Icom IC-7100

16
ANTENNA TUNER OPERATION
16-5
Operating the AT-180
D Before operating
About using antenna:1.
CAUTION:
• NEVER connect the antenna worth than 3:1 anten-
na. Even if the antenna tuner tune this antenna, it
causes to damage the antenna tuner.
• NEVER transmit with the tuner ON if no antenna is
connected. This will damage both the transceiver
and antenna tuner.
• Check the untuned antenna SWR. (Less than 3:1 for
the HF bands; Less than 2.5:1 for the 50 MHz band)
• Before start tuning, monitor the operating frequency
to make sure transmitting won’t cause interference to
other stations on the same frequency.
If the tuner cannot tune the antenna:2.
❍ Check the untuned antenna SWR.
If its SWR is worth than 3:1, adjust the SWR.
❍ Check the transmit power.
If the transmit power is less than 8 W, adjust the RF
power on the Mic gain/RF power adjustment dis-
play.
q Push
MIC/RF PWR
(C) to open the MIC gain/RF
power adjustment display.
w Rotate [BANK] (L) to adjust the RF power.
e Push
MENU
(C) to close the display.
❍ Check the power source voltage/current capacity.
❍ If the tuner still cannot reduce the SWR to less than
1.5:1 after checking the above, perform the follow-
ing:
• Try manual tuning one or more times.
• Adjust the antenna feedline length. (This is effec-
tive for higher frequencies in some cases.)
•
Even if manual tuning does not match the antenna
and the tuner turns OFF the first time, it may match
the antenna the second time.
❍ Tuning a narrow bandwidth antenna
Some antennas, especially for the low bands, have a
narrow bandwidth. These antennas may not be tuned
beyond the edge of their operating bandwidth, there-
fore, manually tune such an antenna as follows:
[Example]: Suppose you have an antenna which
has an SWR of 1.5:1 at 3.55 MHz and
an SWR of 3:1 at 3.8 MHz.
q Select 3.55 MHz and hold down
TUNER/CALL
(L)
for 1 second to start manual tuning.
w Select 3.80 MHz and hold down
TUNER/CALL
(L)
for 1 second to start manual tuning.
L
eft
R
ight
C
enter
D
isplay
The L, R, C or D in the
instructions indicate the
part of the controller.
L: Left side
R: Right side
C: Center bottom
D: Display (Touch screen)