ICOM 910H Satellite Operating Supplement

FM Satellites - UO-14 and AO-27

1. Connect a 2 Meter antenna and a 70 CM antenna to the ICOM 910H.

2. Take out of satellite mode if already in satellite mode.

3. With SUB indicator off, Tune Main Band (upper frequency on the readout) to satellite's uplink frequency - the frequency you need to transmit on to reach the satellite. UO-14 it's 145.975 MHz; AO-27 it's 145.850 MHz.

4. With SUB indicator on, Tune Sub Band (lower frequency on the readout) to satellite's downlink frequency - the frequency you need to receive the satellite on. UO-14 it's 435.070 MHz; AO-27 it's 436.975 MHz. Because of the doppler shift these 2 satellites will start out about 15 KHz higher than the center frequency, and wind up 15 KHz lower.

5. Turn on your 435 MHz preamp; satellites are not that strong.

6. Put speaker on Subband (outermost) jack.

7. Normal RCV tune - have SUB on. To adjust XMT frequency - turn off SUB. Now theICOM 910H is set to full duplex with no tranmitter tracking when you tune the receiver for doppler shift. In Satellite Mode, you can't turn off the tracking and still see both frequencies on the front panel.

8. Set both Main and Subband to FM mode, and .1 tune rate.

9. Use lower SUB AF control for audio volume. - The SUB can't transmit unless in satellite mode.

10. If you want to blank the downlink audio on transmit to avoid riding the audio gain control, ( I'm not sure why you would really want to), hit the SET, & TRANSMIT keys, then press the DOWN key to display "ON AUDIO". Turn main tuning knob for "OFF AUDIO". Now the rig will act like an HF rig instead of like a full duplex satellite radio.

11. During reception of these FM satellites, keep the lighted indicator constantly on. If it starts to blink, the discriminator is tuned to the side and the audio will start to distort.

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Using the ICOM 910H on AO-40

1. Turn on Satellite Mode, Reverse by pressing the Satellite and the F Int keys.

2. Press the SCAN key and tune the Main band to 145.320 MHz (upper frequency on the readout), USB. (Assuming your downconverter has output on the 2 Meter band).

3. Press the SWAP key and tune the Sub band to 435.666 MHz (lower frequency on the readout), LSB. If you want to set up for L band uplinking, tune the Sub band to 1269.384 MHz (lower frequency on the readout), LSB. You can set the tune rate to either 1 or 10 Hz steps.

4. Press SCAN which decouples the tracking, tune in AO-40's middle beacon, and then press SCAN again to recouple the tracking. If you don't have it displayed; it is not going to be tracking. Now the uplink will be close enough to the correct frequncy to hear your downlink.

5. Tune up or down the band to the edges where you won't bother anyone, and then press SCAN to unlock the transmit VFO. Now talk into the microphone, and find yourself on the downlink echo, and tune in for best natural pitch. Press SCAN, and you will be reverse tracking anywhere on the passband.

6. Turn off "SUB" on the display or the tuning will be backwards.

7. If you have the DSP Option, and it really is worth it, hit the SET key and the NR key below the display. Turn the dial to a setting of 3 or more, your preferrence for how aggressive the DSP is with white noise. Press SET again to exit.

8. Some people also like to use voice compression if transmitting through AO-40. If so, press SET and the COMP key above the microphone jack. Tune the main knob to the desired setting, 65 is a good start. Press SET again to exit.

9. Tune in a station. Press and hold the NR key for 1 second and see the difference. Listen to your downlinked transmission, and hit the COMP key and see the difference. Adjust NR and COMP to suit yourself.

Robert W0LMD