Icom IC-7600, Instruction Manual, Page: 46 / 196

37
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 AM and FM. It is
also available for other modes.
• 12 to 1 o’clock position is recommended for any setting of
the [RF/SQL] control.
• The control can be set as ‘Auto’ (RF gain control in SSB,
CW, RTTY and PSK. Squelch control in AM and FM)
or squelch control (RF gain is fixed at maximum) in the
Others set mode, as follows. (p. 136)
SET MODE OPERATION
RF+SQL
(default)
Can be used in all modes.
Functions as noise squelch or S-meter
squelch in the FM modes, S-meter squelch
only in other modes.
SQL
Operates as a squelch control.
• RF gain is fixed at maximum sensitivity.
AUTO
Operates as an RF gain control in the SSB,
CW, RTTY and PSK modes.
• Squelch is fixed open.
Operates as a squelch control in
the
AM
and FM modes.
• RF gain is fixed at maximum 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
maximum sensitivity.
• Rotating counterclockwise from the maximum position
reduces 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.
[RF/SQL]
• When setting as RF gain/squelch control
Maximum
RF gain
S-meter
squelch
Noise squelch (FM mode)
Squelch is
open.
RF gain
adjustable
range
Recommended level
• When functioning as RF gain control
(Squelch is fixed open: SSB, CW, RTTY, PSK only)
Minimum RF gain
Adjustable
range
Maximum
RF gain
• When functioning as squelch control
(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)
While rotating the RF gain control, noise may be
heard. This comes from the DSP unit and does not
indicate an equipment malfunction.