Icom IC-471H Instruction Manual page 19

Scan restarts
Scan starts
Turning Tuning Control
(Frequency jumps to the high edge)
Scan stops
Scan restarts
Turning Tuning Control
(from this} frequency)
High edge Low edge
NOTE: The auto-stop functions with SSB or CW signals,
but the scan does not always stop at the exact
carrier frequency. When the scan stops on a signal,
tune into the signal for better reception by push-
ing a MODE switch for the proper mode (if dif-
ferent) and by rotating the TUNING CONTROL.
5-4-4 RESUMING SCAN
All scan modes are provided with the resume scan function.
When the scan has been stopped by the auto-stop function,
the scan will restart after a specified delay time (about
10 seconds).
SIGNAL RECEIVED
NO SIGNAL пе Ел
1 L— fied —4 t t
S/S pushed Specie S/S pushed S/S pushed
M | |
Scan starts
Autostop
— Scan restarts {Manual
stop) (Manual
restarts)
5-5 558 OPERATION
5-5-1 RECEIVING
After connecting an antenna, microphone, etc., set knobs
and switches as follows.
POWER SWITCH OFF (OUT)
T/R SWITCH RECEIVE (DOWN)
VOX SWITCH OFF (OUT)
NOISE BLANKER SWITCH OFF (OUT)
AGC SWITCH SLOW (OUT)
METER SWITCH OFF (OUT)
PREAMP SWITCH OFF (OUT)
AF GAIN CONTROL
RF GAIN CONTROL
SQUELCH CONTROL
TONE CONTROL
Completely Counterclockwise
Completely Clockwise
Completely Counterclockwise
Center (12 o'clock) position
TUNING RATE SWITCH OFF (OUT)
DFS SWITCH OFF (OUT)
SPLIT SWITCH OFF (OUT)
DIAL LOCK SWITCH OFF (OUT)
Now push the POWER switch in. The meter lamp will be
– 17 –
illuminated, after a few seconds, a frequency and mode
memorized in the VFO A, and memory channel number
"01" will be shown on the frequency display.
Push the desired mode switch (USB or LSB), if the dis-
played mode is different than the desired one.
In-SSB operation there are both USB (upper side band) and
LSB (lower side band). USB is usually used on the band,
while LSB is usually used for satellite communications.
Select the mode according to your use.
Slowly turn the AF GAIN control clockwise to a comfor-
table level. Rotate the tuning knob until a signal is received.
The meter needle will move according to the signal strength,
so tune for the highest possible meter reading and the
clearest audio. If you cannot get a clear signal, you may be
receiving in the opposite sideband. If so, change the mode
to the proper sideband.
Adjust the RF GAIN control and TONE control for com-
fortable reception.
If squelch operation is required to cut out noise when no
signal is received, turn the SQUELCH control clockwise
until the noise from the speaker stops and leave it just
below this threshold.
For tuning, memory channel operation and scanning opera-
tion, please refer to 5 - 1 HOW TO TUNE on page 9,
5 - 2 MEMORY CHANNEL OPERATION on page 14 and
5-4 SCANNING OPERATION on раде 16.
5-5-2 NOISE BLANKER
Push the NB (NOISE BLANKER) switch in when there is
pulse type noise, such as ignition noise from automobile
motors. The noise will be suppressed and even weak signals
will be received comfortably. The noise blanker may not
work as effectively when there is a strong signal on a nearby
frequency or when there is continuous (not pulse type)
noise.
5-5-3 AGC (AUTOMATIC GAIN CONTROL)
The 1C-471H has a fast attack/slow release AGC system
which holds the peak voltage of rectified IF signals from
the IF amplifier circuit for a certain period, facilitating
reading of the S-meter function.
For normal SSB reception, set the AGC switch in the OUT
(slow) position. When tuning or receiving signals with short
interval fading, set the AGC switch in the FAST (pushed
IN) position. At this time, the time constant of the circuit
is shortened.
5-5-4 PREAMP SWITCH (When external preamp unit
is installed)
Push the PREAMP switch in when receiving weak signals.
In the pushed-in position, an RF preamplifier is inserted