Icom IC-R9500 Instruction Manual - Page 57

4 RECEIVE MODES D Convenient functions for FSK • Preamp (p. 5-9) ➥ Push [P.AMP] several times to set the preamp OFF, preamp 1 ON or preamp 2 ON. Only ON/OFF is available above 30 MHz. • "P.AMP1" or "P.AMP2" appears when the preamp 1 or preamp 2 is ON below 30 MHz. "P.AMP ON" appears above 30 MHz. • Attenuator (p. 5-9) ➥ Push [ATT] several times to set the attenuator in 6 dB steps for HF bands, or 10 dB step for 30-1150 MHz. Only 20 dB is available for 1150-3335 MHz. • "ATT" and attenuation level appear when the attenu- ator is ON. • Noise blanker (p. 5-15) ➥ Push [NB] switch to turn the noise blanker ON and OFF, and then rotate [NB] control to adjust the threshold level. • Noise blanker indicator (above [NB] switch) lights when the noise blanker is ON. • Push [NB] for 1 sec. to enter noise blanker set mode. • Twin PBT (passband tuning) (p. 5-11) ➥ Rotate [TWIN PBT] controls (inner/outer). • Push [PBT CLEAR] to clear the settings. • Noise reduction (p. 5-16) ➥ Push [NR] switch to turn the noise reduction ON and OFF. • Rotate [NR] control to adjust the noise reduction level. • Noise reduction indicator (above [NR] switch) lights when the noise reduction is ON. • Manual notch filter (p. 5-16) ➥ Push [NOTCH1] or [NOTCH2] switch to turn the manual notch function ON or OFF. • Rotate [NOTCH] control to set the notch frequency. • Notch indicator (above [NOTCH1] or [NOTCH2] switch) lights when either the manual notch is ON. • AGC (auto gain control) (p. 5-10) ➥ Push [AGC] switch several times to select AGC FAST, AGC MID or AGC SLOW. ➥ Push [AGC VR] to turn the AGC time constant manual setting ON or OFF. • Rotate [AGC] control to adjust the time constant. • 1⁄4 function (p. 3-6) ➥ Push [1/4] to turn the 1⁄4 function ON or OFF. D About FSK reverse mode FSK FSK-R TONE SHIFT SHIFT TONE f1 f2 BFO f1 f2 BFO D Twin peak filter [APF/TPF] Received characters are occasionally garbled when the received signal has Mark and Space tones reversed. This reversal can be caused by incorrect TNC connections, setting, commands, etc. To receive reversed FSK signals correctly, select FSK-R mode. ➥ During FSK mode, push and hold [FSK] for 1 sec. to select FSK and FSK-R mode. The twin peak filter changes audio frequency response by boosting the mark and space frequencies (2125 and 2295 Hz) for better reception of FSK signals. ➥ During FSK mode, push [APF/TPF] to turn the twin peak filter ON and OFF. • " TPF " appears in the LCD and the [APF/TPF] indicator above this switch lights green while the filter is in use. NOTE: When the twin peak filter is in use, the received audio output may increase. This is normal, not a malfunction. 4-11