Att - Yaesu FT DX 9000 CONTEST - MANUAL 2 Operation Manual

C
ONVENIENT
Even with the IPO function on, extremely strong local signals or high noise can still degrade reception. In such situations,
you can use the ATT switch to insert 3, 6, 12, or 18-dB of RF attenuation in front of the RF amplifier.
Rotate the ATT switch (#
tion level, per the chart below.
To restore full signal strength through the Attenuator cir-
cuit area, set the ATT switch to the "0" position.
0 dB Attenuator is Off
3 dB The incoming signal power is reduced by 3 dB (signal volt-
age reduced by 1/1.4)
6 dB The incoming signal power is reduced by 6 dB (signal volt-
age reduced by 1/2)
12 dB The incoming signal power is reduced by 12 dB (signal volt-
age reduced by 1/4)
18 dB The incoming signal power is reduced by 18 dB (signal volt-
age reduced by 1/8)
Advice
If background noise causes the S-meter to deflect on clear
frequencies, turn the ATT knob clockwise until the S-
meter drops to about "S-1." This setting optimizes the
trade-offs between sensitivity, noise, and interference im-
munity. Also, once you have tuned in a station you want to
work, you may want to reduce sensitivity further (or add
more attenuation) by turning the ATT knob to a more
clockwise setting. This reduces the strength of all signals
(and noise) and can make reception more comfortable, im-
portant especially during long QSOs.
When looking for weak signals on a quiet band, you will
want maximum sensitivity, so the IPO should be disabled
and the ATT knob should be set to "0." This situation is
typical during quiet times on frequencies above 21 MHz,
and when using a small or negative-gain receiving antenna
on other bands.
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F
EATURES

ATT

) to set the desired attenua-
ATT switch
FT 9000 C
DX ONTEST
O M
PERATION ANUAL