Icom IC-7600 Instruction Manual - Page 79

■ Preamplifier 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. ➥ P ush [P.AMP] (MF3) several times to set the preamp OFF, preamp 1 ON or preamp 2 ON. ➥ P ush and hold [P.AMP] (MF3) for 1 sec. to turn the preamp function OFF. For all HF and 50 MHz bands High-gain preamp for 24 MHz band and above (Available for all HF and 50 MHz bands) ✔ 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). ■ Attenuator 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. ➥ P ush [ATT] (MF4) several times to set the attenuator 6 dB, 12 dB, 18 dB or attenuator OFF. ➥ P ush and hold [ATT] (MF4) for 1 sec. to turn the attenuator function OFF. 6 dB attenuation 12 dB attenuation 18 dB attenuation 4 RECEIVE AND TRANSMIT P.AMP 1 2 3 4 5 6 7 8 9 10 11 12 13 14 ATT 15 16 17 18 19 20 21 72