User manual ICOM IC-720

[. . . ] We would like to take a few moments of your time to thank you for making the IC-720 your radio of choice, and hope you agree with Icom's philosophy of "technology first. " Many hours of research and development went into the design of your IC-720. D FEATURES Ultimate receiver performance: third-order intercept (IP3) of +40 dBm (HF bands only), both main and sub Independent identical receiver circuits for main and sub bands provide perfect no-compromise Dualwatch operation Built-in Baudot RTTY and PSK31 modulator/demodulator and direct PC keyboard connection capability for RTTY and PSK31 operation without a PC Upgraded real-time spectrum scope-- center frequency and fix frequency modes, plus mini-scope displays 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-720. EXPLICIT DEFINITIONS WORD R WARNING CAUTION NOTE DEFINITION Personal injury, fire hazard or electric shock may occur. No risk of personal injury, fire or electric shock. TRADEMARKS Icom, Icom Inc. and the logo are registered trademarks of Icom Incorporated (Japan) in the United States, the United Kingdom, Germany, France, Spain, Russia and/or other countries. i PRECAUTIONS R WARNING HIGH RF VOLTAGE! [. . . ] Up to 500 kHz band width can be specified, so either edge frequency will be set to the difference between higher and lower frequencies become 5 to 500 kHz automatically while setting another edge frequency. Set the scope edge frequencies for fix mode scope when 15 to 20 MHz band is selected. · Set the frequencies within 15. 000 to 20. 000 MHz range in 1 kHz steps. Up to 500 kHz band width can be specified, so either edge frequency will be set to the difference between higher and lower frequencies become 5 to 500 kHz automatically while setting another edge frequency. Set the scope edge frequencies for fix mode scope when 20 to 22 MHz band is selected. · Set the frequencies within 20. 000 to 22. 000 MHz range in 1 kHz steps. Up to 500 kHz band width can be specified, so either edge frequency will be set to the difference between higher and lower frequencies become 5 to 500 kHz automatically while setting another edge frequency. Set the scope edge frequencies for fix mode scope when 22 to 26 MHz band is selected. · Set the frequencies within 22. 000 to 26. 000 MHz range in 1 kHz steps. Up to 500 kHz band width can be specified, so either edge frequency will be set to the difference between higher and lower frequencies become 5 to 500 kHz automatically while setting another edge frequency. 5-7 5 FUNCTIONS FOR RECEIVE D Scope set mode (continued) Set the scope edge frequencies for fix mode scope when 26 to 30 MHz band is selected. · Set the frequencies within 26. 000 to 30. 000 MHz range in 1 kHz steps. Up to 500 kHz band width can be specified, so either edge frequency will be set to the difference between higher and lower frequencies become 5 to 500 kHz automatically while setting another edge frequency. Set the scope edge frequencies for fix mode scope when 30 to 45 MHz band is selected. · Set the frequencies within 30. 000 to 45. 000 MHz range in 1 kHz steps. Up to 500 kHz band width can be specified, so either edge frequency will be set to the difference between higher and lower frequencies become 5 to 500 kHz automatically while setting another edge frequency. Set the scope edge frequencies for fix mode scope when 45 to 60 MHz band is selected. · Set the frequencies within 45. 000 to 60. 000 MHz range in 1 kHz steps. Up to 500 kHz band width can be specified, so either edge frequency will be set to the difference between higher and lower frequencies become 5 to 500 kHz automatically while setting another edge frequency. 5-8 FUNCTIONS FOR RECEIVE 5 I Preamplifier The preamp amplifies received signals in the receiver front end, to improve the S/N ratio and sensitivity. Set this to preamp 1 or preamp 2 when receiving weak signals. [P. AMP] Push [P. AMP] several times to set the preamp OFF, preamp 1 ON or preamp 2 ON. For all HF bands High-gain preamp for 24 MHz band and above About the "P. AMP2" The "P. AMP 2" is a high gain receive amplifier. When the "P. AMP 2" is used during times of strong electric fields, distortion sometimes results. !0 Push [EXIT/SET] to exit the AGC set mode screen. 5-11 5 FUNCTIONS FOR RECEIVE I Twin PBT operation In general PBT (Passband Tuning) electronically narrows the IF passband width by shifting the IF frequency to slightly outside of the IF filter passband to reject interference. The IC-720 uses DSP for the PBT function. Moving both [TWIN PBT] controls to the same position shifts the IF. [TWIN PBT] for main [TWIN PBT] for sub The LCD shows the passband width and shift frequency graphically. Current passband width and shift frequency is displayed in the filter set screen. To set the [TWIN PBT] controls to the center positions, push [PBT CLR] for 1 sec. The variable range depends on the passband width and mode. The edge of the variable range is half of the passband width, and PBT is adjustable in 25 or 50 Hz steps. · [TWIN PBT] should normally be set to the center positions (PBT setting is cleared) when there is no interference. · When PBT is used, the audio tone may be changed. · While rotating [TWIN PBT], noise may occur. This comes from the DSP unit and does not indicate an equipment malfunction. [PBT CLEAR] for main [PBT CLEAR] for sub Shows filter width, shifting value and condition · PBT operation example Both controls at center position PBT1 PBT2 Cutting a lower passband PBT1 PBT2 Cutting both higher and lower passbands PBT1 PBT2 Passband Passband IF center frequency Interference Desired signal Interference Interference Desired signal 5-12 FUNCTIONS FOR RECEIVE 5 I IF filter selection [FILTER] for main [FILTER] for sub The transceiver has 3 passband width IF filters for each mode. For SSB, CW and PSK modes, the passband width can be set within 50 to 3600 Hz in 50 or 100 Hz steps. [. . . ] i Click [Yes] if you want to start the firmware update. Click to start the firmware update 16-8 UPDATING THE FIRMWARE 16 o The screen as at left is displayed. · The following dialog appears in the IC-720 display. RWARNING!: NEVER turn the IC-720 power OFF at this stage. The transceiver firmware will be damaged. !0 Click [OK] to finish the firmware update. · The "FIRMWARE UPDATING" dialog as above disappears. !1 Push [POWER] to turn the IC-720 power OFF, then ON again. Click [OK] to finish the firmware update. !2 Depending on the updating, one to four dialogs as at left appears in the IC-720 display in sequence. RWARNING!: NEVER turn the IC-720 power OFF at this stage. The transceiver firmware will be damaged. [. . . ]