Icom IC-7700 Instruction Manual - Page 97

■ Preamplifier P.AMP ■ Attenuator ATT 5 FUNCTIONS FOR RECEIVE 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] (MF3) several times to set the preamp OFF, preamp 1 ON or preamp 2 ON. ➥ Push and hold [P.AMP] (MF3) for 1 sec. to turn the preamp function OFF. P.AMP 1 For all HF bands P.AMP 2 High-gain preamp for 24 MHz band and above ✔ About the "P.AMP2" The "P.AMP 2" is a high gain receive amplifier. When the "P.AMP 2" is used in the presence of strong electromagnetic fields, distortion sometimes results. In such cases, use the transceiver 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 when using low-gain antennas, or while using a narrow band antenna (such as small loop, a Beverage antenna or a short Yagi antenna). The attenuator prevents a desired signal from distortion when very strong signals are near the desired frequency or when very strong electromagnetic fields, such as from broadcast stations near your location. ➥ Push [ATT] (MF4) several times to set the attenuator 6 dB, 12 dB, 18 dB or attenuator OFF. ➥ Push and hold [ATT] (MF4) for 1 sec. to turn the attenuator function OFF. ATT 6 dB 6dB attenuation ATT 12 dB 12dB attenuation ATT 18 dB 18dB attenuation 5-9