Icom IC-RX7 User manual

S-14510XZ-C1
Aug. 2008
WIDEBAND RECEIVER

This service manual describes the latest service information
for the IC-RX7 WIDEBAND RECEIVER at the time of
publication.
NEVER connect the receiver to an AC outlet or to a DC
power supply that uses more than specifed. This will ruin
the receiver.
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.
To upgrade quality, any electrical or mechanical parts and
internal circuits are subject to change without notice or
obligation.
MODEL VERSION RX FREQUENCY RANGE (MHz)
IC-RX7
[EUR01] 0.150–1300.000
[UK-01]
[USA-01] 0.150–821.995 851.000–866.995
896.000–1300.000
[EXP-01] 0.150–1300.000[CHN-01]
[CAN-01]
Be sure to include the following four points when ordering
replacement parts:
1. 10-digit Icom parts numbers
2. Component name
3. Equipment model name and unit name
4. Quantity required
<ORDER EXAMPLE>
1110003491 S.IC TA31136FNG IC-RX7 MAIN UNIT 5 pieces
8820001210 Screw 2438 screw IC-RX7 Top cover 10 pieces
Addresses are provided on the inside back cover for your
convenience.
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.
ORDERING PARTS
1. Make sure that the problem is internal before
disassembling the receiver.
2. DO NOT open the receiver 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 tuning 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 throughly
before connecting a test equipment to the receiver.
REPAIR NOTES
INTRODUCTION
CAUTION
UNIT ABBREVIATIONS:
L=LOGIC UNIT
M=MAIN UNIT

TABLE OF CONTENTS
SECTION 1 SPECIFICATIONS
SECTION 2 INSIDE VIEWS
SECTION 3 DISASSEMBLY INSTRUCTION
SECTION 4 CIRCUIT DESCRIPITON
4-1 MAIN UNIT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
4-2 1st VCO UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
4-3 2nd VCO UNIT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
4-4 VOLTAGE DIAGRAMS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
4-5 PORT ALLOCATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5
SECTION 5 ADJUSTMENT PROCEDURES
5-1 PREPARATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
5-2 FREQUENCY ADJUSTMENT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
SECTION 6 PARTS LIST
SECTION 7 MECHANICAL PARTS
SECTION 8 BOARD LAYOUTS
SECTION 9 BLOCK DIAGRAM
SECTION 10 VOLTAGE DIAGRAMS
LOGIC UNIT (Left side). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1
LOGIC UNIT (Right side). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-2
MAIN UNIT (Left side) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-3
MAIN UNIT (Right side). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4
1st VCO UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5
2nd VCO UNIT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5

1 - 1
SECTION 1 SPECIFICATIONS
DGeneral
• Frequency coverage : (Unit: MHz)
USA 0.150–821.995, 851.000–866.995,
896 000–1300.000
Other than USA 0.150–1300.000
• Number of memory channels : 1600 channels (Memory channels)
200 channels (Auto write channels)
25 channels (Scan edge channels)
• Receive modes : FM, AM, WFM
• Frequency resolu ion : 5, 6.25, 7.5, *8.33,*9, 10, 12.5, 15, 20,
25, 30, 50, 100, 125, 200 kHz
*selectable depending on the operating frequency band.
• Operating temperature range : –10°C to +60˚C; +14˚F to +140˚F
• Reference frequency stability : ±6 ppm (–10˚C to +60˚C; +14˚F to +140˚F)
• Power supply requirement : BP-244 (Li-Ion battery pack),
(Negative ground) BP-262 (3 AA (LR6) alkaline cells) or
5.1 to 6.9 V DC (with CP-18A/E)
• Current drain (backlight OFF with BP-244 (3.7V DC):
rated audio 150 mA typical
receive standby 100 mA typical
power saved 35 mA typical
• Antenna connector type : SMA
• Antenna impedance : 50 Ω(unbalanced)
• Dimensions (proj. not included) : 57(W) ×128(H) ×23(D) mm
21⁄4(W)×51⁄32(H)×29⁄32(D) in
• Weight (approx.) :200 g; 7.1 oz (with the ant.and BP-244)
• AF output power (at 3.7 V DC) :More than 600 mW at 70% modulation,
10% distortion with an 8 Ωload
• Ext. speaker connector : 3-conductor 3.5 (d) mm (1⁄8″)/8 Ω
DReceiver
• Receive system :Triple-conversion superheterodyne
• Intermediate frequencies : 1st : 429.1 MHz,
2nd : 19.65 MHz (FM/AM),
20.75 MHz (WFM)
3rd : 450 kHz (FM/AM),
1.55 MHz (WFM)
• Sensitivity (except spurious points) :
FM (1 kHz/3.5 kHz Dev.; 12 dB SINAD)
1.625–4.995 MHz Less than 0 56 μV
5.000–246.995 MHz Less than 0.4 μV
247.000–832.995 MHz Less than 0 56 μV
833.000–1300.000 MHz Less than 0.79 μV (Except USA version)
851.000–866.995 MHz Less than 1 3 μV (USA version only)
896.000–1300.000 MHz Less than 0.79 μV (USA version only)
WFM (1 kHz/52.5 kHz Dev.; 12 dB SINAD)
76.000–108.000 MHz Less than 1 8 μV
175.000–221.995 MHz Less than 1 8 μV
470.000–770.000 MHz Less than 2 5 μV
AM EXT-ANT (DX) (1 kHz/30% MOD.;10 dB S/N)
0.495–4.995 MHz Less than 2 5 μV
5.000–29.995 MHz Less than 1 8 μV
118.000–136.000 MHz Less than 1 8 μV
222.000–246.995 MHz Less than 1 8 μV
247.000–329.995 MHz Less than 1 8 μV
• Selectivity :
AM/FM More han 15 kHz/–9 dB
Less than 30 kHz/–60 dB
WFM More han 150 kHz/–6 dB

2 - 1
SECTION 2 INSIDE VIEWS
• LOGIC UNIT
• MAIN UNIT
TONE CONTROLER (AF SW)
(IC20)
CLONE BUFFER
(IC8)
EEPROM
(IC14)
EEPROM
(IC15)
3V line SW
(Q28)
CPU
(IC17)
3V REG
(IC4)
3.2V REGULATOR
(IC3)
TONE FILTER
(IC12)
1STVCO REFERENCE FREQUENCY
OSCILLATOR
(X1)
DISCRIMINATOR
(X3)
3rd IF FILTER
(FI3)
2NDVCO

1-1-32, Kamiminami, Hirano-ku, Osaka 547-0003, Japan S-14510XZ-C1
© 2008 Icom Inc.