D Tuner Operation; D Manual Tuning - Icom IC-7600 Instruction Manual

8
ANTENNA TUNER OPERATION
■ Antenna tuner operation
The nternal automatc antenna tuner matches the
transcever to the connected antenna automatcally.
After the tuner matches an antenna, the varable capac-
tor settngs are memorzed as a preset pont for each
frequency range (100 kHz steps). Therefore, when you
change the frequency range, the varable capactors are
automatcally preset to the memorzed settng.
CAUTION: NEVER transmt wth the tuner ON
when no antenna s connected. Ths wll damage
the transcever. Be careful of the antenna selecton.
✔ For your convenience
When you purchase a brand-new antenna, or you want
to change the antenna settngs, you can erase the all
of the nternal antenna tuner preset ponts wth "Tuner
Preset Memory Clear" n others set mode. (p. 130)

D Tuner operation

➥ Push [TUNER] to turn the nternal antenna tuner
ON. The antenna s tuned automatcally when the
antenna SWR s hgher than 1.5:1.
• When the tuner s ON,
lghts green.
• Whle tunng,

D Manual tuning

Durng SSB operaton at low voce levels, the nternal
tuner may not automatcally tune correctly. In such
cases, manual tunng s helpful.
➥ Push and hold [TUNER] for 1 sec., to start man-
ual tunng.
• A sdetone s emtted and the ndcator on the
swtch blnks red whle tunng.
• If the tuner cannot reduce the SWR to less than
1.5:1 after 20 sec. of tunng, the ndcator on the
swtch goes out.
❍ If the tuner cannot tune the antenna
Check the following and try again:
• the [ANT] connector selecton.
• the antenna connecton and feedlne.
• the untuned antenna SWR. (Less than 3:1 for HF
bands; Less than 2.5:1 for 50 MHz band)
• the transmt power. (8 W for HF bands; 15 W for
50 MHz band)
• the power source voltage/capacty.
If the tuner cannot reduce the SWR to less than 1.5:1
after checkng the above, perform the followng:
• repeat manual tunng several tmes.
• adjust the antenna feedlne length. (Ths s effectve
for hgher frequences n some cases.)
Even f the manual tune does not tune the antenna and
the tuner turns OFF at the frst tme, t may tune the
antenna at the second tme.
113
the ndcator on the swtch
the ndcator on the swtch blnks.
NOTES:
• NEVER transmt wthout an antenna properly con-
nected to antenna port n use.
• When 2 antennas are connected, select the
antenna to be used wth [ANT] (MF1).
• If the SWR s hgher than about 1.5:1 when tun-
ng farther than 100 kHz from an antenna's pro-
grammed preset pont, push and hold [TUNER] for
1 sec. to start manual tunng.
• The nternal tuner may not be able to tune n
AM mode. In such cases, push and hold [TUNER]
for 1 sec. to manually tune.
TUNER
❍ Tuning a narrow bandwidth antenna
Some antennas, especally for the low bands, have
a narrow bandwdth. These antennas may not be
tuned beyond the edge of ther operatng bandwdth,
therefore, tune such an antenna as follows:
[Example]: Suppose you have an antenna whch
has an SWR of 1.5:1 at 3.55 MHz and
an SWR of 3:1 at 3.8 MHz.
q Set 3.55 MHz and push and hold [TUNER] for
1 sec. to start manual tunng.
w Set 3.80 MHz and push and hold [TUNER] for
1 sec. to start manual tunng.