159
13
ANTENNA TUNER OPERATION
M
)FTHETUNERCANNOTTUNETHEANTENNACHECKTHE
FOLLOWINGANDTRYAGAIN
sTHECORRECTANTENNACONNECTORSELECTION
sTHEANTENNACONNECTIONANDFEEDLINE
sTHEUNTUNEDANTENNA372,ESSTHANFORTHE
(&BANDS,ESSTHANFORTHE-(ZBAND
sTHETRANSMITPOWER7FORTHE(&BANDS7FOR
the 50 MHz band)
sTHEPOWERSOURCEVOLTAGECURRENTCAPACITY
If the tuner still cannot reduce the SWR to less than
1.5:1 after checking the above, perform the following:
sTRYMANUALTUNINGONEORMORETIMES
sADJUSTTHEANTENNAFEEDLINELENGTH4HISISEFFECTIVE
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 an-
tenna the second time.
M
4UNINGANARROWBANDWIDTHANTENNA
Some antennas, especially for the low bands, have
a narrow bandwidth. These antennas may not be
tuned beyond the edge of their operating bandwidth,
therefore, manually tune such an antenna as follows:
;%XAMPLE=
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] for 1
second. to start manual tuning.
w
Select 3.80 MHz and hold down [TUNER] for 1
second to start manual tuning.
./4%3
s4HEINTERNALANTENNATUNERCANONLYTUNETHE(&
and 50 MHz bands— the 144 MHz, 430 MHz and
1200 MHz* bands cannot be tuned.
s
NEVER
transmit without an antenna properly con-
nected to each antenna port in use.
s7HEN ANTENNAS ARE CONNECTED SELECT THE AN
-
TENNATOBEUSEDWITH;!.4s-%4%2=
s)FTHE372ISHIGHERTHANABOUTWHENTUN
-
ing farther than 100 kHz from an antenna’s pro-
grammed preset point, hold down [TUNER] for
1 second to start manual tuning.
s4HEINTERNALTUNERMAYNOTBEABLETOTUNEIN
the
AM mode. In such cases, hold down [TUNER] for
1 second to manually tune.
[TUNER]
N
!NTENNATUNEROPERATION
The internal automatic antenna tuner automatically
matches the transceiver to the selected antenna. After
the tuner matches an antenna, the variable capacitor set-
tings are memorized as a preset point for each frequency
range (100 kHz steps). Therefore, when you change the
frequency range, the variable capacitors are automati-
cally preset to the memorized setting.
#!54)/..%6%2
transmit with the tuner ON when
no antenna is connected. This will damage the trans-
ceiver. Be careful of the antenna selection.
For your convenience
When you purchase a brand-new antenna, or you
want to change the antenna settings, you can erase all
of the internal antenna tuner preset points with “Tuner
Preset Clear” in the Set mode. (p. 163)
D
4UNEROPERATION
±
Push [TUNER] to turn ON the internal antenna
tuner. The antenna is automatically tuned when the
antenna SWR is higher than 1.5:1.
s7HENTHETUNERIS/.h
” appears.
D
-ANUALTUNING
Transmitting in SSB with a soft voice, the internal tuner
may not automatically tune correctly. In such cases,
manual tuning is helpful.
±
Hold down [TUNER] for 1 second to start manual
tuning.
s!SIDETONESOUNDSh
” blinks and the TX/RX indi-
cator (MAIN Band) lights red while tuning.
s)FTHETUNERCANNOTREDUCETHE372TOLESSTHAN
after 20 sec. of tuning, “
” disappears and the TX/
RX indicator (MAIN Band) goes out.
