IC-7300_serv.pdf

S-15218XZ-C1 March 2016 HF/50 MHz TRANSCEIVER This service manual describes the latest technical informa- tion for the IC-7300 HF/50 MHz TRANSCEIVER, at the time of pub- lication. NEVER connect the transceiver to a DC power supply that uses more than the specifi ed voltage. This will ruin the trans- ceiver. DO NOT expose the transceiver to rain, snow or liquids. DO NOT reverse the polarities of the power supply when di- rectly applying power to the transceiver/circuit. DO NOT apply an RF signal of more than 20 dBm (100 mW) to the antenna connector. This could damage the transceivers front-end. To upgrade quality, any electrical or mechanical parts and internal circuits are subject to change without notice or obligation. 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 1180004830 XC6222A331MR IC-7300 MAIN UNIT 5 pieces 8110010940 3765 U-COVER IC-7300 CHASSIS 1 piece Addresses are provided on the inside back cover for your convenience. ORDERING PARTS 1. Make sure that the problem is internal before disassem- bling the transceiver. 2. DO NOT open the transceiver until the transceiver is dis- connected 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 trans- ceiver is defective. 6. NEVER directly transmit power into any test equipment such as Standard Signal Generator or a Sweep Generator, otherwise the RF power may damage them. 7. ALWAYS connect a 50 dB to 60 dB attenuator between the transceiver and such test equipment. 8. READ the instructions of the test equipment thoroughly before connecting it to the transceiver. REPAIR NOTES INTRODUCTIONSERVICE CAUTION 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, Australia, New Zealand, and/or other countries. MODELVERSION VERSION NUMBER OPERATABLE BANDS IC-7300 USA#02HF/50 MHz EUR#03HF/50/70 MHz ITR#05 ESP#06 TPE#07HF/50 MHz KOR#08 EXP#12 TABLE OF CONTENTS SECTION 1 SPECIFICATIONS SECTION 2 INSIDE VIEWS SECTION 3 CIRCUIT DESCRIPTION 3-1 PA UNIT . 3-1 3-2 RF UNIT . 3-2 3-3 MAIN UNIT . 3-3 SECTION 4 ADJUSTMENT PROCEDURE 4-1 PREPARATION . 4-1 4-2 RECEIVE ADJUSTMENTS . 4-2 4-3 TX IDLING CURRENT ADJUSTMENTS . 4-3 4-4 TX POWER ADJUSTMENTS . 4-4 4-5 TX AMPLIFIER ADJUSTMENTS . 4-5 4-6 FREQUENCY ADJUSTMENTS . 4-6 SECTION 5 PARTS LIST SECTION 6 MECHANICAL PARTS SECTION 7 BOARD LAYOUTS SECTION 8 GENERAL WIRING SECTION 9 BLOCK DIAGRAM SECTION 10 SCHEMATIC DIAGRAM 1-1 SECTION 1 SPECIFICATIONS M General Frequency coverage (unit: MHz): Receiver 0.030000 74.800000*1 Transmitter 1.800000 01.999999*2 3.500000 03.999999*2 5.255000 05.405000*2 7.000000 07.300000*2 10.100000 10.150000*2 14.000000 14.350000*2 18.068000 18.168000*2 21.000000 21.450000*2 24.890000 24.990000*2 28.000000 29.700000*2 50.000000 54.000000*2 70.000000 70.500000*2 *1 Some frequency ranges are not guaranteed. *2 Depending on the transceiver version. Operating modes: USB/LSB (J3E), CW (A1A), RTTY (F1B), AM (A3E) and FM (F3E) Number of memory channels: 101 (including 2 scan edges) Antenna connector: SO-239 (antenna impedance: 50 unbalanced) Power supply requirement: 13.8 V DC (15%) Operating temperature range: 10C to +60C, +14F to +140F Frequency stability: Less than 0.5 ppm (10C to +60C, +14F to +140F) Frequency resolution: 1 Hz (minimum) Power consumption: Receive Standby 0.9 A Maximum audio 1.25 A Transmit Maximum power 21.0 A Dimensions (projections not included): 240 (W)94 (H)238 (D) mm, 9.4 (W)3.7 (H)9.4 (D) in Weight (approximately): 4.2 kg, 9.3 Ib M Transmitter Transmit output power: HF and 50 MHz bands SSB/CW/RTTY/FM 2100 W AM 125 W 70 MHz band*2 SSB/CW/RTTY/FM 250 W AM 112.5 W *2 Depending on the transceiver version. Modulation system: SSB P.S.N. modulation AM Low power modulation FM Reactance modulation Spurious emission: Harmonics Less than 50 dB (1.828 MHz) Less than 63 dB (50 MHz band) Less than 60 dB (70 MHz band*2) Out-of-band emission Less than 40 dB (1.828 MHz) Less than 60 dB (50 MHz band) Less than 60 dB (70 MHz band*2) *2 Depending on the transceiver version. Carrier suppression: More than 50 dB Unwanted sideband suppression: More than 50 dB Input impedance (microphone): 600 1-2 M Receiver Receive system: Direct sampling superheterodyne Intermediate frequency: 36 kHz Sensitivity (Filter: SOFT): SSB/CW (at 10 dB S/N) 1.8 29.999999 MHz Less than 123 dBm (0.16 V) (P.AMP1 ON) 50 MHz band Less than 125 dBm (0.13 V) (P.AMP2 ON) 70 MHz band*2 Less than 123 dBm (0.16 V) (P.AMP2 ON) *2 Depending on the transceiver version. AM (at 10 dB S/N) 0.5 1.8 MHz Less than 85 dBm (12.6 V) (P.AMP1 ON) 1.8 29.999999 MHz Less than 101 dBm (2.0 V) (P.AMP1 ON) 50 MHz and 70 MHz bands Less than 107 dBm (1.0 V) (P.AMP2 ON) FM (at 12 dB SINAD) 28.0 29.7 MHz Less than 113 dBm (0.5 V) (P.AMP1 ON) 50 MHz and 70 MHz bands Less than 119 dBm (0.25 V) (P.AMP2 ON) Squelch sensitivity (threshold): SSB Less than 92 dBm (5.6 V) FM Less than 117 dBm (0.3 V) (HF band: P.AMP1 ON, 50 MHz band: P.AMP2 ON) Selectivity (Filter: SHARP): SSB (BW=2.4 kHz) More than 2.4 kHz/6 dB Less than 3.4 kHz/40 dB CW (BW=500 Hz) More than 500 Hz/6 dB Less than 700 Hz/40 dB RTTY (BW=500 Hz) More than 500 Hz/6 dB Less than 800 Hz/40 dB AM (BW=6 kHz) More than 6.0 kHz/6 dB Less than 10 kHz/40 dB FM (BW=15 kHz) More than 12.0 kHz/6 dB Less than 22 kHz/40 dB Spurious and image rejection: More than 70 dB (except for ADC aliasing) Audio output power: More than 2.5 W (at 10% distortion into the 8 load, at the 1 kHz reference) Output impedance (Speaker): 8 RIT variable range: 9.999 kHz M Antenna tuner Tunable impedance range: 16.7150 (unbalanced) (less than 3:1 VSWR) Tuning accuracy: Less than 1.5:1 VSWR Tuning time (approximately): 23 seconds (average) 15 seconds (maximum) LAll stated speciications are typical and subject to change without notice or obligation. 2-1 SECTION 2 INSIDE VIEWS MAIN UNIT AF LPF (IC1002) 32 MB FLASH MEMORY (IC902) 64 MB FLASH MEMORY (IC391) CPU (IC301) REAL TIME CLOCK (IC381) 8-Bit SHIFT REGISTER (IC141) DSP (IC901) D/A CONVERTER (IC1331) 3.3 V REGULATOR (IC241) ADJUSTABLE STEP-DOWN CONVERTER (IC261) ADJUSTABLE STEP-DOWN CONVERTER (IC251) 8 V REGULATOR (IC271) 8 V REGULATOR (IC276) DC AMP (IC151) DATA LINE BUFFER (IC701) D/A CONVERTER (IC971) FPGA (IC1351) 3 V REGULATOR (IC1318) USB CODEC (IC661) USB HUB (IC621) AF AMP (IC721) USB HUB CLOCK (6 MHz) (X621) DSP CLOCK (12.288 MHz) (X901) EEPROM (IC351) BACKUP BATTERY (FOR THE REAL TIME CLOCK) (BT381) CPU CLOCK (48 MHz) (X301) A/D CONVERTER (IC1001) CLOCK FILTER (FI1221) D/A CONVERTER (IC991) LVDS DRIVER (IC121) DC AMP (IC135) DC AMP (IC791) USB BRIDGE (IC641) ADJUSTABLE STEP-DOWN CONVERTER (IC201) ELECTRIC DOUBLE-LAYER CAPACITOR (C243) ADJUSTABLE STEP-DOWN CONVERTER (IC221) DC AMP (IC125) ANALOG SW (IC691) DC AMP (IC972) AF AMP (IC992) 1 MB SRAM (IC1401) 2-2 RF UNIT 5 V REGULATOR (IC1061) RF AMP (Q101) YGR AMP (IC1031) 8-bit SHIFT REGISTER (IC1303) 8-bit SHIFT REGISTER (IC1302) PRE-AMP (Q1411) ALC PIN DIODES (D1021 and D1041) ALC AMP (IC1501) 8-bit SHIFT REGISTER (IC1301) DC AMP (IC1502) 2-3 PA UNIT TX POWER AMP (Q132) RF AMP (Q101) DC AMP (IC981) 8-bit SHIFT REGISTER (IC751) DRIVE AMP (Q121) PRE-DRIVE AMP (Q111) TX POWER AMP (Q131) 9 V REGULATOR (IC221) CURRENT MONITOR (IC211) 2-4 10 dB ATTENUATOR TUNING CIRCUIT TUNER UNIT POWER DETECTOR (D1201) SWR DETECTOR (D1505) 8-bit SHIFT REGISTER (IC2821) 8-bit SHIFT REGISTER (IC2811) 8-bit SHIFT REGISTER (IC2831) DC AMP (IC1901) 8-bit SHIFT REGISTER (IC2841) IMPEDANCE DETECTOR (D1701) COMPARATOR (IC1701) PHASE DETECTOR (D1311 and D1312) 3-1 SECTION 3 CIRCUIT DESCRIPTION PA AND TUNER UNITS (Receive circuits) PA AND TUNER UNITS (Transmit circuits) PHASEI PHASE DET SWR DET SWRL ATT IMPI D961,D962 PWR/SWR DET MUTELPF RL801 From the TX circuits TPWRLBUFF D1505 IMP DET D1271 TUNE NET TUNER UNIT IC1701 HF/50 MHz/70 MHz D1311 D1312 PA UNIT fc=76 MHz Q811 D811/D812 IC1701 POWER DET D1201 IC1901 3-1 PA UNIT The PA UNIT is composed of the transmit power amplifi er, harmonic fi lters, and sensing circuits for the transmit power and SWR. (1) RECEIVE SIGNAL PROCESSING The received signal from the TUNER UNIT is passed through the TX/RX SW (RL801), and applied to the RF UNIT through the LPF whose cut-off frequency is 76 MHz, and the TX mute switch (Q811, D811 and D812). To prevent abnormal oscillations caused by feedback of the transmit signal, the TX mute switch connects the transmit line to ground while receiving. (2) TRANSMIT SIGNAL PROCESSING DRIVE AMPLIFIER The transmit signal from the RF UNIT is sequentially ampli- fi ed by the RF amplifi er (Q101), pre-drive amplifi er (Q111) and drive amplifi er (Q121). These RF amplifi ers are the high gain source-grounded amplifi ers. The idling current of drive amplifi er (Q121) is appropriately adjusted to compensate for variation in gain. POWER AMPLIFIER The transmit signal from the drive amplifi er (Q121) is applied to the push-pull power amplifi er (Q131 and Q132) to be ampli- fi ed up to 100 watts (for the HF/50 MHz band) or 50 watts (for the 70 MHz band). The idling current of the power amplifi er is appropriately adjusted to compensate for variation in gain. LPF The transmit signal from the power amplifi er is fi ltered by one of the LPFs that is selected according to the transmit frequency. These LPFs are the Chebyshev fi lters with sharp cut-off characteristics, to reduce the harmonic components in the transmit signal. There are 7 BPFs with different cut-off frequencies. The LPFs are selected by the relays on both sides of each LPF, accord- ing the transmit frequency. FORWARD AND REFLECT WAVES DETECTION CIRCUIT The transmit signal is passed through the SWR detection cir- cuit, which is composed of the CM coupler and rectifi er diodes (D961 and D962). The forward and refl ect waves are detected, resulting in the forward wave and refl ect wave sensing volt- ages. The sensing voltages are amplifi ed by the buffer (IC981), and then applied to the CPU in the MAIN UNIT for monitoring. The amplifi ed transmit signal is applied to the antenna, through the TUNER UNIT. LPF LPF DRIVE AMP LPF PWR AMP Q131 Q132 LPF DRIVE PRE LPF LPF LPF RF AMP D961,D962 PWR/SWR DET RL801 To the RX circuit 14.35-21.45 MHz 0.03-2.0 MHz 2.0-4.0 MHz PA UNIT 21.45-33.0 MHz 33.0-76 MHz Q111 7.3-14.35 MHz Q121 4.0-7.3 MHz Q101 PHASEI PHASE DET SWR DET SWRL ATT IMPI SW11SW11 TPWRLBUFF D1505 IMP DET D1271 TUNE NET TUNER UNIT IC1701 HF/ 50 MHz/ 70 MHz D1311 D1312 IC1701 POWER DET D1201 IC1901 TX signal RX signal 3-2 RF UNIT (Receive circuits) ATT PRE AMP Q1211 Q1212/Q1213 LPF LPF A HPF A RF HPF MUTE BPF BPF BPF BPF BPF BPF BPF BPF LPF BPF BPF BPF BPF 0.03-1.59 MHz 1.60-74.80 MHz To the TX AMP D1081D1083 D1001 50.00-54.00 MHz 22.00-29.99 MHz 30.00-49.99 MHz 54.01-69.99 MHz 70.00-74.80 MHz 15.00-21.99 MHz 2.00-2.99 MHz 4.50-6.49 MHz 10.00-14.99 MHz 3.00-4.49 MHz 1.60-1.99 MHz 8.00-9.99 MHz 6.50-7.99 MHz 1.60-30.00 MHz RF UNIT 3-2 RF UNIT The RF UNIT is composed of the receive and transmit RF circuits. The received signal from the PA UNIT is passed to the MAIN UNIT through the attenuator, fi lter, and preamp. The transmit signal from the MAIN UNIT is passed to the PA UNIT through the fi lter, ALC circuit, and YGR AMP. (1) RECEIVE SIGNAL PROCESSING The received signal from the PA UNIT is passed through the RX mute switch (D1001), passes through or bypasses the attenuator (D1081 D1083) according to the Attenuator function setting, and is then applied to the fi lter circuit. The attenuator (D1081 D1083) is controlled to change the at- tenuation level to between 0 dB (bypass) and 20 dB. The fi lter circuit is composed of 15 fi lters. The received signal is passed through the fi lter that is selected according to the receive frequency. The received signals of 1.6 MHz and below are passed through only LPF (A). The received signals of 1.6 MHz and above are passed through HPF (A), which is designed to prevent interference by strong MF band broadcast stations. This HPF is designed to obtain more than 20 dB of isolation for 1.6 MHz and lower frequencies. The received signals of 1.6 MHz and above are also passed through one of the BPFs, according to the selected operating band. The fi ltered signal is then applied to the preamp circuit. The received signal may be amplifi ed by P.AMP1 (normal gain) or P.AMP2 (higher gain), or bypass both, according to the Pre- amp function setting. The received signal from the preamp circuit is then applied to the MAIN UNIT. TX signal RX signal 3-3 3-2 RF UNIT (continued) (2) TRANSMIT SIGNAL PROCESSING The transmit signal from the MAIN UNIT is passed through one of the BPFs in the fi lter circuit. The fi ltered signal level is adjusted by the gain controller (D1051 and D1052), which compensates the level difference in the band. The transmit signal is then amplifi ed by the YGR AMP (IC1031) to obtain the input level needed in the transmit amplifi er circuit. PRE AMP Q1411 LPF YGR AMP IC1031 PIN D1021 ATT PIN D1041 ATT HPF ATT ALC ALC BPF BPF BPF BPF BPF BPF BPF BPF LPF BPF BPF BPF BPF 0.03-1.59 MHz 1.60-74.80 MHz D1051 D1052 22.00-29.99 MHz 50.00-54.00 MHz(TX) 30.00-49.99 MHz 54.01-69.99 MHz 70.00-72.00 MHz(TX) 15.00-21.99 MHz 2.00-2.99 MHz 4.50-6.49 MHz 10.00-14.99 MHz 3.00-4.49 MHz 8.00-9.99 MHz 6.50-7.99 MHz 1.60-30.00 MHz RF UNIT RF UNIT (Transmit circuits) The signal level is also adjusted by the ALC circuit (D1201 and D1041), which is located at the input and output of YGR AMP (IC1031). The ALC circuit automatically adjusts the transmit signal level according to the transmit power sensing voltage. The level-adjusted transmit signal is then applied to the PA UNIT. TX signal RX signal 3-4 3-3 MAIN UNIT The IC-73