Icom IC-7800 Instruction Manual - Page 91

I Preamplifier [P.AMP] I 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] several times to set the preamp OFF, preamp 1 ON or preamp 2 ON. For all HF bands 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 during times of strong electric 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 electric fields 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). The attenuator prevents a desired signal from distortion when 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 set the attenuator 6 dB, 12 dB, 18 dB or attenuator OFF. ➥ Push [ATT] for 1 sec. several times to set the attenuator 3 dB, 6 dB, 9 dB, 12 dB, 15 dB, 18 dB, 21 dB or attenuator OFF. 3 dB attenuation 15 dB attenuation 6 dB attenuation 18 dB attenuation 9 dB attenuation 21 dB attenuation 12 dB attenuation 5-9