Receive Functions; Mode Selection; Squelch And Rf Gain - Icom IC-R75 Instruction Manual

5

RECEIVE FUNCTIONS

■ Mode selection

The following modes are available in the IC-R75:
SSB (LSB/USB), CW, CW REV (CW reverse), FM,
AM, RTTY and RTTY REV (RTTY reverse).
➥ Push [SSB] to toggle between LSB and USB.
➥ Push [CW/RTTY] momentarily to toggle between
CW and RTTY.
➥ Push [CW/RTTY] for 2 sec. to toggle between CW
and CW reverse or RTTY and RTTY reverse.
➥ Push [AM] to select AM.
➥ Push [FM] to select FM.
The selected mode is indicated in the function
display.

■ Squelch and RF gain

The receiver uses the same control, [RF/SQL], to
adjust one of either the RF gain or the squelch.
[RF/SQL] adjusts either the RF gain or the squelch
depending on the operating mode selected and the
condition of the RF/SQL item in set mode (p. 30).
• [RF/SQL] control priority
Set mode
setting
Sq (SQL)
At (AUTO)
rS (RF/SQL)
* The RF gain is set to maximum level when the [RF/SQL]
is set as [SQL] control.
The RF (Radio Frequency) gain is used to adjust the
receiver gain.
• Shallow rotation moves the S-meter to the right indicating
the signal strength which can be received.
The recommended position for RF gain is the 12
o'clock position since this sets RF gain to the max.
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 available for the other modes.
• When operating in FM, first rotate the control fully
counterclockwise. Then, rotate the control clockwise to
the point where the noise just disappears. This is the best
position. The squelch does not open for weak signals
14
USB, LSB,
AM, FM
CW, RTTY
SQL* SQL*
RF GAIN SQL*
RF/SQL RF/SQL
OPERATING MODE SELECTION
CW/RTTY
CW CW REV
SSB
LSB
AM
Push momentarily
FM
Push momentarily
Push mode switch
for 2 sec.
when it is set too deep.
• A segment appears in the S-meter to indicate the
S-meter squelch level.
• When set as the [RF/SQL] control
Recommended level
Squelch is open.
RF gain adjustable
range
• When set as the [SQL] control
Noise squelch (FM mode)
Noise squelch threshold
(FM mode)
Squelch is open.
Shallow
• When set as the [RF] control
Maximum RF gain
Adjustable range
Minimum RF gain
RTTY RTTY REV
USB
AM
FM
Push mode switch
momentarily.
Noise squelch (FM mode)
Maximum RF gain
S-meter squelch
S-meter squelch
threshold
S-meter squelch
Deep