Icom IC-R75 Instruction Manual - Page 18

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. OPERATING MODE SELECTION CW/RTTY CW CW REV RTTY RTTY REV SSB LSB USB AM Push momentarily AM FM Push momentarily FM Push mode switch for 2 sec. Push mode switch momentarily. ■ 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 USB, LSB, CW, RTTY Sq (SQL) SQL* AM, FM SQL* At (AUTO) RF GAIN SQL* rS (RF/SQL) RF/SQL 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 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 Noise squelch (FM mode) Maximum RF gain S-meter squelch • When set as the [SQL] control Noise squelch threshold (FM mode) Noise squelch (FM mode) S-meter squelch threshold Squelch is open. S-meter squelch Shallow Deep • When set as the [RF] control Maximum RF gain Adjustable range Minimum RF gain 14