ICOM IC-703 ユーザーズマニュアル

24

3

BASIC OPERATION

■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 mode. It is also

available 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 maximum) in initial set mode (p. 79). See below right.

• The 11 to 12 o’clock position is recommended for any set-

ting of the [RF/SQL] control.

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.

(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.

(Squelch is

fixed open; SSB, CW, RTTY only)

(RF gain is

fixed at maximum)

Squelch is 
open.

S-meter
squelch

S-meter squelch
threshold

Noise squelch 
threshold
(FM mode)

Shallow

Deep

Noise squelch (FM mode)

Minimum RF gain

Adjustable
range

Maximum
RF gain

Recommended level

RF gain 
adjustable
range

Maximum
RF gain

S-meter
squelch

Noise squelch (FM mode)

Squelch is 
open.

[RF/SQL]

RF+SQL

Can be used in all modes.

(default)

Functions as noise squelch or S-meter
squelch in AM and FM modes; S-
meter squelch only in other modes.

SQL

Operates as a squelch control.

• RF gain is fixed at maximum sensitivity.

Operates as an RF gain control in
SSB, CW and RTTY modes.

AUTO

• Squelch is fixed open.

Operates as a squelch control in AM
and FM modes.

• RF gain is fixed at maximum sensitivity.