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Icom IC-756 Instruction Manual

Summary of IC-756

  • Page 1

    Instruction manual i756 hf/50 mhz all mode transceiver.

  • Page 2

    R warning high voltage! Never attach an antenna or internal antenna connector during trans- mission. This may result in an electrical shock or burn. R never apply ac to the [dc13.8v] socket on the transceiver rear panel. This could cause a fire or ruin the transceiver. R never apply more than 16 v d...

  • Page 3

    Unpacking table of contents ii q w e r t accessories included with the ic-756: qty. Q dc power cable (opc-025a) .............................. 1 w hand microphone (hm-36) .................................. 1 e spare fuses (fgb 20 a) ...................................... 2 r spare fuse (fgb 5 a) ......

  • Page 4: Panel Description

    1 1 panel description ■ front panel timer power transmit phones elec-key mic tuner monitor nb nr af bal nr rf/sql mic gain rf power comp key speed bk-in delay s po 0 10 1 1 1.5 2 3 5 9 +20 +40 +60db 25 50 100 ％ ∞ swr alc f-1 ssb f-2 f-3 f-4 f-5 cw rtty am fm hf/50mhz transceiver i756 1ß vfo vfo 14.1...

  • Page 5

    2 1 panel description i rf gain control/squelch control [rf/sql] (outer control) 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 ...

  • Page 6

    Nb nr bal nr comp key speed bk-in delay apf apf lock tx rx auto notch twin pbt cw pitch f-1 ssb f-2 f-3 f-4 f-5 speech lock rit/ tx tx rit clear cw rtty am fm split mp-w mp-r dual watch vfo/ memo main/ sub change 1.8 1 3.5 2 7 3 10 4 14 5 18 6 21 7 24.5 8 28 9 gene ・ 50 0 f-inp ent ▲ ▼ mw m-cl ts xf...

  • Page 7

    • turns the speech compressor on and off in ssb and am modes. (p. 34) • enters memory keyer set mode in cw mode. (pgs. 35, 36) • turns the 1 ⁄ 4 function on and off in rtty mode. (p. 24) - 1 ⁄ 4 function sets dial rotation to 1 ⁄ 4 of normal for fine tuning. ✔ what is the speech compressor? The spee...

  • Page 8

    5 1 panel description #0 lock switch [lock] (p. 38) turns the dial lock function on and off. #1 rit/ ∂ ∂ tx control [rit/ ∂ ∂ tx ] (p. 29) shifts the receive and/or transmit frequency without changing the transmit and/or receive frequency while the rit and/or ∂ tx functions are on. - rotate the cont...

  • Page 9

    6 1 panel description #6 audio peak filter control [apf ] (inner control; p. 27) varies the peak frequency of the audio peak filter to pick out a cw signal from interference while the apf function is on. #7 audio peak filter switch [apf ] (p. 27) • turns the audio peak filter on and off when pushed....

  • Page 10

    7 1 panel description $7 memory up/down switches [ y y ]/[ z z ] (p. 41) • select the memory channel number for the se- lected readout. - memory channels can be selected both in vfo and memory modes. • select the desired memory channel directly after pushing [f-inp] and a memory channel number. $8 m...

  • Page 11: Microphone

    • microphone connector (front panel view) caution: do not short pin 2 to ground as this can damage the internal 8 v regulator. Y gnd (ptt ground) t ptt r main readout squelch switch q microphone input w +8 v dc output e frequency up/down u gnd (microphone ground) i main readout af output (varies wit...

  • Page 12: Lcd Display

    9 1 panel description 1ß vfo 14.195.000 vfo usb usb usb 14.100.00 14.205.000 14.205.000 usb usb usb 14.100.00 56 56 ß marker marker hold hold max-h max-h exit exit ant 1 meter po p.Amp off att off agc mid vox off comp off span span t x 2.4k 2.4k 9 2.8k 2.8k 455 455 12:34 12:34 g r i d 2 . 5 k 1 0 d ...

  • Page 13: 80%

    10 1 panel description 80% 95% f-1 f-1 f-2 f-3 f-4 f-5 [ 1 5 k ] [ ] [ n o n e ] [filter selection] [filter selection] 9mhz 9mhz 455khz 455khz def def exit exit agc agc mid mid vox vox off off comp comp off off s s b 2 . 4 k [ 1 5 k ] [ 9 k ] [ ] [ n o n e ] 2 . 8 k 9 8 - - . - - - . - - - - - - - -...

  • Page 14: Rear Panel

    Q receive antenna connector [rx ant] (p. 15) connects a 50 Ω general coverage antenna with an rca connector. W tuner control socket [tuner] (p. 15) accepts the control cable from an optional ah-3 hf automatic antenna tuner . E accessory socket 1 [acc(1)] r accessory socket 2 [acc(2)] enable connecti...

  • Page 15

    12 1 panel description !1 antenna connector 1 [ant1] !2 antenna connector 2 [ant2] (pgs. 13, 14) accept a 50 Ω antenna with a pl-259 connector. Note: when using an optional ah-3 hf automatic antenna tuner , connect it to the [ant1] connector. The internal antenna tuner activates for [ant2] and deact...

  • Page 16: Unpacking

    ■ unpacking after unpacking, immediately report any damage to the delivering carrier or dealer. Keep the shipping cartons. For a description and a diagram of accessory equip- ment included with the ic-756, see unpacking on p. Ii of this manual. ■ selecting a location select a location for the transc...

  • Page 17: Required Connections

    Timer power transmit phones elec-key mic tuner monitor nb nr mic gain rf power comp key speed bk-in delay af rf/sql bal nr apf lock tx rx auto notch twin pbt apf cw pitch s po 0 10 1 1 1.5 2 3 5 9 +20 +40 +60db 25 50 100 ％ ∞ swr alc f-1 ssb f-2 f-3 f-4 f-5 speech lock rit/ tx tx rit clear cw rtty am...

  • Page 18: Advanced Connections

    15 2 installation and connections ■ advanced connections • front panel timer power transmit phones elec-key mic tuner monitor nb nr mic gain rf power comp key speed bk-in delay af rf/sql bal nr apf lock tx rx auto notch twin pbt apf cw pitch s po 0 10 1 1 1.5 2 3 5 9 +20 +40 +60db 25 50 100 ％ ∞ swr ...

  • Page 19: Power Supply Connections

    16 2 installation and connections ■ power supply connections use an optional ps-85 dc power supply , etc. When operating the transceiver with ac power. Refer to the diagrams below. Connecting an icom dc power supply to dc power socket ps-85 ac outlet ac cable transceiver connecting a non-icom dc pow...

  • Page 20: Linear Amplifier Connections

    17 2 installation and connections ■ linear amplifier connections transceiver ground ic-4kl remote controller coaxial cable (supplied with the ic-4kl) acc cable (supplied with the ic-4kl) acc ic-4kl remote control cable (supplied with the ic-4kl) ac outlet (220–240 v) to an antenna ant1 acc(2) use th...

  • Page 21

    18 2 installation and connections ■ external antenna selector or antenna tuner connections connecting the ex-627 ground coaxial cable (supplied with the ex-627) acc cable (supplied with the ex-627) ex-627 ant1 acc(2) connecting the ah-3 coaxial cable (from the ah-3) long wire or optional ah-2b groun...

  • Page 22

    To connect a terminal unit, tnc or scan converter, refer to the diagram below. For rtty operation the optional 250 hz cw narrow filters may not pass rtty signals. Be sure to select the appropriate if filters corresponding to the signal width. (p. 28) af input ground (gnd) ptt squelch input* rtty key...

  • Page 23

    Description command frequency setting 05 operating mode lsb usb am cw rtty fm 06 vfo mode selection main ↔ sub main = sub dualwatch off dualwatch on main readout selection sub readout selection 07 memory mode selection memory channel selection 08 memory write memory transfer to vfo memory clear 09 0...

  • Page 24: Frequency Setting

    21 3 frequency setting ■ when first applying power (cpu resetting) before first applying power, make sure all connections required for your system are complete by referring to chapter 2. Then, reset the transceiver using the follow- ing procedure. Note: resetting clears all programmed con- tents in ...

  • Page 25: Vfo Description

    • differences between vfo mode and memory mode 22 3 frequency setting ■ vfo description vfo is an abbreviation of variable frequency oscilla- tor, and traditionally refers to an oscillator. The transceiver’s vfo is somewhat different. The vfo of the ic-756 acts like a computer’s window and can show ...

  • Page 26

    23 3 frequency setting ■ frequency setting with the tuning dial ■ direct frequency entry with the keypad • for ham band use q push the desired band key on the keypad 1–3 times. - 3 different frequencies can be selected on each band with the band key. (see “triple band stacking register” below.) w ro...

  • Page 27: Advanced Tuning Functions

    Auto tuning step function (am/fm only) when selecting am or fm, the quick tuning step is au- tomatically selected by the auto tuning step function. 24 3 frequency setting ■ advanced tuning functions quick tuning step the operating frequency can be changed in khz steps (1, 5, 9 or 10 khz selectable) ...

  • Page 28: Twin Pbt Operation

    ■ twin pbt operation the twin pbt (passband tuning) function electronically narrows the receiver’s if passband widths to reduce interference. Moving both [twin pbt] controls to the same position shifts the if. - the lcd shows the passband width graphically. Variable range depends on the filter selec...

  • Page 29: Auto Notch Function

    26 4 receive and transmit ■ auto notch function the auto notch function automatically attenuates more than 3 beat tones, tuning signals, etc., even if they are moving. The auto notch functions in ssb mode only. Q select ssb mode. W push [auto notch] to turn the auto notch func- tion on. E push [auto...

  • Page 30: Apf Function

    The received cw audio pitch and monitored cw audio can be adjusted to suit your preferences (300 to 900 hz) without changing the operating frequency. The received cw audio pitch can be adjusted in 3 hz steps. ■ apf function the apf (audio peak filter) changes the receive fre- quency response by boos...

  • Page 31: Filter Selection

    The filter selection switches the if passband width as shown in the table at right. The filter selection is automatically memorized in each mode. When an optional filter is installed, set the optional fil- ter setting in set mode. (p. 55) optional filters are not selected by default. Q if the start ...

  • Page 32: Rit and

    When you find a dx station on 21.025 mhz/cw and the station is picking up stations transmitting slightly up from 21.025 mhz. Q push [rit] and [ ∂ tx] to turn both the rit and ∂ tx functions on. W rotate [rit/ ∂ tx] to find the dx station’s receive fre- quency. E when you find the dx station’s receiv...

  • Page 33: Dualwatch Operation

    30 4 receive and transmit dualwatch monitors 2 frequencies with the same mode simultaneously. During dualwatch, both frequencies should be on the same band because the bandpass filter in the rf cir- cuit is selected for the main readout frequency. Q set a desired frequency. W push [dualwatch] for 2 ...

  • Page 34: Split Frequency Operation

    31 4 receive and transmit split frequency operation allows you to transmit and receive in the same mode on two different frequen- cies. The split frequency operation is basically per- formed using 2 frequencies on the main and sub readouts. Following is an example of setting 21.290 mhz for re- ceivi...

  • Page 35: Quick Split Function

    32 4 receive and transmit when you find a dx station, an important considera- tion is how to set the split frequency. When you push the [split] switch for 2 sec., split fre- quency operation is turned on, the sub readout is equalized to the main readout frequency and enters standby for transmit freq...

  • Page 36: Monitor Function

    33 4 receive and transmit the monitor function allows you to monitor your trans- mit if signals in any mode through the speaker. Use this to check voice characteristics while adjusting transmit tones. (p. 54) the cw sidetone functions re- gardless of the [monitor] switch setting. Q push [monitor]. -...

  • Page 37: Meter Function

    34 4 receive and transmit the transceiver has 3 transmit meter functions for your convenience. Select the desired meter with the [meter] switch. • push [meter] to select rf power (po), swr or alc for transmit metering. ■ meter function the rf speech compressor increases average rf output power, impr...

  • Page 38: Electronic Cw Keyer

    35 4 receive and transmit the transceiver has an electronic keyer. Keying speed can be adjusted with [key speed]. Keying weight, the ratio of dot : space : dash, can be set from 1 : 1 : 2.8 to 1 : 1 : 4.5 in keyer set mode. • setting the electronic keyer q push [cw] to select cw mode. W push [keyer]...

  • Page 39: Memory Keyer

    36 4 receive and transmit the memory keyer memorizes and can re-transmit 4 cw key codes for often-used cw sentences, antenna types, etc. Total capacity of the memory keyer is 55 characters in each memory channel. • programming the memory keyer q push [cw] to select cw mode. W push [keyer] to select ...

  • Page 40: Spectrum Scope Screen

    37 4 receive and transmit this function allows you to display the relative strengths of signals around the center frequency. The span can be set to ± 12.5 khz, ± 25 khz, ± 50 khz and ± 100 khz. Ideal for monitoring band conditions in an instant. Q if the start up screen is not selected (if [f-5]’s f...

  • Page 41: Repeater Operation

    38 4 receive and transmit a repeater amplifies received signals and retransmits them at a different frequency. When using a repeater, the transmit frequency is shifted from the receive fre- quency by an offset frequency. A repeater can be ac- cessed using split frequency operation with the shift fre...

  • Page 42: Antenna Tuner Operation

    ■ antenna tuner operation the internal automatic antenna tuner matches the transceiver to the connected antenna automatically. Once the tuner matches an antenna, the variable ca- pacitor angles are memorized as a preset point for each frequency range (100 khz steps). Therefore, when you change the f...

  • Page 43: Warning: High Voltage!

    • ah-3 hf automatic antenna tuner the ah-3 matches the ic-756 to a long wire antenna more than 3 m/10 ft long (3.5 mhz and above) or more than 12 m/40 ft long (1.8 mhz and above). • see p. 18 for the transceiver and ah-3 connection. • see the ah-3 instruction manual for ah-3 installation and antenna...

  • Page 44: Memory Operation

    41 5 memory operation ■ memory channels the transceiver has 101 memory channels. The mem- ory mode is very useful for quickly changing to often- used frequencies. All 101 memory channels are tunable which means the programmed frequency can be tuned temporarily with the tuning dial, etc. In memory mo...

  • Page 45: Memory Channel Screen

    42 5 memory operation ■ memory channel screen the memory channel screen simultaneously shows 9 memory channels and their programmed contents. You can select a desired memory channel from the memory channel screen. • selecting a memory channel using the memory channel screen q if the start up screen ...

  • Page 46: Memory Channel Programming

    43 5 memory operation ■ memory channel programming memory channel programming can be preformed ei- ther in vfo mode or in memory mode. • programming in vfo mode q set the desired frequency and operating mode in vfo mode. W push [ y ]/[ z ] several times to select the desired memory channel. - memory...

  • Page 47: Frequency Transferring

    44 5 memory operation • transferring in vfo mode this is useful for transferring programmed contents to vfo. Q select vfo mode with [vfo/memo]. W select the memory channel to be transferred with [ y ]/[ z ]. - memory channel screen is convenient for selecting the desired channel. - memory channel co...

  • Page 48: Memory Names

    45 5 memory operation all memory channels (including scan edges) can be tagged with alphanumeric names of up to 10 charac- ters each. Letters (capitals), numerals, some symbols ( ⁄ , ?, m ) and spaces can be used. • editing (programming) memory names q if the start up screen is not selected (if [f-5...

  • Page 49: Memo Pads

    46 5 memory operation • writing frequencies and operating modes into memo pads you can simply write the accessed readout frequency and operating mode by pushing [mp-w]. When you write a 6th frequency and operating mode, the oldest written frequency and operating mode are automatically erased to make...

  • Page 50: Scans

    47 6 scans ■ scan types ■ preparation • channels for programmed scan: program scan edge frequencies into scan edge mem- ory channels p1 and p2. For ∂ f scan: set the ∂ f span ( ∂ f scan range) in the scan screen. For memory scan: program 2 or more memory channels except scan edge memory channels. Fo...

  • Page 51: Programmed Scan Operation

    48 6 scans q if the start up screen is not selected (if [f-5]’s func- tion is [exit]), push [f-5] one or more times to exit. W select vfo mode. E select the desired operating mode. - the operating mode can also be changed while scan- ning. R push [ (f-4) scan] to select the scan screen. T set [rf/sq...

  • Page 52: Fine Programmed Scan/fine

    49 6 scans fine scan functions as programmed or ∂ f scan, but scan speed decreases when the squelch opens and does not stop. The scanning tuning step shifts from 50 hz to 10 hz while the squelch opens. Q select the scan screen from the start up screen by pushing [ (f-4) scan]. W set for programmed s...

  • Page 53: Select Memory Scan Operation

    50 6 scans q if the start up screen is not selected (if [f-5]’s func- tion is [exit]), push [f-5] one or more times to exit. W select memory mode. E select the desired operating mode. - the operating mode can also be changed while scan- ning. R push [ (f-4) scan] to select the scan screen. T set [rf...

  • Page 54: Clock and Timers

    51 7 clock and timers the transceiver has a built-in 24-hour clock with power-off and power-on timer functions. This is useful when logging qso’s and so on. The clock indication is always displayed except after pushing [f-inp]. Q if the start up screen is not selected (if [f-5]’s func- tion is [exit...

  • Page 55: Setting Power-Off Period

    52 7 clock and timers the transceiver can be set to turn off automatically after being activated via the power-on timer. The power-off period can be set to 5–120 min. In 5 min. Steps. Q if the start up screen is not selected (if [f-5]’s func- tion is [exit]), push [f-5] one or more times to exit. W ...

  • Page 56: Set Mode

    53 8 set mode ■ set mode description set mode is used for programming infrequently changed values or conditions of functions. This trans- ceiver has a level set mode, display set mode, timer set mode and miscellaneous (others) set mode. • set mode operation q if the start up screen is not selected (...

  • Page 57: Level Set Mode

    Tx tone (treble) this item adjusts the treble level of the transmit audio tone in ssb/am mode from –12 db to +12 db in 2 db steps. 54 8 set mode tx tone (bass) this item adjusts the bass level of the transmit audio tone in ssb/am mode from –12 db to +12 db in 2 db steps. ■ level set mode 0 d b 0 db ...

  • Page 58: Timer Set Mode

    55 8 set mode power-on timer set this item sets the power-on time. See p. 51 for details. Time (now) this item sets the current time for the built-in 24-hour clock. See p. 51 for details. ■ timer set mode 1 5 : 0 0 push [ (f-4) set] to enter the time. 1 5 : 0 0 push [ (f-4) set] to enter the time. P...

  • Page 59

    56 8 set mode beep (band edge) a beep sounds when an operating frequency enters or exits an amateur band. This functions independent of the confirmation beep setting (above). The volume level can be set in level set mode. (p. 54) beep (confirmation) a beep sounds each time a switch is pushed to con-...

  • Page 60

    57 8 set mode fm split offset (hf) this item sets the offset (difference between transmit and receive frequencies) for the quick split function. However, this setting is used for hf bands in fm mode only and is used to input the repeater offset for an hf band. The offset frequency can be set from –4...

  • Page 61

    58 8 set mode tuner (ptt start) tuning of the internal antenna tuner can be started automatically at the moment the ptt is pushed after the operating frequency is changed (more than 1% from last-tuned frequency). O n o f f automatic ptt start on automatic ptt start off (default) [ant] switch you can...

  • Page 62

    59 8 set mode ■ miscellaneous (others) set mode (continued) speech speed when the optional ut-102 voice synthesizer unit is installed, you can select between faster or slower syn- thesizer output. See p. 61 for unit installation. H i g h l o w faster announcement (default) slower announcement speech...

  • Page 63

    60 8 set mode ci-v transceive transceive operation is possible with the ic-756 con- nected to other icom hf transceivers or receivers. When “on” is selected, changing the frequency, op- erating mode, etc. On the ic-756 automatically changes those of connected transceivers (or re- ceivers) and vice v...

  • Page 64: Option Installations

    61 9 option installations the ut-102 announces the accessed readout’s fre- quency, mode, etc. (s-meter level can also be an- nounced—p. 59) in a clear, electronically-generated voice, in english (or japanese). Q remove the top and bottom covers as shown above. W remove the protective paper attached ...

  • Page 65: Optional If Filters

    62 9 option installations several if filters are available for the ic-756. You can install 2 filters for 9 mhz and 455 khz if. Choose ap- propriate filter(s) for your operating needs. 9 mhz optional filters: fl-100 cw narrow filter 500 hz/–6 db fl-101 cw narrow filter 250 hz/–6 db fl-223 ssb narrow ...

  • Page 66: Maintenance

    63 10 maintenance ■ troubleshooting the following chart is designed to help you correct problems which are not equipment malfunctions. If you are unable to locate the cause of a problem or solve it through the use of this chart, contact your nearest icom dealer or service center. Problem possible ca...

  • Page 67: Fuse Replacement

    Circuitry fuse replacement the 13.8 v dc from the dc power cable is applied to all units in the ic-756, except for the power amplifier, through the circuitry fuse. This fuse is installed in the pa unit. Q remove the top cover as shown on p. 61. W remove 11 screws from the pa shielding plate, then re...

  • Page 68: Tuning Dial Brake Adjustment

    65 10 maintenance the tension of the tuning dial may be adjusted to suit your preference. The brake adjustment screw is located on the right side of the tuning dial. See the figure at right. Turn the brake adjustment screw clockwise or coun- terclockwise to obtain a comfortable tension level while t...

  • Page 69: Internal Views

    Pa fuse (fgb 5 a) pa unit clock backup battery filter unit internal antenna tuner 66 11 internal views • top view rf unit r572 optional voice synthesizer level adj. Space for optional 455 khz filter pll unit space for optional 9 mhz filter space for optional voice synthesizer (ut-102) main unit spac...

  • Page 70: Specifications

    67 12 specifications ■ general • frequency coverage: receive 1 0.030–60.000 mhz* 1 transmit 0 1.800– 0 1.999 mhz* 2 0 3.500– 1 3.999 mhz* 2 0 7.000– 1 7.300 mhz* 2 10.100–10.150 mhz 14.000–14.350 mhz 18.068–18.168 mhz 21.000–21.450 mhz 24.890–24.990 mhz 28.000–29.700 mhz 50.000–54.000 mhz* 2 * 1 som...

  • Page 71: Options

    68 13 options ic-4kl hf 1 kw linear amplifier full-duty 1 kw linear amplifier including an automatic antenna tuner. Has automatic tuning and band selection capability. Full break-in (qsk) operation is possible. The amplifier/power supply unit and the remote control unit are separated. Ex-627 automat...

  • Page 72

    6-9-16 kamihigashi, hirano-ku, osaka 547, japan a-5415h-1ex- e printed in japan copyright © 1996 by icom inc. Count on us!.