Icom IC-9700 Instruction Manual basic - Page 54

7 SATELLITE COMMUNICATION Loop test procedure Decide on a usable satellite, and point your antenna towards it. LMonitored audio may cause howling. Using headphones is recommended. 1. Set the downlink frequency (receive frequency) in the Main band to match the beacon frequency. About the Loop test: Loop test is a method to confirm the communication status between your station and the satellite. By transmitting your voice (Example: your call sign), check the received audio. 5. While rotating MAIN DIAL , speak at your normal voice level to the microphone. LThe beacon frequency drifts (Doppler effect). Rotate MAIN DIAL to adjust the frequency. 2. When you can receive the beacon, rotate MAIN DIAL to select a frequency within the satellite's coverage, as the downlink frequency on the MAIN band. ••Adjust the uplink frequency so that your voice is clearly heard. 6. Touch [SUB]. ••The Sub band is unselected. Using the spectrum scope You can visually check the signal presence on the Spectrum Scope screen. MENU » SCOPE LSelect a vacant frequency within the satellite's coverage. Monitor the operating frequency to make sure transmitting won't cause interference to other stations. 3. Push [PTT] on the microphone to transmit. (or push [TRANSMIT] on the transceiver) 4. Touch [SUB]. ••The Sub band is selected. LBy touching on the waterfall zone on the SPECTRUM SCOPE screen, you can directly tune your frequency on the displayed area of the band. LRefer to Section 5 for details on the Scope screen. About the Doppler effect: Since the speed of satellite is high, the uplink and downlink frequency appear to drift due to the Doppler effect. As the satellite is moving towards your station, the downlink or uplink frequency appears to be higher, and is lower as the satellite is moving away. Therefore, you need to precisely adjust the uplink or downlink frequency to compensate for the frequency drift. 7-2