬁ er (Q11) via the band switch (D15). The buffer-ampliﬁ ed signals are applied to the RF ampliﬁ er (IC5, pin 1) via HPF (L35, L38, C89, C92, C93, C100, C103). The amplified signals are output from pin 4, and applied to the mixer (IC6, pin 1) and down-converted. The down converted signals are output from pin 6, then applied to the RF circuits via LPF (L66, C190, C193) and band switch (D42). The LO frequencies and convered frequencies are shown as below.

RX frequency LO frequency Convered frequency

1300–1700 MHz 1001 MHz 350–700 MHz

1700–2300 MHz 1001 MHz 700–1300 MHz

2300–2700 MHz 2002 MHz 350–700 MHz

2700–3300 MHz 2002 MHz 700–1300 MHz

4-1-2 1st IF CIRCUITS

The 1st IF circuits contain a 1st mixer, 1st IF ampliﬁ er and 1st IF ﬁ lter. The 1st IF mixer converts the received signals into a ﬁ xed frequency of the 1st Intermediate Frequency (IF) signal. The converted 1st IF signal is filtered at the 1st IF ﬁ lters, then ampliﬁ ed at the 1st IF ampliﬁ er.

The converted signals from the RF circuits are applied to the 1st IF mixer (IC14, pins 4, 5) and converted into the 266.7 MHz 1st IF signal by being mixed with the 1st LO (Local Oscillator) signals from the 1st-VCO’s.

The converted IF signal is passed through the 1st IF filter (FI1) to ﬁ lter out the unwanted signals, then applied to the 1st IF ampliﬁ er (Q44). The ampliﬁ ed 1st IF signal is then applied to the 2nd mixer (IC19, pin 4) via attenuator (R263, R264).

4-1-3 2nd IF CIRCUITS (MAIN UNIT)

The 2nd IF circuits contain the 2st mixer, 2nd IF amplifier and the 2nd IF ﬁ lters.

4-1-4 NOISE BLANKER CIRCUIT

The noise blanker (NB) circuit reduces pulse type noises in the received signals. When the received signals contain pulse type noise components, the NB circuit reduces the noisy AF signals by cutting off the 2nd IF line.

In AM, SSB or CW mode and the NB function is activated, a portion of the 2nd IF signal from the band switch (D70, D71) is ampliﬁ ed at NB ampliﬁ er (Q68) and applied to the IF IC (IC16, pin 2).

When the 2nd IF signal contains a pulse noise, the RSSI signal corresponding to the pulse noise level is output from pin

17. The output RSSI signal turns Q49 ON and Q65 turns OFF, thus the Q66 is inactivated and the 2nd IF signal is cut off.

4-1-5 3rd IF AND DEMODULATOR CIRCUITS (MAIN-A/B UNIT)

The 2nd IF signal is converted into the 3rd IF signal (except WFM mode) and demodulated in the IF IC. The IF IC contains a 3rd mixer, limiter ampliﬁ er, quadrature detector, etc. in its package.

In FM mode, the 2nd IF signal from the 2nd IF amplifier (Q66) is applied to the IF IC (IC24, pin 16) via mode switch (D78) and IF gain control circuit (D97).

The applied 2nd IF signal is converted into the 3rd IF signal by being mixed with 3rd LO signal from the TCXO (X1), at the 3rd mixer in the IF IC (IC24).㩷The converted 3rd IF signal is output from pin 3 and applied to the 3rd IF ampliﬁ er (Q62). The ampliﬁ ed 3rd IF signal is passed through one of the 3rd IF ﬁ lter according to the receiving mode.

The filtered 3rd IF signal is applied to the limiter amplifier (IC24, pin 5), then applied to the demodulator circuit (pin 10, X2) and FM-demodulated. The FM-demodulated AF signals are output from pin 9, then applied to the AF circuits.

In AM and CW mode, the 3rd IF signal from the 3rd IF ﬁ lter is applied to the 3rd IF amplifier (Q61). The amplified 3rd IF is applied to the AM demodulator circuit (D75) via the buffer ampliﬁ er (Q63). The AM-demodulated AF signals are applied to AF circuits via the AF selector (IC27, pins 3, 4).

The 1st IF signal from the 1st IF circuits is converted into the 10.7 MHz 2nd IF signal by being mixed with the 2nd LO signals from the 2nd-VCO.

The converted 2nd IF signal is applied to the 2nd IF ampliﬁ er (Q60). The ampliﬁ ed 2nd IF signal is passed through the 2nd IF ﬁ lter to ﬁ lter out the unwanted signals.

In SSB mode, the 3rd IF signal from the buffer amplifier (Q63) are applied to the AF mixer (IC23, pin 6) and converted into the AF signal by being mixed with the 447.3–

452.7 kHz BFO signal from the DDS circuits. The converted audio signals are applied to the AF selector (IC27, pin 1) after being ﬁ ltered at the HPF (IC31, pins 1, 4).

In WFM mode, the 2nd IF signal is applied to the IF IC (IC16, pin 2) via the 2nd IF ampliﬁ er (Q66) and mode switch (D90, D91). The 2nd IF signal is amplified at the limiter amplifier, then applied to the demodulator circuit (pins 11, 12, X2) and FM-demodulated. The FM-demodulated AF signals are output from pin 8, then applied to the AF circuits via the AF selector (IC27, pins 8, 9).

*MAIN-A UNIT only

4 - 2

<3rd IF AND DEMODULATOR CIRCUITS (FM)>

3rd IF signal to the AM demodulator circuits

D/A converter

FM-demodulated signals to the AF circuits

<2nd IF AND DEMODULATOR CIRCUITS (WFM)>

IC8

Quodrature

Detector

Noise

Amp.

D94D96

BPF

FI9

D69D73

Limit’r

Amp.

735

RSSI

BPF

FI8

BPF

FI7

BPF

Detector

Noise

D93D95

D68D72

Q62

3rd IF amp.

10.25 MHz 3rd LO signal

Q71

REF amp.

Q80

REF amp.

TCXO

IF IC (IC24)

1110

+5V

Q73

1312

“NOISE” signal to the CPU (IC18, pin 16)

“RSSI” signal to theAGC amplifier (Q67)

2nd IF signal from the 2nd IF circuits

Limit’r

Amp.

Quodrature

Detector

FM-demodulated signals to the AF circuits

1112

4-1-6 AF CIRCUITS (LOGIC UNIT)

The demodulated AF signals from the demodulator circuits are ampliﬁ ed and ﬁ ltered in the AF circuits.

In FM mode, the demodulated AF signals from the demodulator circuits are passed through the AF select switch (IC4, pins 1, 7) and BPF (IC27, pins 1, 3 and 5, 7), then applied to the AF ampliﬁ er (Q18).

In other than FM mode, the demodulated AF signals from the demodulator circuits are passed through the AF select switch (MAIN-A/B; UNIT ;IC27, pins 8, 9; WFM, pins 3, 4; AM, pins 1, 2; SSB), then applied to the AF ampliﬁ er (Q18).

The amplified AF signal are applied to the electric volume (IC17, pins 6, 7) for level adjustment. The level adjusted AF signals are passed through the speaker mute switch (Q12) and applied to the AF power amplifier (IC12, pin 1). The power-amplified AF signals are applied to the internal speaker via J1 (J6) or an external speaker/ear phone via the phone switch (S1), attenuator (R19, R20) and J1 (J6).

• AF CIRCUITS

IF IC

(IC24)

WFM

IF IC

(IC16)

AM demodulator

(D75)

From the BFO

IC4

selector

AF mixer (IC23)*

SSB

IC27

BPF

IC27

selector

AF Amp.

MAIN-A/B UNIT LOGIC UNIT

Q18

IC17

67 14

Ele. VR

Q15

AF Amp.

Limit’r

Amp.

RSSI

Limit’r

Amp.

IF IC (IC16)

“RSSI” signal to the NB circuits

2nd IF signal from the 2nd IF circuits

In the USB (Universal Serial Bus) audio output mode, the AF signals from the AF ampliﬁ er (Q18) are applied to another AF ampliﬁ er (Q15). The ampliﬁ ed AF signals are passed through the USB audio selector (IC2038, pins 1, 3), then applied to the USB audio IC (IC16, pin 12) then converted into the USB audio data. The converted audio data is applied to the connected PC via the USB HUB (IC32, pins 5, 6 and 2, 3).

4-1-7 SQUELCH CIRCUIT

• NOISE SQUELCH (MAIN-A/B UNITS)

The noise squelch mutes the AF output signals when no RF signals are received. By detecting noise components in the demodulated AF signals, the squelch circuit toggles the AF power ampliﬁ er ON and OFF.

A portion of the demodulated signals from the IF IC (IC24, pin 9) are applied to the D/A converter (IC8, pin 1) for level adjustment. The level-adjusted AF signals are output from pin 2, and passed through the noise filter (R421, R417, C520, C523). The ﬁ ltered noise signals are then applied to the noise amplifier (IC24, pins 7, 8) to be amplified noise components only. The amplified noise components are converted into the

Phone switch (S1)

D+

D–

AT T

USB connector

(J2)

(CHASSIS; J6)

Speaker (CHASSIS; SP1)

To the PC

*MAIN-A UNIT only

D+

D–

Powe r Amp.

IC12

USB HUB

Q12, D8

mute sw.

IC16 IC32

126

USB audio

4 - 3

pulse-type signal at the noise detector section, and output from pin 13 as the “NOIS” signal. The “NOIS” signal is applied to the CPU (IC18, pin 16). And the CPU outputs control signals “LSTB,” “VDAT,” “VCK” from pins 61, 57, 58, to the expander (IC34) according to the “NOIS” signal level. Then the expander outputs “SPPWR” signal from pin 7 to toggle the AF+8V regulator (Q5, Q8) ON and OFF.

The expander also outputs “SPMUTE” signal to the speaker switch (Q12, D28) at the same time, to disconnect the AF line.

• TONE SQUELCH (LOGIC UNIT)

The tone squelch detects the tone (CTCSS/DTCS) signal in the demodulated AF signals, and opens the squelch only when the matched sub-audible tone frequency is detected in the received signal.

While the tone squelch is in use, and the received signal contains no sub-audible tone or mismatched tone frequency, the tone squelch mutes the AF signals even if the noise squelch is open.

A portion of the demodulated AF signals from the IF IC (MAIN-A/B; IC24, pin 9) are passed though the tone filter (IC21/IC2021, pins 5, 7) to suppress unwanted voice signals. The ﬁ ltered tone signals are applied to the CPU (IC18, pin 93/85).

• 1st VCO’s

The 1st VCO is composed by two VCO’s; as the 1st LO signal generator for 0.01–483.29 MHz and 483.3–3300 MHz reception range.

[When receiving 0.01–265.6999 MHz signals]

-1st VCO 1 (Q28, D53)-

Generates 532.4–749.95 MHz LO signals. The VCO output signal is buffer-ampliﬁ ed by Q27. The buffer ampliﬁ ed signals are passed through the LO siwtch (D58) and buffer ampliﬁ er (IC15, pins 1, 4).

-1st VCO 2 (Q30, D54)-

Generates 750–1066.65 MHz LO signals. The VCO output signal is buffer-ampliﬁ ed by Q29. The buffer ampliﬁ ed signals are passed through the LO siwtch (D59) and buffer ampliﬁ er (IC15, pins 1, 4).

The buffer ampliﬁ ed VCO output signals from pin 4 of IC15 are passed through the attenuator (R137, R138, R152), LO switch (D57) and another attenuator (R153, R154, R156), and applied to the divided LO signals are buffer-amplified by Q34, and then passed through the HPF (L113, C316, C321), LPF (L115, L118, C326, C322), LO switch (D85) and attenuator (R214, R217, R226), before being applied to the 1st mixer (IC14, pins 1, 6).

/2 frequency divider (IC11, pin 2). The

The CPU decodes the CTCSS/DTCS signal, and outputs control signals “LSTB,” “VDAT,” “VCK” from pins 61, 57, 58, to the expander (IC34) according to the applied CTCSS/DTCS signal. Then the expander outputs “SPPWR” signal from pin 7 to toggle the AF+8V regulator (Q5, Q8) ON and OFF.

The expander also outputs “SPMUTE” signal to the speaker switch (Q12, D28) at the same time, to disconnect the AF line.

4-1-8 BANDSCOPE CIRCUITS* (MAIN-A UNIT)

A portion of the 2nd IF signal from the 2nd mixer (IC19, pin

5) is applied to the IF IC (IC20, pin 16) via the 2nd IF ﬁ lter (FI2). The 2nd IF signal is converted into the 3rd IF signal by being mixed with 3rd LO signal from the DDS circuits, at the 3rd mixer in the IF IC (IC20).䇭The converted 3rd IF signal is output from pin 3 and passed through the 3rd IF ﬁ lter FI4. The ﬁ ltered signal is ampliﬁ ed at the limiter ampliﬁ er in the IC to produce the RSSI signal which corresponding to the received signal level.

The RSSI signal “SCAD” is output from pin 12, and applied to the CPU (IC18, pin 89). The CPU converts the RSSI signal into the digital signal, and outputs to connected PC via USB HUB (IC32, pins 19, 20 and 2, 3) to indicate the received signal level for bandscope function on the PC screen.

4-2 PLL CIRCUITS

4-2-1 VCO CIRCUITS (MAIN-A/B UNITS)

DOWN CONVERTER VCO*

The down converter VCO (Q19, D43) generates the 1001 MHz LO signals for down conversion.

The VCO output signals are buffer amplified by Q13, and applied to the mixer (IC6, pin 3) for frequency downconversion, via the band switches (D11, D12, D21, D22).

When the recceiving 2000 MHz and above, the VCO outputs are doubled by being passed through the HPF (L23, C61, C69, C75), and applied to the mixer (IC6, pin 3) as the 2002 MHz LO signals via the band switches (D12, D22).

[When receiving 266.7–33000 MHz signals]

-1st VCO 1 (Q28, D53)-

-1st VCO 2 (Q30, D54)-

The buffer ampliﬁ ed VCO output signals from pin 4 of IC15 are passed through the attenuator (R137, R138, R152) and LO switches (D60, D84) and BPF (L107, L108, C276, C278, C288, C292, C298), before being applied to the 1st mixer (IC14, pins 1, 6).

• 2nd VCO

The 2nd VCO (Q47, D62, D63) generates the LO signals for producing 2nd IF signal. The oscillated signals are buffer ampliﬁ ed by Q50, and applied to the 2nd mixer (IC19, pin 1) via LPF (L158, C456, C459, C462) and attenuator (R276).

4-2-2 PLL CIRCUITS (MAIN-A/B UNIT)

The PLL circuits provide stable oscillation of the receive LO frequencies. The PLL circuit compares the phase of the divided VCO frequency with the reference frequency. The PLL output frequency is controlled by the divided ratio (N-data) from the CPU.

• DOWN CONVERTER PLL*

A portion of the VCO output signals are amplified at the buffer ampliﬁ er (Q14) and then applied to the PLL IC (IC4, pin 8). The applied signals are divided at the prescaler and programmable counter according to the N-data “DAT1” from the expnader (IC3, pin 2) controlled by the CPU (LOGIC UNIT; IC18). The divided signal is phase compared with the reference frequency from the reference ampliﬁ er (Q5) at the phase comparator.

4 - 4

*MAIN-A UNIT only

The phase difference is output from pin 5 as a pulse type signal after being passed through the internal charge pump. The output signal is applied to the VCO (Q19, D43) after being converted into the DC voltage (lock voltage) at the loop filter (R84, R102, R106, C180, C188, C202, C645, C646).

• 1st PLL

-1st VCO 1 (Q28, D53)-

A portion of the VCO output signals from the buffer ampliﬁ er (IC12, pin 4) are applied to the PLL IC (IC10, pin 8) via the buffer amplifier (Q39). The applied signals are divided at the prescaler and programmable counter according to the N-data “DAT1” from the expnader (IC7, pin 2) controlled by the CPU (IC18). The divided signal is phase compared with the reference frequency at the phase comparator.

The phase difference is output from pin 5 as a pulse type signal after being passed through the internal charge pump. The output signal is applied to the VCO (Q27, Q28, D52, D53) after being converted into the DC voltage (lock voltage) at the loop ﬁ lter (Q35, Q36).

-1st VCO 2 (Q30, D54)-

• 2nd PLL

A portion of the VCO (Q47, D62, D63) output signals from the buffer (Q50) are applied to the PLL IC (IC13, pin 11) via the buffer (Q41). The applied signals are divided at the prescaler and programmable counter according to the N-data “DAT1” from the expnader (IC3, pin 2) controlled by the CPU (IC18). The divided signal is phase compared with the reference frequency from the reference ampliﬁ er (Q31) at the phase comparator.

The phase difference is output from pin 5 as a pulse type signal after being passed through the internal charge pump. The output signal is applied to the VCO (Q47, D62, D63) after being converted into the DC voltage (lock voltage) at the loop ﬁ lter (R235, R238, C354, C355, C362).

If the oscillated signal drifts, its phase changes from that of the reference frequency, causing a lock voltage change to compensate for the drift in the oscillated frequency.

PLL IC

PLL unlock detect signal

PLL strobe signal

PLL crock signal

PLL serial data (N-data)

Reference frequency signal

4-3 DIGITAL MODE OPERATION WITH UT-122

DATA interface

Reference

counter

†

A portion of the 450 kHz 3rd IF signal from IF IC (MAIN-A UNIT; IC24, pin 13) is applied to the LOGIC UNIT via the IF ampliﬁ er (MAIN-A UNIT; Q76, Q77). The applied 3rd IF signal is passed through the IF switch (LOGIC UNIT; IC2028, pins 1, 7) and buffer amplifier (LOGIC UNIT; Q2023), then applied to the attached UT-122 via J2017 (pin 11).

The applied 3rd IF signal is passed through the IF filter (UT-122; FI1) to remove unwanted signals, and applied to the A/D converter (UT-122; IC8, pin 3) to be converted into the digital signal via BPF. The converted digital signal is then applied to the DSP (Digital Signal Proccesor; IC7) and demodulated. The demodulated signal is then applied to the liner codec (UT-122; IC9) to be converted in to the analog audio signals.

Programmable

Phase

detector

Prescaler

counter

Charge

pump

Buffer

Loop

filter

amp.

VCO

Buffer amp.

to a mixer

The converted audio signals are applied to the same AF circuits as analog receiving from the AF switch (IC23, pin 7).

†

Optional product (DIGITAL UNIT for R2500; [USA-2])

4 - 5

4-4 POWER SUPPLY CIRCUITS

VOLTAGE LINE DESTINATION VOLTAGE LINE DESTINATION

HV Same voltage as the connected power supply. AP5V Optional UT-122.

AF+8V AF power ampliﬁ er (IC12). OP5V Optional UT-108/UT-118.

L5V

+33V Loop ﬁ lter (MAIN-A/B UNITS; Q35, Q36). A+8V

USB3.3V USB HUB (IC20, IC32), USB audio IC (IC16). –5V AGC ampliﬁ er (MAIN UNIT; IC25).

Electric volume (IC17), tone ﬁ lter (IC21), AF switch (IC4, IC23), etc.

A+5V

MAIN-A UNIT.

VOLTAGE LINE DESTINATION

DPLL3.3V Down converter circuit; PLL IC (IC4).

D3.3V

PLL3.3V 1st and 2nd PLL circuits; PLL IC (IC10, IC13).

5V Divider (IC11), reference oscillator (X1), etc.

DVCO5V

Down converter circuit; mixer (IC6), RF ampliﬁ er (IC15), etc.

Down converter circuit; VCO (Q19, D43), buffer (Q14), etc.

VOLTAGE LINE DESTINATION

BPLL3.3V 1st and 2nd PLL circuits; PLL IC (IC10, IC13).

B1/2 5V Divider (IC11).

*R2500 only

4 - 6

4-5 CPU PORT ALLOCATION

4-5-1 CPU (LOGIC UNIT; IC18)

Pin No.

16 NOIS

17 BNOIS

18 PWRSW

19 BMST3*

20 CCS

21 BP1STB*

22 BP2STB*

23 BDSTB*

27 PDIN Input port for USB data.

28 PDOUT Outputs USB data.

31 SCL Outputs clock signal to the EEPROM (IC14, pin 5).

33 OPSO

34 OPSI

35 OPSCK

36 AIRQ

37 ASTB

38 ASI

39 ASO

40 ACK

41 DSPS

42 IMST

43 BUSY

44 SDL I/O port for EEPROM (IC14, pin 6).

45 OPAFSEL

46 OPAFINH

47 BOPAFSEL*

48 BOPAFINH*

PORT

NAME

4 BMST2

5 BCK

8 BMST1

9 CSHIFT

DESCRIPTION

Outputs strobe signal to the expander (MAIN-B UNIT; IC18, pin1).

Outputs clock signal to the expander (MAIN-B UNIT; IC17, pin 3).

Outputs strobe signal to the expander (MAIN-B UNIT; IC3, pin1).

Outputs clock frequency shift signal to the clock shift circuit (D6).

Input port for “NOIS” signal from the IF IC (MAIN-A UNIT; IC24, pin 13).

Input port for “BNOISE” signal from the IF IC (MAIN-B UNIT; IC24, pin 13).

Input port for power witch (CHASSIS; S1). “Low”=While the power switch is turned.

Outputs strobe signal to the expander (MAIN-B UNIT; IC17, pin 1).

Outputs optional unit select signal to the attached optional unit via the pin 20 of J2018. “High”=While the optional unit is attached.

Outputs PLL strobe signla to the 1st PLL IC (MAIN-B UNIT; IC10, pin 11).

Outputs PLL strobe signla to the 2nd PLL IC (MAIN-B UNIT; IC13, pin 13).

Outputs strobe signal to the D/A converter (MAIN-B; IC8, pin 6).

Output serial data to the attached optional unit via the pin 18 of J2018.

Input port for serial data from the attached optional unit via the pin17 of J2018.

Outputs clock signal to the Attached optional unit via the pin 16 of J2018.

Input port for data request signal from the attached UT-122 via the pin 19 of the J2017.

Outputs strobe signal to the attached UT-122 via the pin 20 of the J2017.

Input port for serial data from the attached UT-122 via the pin 17 of the J2017.

Outputs serial data to the attached UT-122 via the pin 18 of the J2017.

Outputs clock signal to the attached UT-122 via the pin 16 of the J2017.

Outputs DSP select signal to the attached DSP unit via pin 7 of J15.

Outputs DSP strobe signal to the attached DSP unit via pin 3 of J15.

Outputs busy signal to the attached optional unit via pin 7 of J7.

Outputs control signal to the AF switch (IC23, pin 5). “High”=While the optional unit is activated.

Outputs control signal to the AF switch (IC23, pin 2). “High”=The AF line for the optional unit is dis-

connected. Outputs control signal to the AF switch

(IC2031, pin 5). “High”=While the optional unit is activated.

Outputs control signal to the AF switch (IC2031, pin 2). “High”=The AF line for the optional unit is dis-

connected.

Pin No.

PORT NAME

49 RXMUTE

53 APAFSEL

54 APAFINH

57 VDAT

58 VCK

59 VSTB

61 LSTB

64 PWR

65 DTMSTD

66 DTMSD

67 DTMCK

70 PDSTB

73 VBUS

75 DSTB

76 P2STB

77 P1STB

78 DPSTB

79 MST0

80 MST1

81 MST2

82 BCMAD*

83 BVSCAF*

85 BRTONE*

86 BSMAD*

88 TEMP Input port for internal temperature detection.

89 SCAD

90 CMAD

91 VSCAF

93 RTONE

98 USBPOW

Input port for mute signal from the attached optional unit via the pin 24 of J2018. “High”=While the audio output is muted.

Outputs control signal to the AF switch (IC4, pin 5). “High”=While the UT-122 is in use.

Outputs control signal to the AF switch (IC4, pin

2). “High”=While the attached UT-122 is inactivated.

Outputs serial data to the electric volume (IC17, pin 16).

Outputs clock signal to the electric volume (IC17, pin 15).

Outputs strobe signal to the electric volume (IC17, pin 14).

Outputs strobe signal to the expander (IC34, pin 1).

Outputs control signal to the power controller (Q4, Q6). “High”=While the receivers power is ON.

Input port for detecting signal from the DTMF decoder (IC19, pin 14). “High”=When the DTMF signal is detected.

Input port for DTMF signal from the DTMF decoder (IC19, pin 9).

Outputs clock signal from the DTMF decoder (IC19, pin 11).

Outputs strobe signal to the DDS IC (MAIN-A UNIT; IC22, pin 41).

Input port for USB connection detecting signal from the VBUS line. “High”=While a PC is connected through [USB] con nector on the receiver's main unit.

Outputs strobe signal to the D/A converter (MAIN-A; IC8, pin 6).

Outputs strobe signal to the 2nd PLL IC (MAIN-A UNIT; IC13, pin 13).

Outputs strobe signal to the 1st PLL IC (MAIN-A UNIT; IC12, pin 11).

Outputs strobe signal to the down converter PLL IC (MAIN-A UNIT; IC4, pin 11).

Outputs strobe signal to the expander (MAIN-A; IC3, pin 1).

Outputs strobe signal to the expander (MAIN-A; IC18, pin 1).

Outputs strobe signal to the expander (MAIN-A; IC3, pin 1).

Input port for RSSI signal from the RSSI signal selector (MAIN-A; IC30, pin 1).

Input port for VSC signal from the tone filter (IC2021, pin 7).

Input port for CTCSS signals from the tone ﬁ lter (MAIN-B UNIT; IC21, pin 1).

Inputport for RSSI signal from the IF IC (MAIN-A/B UNITS; IC16, pin 13).

Input port for RSSI signal from the IF IC (MAIN-A/ B UNITS; IC20, pin 5) for band scope function.

Input port for RSSI signal from the IF IC (MAIN-A UNIT; IC30, pin 1) for AFC function.

Input port for VSC signal from the tone filter (IC21, pin 1).

Input port for CTCSS signals from the tone ﬁ lter (MAIN-A UNIT; IC21, pin 7).

Outputs voltage line control signal to the 3.3V regulator (IC1, Q31, Q32, Q33). “High”=During in the USB audio mode.

DESCRIPTION

*R2500 only

4 - 7

SECTION 5 ADJUSTMENT PROCEDURES

5-1 PREPARATION

When adjusting IC-R1500/R2500, controller for the R1500/R2500 and JIG cable (see the illust below) are required.

¤ REQUIRED TEST EQUIPMENTS

EQUIPMENT GRADE AND RANGE EQUIPMENT GRADE AND RANGE

Standard signal generator (SSG)

Frequency counter

CAUTION!: BACK UP the originally programmed memory data in the receiver before starting the adjustment.

There is possiblity of losing original memory data when the adjustment is finished.

Before starting adjustment:

• Remove the top cover and sheild cover on the MAIN-A UNIT. (Refer to the “SECTION 3” for details)

• Set the AF switch to “PHONES.” (Refer to the instruction manual for details)

Frequency range : 0.1–3300 MHz Output level : 0.1 µV to 32 mV (–127 to –17 dBm)

Frequency range : 0.1–30 MHz Frequency accuracy : ±1 ppm or better Sensitivity : 100 mV or better

AC milliwattmeter Measuring range : 10 µW to 100 mW

External speaker

Input impedance : 8 Capacity : More than 5 W

Ω

HCT

IWS

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ENTERING ADJUSTMENT MODE

Set the direction of the [VOL] to 12 o'clock (11–1 o'clock).

Push and hold [TS•MODE]+[ATT•PRIO]+[NB•AGC]

+[MONI•T/T-SCAN] key, and turn the power switch (MAIN UNIT) ON.

KEY ASSIGNMENTS FOR THE ADJUSTMENT MODE

• [SET•LOCK] : Selects the next adjustment item.

• [S.MW•MW] :

Selects the previous adjustment item.

• CONTROLLER

[SET•LOCK]

[TS•MODE]

[VOL]

• [DIAL] :

Adjusts the value for the item manually.

• [TS•MODE] : Adjusts the value for the item automatically. Stores the set value.

• [V/MHz•SCAN] : Verify the adjustment value for the item.

• [VOL] : Adjust the audio output level.

ENTERING ADJUSTMENT MODE

Set the direction of the [VOL] (Right) to 12 o'clock

(11–1 o'clock).

Push and hold [MAIN•NB]+[MAIN•AGC]+[ATT•PRIO]

+[MODE•SCAN] key, and turn the power switch (MAIN UNIT) ON.

KEY ASSIGNMENTS FOR THE ADJUSTMENT MODE

• [MAIN•NB] : Selects the next adjustment item.

• [VFO/MR•S.MW] (Right band) :

Selects the previous adjustment item.

[S.MW•MW]

[DIAL]

[V/MHz•SCAN]

• DISPLAY EXAMPLE

• CONTROLLER

[MAIN•AGC]

PWR

MAIN AGC

VFO/MR

S.MW

MHz

[MODE•SCAN]

Adjustment item

ATT

MONI

MODE

SCAN

T/T-SCAN

PRIO

[NB•AGC]

[ATT•PRIO]

SQLSQL

[ATT•PRIO]

[MONI•T/T-SCAN]

Adjustment frequency

[SET•SKIP]

SET

MAIN

[MAIN•NB]

SKIP

VFO/MR

VOLVOL

DIALDIAL

[VFO/MR]

S.MW

MHz

[VOL]

[DIAL]

• [DIAL] (Right band) :

Adjusts the value for the item manually.

• [SET•SKIP] : Adjusts the value for the item automatically. Stores the set value.

• [ATT•PRIO] : Verify the adjustment value for the item.

• [VOL] (Right band)

: Adjust the audio output level.

• DISPLAY EXAMPLE

MAIN-A UNIT adjustment

MAIN-B UNIT adjustment

5 - 2

5-2 MAIN-A UNIT ADJUSTMENT

ADJUSTMENT OPERATION VALUE

REFERENCE FREQUENCY

[REF]

BPF [LT1]–[HTF]

–

AGC GAIN (FM) [AGF]

(AM) [AGA]

IF GAIN (FM) [IFF]

(AM) [IFA]

†

Refer to the “ADJUSTMENT ITEM LIST“ on page 5-7.

‡

The output level of the standard signal generator (SSG) is indicated as the SSG's open circuit.

*Displayed on the controller's display.

1 • Connect a frequency counter to the J5 connector on the MAIN-A

UNIT (see the illust below).

2 • Push [TS•MODE]/[SET•SKIP] to store the set value.

1 • Preset the adjustment items as below before the “BPF“ adjustment.

[AGA] : “8A” [IFA] : “25”

2 • Connect an SSG to the antenna connector “ANT1” and set as;

Frequency : Speciﬁ ed frequency* Modulation : none Level : Speciﬁ ed level

†

3 • Push [TS•MODE]/[SET•SKIP] to store the adjustment value.

4 • Repeat 2–3 for each speciﬁ ed frequency and level for [LT1] to [HTF].

1 • Connect an SSG to the antenna connector and set as;

Frequency : Speciﬁ ed frequency* Mode : FM Modulation : 1 kHz Deviation : 3.5 kHz Level : +34 dBµ (–73 dBm)

‡

2 • Connect a speaker and milliwatt meter then set the audio output level

to 50 mW with [VOL].

3 • Push [SET•LOCK]/[MAIN•NB] to select next adjustment item.

4 • Set the SSG as;

Frequency : Speciﬁ ed frequency* Mode : AM Modulation : 1 kHz Deviation : 70% Level : +34 dBµ (–73 dBm)

‡

5••Set the audio output level to 50 mW with [DIAL].

Verify that the demodulated audio signals are not distorted badly.

6 • Push [TS•MODE]/[SET•SKIP] to store the adjustment value.

1 • Set the SSG as;

Level : OFF

2 • Connect a speaker and milliwatt meter then set the audio output level

to 50 mW with [VOL].

3 • Push [SET•LOCK]/[MAIN•NB] to select next adjustment item.

4 • Set the audio output level to 80 µW with [DIAL]. 80 µW

5 • Push [TS•MODE]/[SET•SKIP] to store the adjustment value.

10.25000 MHz

Automatic adjustment

50 mW

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2EMOVETHESHEILDCOVER

5 - 3

5-2 MAIN-A UNIT ADJUSTMENT (coninued)

ADJUSTMENT OPERATION VALUE

S-METER [NS0]–[WS6]

–

S-METER FLATNESS [L1]–[LEH]

–

BAND SCOPE [SC0]–[SC6]

–

CENTER METER [CML] (LOW)

[CMH] (HIGH) 1 • Set the SSG as;

SQUELCH [SQL]

RSSI [RS0]–[RS6]

–

RSSI FLATNESS [R5L]–[R8H]

–

†

Refer to the “ADJUSTMENT ITEM LIST“ on page 5-7.

‡

The output level of the standard signal generator (SSG) is indicated as the SSG's open circuit.

*Displayed on the controller's display.

1 • Set the SSG as;

Frequency : Speciﬁ ed frequency* Modulation : None Level : Speciﬁ ed level

†

2 • Push [TS•MODE]/[SET•SKIP] to store the adjustment value.

3 • Repeat 1–2 for each speciﬁ ed frequency and value for [NS0] to [WS6].

1 • Set the SSG as;

Frequency : Speciﬁ ed frequency* Modulation : None Level : Speciﬁ ed level

†

2 • Push [TS•MODE]/[SET•SKIP] to store the adjustment value.

3 • Repeat 1-2 for each speciﬁ ed frequency and value for [L1] to [LEH].

1 • Set the SSG as;

Frequency : Speciﬁ ed frequency * Modulation : None Level : Speciﬁ ed level

†

2 • Push [TS•MODE]/[SET•SKIP] to store the adjustment value.

3 • Repeat 1–2 for each speciﬁ ed frequency and value for [SC0] to [SC6].

1 • Set the SSG as;

Frequency : 3 kHz lower than speciﬁ ed frequency* Modulation : None Level : +34 dBµ (–73 dBm)

‡

2 • Push [TS•MODE]/[SET•SKIP] to store the adjustment value.

Frequency : 3 kHz higher than speciﬁ ed frequency* Modulation : None Level : +34 dBµ (–73 dBm)

‡

2 • Push [TS•MODE]/[SET•SKIP] to store the adjustment value.

1 • Set the SSG as;

Frequency : Speciﬁ ed frequency* Mode : FM Modulation : 1 kHz Deviation : 3.5 kHz Level : –13 dBµ (–120 dBm)

‡

2 • Set the [SQL] value to close the squelch with [DIAL]. Then set the

[SQL] value at the point where the audio signals just appear.

3 • Turn the SSG output OFF, and verify that the squelch is closed.

4 • Push [TS•MODE]/[SET•SKIP] to store the adjustment value.

1 • Set the SSG as;

Frequency : Speciﬁ ed frequency* Modulation : None Level : Speciﬁ ed level

†

2 • Push [TS•MODE]/[SET•SKIP] to store the adjustment value.

3 • Repeat 1–2 for each speciﬁ ed frequency and value for [RS0] to [RS6].

1 • Set the SSG as;

Frequency : Speciﬁ ed frequency* Modulation : None Level : Speciﬁ ed level

†

2 • Push [TS•MODE]/[SET•SKIP] to store the adjustment value.

3 • Repeat 1–2 for each speciﬁ ed frequency and value for [R5L] to [R8H].

Automatic adjustment

5 - 4

+ 50 hidden pages

Icom IC-r2500, IC-r1500 Service Manual

INTRODUCTION CAUTION

TABLE OF CONTENTS

SECTION 1 SPECIFICATIONS

SECTION 2 INSIDE VIEWS

SECTION 3 DISASSEMBLY INSTRUCTIONS

SECTION 4 CIRCUIT DESCRIPTION

SECTION 5 ADJUSTMENT PROCEDURES