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6
FUNCTIONS FOR TRANSMIT
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Measuring SWR
The IC-7410 has a built-in circuit for measuring an-
tenna SWR— no external equipment or special adjust-
ments are necessary.
The IC-7410 can measure SWR two ways— spot mea-
surement and plot measurement.
D
Spot measurement
q
Push [TUNER] once or twice to turn OFF the an-
tenna tuner.
w
Hold down [ANT•METER] for 1 second, once or
twice, to select the SWR meter.
e
Push [RTTY] to select the RTTY mode.
r
Push [TRANSMIT] on the transceiver, or [PTT] on
the microphone to transmit.
t
Rotate the [RF PWR] control clockwise past the 12
o’clock position for more than 30 W of output power
(30%).
y
Read the SWR on the SWR meter.
u
Push [TRANSMIT] or release [PTT] to receive.
The built-in antenna tuner matches the transmitter to
the antenna only when the SWR is less than 3:1*.
*2.5:1 in the 50 MHz frequency band.
D
Plot measurement
Plot measurement allows you to measure the SWR
over an entire band.
q
Push [MENU] to display the “M2” screen (Menu 2),
then push [SWR](F-3).
• The SWR graph screen appears.
w
Rotate the [RF PWR] control clockwise past the 12
o’clock position for more than 30 W of output power
(30%).
e
Set the center frequency for the SWR to be mea-
sured.
r
Hold down [F-5] for 1 second one or more times
to set the SWR measuring step to 10, 50, 100 or
500 kHz.
t
Push [F-3] one or more times to select the number
of measuring steps to 3, 5, 7, 9, 11 or 13.
y
Push [F-1] to start the measuring.
u
Push [TRANSMIT] on the transceiver, or hold down
[PTT] on the microphone to transmit, to measure
the SWR.
• A frequency marker, “
∫
,” appears below the SWR
graph.
i
Push [TRANSMIT] again or release [PTT] to move
the frequency marker and frequency indication to
the next frequency to be measured.
o
Repeat steps
u
and
i
to measure the SWR over
the entire frequency range.
!0
When the measured SWR is less than 1.5:1, the
antenna is well matched with the transceiver in the
measured frequency range.
M E M
S C A N
S W R T C O N
V S C
M2
SWR
1 0 k
S T E P
Push
Start measuring
Select number of SWR measuring steps
Select SWR measuring step
•
Measuring
(after pushing [F-1])
SWR
1 0 k
S T E P
A frequency marker appears and moves
after measurement.
When measurement points are set out-
side of the operable frequency band, the
frequency marker blinks.
— 1.0:1
— 1.5:1
— 2.0:1
— 3.0:1
A G C
1 ⁄ 4
R T T Y
S C P
M1
The best match is in this range.
Typical display SWR varying between 1 and 2,
full scale up to SWR 4.0:1.
