Page 68
FT-897D O
PERATING
M
ANUAL
A
PPENDIX
S
ETUP
OF
M
EMORIES
FOR
L
OW
E
ARTH
O
RBIT
(
LEO
)
FM S
ATELLITE
O
PERATION
Although the
FT-897D
is not capable of “full duplex” op-
eration (simultaneous transmission and reception), its flex-
ible memory system is ideal for configuring a set of memo-
ries for LEO satellite work.
The example below is designed around the popular satellite
UO-14
, but the same principles apply to operation using
AO-27, SO-35, and other such satellites.
First, set up a table of the required operating frequencies.
For UO-14, a typical setup table is shown below:
Channel #
Rx Freq.
Tx Freq.
Notes
1
435.080
145.970.0
AOS
2
435.075
145.972.5
3
435.070
145.975.0
Mid Pass
4
435.065
145.977.5
5
435.060
145.980.0
LOS
AOS = Acquisition of Signal (Beginning of Pass)
LOS = Loss of Signal (End of Pass)
The above frequencies are nominal, and the changing fre-
quencies reflects the Doppler Shift which occurs on such
satellites, which display rapid apparent motion relative to
an earth-based observer. But if we can accommodate a set
of several frequency pairs in our memory system, frequen-
cies that reflect the frequency relationships encountered
during a typical pass, we will have a good chance of having
our frequencies properly aligned when it is time for making
a QSO.
So we need to store the above frequency matrix into memo-
ries. Note that the receiving frequency and transmitting fre-
quency are on different bands. Therefore, we will use the
“Split Frequency Memory” storage technique described on
page 42.
First, press the [
F
] key momentarily, then rotate the
MEM/
VFO CH
knob to select Multi Function Row “a” [
A
/
B
,
A=B
,
SPL
]. Press the [
A
](
A
/
B
) key, if necessary, to select VFOa.
Now press the
BAND
(
DWN
) or
BAND
(
UP
) key to select
the 70 cm band. Check the setting of Menu Mode
No-004
[
AM&FM DIAL
]
. and set this to “
ENABLE
” to allow smaller
frequency increments to be accommodated.
Set the VFOa operating frequency to 435.0800.00 MHz.
Now press the [
A
](
A
/
B
) key in Multi Function Row “a” to
select VFOb, and set VFOb to 145.970.00 MHz. Again press
the [
A
](
A
/
B
) key to return to VFOa. Be sure that both VFOs
are set to the FM mode, as well.
Press the [
F
] key momentarily, and rotate the
MEM/VFO
CH
knob one click clockwise to select Multi Function Row
“b” [
MW
,
SKIP
,
TAG
].
Press the [
A
](
MW
) key momentarily, then rotate the
MEM/
VFO CH
knob while the memory channel number is blink-
ing; select memory channel
M-001
, then press and hold in
the [
A
](
MW
) key until you hear the double beep. We have
just stored the first downlink (earth station receiving) fre-
quency into memory.
Press the [
F
] key momentarily, then rotate the
MEM/VFO
CH
knob one click counter-clockwise 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 [
F
] key momentarily, and rotate the
MEM/
VFO CH
knob one click clockwise to re-select Multi Func-
tion Row “b” [
MW
,
SKIP
,
TAG
]. Press the [
A
](
MW
) key
momentarily; 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) fre-
quency 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.
Return to Multi Function “b” [
MW
,
SKIP
,
TAG
], and repeat
the Split Memory storage process, selecting memory chan-
nel
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 fre-
quencies 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
MEM/VFO CH
knob to select channel
M-001
. This will be the first fre-
quency 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 down-
link 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
MEM/VFO CH
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 down-
link 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 TAG
]
to label each satellite
memory (for example, “
UO-14a
” ~ “
UO-14e
” for the above
five channels).
A complete set of frequencies may be stored for each LEO
satellite you wish to utilize, and once configured, the
FT-
897D
provides a flexible and easy-to-use earth station ca-
pability for these popular satellites.
