User manual ICOM IC-751

[. . . ] This may result in an electrical shock or burn. Place unit in a secure place to avoid inadvertent use by children. R NEVER apply AC to the [DC13. 8V] jack on the transceiver rear panel. This could cause a fire or ruin the transceiver. During mobile operation, DO NOT operate the transceiver without running the vehicle's engine. When transceiver power is ON and your vehicle's engine is OFF, the vehicle's battery will soon become exhausted. This will avoid possible damage to the transceiver by ignition voltage spikes. [. . . ] +20. . . +40. . . + 60dB . . +20 . . . +40 . . . +60dB 025 25 50 100% 1. 5 1. 5 2 2. 5 2. 5 3 ALC COMP s SWR reading The SWR meter indicates the SWR over the transmission line in all modes. Less than 1. 5:1 SWR meter 5 10 9 25 50 2 10 3 20 dB q Push [TUNER] to turn the antenna tuner OFF. t Rotate [RF POWER] clockwise past the 12 o'clock position for more than 30 W output power (30%). u Read the SWR on the SWR meter. + 20 1 + 40 100 + 60dB S Po 0 1 1. 5 SWR 0 COMP ALC The built-in antenna tuner matches the transmitter to the antenna when the SWR is lower than 3 : 1. 36 RECEIVE AND TRANSMIT 5 s Speech compressor The RF speech compressor increases average RF output power, improving signal strength and readability in SSB. u Adjust the [COMP] control so that the COMP meter reads within 10 dB and 20 dB. COMP meter 5 10 9 25 50 23 20 10 dB · Speech compressor q Select USB or LSB mode. to toggle between narrow, middle or wide transmit filter. · Transmit filter width: NAR 2. 0 kHz MID 2. 6 kHz WIDE 2. 9 kHz 1 + 20 + 40 100 + 60dB S Po 0 1 1. 5 SWR 0 COMP ALC When the ALC meter peaks above the ALC zone, your transmitted voice may be distorted. · Compression level setting q Select USB or LSB mode. w Preset the transceiver as follows: [COMP] function : OFF [METER] function : ALC [MIC GAIN] control : Center position [COMP] control : Center position [RF POWER] control : Max. r Adjust the [MIC GAIN] control so that the ALC meter reads within the ALC zone, whether or not you speak softly or loudly. t Push [COMP] momentarily to turn the speech compressor ON. [METER] switch [MIC GAIN] control [RF POWER] control [COMP] switch [COMP] control 37 5 RECEIVE AND TRANSMIT s Digital voice recorder The transceiver has a total of 8 memory channels, 4 each for transmit and receive, of digital voice memories. Providing a transmission memory is very convenient for repeated CQ and number transmissions at contest times, as well as when making consecutive calls in DX'pedition. · Playing the recorded audio q Push [EXIT] one or more times to close a multifunction screen, if necessary. r Push [(F-1)PLAY] to select the voice memory screen. · If the transmit voice memory channel (T1­T4) appears, push [(F-5)T/R] to select receive voice memory channel. AGC MID VOX OFF COMP OFF WIDE R1 VOICE RECORDER R1 R1 R2 R2 R3 R3 R4 R4 RX RX M E M O R Y · Recording a received audio q Push [EXIT] one or more times to close a multifunction screen, if necessary. e Push [(F-2)VOICE] to call up the voice recorder screen. AGC MID VOX OFF COMP OFF WIDE PLAY VOICE RECORDER VOICE R E C O R D E R MENU V O I C E RECORDER M E N U P L A Y T X 15sec. r Rotate the tuning dial to adjust the transmit voice level. · Push [(F-5)DEF] to select the default condition. AGC MID VOICE RECORDER SEND T2 T3 T4 T/R T1 T1 T2 T2 CQ J A 3 Y U A C Q JA3YUA 10s 10s ------------TX_LEVEL TX LEVEL 50% t Push the desired memory channel, [(F-1)T1] ­ [(F-4)T4], momentarily to transmit the contents. AGC MID VOX OFF COMP OFF WIDE T1 VOICE RECORDER SEND VOX OFF COMP OFF WIDE T1 T3 T3 T4 T4 T2 T3 T4 DEF T1 T1 T2 T2 T3 T3 T4 T4 CQ J A 3 Y U A C Q JA3YUA 10s 10s ------------- t Push [EXIT] to return to the voice recorder screen. TX TX M E M O R Y T2 T3 T4 T/R y Push the selected memory channel, [(F-1)T1] ­ [(F-4)T4], again to stop, if desired. u Push [EXIT] twice to exit voice memory screen. · Transmit monitor function The monitor function can be automatically turned ON while transmitting a voice memory message. e Rotate the tuning dial to turn the monitor function ON and OFF. · Push [(F-3)DEF] to select the default condition. AGC MID VOX OFF COMP OFF WIDE DEF VOICE SET A uto Monitor Auto Monitor ON r Push [EXIT] to return to the voice recorder screen. 40 RECEIVE AND TRANSMIT 5 s RTTY decoder The transceiver has an RTTY decoder for Baudot (mark freq. : 2125 Hz, shift freq. : 170 Hz, 45 bps). An external terminal unit (TU) or terminal node controller (TNC) is not necessary for receiving a Baudot signal. q Push [EXIT] one or more times to close a multifunction screen, if necessary. e Push [(F-2)DECODE] to turn the RTTY decoder ON. · RTTY decoder screen appears. AGC MID RTTY FIL ON u Push [(F-2)CLR] for 2 sec. i Push [EXIT] to exit the RTTY decoder screen. · Setting the decoder threshold level Adjust the RTTY decoder threshold level if some characters are displayed when no signal is received. e Rotate the tuning dial to adjust the RTTY decoder threshold level. · Push [(F-3)DEF] to select the default condition. AGC MID RTTY FIL ON RTTY DECODE **** RTTY Decode Monitor **** **** RTTY Decode Monitor **** 45bps BAUDOT Mark=2125, Shift=170 45bps BAUDOT Mark=2125, Shift=170 UnShift On Space support (SET-OTHERS) UnShift On Space support (SET-OTHERS) New Line Code selectable (SET-OTHERS) New Line Code selectable (SET-OTHERS) If RTTY-FIL is OFF, Please turn ON. -------------------------------------------THRESHOLD 9 RTTY DECODE 1/4 OFF HOLD CLR ADJ WIDE **** RTTY Decode Monitor **** **** RTTY Decode Monitor **** 45bps BAUDOT Mark=2125, Shift=170 45bps BAUDOT Mark=2125, Shift=170 UnShift On Space support (SET-OTHERS) UnShift On Space support (SET-OTHERS) New Line Code selectable (SET-OTHERS) New Line Code selectable (SET-OTHERS) If RTTY-FIL is OFF, Please turn ON. -------------------------------------------ADJ THRESHOLD 9 1/4 OFF r If the RTTY filter is turned OFF, push [RTTY FIL] to turn the function ON. · The RTTY decoder does not function when the RTTY filter is turned OFF. DEF ADJ WIDE r Push [EXIT] to return to the RTTY decoder screen. t Push [(F-1)HOLD] to freeze the current screen. · "HOLD" appears while the function is in use. y Push [(F-5)WIDE] to toggle the normal or wide screen space. ANT 1 The UnShift On Space (USOS) function and new line code can be set in the miscellaneous (others) set mode. 70, 71) BW 350 TX SFT 0 RTTY RTTY qw:pp FIL2 FIL FIL2 FIL V F O qrqotpp VFO 14. 100. 00 METER Po P. AMP 1 ATT OFF AGC MID VOX OFF COMP OFF WIDE HOLD RTTY DECODE **** RTTY Decode Monitor **** **** RTTY Decode Monitor **** 45bps BAUDOT Mark=2125, Shift=170 45bps BAUDOT Mark=2125, Shift=170 UnShift On Space support (SET-OTHERS) UnShift On Space support (SET-OTHERS) New Line Code selectable (SET-OTHERS) New Line Code selectable (SET-OTHERS) If RTTY-FIL is OFF, Please turn ON. [. . . ] e Set the frequency to the standard frequency station minus 1 kHz. · When receiving WWV (10. 000. 00 MHz) as a standard frequency, set the operating frequency for 9. 999. 00 MHz. · Other standard frequencies can also be used. ANT 1 è DEF WIDE o Adjust the calibration pot on the right side panel of the transceiver for a zero beat with the received standard signal as shown below. · Zero beat means that two signals are exactly the same frequency, resulting in a single tone being emitted. BW 2. 4k SFT 0 USB FIL2 qw:pp TX METER Po VFO oooopp 1 14. 100. 00 USB r Push [EXIT] one or more times to close a multifunction screen, if necessary. y Push [(F-4)OTHERS] to enter miscellaneous (others) set mode. !0 Rotate the tuning dial counterclockwise to turn the calibration marker OFF. !1 Push [EXIT] twice to exit set mode. 76 INTERNAL VIEWS · Top view 12 PA unit Internal antenna tuner PA fuse (FGB 5 A) FILTER unit · Bottom view RF unit Clock backup battery PLL unit Space for optional voice synthesizer (UT-102) MAIN unit 77 13 CONTROL COMMAND s Remote jack (CI-V) information · 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. [. . . ]