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

3
BASIC OPERATION
3-2 Squelch and receive (RF)
sensitivity
[RF/SQL]
When setting as RF gain/squelch control
Squelch
open
RF gain
range
When setting as RF gain (squelch is fixed open)
Max. RF gain
RF gain
operating
range
Minimum
RF gain
sensitivity
When setting as squelch (RF gain is fixed at max.)
Squelch
threshold
Squelch
open
12
Noise squelch
range
RF gain
max.
sensitivity
S-meter
squelch
range
Max.
RF gain
sensitivity
Noise squelch
operating range
S-meter squelch
threshold
S-meter squelch
operating
range
Adjusts the RF gain and squelch threshold level. The
squelch removes noise output from the speaker
(closed condition) 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. 61). See below left.
• 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.
Functions as noise squelch or S-
RF + SQL
(default) meter squelch in 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.
RF
• Squelch is fixed open.
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