User manual ICOM IC-746

[. . . ] 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!NEVER attach an antenna or internal antenna connector during transmission. [. . . ] In this case turn the function OFF. [NB] 39 5 FUNCTIONS FOR RECEIVE 5-7 Noise reduction [NR] DSP 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. Push [NR] to toggle noise reduction ON and OFF. · "NR" appears when noise reduction is ON. Rotate the [NR] control to obtain the desired level of noise reduction. · Clockwise rotation increases the level of noise reduction; counterclockwise rotation decreases the level of noise reduction. [NR] 5-8 Auto notch (ANF) function DSP The auto notch function automatically attenuates more than 3 beat tones, tuning signals, etc. , even if they are moving. This function is only available in SSB, AM and FM modes. Push a mode key to select SSB, AM or FM mode. Push [APF/ANF] to toggle the auto notch filter ON and OFF. · "ANF" appears when the function is ON. [APF/ANF] 5-9 Dial lock function Lights when the dial lock function is ON The dial lock function prevents accidental frequency changes caused by inadvertently rotating the tuning dial. This function electronically locks the tuning dial. Push [LOCK] to toggle the dial lock function ON and OFF. · When the dial lock function is turned ON, the [LOCK] indicator lights red. [LOCK] 40 FUNCTIONS FOR RECEIVE 5 5-10 Twin PBT [TWIN PBT] 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. 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. · Not available in FM mode. M1 AGC DUP CMP TCN SCP Twin PBT graphic indication PBT OPERATING EXAMPLE center passband passband IF shift pass band IF center frequency interference desired signal inteference desired signal IF center freq. interference 41 5 FUNCTIONS FOR RECEIVE 5-11 Selecting IF filters Optional filters can be installed in the IF stage of the IC-746 (p. 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. FILTER CONSTRUCTION 9 MHz IF filter through FL-272 (2. 4 kHz) (standard) 9 MHz (optional 1) 9 MHz (optional 2) Mixer 455 kHz IF filter CFJ455k (2. 4 kHz) (standard) SFPC455G (9 kHz) (standard) SFPC-455E (15 kHz) (standard) 455 kHz (optional) 3rd LO · 9 MHz optional filters FL-101 (250 Hz) FL-232 (350 Hz) FL-100 (500 Hz) FL-223 (1. 9 kHz) FL-103 (2. 8 kHz) · 455 kHz optional filters FL-53A (250 Hz) FL-52A (500 Hz) FL-222 (1. 8 kHz) FL-96 (2. 8 kHz) FL-257 (3. 3 kHz) NOTE: one 455 kHz optional filter can be installed; two 9 MHz optional filters can be installed. s FILTER PROGRAM MODE SETTINGS Push [FILTER] for 2 sec. to select filter program mode. Push a mode key to select an operating mode for the filter setting. Push [FILTER] to set the filter condition to normal or narrow. · "NAR" appears when narrow is selected. Push [F2](9M) or [F4](455k) one or more times to select a 9 MHz filter or a 455 kHz filter, respectively. Repeat steps to to set filters for other operating modes, if desired. [FILTER] Push [MENU] to return to regular operation. NOTE: See p. 78 for activating the installed optional 9M 455k FIL 2. 4k - 2. 4k F1 F2 F3 F4 F5 filter(s). Selects 9 MHz band filter Selects 455 kHz band filter FIL 9M 455k 2. 4k - 2. 4k 42 FUNCTIONS FOR TRANSMIT 6-1 VOX function 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. Select a phone mode (SSB, AM, FM). Push [VOX/BK-IN] to turn the VOX function ON and OFF. · "VOX" appears when the function is ON. [. . . ] audio 2. 0 A : 287(W)×120(H)×316. 5(D) mm 115/16(W)×423/32(H)×1215/32(D) in : 8. 9 kg; 19 lb 10 oz : 2-conductor 3. 5 (d) mm (1/8") · RIT variable range · Audio output power More than 70 dB More than 60 dB (144 MHz) : ±9. 999 kHz : More than 2. 0 W (at 13. 8 V DC with an 8 load) All stated specifications are subject to change without notice or obligation. SUPPLIED ACCESSORIES DC power cable (OPC-025A) . 1 1 2 1 1 TRANSMITTER · Output power : USB, LSB, FM 5­100 W AM 5­40 W · Modulation system : USB, LSB, AM Balanced modulation FM Variable reactance modulation · Spurious emissions : Less than ­50 dB (HF) Less than ­60 dB (50/144 MHz) · Carrier suppression : 40 dB · Unwanted sideband : 50 dB · :TX variable range : ±9. 999 kHz · Mic. connector : 8-pin connector (600 ) 84 t 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. 5­28 MHz bands with the AH-4 Light weight switching regulator system power supply. · Output voltage: 13. 8 V DC · Max. [. . . ]