User manual ICOM IC-7800

[. . . ] i7800 Instruction Manual THE TRANSCEIVER A-6328H-1EX-r Printed in Japan © 2004 Icom Inc. FOREWORD Congratulations!You are the owner of the world's most advanced amateur HF/50 MHz transceiver-- IC-7800. The IC-7800 is designed and built with Icom's superior technology and craftsmanship. With proper care, this product should provide you with years of trouble-free operation. [. . . ] 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. In such cases, use the transceiver with the "P. AMP 1" or "P. AMP OFF" setting. The "P. AMP 2" is most effective when: · Used on bands above 24 MHz and when electric fields are weak. · Receive sensitivity is insufficient during low gain, or while using a narrow band antenna (such as small loop, a Beverage antenna or a short Yagi antenna). I Attenuator The attenuator prevents a desired signal from distortion when very strong signals are near the desired frequency or when very strong electric fields, such as from broadcasting stations, are near your location. [ATT] Push [ATT] several times to set the attenuator 6 dB, 12 dB, 18 dB or attenuator OFF. several times to set the attenuator 3 dB, 6 dB, 9 dB, 12 dB, 15 dB, 18 dB, 21 dB or attenuator OFF. 3 dB attenuation 6 dB attenuation 9 dB attenuation 12 dB attenuation 15 dB attenuation 18 dB attenuation 21 dB attenuation 5-9 5 FUNCTIONS FOR RECEIVE I RIT function The RIT (Receive Increment Tuning) function compensates for off-frequencies of the communicating station. The function shifts the receive frequency up to ±9. 99 kHz in 10 Hz steps without moving the transmit frequency. [RIT/TX] [RIT] q Push [RIT] to turn the RIT function ON and OFF. ·" " and the shifting frequency appear when the function is ON. w Rotate the [RIT/TX] control. · Push [CLEAR] for 1 sec. · Push [CLEAR] momentarily to reset the RIT frequency when the quick RIT/TX clear function is ON. to add the shift frequency to the operating frequency. [CLEAR] D RIT monitor function When the RIT function is ON, pushing and holding [XFC] allows you to monitor the operating frequency directly (RIT is temporarily cancelled). [XFC] For your convenience-- Calculate function The shift frequency of the RIT function can be added/subtracted to the displayed frequency. While displaying the RIT shift frequency, push [RIT] for 1 sec. 5-10 FUNCTIONS FOR RECEIVE 5 I AGC function [AGC] control for main [AGC] control for sub The AGC (auto gain control) controls receiver gain to produce a constant audio output level even when the received signal strength varies greatly. The transceiver has 3 preset AGC characteristics (time constant: fast, mid, slow) for non-FM mode. The FM mode AGC time constant is fixed as `FAST' (0. 1 sec. ) and AGC time constant cannot be selected. [AGC VR] for main [AGC VR] for sub [AGC] D Selecting the preset value q Select non-FM mode. w Push [AGC] several times to select AGC fast, AGC medium (MID) or AGC slow. D Adjusting the AGC time constant q Select non-FM mode. w Push [AGC VR], then rotate [AGC] control to adjust the AGC time constant. · [AGC VR] indicator above the switch lights green. D Setting the AGC time constant preset value q Select the desired mode (not FM mode). e Push [AGC] several times to select FAST time constant. r Rotate the main dial to set the desired time constant for `AGC FAST. ' · Selectable AGC time constant Mode SSB Default (unit: sec. ) Selectable AGC time constant · AGC time constant can be set between 0. 1 to 8. 0 sec. · Push [F-4·DEF] for 1 sec. to select a default value. 0. 3 (FAST) 0. 1, 0. 2, 0. 3, 0. 5, 0. 8, 1. 2, 1. 6, 2. 0, 2. 0 (MID) 2. 5, 3. 0, 4. 0, 5. 0, 6. 0 6. 0 (SLOW) 0. 1 (FAST) 0. 1, 0. 2, 0. 3, 0. 5, 0. 8, 1. 2, 1. 6, 2. 0, 0. 5 (MID) 2. 5, 3. 0, 4. 0, 5. 0, 6. 0 1. 2 (SLOW) t Push [AGC] to select medium time constant. [. . . ] !3 After the dialog disappears, the firmware updating is completed and normal operation screen appears. 16-9 ABOUT CE INSTALLATION NOTES For amateur base station installations it is recommended that the forwards clearance in front of the antenna array is calculated relative to the EIRP (Effective Isotropic Radiated Power). The clearance height below the antenna array can be determined in most cases from the RF power at the antenna input terminals. Different exposure limits have been recommended for different frequencies, a relative table shows a guideline for installation considerations. Below 30 MHz, the recommended limits are specified in terms of V/m or A/m fields as they are likely to fall within the near-field region. [. . . ]