Vertex Standard manual FT-857 Operating Manual 123

APPENDIX

SETUP OF MEMORIES FOR LOW EARTH ORBIT (LEO) FM SATELLITE OPERATION

Press the [FUNC] key momentarily, then rotate the SELECT knob one click counter-clock- wise to re-select Multi Function Row “a” [A/B, A=B, SPL]. Press the [A](A/B) key to select VFOb (145.970 MHz).

Again press the [FUNC] key momentarily, and rotate the SELECT knob one click clock- wise to re-select Multi Function Row “b” [MW, SKIP, TAG]. Press the [A](MW) key mo- mentarily; the “M-001” indicator will flash; press and hold in the microphone’s PTT key, and while holding it in press the [A](MW) key until you hear the double beep. You have now stored the uplink (earth station transmitting) frequency into the same memory register as we did previously for the downlink frequency.

It’s now time to store the other frequencies in the matrix. Return to Multi Function Row “a” [A/B, A=B, SPL], and press the [A](A/B) key to return to VFOa on 435.080.00 MHz. Now rotate the DIAL knob to set the frequency to 435.075.00 MHz. Press the [A](A/B) key again to select VFOb (145.970 MHz), and rotate the DIAL knob to set the frequency to 145.972.50 MHz. Press the [A](A/B) key to return to VFOa on 435.075.00 MHz. Can’t set the frequen- cies using the DIAL. Go to Menu No-004[AM&FM DIAL], and change its setting to “EN- ABLE.”

Return to Multi Function “b” [MW, SKIP, TAG], and repeat the Split Memory storage pro- cess, selecting memory channel M-002 this time when initially storing the 435.075 MHz receiving frequency.

Now repeat this entire process three more times, filling memory channels M-003, M-004, and M-005 with the frequencies shown in the chart above.

When it’s time to operate, press the [V/M] key, if necessary, to recall the Memory mode, and rotate the SELECT knob to select channel M-001. This will be the first frequency pair to be utilized during the UO-14 window of workability when it rises above your local horizon. The Doppler effect will cause the nominal 435.070 MHz downlink frequency to appear higher to you, so utilize memory channel M-001 when the satellite first rises. A few minutes later, switch to M-002, and at mid-pass switch to M-003. As the satellite recedes, switch to M-004 and then M-005 toward the end of the pass.

The SELECT knob recall of these five channels makes Doppler tracking simple; just choose the memory channel producing the best signal! You have already programmed an uplink frequency corresponding to the optimum downlink frequency, so you will not need to try to make difficult VFO adjustments during the brief satellite passes.

The FM passbands used on LEO satellites are sufficiently broad that more precise frequency adjustment is not needed.

To aid in channel identification, remember that you can use Menu Mode No-056[MEM

FT-857 Operating Manual 123