INSTRUCTION MANUAL VHF/HF ALL MODE TRANSCEIVER i746 This device complies with Part 15 of the FCC rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.
IMPORTANT READ THIS INSTRUCTION MANUAL CAREFULLY before attempting to operate the transceiver. SAVE THIS INSTRUCTION MANUAL—This manual contains important safety and operating instructions for the IC-746. PRECAUTIONS RWARNING! HIGH VOLTAGE! NEVER attach an antenna or internal antenna connector during transmission. This may result in an electric shock or burn. RNEVER apply AC to the [DC13.8V] socket on the transceiver rear panel. This could cause a fire or ruin the transceiver.
TABLE OF CONTENTS IMPORTANT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . EXPLICIT DEFINITIONS . . . . . . . . . . . . . . . . . . . . . BUILT-IN DSP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TABLE OF CONTENTS . . . . . . . . . . . . . . . . . . . . . ii ii ii ii iii 1 PANEL DESCRIPTION . . . . . . . . . . . . . . . . . . 2–7 1-1 Front panel . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 PANEL DESCRIPTION 1-1 Front panel Å TUNER 1 ANT POWER NR APF TRANSMIT 2 6 7 Å 8 9 PHONES 3 NR ELEC-KEY AF APF/ANF RF/SQL 4 MIC !0 !1 !2 ı !3 5 q POWER SWITCH [POWER] ➥ Push momentarily to turn power ON. (p. 11) • Turn the optional DC power supply ON in advance. ➥ Push and hold to turn power OFF. w TRANSMIT SWITCH [TRANSMIT] Toggles between transmit and receive. • The [TX] indicator lights red while transmitting and the [RX] indicator lights green when the squelch is open.
PANEL DESCRIPTION !3 RF GAIN/SQUELCH CONTROL [RF/SQL] (p. 12) Adjusts the RF gain and squelch threshold level. The squelch removes noise output from the speaker (closed condition) when no signal is received. • Setting RF gain Maximum RF gain Maximum RF gain sensitivity Adjustable range • The squelch is particularly effective for FM. It is also available for other modes.
1 PANEL DESCRIPTION Ç Î Î 1.8 1 3.5 2 7 3 10 4 14 5 18 6 21 7 24 8 28 9 GENE • 50 0 144ENT F-INP @7 SPLIT @8 A/B @9 TS #0 @6 ´ Ç HF/VHF TRANSCEIVER @6 KEYPAD (p. 14) ➥ Push a key to select an operating band. • [GENE] selects the general coverage band. ➥ Push the same key 2 or 3 times to call up stacked frequencies in the band. • Icom’s band stacking register memorizes 3 frequencies (and modes) in each band. @7 FREQUENCY INPUT SWITCH [F-INP] (p.
PANEL DESCRIPTION ´ #1 #2 #3 #4 MP-W TX XFC #5 #6 #7 $0 $1 1 $2 MP-R RX LOCK RIT TX CLEAR RIT/ TX $3 $4 #8 SPEECH LOCK #9 #1 TUNING DIAL Changes the displayed frequency, selects set mode items, etc. #2 TRANSMIT FREQUENCY CHECK SWITCH [XFC] (pgs. 34, 38, 45, 47) Monitors the transmit frequency when pushed and held when the split frequency function is ON. • While pushing this switch, the transmit frequency can be changed with the tuning dial, keypad or the memo pad.
1 PANEL DESCRIPTION Ï Ï TWIN PBT $5 M VFO $6 V/M CALL $8 MW M-CL M-CH $7 $9 %0 $5 PASSBAND TUNING CONTROLS [TWIN PBT] (p. 41) Adjust the receiver’s “passband width” of the 455 kHz and 9 kHz IF filters for the inner and outer controls, respectively. • Passband width and center frequency are displayed in the function display. • Set to the center positions when not in use. • Variable range depends on the filter selection. ±1.29 kHz in 15 Hz steps and ±258 Hz in 3 Hz steps are available.
PANEL DESCRIPTION 1 1-3 Function display 1 EXT 2 TUNE 3 4 1 ANT 2 LSBUSBCW RTTY RAM WFM NAR 1 4 5 7 1 S Po 3 5 20 9 50 20 40 60 RIT TX 100% 1.5 2 VOX F BK IN COMP MONI 3 P. AMPATT AGC OFF 1 2 F S NB SPLIT DUP XFC TSQL RIT CALL BLANK VFOA VFOB MEMO ALC SWR 1 !7 7 9 8 6 TX CH M1 AGC DUP CMP TCN SCP q ANTENNA TUNER INDICATORS (pgs. 59, 79) ➥ “TUNE” appears when the antenna tuner is ON; “TUNE” appears and flashes during manual tuning.
2 MENU SELECTION Depending on the mode and menu item selected, the action of the multi-function keys ([F1] to [F5]) changes. Pushing [MENU] toggles between menu set 1 (M1) and menu set 2 (M2) in the function display. 2-1 Menu set 1 flow chart SSB MODE RTTY MODE M1 AGC DUP 1/4 RTY SCP USB 1 ANT F1 1 S Po 3 5 7 20 9 20 40 60 100% 50 1.5 2 1 F4 RTTY MENU AGC (p. 29) RTY RTTY Mark S 2125 M1 AGC DUP CMP TCN SCP F1 F2 F1 F5 To band scope menu CH 3 P.
MENU SELECTION 2 2-2 Menu set 2 flow chart USB 1 ANT 1 S Po 3 5 7 20 9 20 40 60 BLANK VFOA 100% 50 ALC SWR 1 1.5 2 CH 3 P. AMP AGC 1 SET MODE S F5 M2 SCN MEM LCD F2 F1 SET Beep Level 50% SET F3 F1 F5 F2 LCD MENU SCAN MENU (pgs. 56–58) VFO MODE F3 SCN PRO ∂F (p. 60) (p. 66) LCD LCD Contrast 50% ∂F + -10k FIN SPN SET F2 F1 F2 F1 F3 F4 F5 MEMORY NAME MENU MEMORY MODE SCN MEM ∂F ∂F + -10k SEL SPN SET F-2 F-1 F-3 F-4 F2 (p. 53) 14.
3 BASIC OPERATION 3-1 Before operating Before applying power for the first time, check the following points: Å BEFORE APPLYING POWER ➥ Is the connected external power supply capable of delivering more than 20 A? ➥ Are the antenna(s) connected properly? • [ANT1/2]: HF/50 MHz antenna • [144MHz]: 144 MHz antenna ➥ Is the transceiver properly grounded? (p. 70) ➥ Is external equipment, such as a linear amplifier connected properly? (p.
BASIC OPERATION ı APPLYING POWER 3 When applying power to the transceiver for the first time, it’s a good idea to reset the CPU (see p. 81 for details) as follows: [F-INP] [M-CL] [POWER] While pushing [F-INP] + [M-CL], push [POWER] to turn power ON. • After the CPU has been reset, turn power ON by pushing [POWER] only. • Push [POWER] for 1 sec. to turn power OFF. ☞ NOTE: When first applying power or when operat- USB 1 ANT ing in cold environments, the display may flicker or appear faint.
3 BASIC OPERATION 3-2 Squelch and receive (RF) sensitivity Adjusts the RF gain and squelch threshold level. The squelch removes noise output from the speaker (closed condition) when no signal is received. • The squelch is particularly effective for FM. It is also available for other modes. • The control can be set as the RF gain control only (squelch is fixed open) or squelch control (RF gain is fixed at maximum) in set mode (p. 61). See below left.
BASIC OPERATION 3-3 Selecting VFO/memory mode [V/M] 3 Rotating the tuning dial selects frequencies in VFO mode or pre-programmed memories in memory mode. Push [V/M] to toggle between memory and VFO modes. • Pushing [V/M] for 2 sec. transfers the contents of the selected memory channel to VFO mode (p. 50). ■ VFO DISPLAY (default) USB 1 ANT 1 S Po 3 5 7 20 9 ■ MEMORY DISPLAY (default) 20 40 60 VFOA ALC SWR 1 1.5 2 CH 3 P. AMP ■ WHEN OPERATING IN VFO A 20 7 9 20 40 1.
3 BASIC OPERATION 3-5 Setting a band and frequency Å SETTING AN OPERATING BAND Band keys BAND 1.9 MHz 3.5 MHz 7 MHz 10 MHz 14 MHz 18 MHz 21 MHz 24 MHz 28 MHz 50 MHz 145 MHz General REGISTER 1 1.900000 CW 3.550000 LSB 7.050000 LSB 10.120000 CW 14.100000 USB 18.100000 USB 21.200000 USB 24.950000 USB 28.500000 USB 50.100000 USB 145.000000 USB 15.000000 USB ■ USING THE BAND STACKING REGISTERS 3.5 2 7 See the table below for a list of the bands available and the default settings for each register.
BASIC OPERATION ı SETTING A FREQUENCY WITH THE TUNING DIAL 3 Frequencies can be selected with the tuning dial or directly with the keypad (p. 17). When using the tuning dial, the frequency changes according to the set tuning step. Tuning step defaults differ depending on operating mode as shown below. SSB/CW/RTTY: 10 Hz AM: 1 kHz FM: 10 kHz Tuning dial ■ BAND EDGE WARNING BEEPS ➥ Rotate the tuning dial clockwise to increase the frequency; counterclockwise to decrease the frequency.
3 BASIC OPERATION ■ TOGGLING THE TS FUNCTION ON AND OFF The tuning step function can be turned ON and OFF. When the TS function is ON (default), rotating the tuning dial changes the frequency in the set tuning steps. ➀ Push [TS] to turn the tuning step function ON, if necessary. • The TS indicator, “Z” appears. ➁ Rotate the tuning dial to change the frequency according to the set tuning step. ➂ Push [TS] again to turn the tuning step function OFF. • The TS indicator, “Z” disappears.
BASIC OPERATION Ç SETTING A FREQUENCY VIA THE KEYPAD Lights when keypad input is activated Keypad [F-INP] 3 The keypad can be used to enter frequencies directly. ➀ Push [F-INP] to activate keypad input. ➁ Enter the desired frequency using the corresponding digit keys on the keypad. • The displayed frequency is cleared and input starts at the far right of the frequency display. • Input “•” (decimal point) between the MHz units and kHz units.
4 USING DIFFERENT OPERATING MODES ➀ Push a band key to select the desired band. ➁ Push [SSB] to select LSB or USB. 4-1 Operating SSB • Below 10 MHz LSB is automatically selected; above 10 MHz USB is automatically selected. Å RECEIVING ➂ Rotate [AF] to set audio to a comfortable listening [BAND] level. ➃ Rotate the tuning dial to tune a desired signal. • S-meter indicates received signal strength. [AF] [SSB] [DIAL] ✔Convenient functions for receive 18 q Preamp and attenuator (p.
USING DIFFERENT OPERATING MODES ı TRANSMITTING Before transmitting, monitor your selected operating frequency to make sure transmitting won’t cause interference to other stations on the same frequency. Band keys [TRANSMIT] 4 ➀ Connect the microphone to the [MIC] connector. ➁ Push a band key to select the desired operating band. ➂ Push [SSB] to select LSB or USB. ➃ Rotate [RF PWR] to select output power. ➄ Push [TRANSMIT] or [PTT] to transmit. • Talk into the microphone at your normal voice level.
4 USING DIFFERENT OPERATING MODES ➀ Push a band key to select the desired band. ➁ Push [CW/RTTY] to select CW or CW-R. 4-2 Operating CW • Push [CW/RTTY] for 2 sec. to toggle between CW and CW-R modes. Å RECEIVING ➂ Rotate [AF] to set audio to a comfortable listening Band keys level. ➃ Rotate the tuning dial to simultaneously tune a signal and its side tone. • S-meter indicates received signal strength.
USING DIFFERENT OPERATING MODES 4 ✔Convenient functions for receive q Preamplifier and attenuator (p. 38) The preamp amplifies received signals in the front end circuit to improve the S/N ration and sensitivity. The attenuator prevents a desired signal from distorting when very strong signals are near the desired frequency or when very strong electric fields, such as from a broadcasting station, are near you. w Noise blanker (p.
4 USING DIFFERENT OPERATING MODES ı TRANSMITTING [TRANSMIT] Band keys Before transmitting, monitor your selected operating frequency to make sure transmitting won’t cause interference to other stations on the same frequency. ➀ Connect an electronic keyer or paddle to the [ELECKEY] jack on the rear panel of the transceiver (p. 68). ➁ Push a band key to select the desired band. ➂ Push [CW/RTTY] to select CW or CW-R. • Push [CW/RTTY] for 2 sec. to toggle between CW and CW-R modes.
USING DIFFERENT OPERATING MODES 4 Ç ELECTRONIC KEYER FUNCTIONS The transceiver has a number of convenient functions for the electronic keyer that can be accessed from the memory keyer menu. (1) Memory keyer settings menu ➀ Push [CW/RTTY] to select CW mode. ➁ Push [MENU] to select M1. ➂ Push [F4] to select the memory keyer menu. ➃ Push one of the multi-function keys ([F1] to [F5]) to select an item in the memory keyer menu. See the diagram below.
4 USING DIFFERENT OPERATING MODES (2) Memory keyer send menu Pre-set characters can be sent using the memory keyer send menu. Contents of the memory keyer are set using the edit menu. ■ TRANSMITTING ➀ Push [TRANSMIT] to set the transceiver to transmit, or set the break-in function ON (p. 44). • When the transceiver is in receive, step ➁ monitors the memory keyer contents, but does not transmit them. Send menu 1 ANT CW NAR 1 1 S Po 3 5 20 7 9 20 40 60 BLANK 100% 50 VFOA ALC SWR 1 1.
USING DIFFERENT OPERATING MODES 4 (3) Memory keyer edit menu The contents of the memory keyer memories can be set using the memory keyer edit menu. The memory keyer can memorize and re-transmit 4 CW key codes for often-used CW sentences, contact numbers, etc. Total capacity of the memory keyer is 50 characters per memory channel. ■ PROGRAMMING CONTENTS ➀ Push [F1]M1 to select memory for editing.
4 USING DIFFERENT OPERATING MODES This menu is used to set the contact (serial) number and count up trigger, etc. (4) Contact number menu 1 ANT CW ➀ Push [F1] or [F2] to select the set contents. ➁ Rotate the tuning dial to set the condition. • See below for details. 1 S Po 3 5 20 7 9 20 40 60 BLANK 100% 50 1.5 2 CH 3 P. AMP 1 (M1).
USING DIFFERENT OPERATING MODES 4 This menu is used to set the CW side tone, memory keyer repeat time, dash weight, paddle specifications, keyer type, etc. (5) CW keyer set menu SET Side Tone Level 50% ➀ Push [F1] or [F2] to select the set contents. ➁ Rotate the tuning dial to set the condition. • See below for details. ➂ Push [MENU] 2 times to return to regular operation F1 F2 F3 F4 F5 (M1).
4 USING DIFFERENT OPERATING MODES 4-3 Operating RTTY (FSK) Before operating RTTY be sure to consult the manual that came with your TNC. Å RECEIVING ➀ Connect RTTY capable TNC and personal computer or an RTTY terminal (p. 68) Band keys ➁ Push a band key to select the desired band. ➂ Push [CW/RTTY] to select RTTY. ➃ Rotate [AF] to set audio to a comfortable listening level. ➄ Rotate the tuning dial to set the desired frequency. • S-meter indicates received signal strength.
USING DIFFERENT OPERATING MODES ı TRANSMITTING Before transmitting, monitor your selected operating frequency to make sure transmitting won’t cause interference to other stations on the same frequency. Band keys [TRANSMIT] 4 ➀ Connect RTTY capable TNC and personal computer or an RTTY terminal (p. 68) ➁ Push a band key to select the desired band. ➂ Push [CW/RTTY] to select RTTY or RTTY-R. • Push [CW/RTTY] for 2 sec. to toggle between RTTY and RTTY-R modes.
4 USING DIFFERENT OPERATING MODES ➀ Push a band key to select the desired band. ➂ Push [AM/FM] to select AM. 4-4 Operating AM • Pushing [AM/FM] toggles between AM and FM operation. Å RECEIVING ➂ Rotate [AF] to set audio to a comfortable listening Band keys level. ➃ Rotate the tuning dial to set the desired frequency. • S-meter indicates received signal strength. • The default tuning step for AM mode is 1 kHz; this can be changed using tuning step program mode (p. 16).
USING DIFFERENT OPERATING MODES ı TRANSMITTING [TRANSMIT] Band keys 4 Before transmitting, monitor your selected operating frequency to make sure transmitting won’t cause interference to other stations on the same frequency. ➀ Connect a microphone to the [MIC] connector. ➁ Push a band key to select the desired band. ➂ Push [AM/FM] to select AM. • Pushing [AM/FM] toggles between AM and FM. ➃ Rotate [AF] to set audio to a comfortable listening level.
4 USING DIFFERENT OPERATING MODES ➀ Push a band key to select the desired band. ➂ Push [AM/FM] to select FM. 4-5 Operating FM • Pushing [AM/FM] toggles between AM and FM operation. Å RECEIVING ➂ Rotate [AF] to set audio to a comfortable listening Band keys level. ➃ Rotate [SQL] to the point where audio noise is just muted. ➄ Rotate the tuning dial to set the desired frequency. • S-meter indicates received signal strength.
USING DIFFERENT OPERATING MODES 4 ✔Convenient functions for receive q Preamplifier and attenuator (p. 38) The preamp amplifies received signals in the front end circuit to improve the S/N ration and sensitivity. The attenuator prevents a desired signal from distorting when very strong signals are near the desired frequency or when very strong electric fields, such as from a broadcasting station, are near you. w Noise reduction (p.
4 USING DIFFERENT OPERATING MODES A repeater amplifies received signals and retransmits them at a different frequency. When using a repeater, the transmit frequency is shifted from the receive frequency by an offset frequency. A repeater can be accessed using split frequency operation with the shift frequency set to the repeater’s offset frequency. 4-6 Repeater operation 1 ANT ➀ Push [A/B] to select VFO A. ➁ Push a band key to select the desired band. ➂ Push [AM/FM] to select FM mode.
USING DIFFERENT OPERATING MODES ■ AUTO REPEATER FUNCTION ☞ NOTE: This function is available for the USA version only. 4 This function automatically activates the repeater settings (DUP or DUP– and tone encoder ON/OFF) when the operating frequency falls within the general repeater output frequency range and deactivates them when outside of the range. Set the auto repeater function ON-1 or ON-2 in set mode in advance. (p.
4 USING DIFFERENT OPERATING MODES 4-7 Packet operation Before operating packet (AFSK) be sure to consult the operating manual that came with your TNC. Å RECEIVING ➀ Connect a TNC and personal computer (p. 68) ➁ Push a band key to select an operating band. ➂ Push a mode key to select an operating mode. Band keys • Generally, LSB is used for packet operation on the HF bands and FM is used for packet operation on the VHF band. ➃ Rotate [AF] to set the audio to a comfortable listening level.
FUNCTIONS FOR RECEIVE 5-1 Simple band scope STEP 0.5k SCP 5 The band scope function allows you to visually check signal condition around a specified frequency. The IC746’s band scope function can be used not only in FM mode but also when operating on HF bands. Sweep indicator Band scope indicator Frequency indicator mark Sweep step indicator INDICATOR DESCRIPTION SWEEP While the band scope is “sweeping,” “ ” appears; while stopped “ ” appears.
5 FUNCTIONS FOR RECEIVE The preamp amplifies received signals in the front end circuit to improve the S/N ratio and sensitivity. Set this to preamp 1 or preamp 2 when receiving weak signals. The attenuator prevents a desired signal from distorting when very strong signals are near the desired frequency or when very strong electric fields, such as from a broadcasting station, are near your location. These can both be set independently for each band. 5-2 Preamp and attenuator ➀ Push [P.
FUNCTIONS FOR RECEIVE The AGC (auto gain control) controls receiver gain to produce a constant audio output level even when the received signal strength is varied by fading, etc. 5-4 AGC function USB 1 ANT 5 ➀ While menu set 1 is displayed, push [F1](AGC) one or more times to select AGC fast or AGC slow. 1 S Po 3 5 7 9 20 20 40 • The corresponding indicator appears in the display. • AGC slow cannot be selected in FM mode. 60 BLANK 100% 50 ALC SWR 1 1.5 2 ➁ Push [F1](AGC) for 2 sec.
5 FUNCTIONS FOR RECEIVE 5-7 Noise reduction DSP [NR] The noise reduction function reduces noise components and picks out desired signals which are buried in noise. The received AF signals are converted to digital signals and then the desired signals are separated from the noise. ➀ Push [NR] to toggle noise reduction ON and OFF. • “NR” appears when noise reduction is ON. ➁ Rotate the [NR] control to obtain the desired level of noise reduction.
FUNCTIONS FOR RECEIVE 5 The PBT function electronically narrows the receiver’s IF passband widths to reduce interference. Moving both [TWIN PBT] controls to the same position shifts the IF. 5-10 Twin PBT [TWIN PBT] ➥ Rotate the [TWIN PBT] controls to adjust this function. See the illustration below. • [TWIN PBT] should normally be set to the center positions when there is no interference. • When PBT is used, the audio tone may change. • PBT may not function with some IF filter combinations.
5 FUNCTIONS FOR RECEIVE Optional filters can be installed in the IF stage of the IC-746 (p. 78). Both 9 MHz and 455 kHz IF filters are available. When an optional filter is installed, set the optional filter setting using filter program mode (see below). Filters can be independently selected for each operating mode. 5-11 Selecting IF filters FILTER CONSTRUCTION 9 MHz IF filter through 455 kHz IF filter CFJ455k (2.4 kHz) (standard) Mixer FL-272 (2.
FUNCTIONS FOR TRANSMIT 6 The VOX function starts transmission without pushing the transmit switch or PTT switch when you speak into the microphone; then, automatically returns to receive when you stop speaking. This function is available for SSB, AM and FM modes. Before using this function, follow the steps below. 6-1 VOX function ➀ Select a phone mode (SSB, AM, FM). ➁ Push [VOX/BK-IN] to turn the VOX function ON and OFF. • “VOX” appears when the function is ON. ➂ Push [VOX/BK-IN] for 2 sec.
6 FUNCTIONS FOR TRANSMIT The break-in function is used in CW mode to automatically toggle the transceiver between transmit and receive when keying. The IC-746 is capable for full break-in or semi break-in. 6-2 Break-in function [KEY SPEED] [VOX/BK-IN] Tuning dial Å SEMI BREAK-IN OPERATION 1 ANT 1 S Po 3 5 7 20 9 During semi break-in operation, the transceiver selects transceive when keying, then automatically returns to receive after a pre-set time from when you stop keying.
FUNCTIONS FOR TRANSMIT 6 The :TX functions shifts the transmit frequency up to ±9.99 kHz in 10 Hz steps without moving the receive frequency. 6-3 :TX function ➀ Push [:TX] to toggle the :TX function ON and OFF. • “:TX” appears when the function is ON. ➁ Rotate the [RIT/:TX] control to set the desired :TX frequency. • Push [CLEAR] to set the :TX frequency to zero. ➂ To cancel the :TX function, push [:TX] again.
6 FUNCTIONS FOR TRANSMIT 6-5 Speech compressor The RF speech compressor increases the average RF output power, improving signal strength and readability in SSB and AM modes. ➀ Push [SSB] or [AM/FM] to select SSB or AM mode. ➁ While menu set 1 is selected, push [F3](CMP) to turn the speech compressor ON. • “COMP” appears when the function is ON. ➂ Set the [MIC GAIN] to the 9 to 12 o’clock position.
FUNCTIONS FOR TRANSMIT 6-6 Split frequency operation Lights during split operation [SPLIT] [XFC] 1 S Po 5 3 7 20 9 [EXAMPLE]: Operating split with VFO A set to receive 7.06200 MHz/LSB; VFO B set to transmit 7.07500 MHz/LSB. ➀ Set VFO A to 7.06200 MHz/LSB mode. ➁ Push [SPLIT] to turn split frequency operation ON. LSB 20 40 60 1.5 2 • “SPLIT” appears and the [SPLIT] indicator lights. • When split frequency operation is ON the function display indicates the transmit frequency.
6 FUNCTIONS FOR TRANSMIT When you push [SPLIT] for 2 sec., split frequency operation is turned ON and VFO B is automatically changed according to the plus/minus shift frequency programmed in set mode (p. 61) or equalized when 0 kHz is programmed as the split shift frequency. Quick split operation is turned ON by default but can be turned OFF in set mode (p. 61). 6-7 Quick split function • Setting the frequency while pushing [XFC] 1 ANT 1 S Po 3 5 7 9 20 LSB 20 40 60 ation ON.
7 MEMORY CHANNELS The transceiver has 101 memory channels (plus 1 call channel). Memory mode is useful for quickly changing often-used frequencies. 7-1 General All 101 memory channels are tuneable, which means the programmed frequency can be tuned temporarily with the tuning dial in memory mode. MEMORY CHANNEL NUMBER MEMORY CHANNEL TRANSFER TO VFO CAPABILITY OVERWRITING CLEAR Regular (split memory) 1–99 Independent transmit and receive frequencies and one mode in each memory channel.
7 MEMORY CHANNELS ➀ Push [V/M] to select memory mode. ➁ Rotate [M-CH] to select a memory channel. ı IN MEMORY MODE LSB 1 ANT 1 S Po 3 5 7 20 9 20 40 60 100% 50 ALC SWR 1 1.5 2 • All memory channels including blank channels can be selected. • Memory channels can also be selected using the microphones [UP]/[DN] keys. CH MEMO 3 7-3 Transferring a memory to VFO [V/M] [M-CH] The contents of a memory channel (frequency, mode, etc.) can be transferred to VFO mode.
MEMORY CHANNELS 7-5 Selecting the call channel [CALL] 7 By default 145.00000 MHz/FM is programmed into the call channel. However, this can be changed to suit your operating preferences (p. 52). ➀ Push [CALL] to select the call channel. • “C” appears. ➁ Push [CALL] again to return to the previous mode. ☞ NOTE: When the call channel is selected via the call switch ([CALL]), the frequency CANNOT be changed using the tuning dial, band keys or by keypad input.
7 MEMORY CHANNELS 7-7 Programming the call channel [MW] [V/M] [M-CH] The call channel is programmed in the same way regular memory channels are. It’s convenient to program a most-often-used frequency into the call channel for quick recall. As with memory channels, the call channel can also hold split frequencies. ➀ Rotate [M-CH] to select the call channel. • “C” appears. ➁ Select a frequency and operating mode to program into the call channel. ➂ Push [MW] for 2 sec.
MEMORY CHANNELS 7-9 Assigning memory names [0]–[9], [•] [MENU] [V/M] Tuning dial [M-CH] Memory names can be assigned to any memory channel. Memory names can be up to 9 characters in length; any of the 127 standard ASCII characters (as on a computer keyboard) can be used. [EXAMPLE]: Programming “DX spot” into memory channel 99. ➀ Push [V/M] to select memory mode, if necessary. ➁ Rotate [M-CH] to select memory channel 99. ➂ Push [MENU] to select menu set 2.
7 MEMORY CHANNELS 7-10 Memo pads The transceiver has a memo pad function to store frequency and operating mode for easy recall. The memo pads are separate from memory channels. The default number of memo pads is 5 but can be increased to 10 in set mode, if desired. Å WRITING FREQUENCIES AND OPERATING MODES INTO A MEMO PAD ➥ Push [MP-W] to store the displayed frequency and operating mode into a memo pad.
8 SCAN OPERATION 8-1 Scan types PROGRAMMED SCAN ∂F SCAN Repeatedly scans between two scan edge frequencies (scan edge memory channels P1 and P2). Repeatedly scans within ∂F span area. Scan edge P1 or P2 Scan edge P2 or P1 Start frequency –∂F frequency +∂F frequency Scan Scan Scan Jump Jump This scan operates in VFO mode. This scan operates in both VFO and memory modes. MEMORY SCAN SELECT MEMORY SCAN Repeatedly scans all programmed memory channels.
8 SCAN OPERATION 8-2 Programmed scan and fine programmed scan [TS] [V/M] Programmed scan searches for signals between scan edge memory channels P1 and P2. The default frequencies for these memories are 0.500000 MHz and 29.99999 MHz, respectively. See p. 56 for programming scan edges. ➀ Push [V/M] to select VFO mode, if necessary. ➁ Push a mode key to select the desired operating mode. • Operating mode can also be selected during scan. [MENU] Mode keys ➂ Push [TS] to select a tuning step.
SCAN OPERATION 8 Memory scan searches through memory channel 1 to 99 for signals. Blank (unprogrammed) memory channels are skipped. 8-3 Memory scan ➀ Push [V/M] to select memory mode, if necessary. ➁ Push [MENU] to select M2. ➂ Push [F1] to select the scan menu. ➃ Push [F1] to start/stop memory scan. • The MHz and kHz decimal points flash during scan. • At least 2 memory channels must be programmed for memory scan to proceed. • Rotating the tuning dial during memory scan cancels the scan.
8 SCAN OPERATION 8-5 :F scan and Fine :F scan Key pad [V/M] :F scan searches on either side of the displayed memory channel or frequency. The frequency range searched on either side of the center frequency (memory channel) is specified by the span. ➀ Push [V/M] to select memory mode or VFO mode, as desired. ➁ Push [MENU] to select M2. ➂ Push [F1] to select the scan menu. ➃ Push [F4] one or more times to select the desired span value.
INTERNAL ANTENNA TUNER 9-1 Before operating [TUNER] 9-2 Tuner operation 9 The internal automatic antenna tuner matches the transceiver to the connected antenna automatically. Once the tuner matches an antenna, the variable capacitor angles are memorized as a preset point for each frequency range (100 kHz steps). Therefore, when you change the frequency range, the variable capacitors are automatically preset to the memorized point. (See p. 62—19 Auto tune.
10 SET MODE 10-1 Selecting set mode Set mode is used for programming infrequently changed values or conditions of functions. ➀ Push [MENU] to select M2, if necessary. ➁ Push [F5] to enter set mode. ➂ Push [F1] or [F2] to change the selected item. • Push and hold [F1] or [F2] to cycle through the available set mode items. ➃ Rotate the tuning dial to set the desired condition for [MENU] a selected item. Tuning dial ➄ Push [MENU] 2 times to exit set mode and select M1.
SET MODE 5. Filter (9MHz-2) When an optional filter is installed in the 9 MHz filter socket (2), this selection is necessary, otherwise the filter cannot be selected. 10 SET Filter (9MHz-2) None FL-103, FL223, FL-100, FL-232 or FL-101 can be selected. See p. 42 for details. 6. Filter (455kHz) When an optional filter is installed in the 455 kHz filter socket, this selection is necessary, otherwise the filter cannot be selected.
10 SET MODE 13. SPLIT LOCK When this item is ON, the tuning dial can be used to adjust the transmit frequency while pushing [XFC] even while the lock function is activated. See p. 47 for split frequency operation details. 14. DUP Offset HF This item sets the offset (difference between transmit and receive frequencies) for the quick split function when operating on an HF band in FM mode only. This is used to input the repeater offset for an HF band.
SET MODE 20. PTT Tune Tuning of the external antenna tuner can be started automatically at the moment the PTT is pushed after is the operating frequency is changed (more than 1% from the last-tuned frequency). 21. ANT Select You can set the antenna connector selection to automatic, manual or non-selection (when using 1 antenna only). 10 SET PTT Tune OFF SET ANT Select Auto When “AUTO” is selected, the antenna switch is activated and the band memory memorizes the selected antenna. See p.
10 SET MODE 26. MIC U/D Speed This item sets the rate at which frequencies are scanned when the microphone [UP]/[DN] switches are pushed and held. High or low can be selected. 27. CI-V Baud Rate This item sets the data transfer rate. 300, 1200, 4800 9600, 19200 bps and “AUTO” are available. SET MIC U/D Speed HIGH SET CI-V Baud Rate Auto When “AUTO” is selected, the baud rate is automatically set according to the connected controller or remote controller. 28.
ADJUSTMENTS 11 The tension of the tuning dial can be adjusted to suit your preference. 11-1 Tuning dial brake The brake adjustment screw is located on the right side of the tuning dial. See figure at left. ➥ Turn the brake adjustment screw clockwise or counterclockwise to obtain a comfortable tension level while tuning the dial continuously and evenly in one direction.
11 ADJUSTMENTS The IC-746 has a built-in circuit for measuring antenna SWR while in SSB mode — no external equipment or special adjustments are necessary. 11-3 Measuring SWR USB 1 ANT 1 S Po 3 5 7 20 9 20 40 60 BLANK 100% 50 VFOA ALC SWR 1 1.5 2 Make sure the antenna whose SWR you want to measure is connected, that output power is set to 30 W or more and that [TUNER] is OFF. ➥ While pushing [PTT], speak (a single, even pitch) into the microphone. CH 3 P.
SETUP AND CONNECTIONS 12 12-1 Front panel ELECTRONIC KEYER HEADPHONES dash dot com When using the internal electronic keyer connect a paddle. TWIN PBT HF/VHF TRANSCEIVER TUNER ANT 1.8 1 3.
12 SETUP AND CONNECTIONS 12-2 Rear panel DC POWER SUPPLY (p. 69) 144 MHz ANTENNA (p. 70) HF/50 MHz ANTENNA (p. 70) [ANT2] Connect a VHF (60–144 MHz) antenna; impedance: 50 Ω. Connect an HF/50 MHz antenna; impedance: 50 Ω. PS-85 (optional) HF/50 MHz ANTENNA (p. 70) [ANT1] + _ ELECTRONIC KEYER Connect an HF/50 MHz antenna; impedance: 50 Ω. Accepts a paddle to activate the internal electronic keyer. ALC JACK (p. 79) Connects to the ALC output jack of a nonIcom linear amplifier. ALC input: 0–4 V.
SETUP AND CONNECTIONS 12 12-3 Selecting a location Select a location for the transceiver that allows adequate air circulation, free from extreme heat, cold, or vibrations, and away from TV sets, TV antenna elements, radios and other electro-magnetic sources. 12-4 Power supply connections Use an optional PS-85 DC POWER SUPPLY or non-Icom power supply, etc. when operating the transceiver with AC power. Refer to the diagrams below.
12 SETUP AND CONNECTIONS To prevent electrical shock, television interference (TVI), broadcast interference (BCI) and other problems, ground the transceiver through the GROUND terminal on the rear panel. 12-5 Grounding For best results, connect a heavy gauge wire or strap t a long earth-sunk copper rod. Make the distance between the GROUND terminal and ground as short as possible.
SETUP AND CONNECTIONS ■ ANTENNA SELECT FUNCTION ( see p. 63) [ANT] 12 The IC-746 has 2 antenna connectors for the HF/50 MHz bands, [ANT1] and [ANT2], and 1 antenna connector for the 144 MHz band; a total of 3 antenna connectors. For each operating band the IC-746 covers, there is a band memory which can memorize a selected antenna. When you change the operating frequency beyond a band, the previously used antenna is automatically selected (see below) for the new band.
12 SETUP AND CONNECTIONS 12-7 Data communications • When connecting to ACC(1) Rear panel view 2 4 1 5 3 8 6 A B C D 7 AMTOR • PACKET E F* • When connecting to [MIC] A C Rear panel view 1 2 7 6 8 3 4 5 PIN NO. NAME 1 RTTY 2 GND 3 4 2 3 8 ACC(2) 1 6 2 5 3 DESCRIPTION SPECIFICATIONS Controls RTTY keying. 7 Modular input Connects to a modulator AF detector output Fixed regardless of [AF] position. Squelch output. Goes to ground when squelch opens MOD 5 AF 6 SQLS 7 13.
SETUP AND CONNECTIONS 12 When operating RTTY, a teletype and demodulator, etc. must be connected as in the diagrams below. The demodulator operates via audio input with a receive tone of 2125 Hz (or 1275 or 1615) and a shift offset of 170 Hz (or 200 or 425 Hz). See p. 29 for details on how to change the receive tone or shift offset.
12 SETUP AND CONNECTIONS 12-9 Remote jack 9–15 V DC ■ CI-V CONNECTION EXAMPLE The transceiver can be connected through an optional CT-17 CI-V LEVEL CONVERTER to a personal computer equipped with an RS-232C port. The Icom Communications Interface-V (CI-V) controls the following functions of the transceiver. personal computer ct- 17 Up to 4 Icom CI-V transceivers or receivers can be connected to a personal computer equipped with an RS-232C port. See p. 64 for setting the CI-V condition using set mode.
SETUP AND CONNECTIONS 12 ■ COMMAND TABLE Cn Sc Description Cn Sc Description 00 01 02 03 04 05 Sets frequency (transceive) Sets mode (transceive) Reads band edge frequency Reads display frequency Reads display mode Sets frequency Sets LSB mode Sets USB mode Sets AM mode Sets CW mode Sets RTTY mode Sets FM mode Sets CW-R mode Sets RTTY-R mode Selects VFO operation Sets VFO A Sets VFO B Sets VFO A=B Exchanges VFO A and B Select memory operation Sets a M-CH (P1=0100/P2=0101/C=0102) Writes to memory Tran
13 OPTIONAL INSTALLATIONS 13-1 Opening the transceiver’s case Follow the case and cover opening procedures shown here when you want to install an optional unit or adjust an internal unit, etc. v CAUTION: DISCONNECT the DC power cable ➀ Remove the 2 screws from the left side of the transceiver to remove the carrying handle. ➁ Remove 6 screws from the top of the transceiver and 6 screws from the sides, then lift up the top cover.
OPTIONAL INSTALLATIONS 13-2 UT-102 VOICE SYNTHESIZER UNIT ;@À 13 The UT-102 announces the accessed readout’s frequency, mode, etc. (S-meter level can also be announced—p. 63) in a clear, electronically-generated voice, in English (or Japanese). ➀ Remove the bottom and shield covers. ➁ Remove the protective paper attached to the bottom of the UT-102 to expose the adhesive strip. ➂ Plug UT-102 into J701 on the MAIN UNIT as shown at left. ➃ Return the top and shield covers to their original positions.
13 OPTIONAL INSTALLATIONS 13-4 Optional IF filters D INSTALLATION ➀ Remove the bottom cover (p. 76). Several IF filters are available for the IC-746. You can install 2 filters for the 9 MHz IF and 1 filter for the 455 kHz IF. Choose appropriate filter(s) for your operating needs. ➁ Turn the transceiver upside down.
OPTIONAL INSTALLATIONS 13-5 Linear amplifier connections 13 Refer to the manual supplied with the IC-PW1 for additional information. CONNECTING THE IC-PW1 Mini-plug cable (supplied with the IC-PW1) To antenna ACC(1) ACC cable (supplied with the IC-PW1) REMOTE ANT Coaxial cable (supplied with the IC-PW1) INPUT 1 REMOTE ACC(2) ANT1 EXCITER 1 2 GND IC-PW1 ground GND IC-746 to AC outlet NOTE: Turn OFF the transceiver’s antenna tuner while tuning the IC-PW1’s tuner.
13 OPTIONAL INSTALLATIONS 13-6 External antenna tuner connections CONNECTING THE AH-4 long wire antenna supplied cable IC-746 ANT 1 GND AH-4 control cable GND ☞ NOTE: The AH-4 must be connected to [ANT1]. [TUNER] D OPERATING THE AH-4 ➀ Connect the AH-4 to the transceiver as shown above. ➁ Push [POWER] to turn transceiver power on. • “EXIT” appears on the display. • The internal antenna tuner automatically enters the “through” condition. ➂ Push [TUNER] for 2 sec.
MAINTENANCE 14-1 Fuse replacement 14 DC POWER CABLE FUSE REPLACEMENT If a fuse blows or the transceiver stops functioning, try to find the source of the problem, and replace the damaged fuse with a new, rated fuse. 30 A fuse v CAUTION: DISCONNECT the DC power cable from the transceiver when changing a fuse. The IC-746 has 2 types of fuses installed for transceiver protection. • DC power cable fuses .............................. FGB 20 A • Circuitry fuse ..............................................
14 MAINTENANCE 14-3 Troubleshooting The following chart is designed to help you correct problems which are equipment malfunctions. POWER SUPPLY PROBLEM Power does not come on when the [POWER] switch is pushed. If you are not able to locate the cause of a problem or solve it through the use of this chart, contact your nearest Icom Dealer or Service Center. POSSIBLE CAUSE DC power connected. cable is improperly Fuse is blown. SOLUTION Reconnect the power cable correctly. REF. p.
14 MAINTENANCE PROBLEM POSSIBLE CAUSE Set the frequency to a ham band. The split frequency function is turned ON with different bands in VFO A and VFO B. Turn OFF the split frequency function. p. 47 Power is set lower power than maximum. Set the output power to maximum. Microphone gain is set too low. Set microphone gain using the [MIC p. 3 GAIN] control. The antenna is not connected properly. Reconnect the antenna connector. — The antenna feed line is cut or shorted.
15 SPECIFICATIONS AND OPTIONS 15-1 Specifications GENERAL • Frequency coverage : Receive Transmit Unit: MHz 0.030– 60.000*1 108.000– 174.000*1 1.800– 1.999*2 3.500– 3.999*2 7.000– 7.300*2 10.100– 10.150 14.000– 14.350 18.068– 18.168 21.000– 21.450 24.890– 24.990 28.000– 29.700 50.000– 54.000*2 144.000– 148.000*2 *1Except for some frequency ranges. *2Depending on version. • Mode • No.
SPECIFICATIONS AND OPTIONS 15 15-2 Options IC-PW1 HF + 50 MHz 1 kW LINEAR AMPLIFIER EX-627 AUTOMATIC ANTENNA SELECTOR Automatically selects the antenna for the selected HF ham band. • Max. input power: 1000 W PEP AH-4 HF AUTOMATIC ANTENNA TUNER AH-2b ANTENNA ELEMENT PS-85 POWER SUPPLY A 2.5 m long antenna element for mobile operation with the AH-4. • Frequency coverage: 3.5–28 MHz bands with the AH-4 SM-20 DESKTOP MICROPHONE Unidirectional, electret microphone for base station operation.
Count on us! A-5482H-1EX-i Printed in Japan © 1997 Icom Inc.
IC-746 addendum 02.9.25 14:54 Page 1 (1,1) IC-746 ADDENDUM On page 53 of the IC-746 Instruction Manual, the text at right appears regarding assigning memory names. The following should be added to the bullet list in step ➅: • Use the keypad to directly input numerals, “0” to “9,” including a decimal point. [0]–[9], [•] [V/M] Memory names can be assigned to any memory channel.
Erratum 02.9.25 15:29 Page 1 (1,1) ERRATUM ERRATUM Please note that the instruction manual for the IC-746 does not list the supplied accessories as shown below. Please note that the instruction manual for the IC-746 does not list the supplied accessories as shown below. Accessories supplied with the IC-746: Accessories supplied with the IC-746: Qty. ➀ DC power cable (OPC-025A) . . . . . . . . . . . . . . . . 1 ➁ Hand microphone (HM-36) . . . . . . . . . . . . . . . . . . 1 ➂ Spare fuses (FGB 20A) .
