Icom IC-7400 Instruction Manual page 9

D D What are you hearing?
Stop and focus on what you are hearing. Do you hear
a lot of noise? Is the signal intelligible? Are you set up
for the right mode? How about the filters?
1. Verify mode
Although your IC-7400 will automatically select USB
or LSB in the HF bands, it will not select any of the
other modes. You will need to select the proper mode
whether CW, RTTY, AM or FM.
2. Reducing interference
Your IC-7400 has many features to reduce QRM and
QRN from the desired signal.
a. Noise Reduction: The noise reduction system on
your IC-7400 is part of the 32-bit DSP. This is used
to reduce the hiss and QRM levels. To activate,
push the [NR] switch located just to the right of the
[PHONES] jack.
[NR] [NR]
b. Adjusting the Noise Reduction: The noise re-
duction is completely variable on how much of the
DSP Noise Reduction is used [NR] level control lo-
cated just above the [NR] switch.
Hint!
The Triple Band Stacking Register will memorize
the last three frequencies used in the band, as well
as the Mode, Filter, Tuner and AGC settings. This
makes band hoping much easier.
Hint!
How far you advance the NR control will determine
how much the noise can be effectively reduced.
Turning the control too far clockwise may cause
some distortion to occur on the received signal. The
NR control should only be turned as far clockwise
as is necessary. Use this control, along with RF
Appears
gain, NB (noise blanker, if needed), and IF filters as
well, to minimize the effects of noise on the target
signal.
QUICK REFERENCE GUIDE
SSB CW/RTTY AM/FM
NR NOTCH
Decreases Increases
OFF
Noise reduction ON
Noise reduction OFF
VI