Icom IC-R9500 Instruction Manual - Page 75

5 RECEIVE FUNCTIONS ■ Preamplifier [P.AMP] During 1150-3335 MHz (ANT2) operation, either the preamplifier or attenuator is activate exclusively. The preamp amplifies received signals in the receiver front end, to improve the S/N ratio and sensitivity. Set this to preamp 1 or preamp 2 when receiving weak signals. ➥ Push [P.AMP] several times to set the preamp OFF, preamp 1 ON or preamp 2 ON. • Below 30 MHz For all HF bands • Above 30 MHz Only ON/OFF is available For all HF bands ✔ About the "P.AMP2" The "P.AMP 2" is a high gain receive amplifier. When the "P.AMP 2" is used when strong signal are present, distortion sometimes results. If this occurs, use the receiver with the "P.AMP 1" or "P.AMP OFF" setting. The "P.AMP 2" is most effective when: • Used on bands above 24 MHz and when signals are weak. • Receive sensitivity is insufficient during low gain, or while using a narrow band antenna (such as small loop, a Beverage antenna or a short Yagi antenna). ■ Attenuator [ATT] The attenuator prevents a desired signal from being distorted by a very strong signals are near the desired frequency or when very strong electric fields, such as from broadcasting stations, are near your location. ➥ Push [ATT] several times to select the desired attenuator or attenuator OFF. • During HF bands operation, 6, 12, 18, 24, 30 dB are available. • During 30-1150 MHz operation, 10, 20, 30 dB are available. • During 1150-3335 MHz operation, only 20 dB is available. ➥ Push and hold [ATT] for 1 sec. to turn OFF the attenuator, when it's ON. • HF bands 6 dB attenuation • 30-1150 MHz 10 dB attenuation 12 dB attenuation 20 dB attenuation 18 dB attenuation 30 dB attenuation 24 dB attenuation 30 dB attenuation • 1150-3335 MHz 20 dB attenuation 5-9