Icom IC-9100 Instruction Manual - Page 53

3 BASIC OPERATION ■ Squelch and receive (RF) sensitivity Adjusts the RF gain and squelch threshold level. The squelch removes noise output to the speaker when no signal is received (closed squelch). • T he squelch is particularly effective for AM and FM, but can also be used in other modes. • T he 12 to 1 o'clock position is recommended for the most effective use of the [RF/SQL] control. • [RF/SQL] can operate as only an RF gain control (Squelch is fixed open) or only a squelch control (RF gain is fixed at maximum sensitivity) depending on the "RF/SQL Control" option in the Set mode. (p. 162) [RF/SQL](MAIN Band) [RF/SQL](SUB Band) SET MODE OPERATING SETTING MODE [RF/SQL] OPERATION RF+SQL (default) FM/DV Operates as an RF gain control, and a noise squelch or Smeter squelch. SSB/CW/RTTY/ AM Operates as an RF gain control, and an Smeter squelch. SQL Operates as only a ALL squelch control. • RF gain is fixed at maximum sensitivity. AUTO Operates as only an SSB/CW/RTTY RF gain control. • Squelch is fixed open. AM/FM/DV Operates as only a squelch control. • RF gain is fixed at maximum sensitivity. ❍ Adjusting RF gain (Receive sensitivity) Normally, [RF/SQL] is set to the 12 o'clock position. Rotate [RF/SQL] to the 11 o'clock position for maximum sensitivity. • Rotating counterclockwise from the maximum position re- duces sensitivity. • The S-meter indicates receive sensitivity. While rotating the RF gain control, noise may be heard. This comes from the DSP unit and does not indicate an equipment malfunction. ❍ Adjusting squelch (Removing non-signal noise) Rotate [RF/SQL] clockwise when no signal is received, until the noise just disappears. • The TX/RX indicator light goes out. • Rotating [RF/SQL] past the threshold point activates the S-meter squelch- this allows you to set a minimum signal level needed to open the squelch. • When functioning as an RF gain/squelch control Squelch is open. Noise squelch (FM/DV modes) Recommended level Maximum RF gain RF gain adjustable range S-meter squelch • When functioning as an RF gain control (Squelch is fixed open; SSB, CW, RTTY only) Adjustable range Minimum RF gain Maximum RF gain • When functioning as a squelch control (RF gain is fixed at maximum.) Noise squelch (FM/DV modes) Noise squelch threshold (FM mode) S-meter squelch threshold Squelch is open. S-meter squelch Shallow Deep 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 44