I Squelch And Receive (Rf) Sensitivity - Icom IC-746PRO Instruction Manual

I Squelch and receive (RF) sensitivity

Adjusts the RF gain and squelch threshold level. The
squelch removes noise output from the speaker
(closed position) when no signal is received.
• The squelch is particularly effective for FM. It is also avail-
able for other modes.
• The control can be set as the RF gain control only (squelch
is fixed open) or squelch control (RF gain is fixed at maxi-
mum) in set mode (p. 82). See below right.
• The 11 to 12 o'clock position is recommended for any set-
ting of the [RF/SQL] control.
SET MODE
Can be used in all modes.
RF+SQL Functions as noise squelch or S-meter
(default) squelch in AM and FM; S-meter
squelch only in other modes.
➥ Operates as a squelch control.
SQL
• RF gain is fixed at max. sensitivity.
➥ Operates as an RF gain control in
SSB, CW and RTTY.
AUTO
• Squelch is fixed open.
➥ Operates as a squelch control in AM
and FM.
• RF gain is fixed at max. sensitivity.
Adjusting RF gain (Receive sensitivity)
Normally, [RF/SQL] is set to the 11 o'clock position.
Rotate [RF/SQL] to the 11 o'clock position for maxi-
mum sensitivity.
• Rotating counterclockwise from the maximum position re-
duces sensitivity.
• The S-meter indicates receive sensitivity.
Adjusting squelch
(Removing non-signal noise)
Rotate [RF/SQL] clockwise when receiving no signal,
until the noise just disappears.
• [RX] indicator light goes out.
• Rotating [RF/SQL] past the threshold point invokes the S-
meter squelch— this allows you to set a minimum signal
level needed to open the squelch.
OPERATION
[RF/SQL] control
• When setting as RF gain/squelch control
Noise squelch (FM mode)
Squelch is
open.
RF gain
adjustable
range
• When functioning as RF gain control
fixed open; SSB, CW, RTTY only)
Adjustable
range
Minimum RF gain
• When functioning as squelch control
fixed at maximum)
Noise squelch (FM mode)
Noise squelch
threshold
(FM mode)
Squelch is
open.
Shallow
BASIC OPERATION
Recommended level
Maximum
RF gain
S-meter
squelch
(Squelch is
Maximum
RF gain
(RF gain is
S-meter squelch
threshold
S-meter
squelch
Deep
3
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