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

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. 81). 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 an 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
24