Convenient Functions For Receive - Icom iC-7850 Instruction Manual

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5
RECEIVE AND TRANSMIT
This section, describes particular operations for each
operating mode, such as operating the Memory keyer
in the CW mode, or operating the Encoder or Decoder
in the RTTY or PSK mode.
If you use functions that are described in Section 6:
Scope operation, Section 7: Functions for Receive, or
Section 8: Functions for Transmit, you can operate the
transceiver more conveniently.

■ Convenient functions for Receive

 All operating modes
Preamplifier (p. 7-2)
The preamp amplifies received signals in the receiver
front end, to improve the S/N ratio and sensitivity. When
receiving weak signals, select to P.AMP 1 or P.AMP 2.
Push [P.AMP] several times to turn ON preamp 1 or
➥
preamp 2 or, to turn OFF the preamp.
• "P.AMP1" or "P.AMP2" is displayed when preamp 1 or
preamp 2 is ON. (The Main and Sub bands have inde-
pendent preamp controls.)
Attenuator (p. 7-2)
The attenuator prevents a desired signal from becom-
ing distorted when very strong signals are near the
frequency, or when very strong electric fields, such as
from broadcasting stations, are near your location.
Push [ATT] several times to set the attenuator in 6
➥
dB steps.
• Hold down [ATT] for 1 second to set the attenuator in 3
dB steps.
• "ATT" and the attenuation level are displayed when the
attenuator is ON.
Notch filter
(p. 7-13)
The Auto notch function uses DSP to automatically at-
tenuates beat tones, tuning signals, and so on, even if
they are moving.
The Manual notch can be set to attenuate a frequency
by rotating the [NOTCH] control.
• When the SSB or AM mode is selected:
Auto notch or Manual notch can be used.
• When the CW, RTTY, or PSK mode is selected:
Only the Manual notch can be used.
• When the FM mode is selected:
Only the Auto notch can be used.
Push the [NOTCH] key to turn the Auto or Manual
➥
notch function ON or OFF.
• Rotate the [NOTCH] control to set the "valley" frequency
for the Manual notch function.
• The Notch indicator (above the [NOTCH] key) lights
when either the Auto or Manual notch function is ON.
 SSB/CW/RTTY/PSK/AM modes
Noise blanker (p. 7-11)
The noise blanker eliminates pulse-type noise such as
the noise from car ignitions.
Push the [NB] key to turn the noise blanker ON or
➥
OFF, and then rotate the [NB] control to adjust the
threshold level.
• The Noise blanker indicator (above the [NB] key) lights
when the noise blanker is ON.
• Hold down the [NB] key for 1 second to enter the Noise
blanker set screen.
Noise reduction
(p. 7-12)
The Noise reduction function reduces random noise
components and enhances desired signals that are
buried in noise. The DSP does the random noise re-
duction function.
Push the [NR] key to turn the Noise reduction ON
➥
or OFF.
• Rotate the [NR] control to adjust the noise reduction
level.
• The Noise reduction indicator (above the [NR] key) lights
when the Noise reduction is ON.
AGC
(p. 7-4)
The AGC (Auto Gain Control) controls receiver gain to
produce a constant audio output level even when the
received signal strength greatly varies.
Twin PBT (p. 7-5)
The PBT (Passband Tuning) electronically narrows
the IF passband width by shifting the IF frequency to
slightly outside of the IF filter passband, to reject inter-
ference. The IC-7850 uses DSP for the PBT function.
Moving both the [TWIN PBT] controls to the same po-
sition shifts the IF.
Rotate the [TWIN PBT] controls (inner/outer).
➥
• Hold down [PBT CLEAR] for 1 second to clear the set-
tings.
5-2