Icom IC-7100 Instruction Manual

Also see for IC-7100: Finger touch operation Specification Basic Manual Service manual Advanced instructions

Contents

Icom IC-7100 Instruction Manual Manual pdf 49 page image

5 FUNCTIONS FOR RECEIVE5-2Previous viewPreamplifierDThe preamplifier amplifies weak signals in the receiverfront end, to improve the S/N ratio and sensitivity.Turn ON this function when receiving weak signals.(Frequency band: HF/50 MHz)➥ Push P.AMP ATT (C) one or more times to set the pre-amp OFF, preamp 1 ON or preamp 2 ON.• Either “P.AMP1” or “P.AMP2” is displayed when the pre-amp 1 or preamp 2 is ON.• No icon is displayed when the preamplifi er is OFF.P.AMP1 Wide dynamic range preamplifier. It is mosteffective for the 1.8 to 21 MHz bands.P.AMP2 High-gain preamplifier. It is most effectivefor the 24 to 50 MHz bands.(Frequency band: 144/430 MHz)➥ Push P.AMP ATT (C) turn the Preamplifi er ON or OFF.• “P.AMP” appears when the preamplifi er is ON.• No icon is displayed when it’s OFF.AttenuatorDThe attenuator prevents a desired signal from beingdistorted when very strong signals are near the signal’sfrequency, or when very strong electromagnetic fields,such as from broadcast stations are near your location.These can both be independently set for each band.➥ Hold down P.AMP ATT (C) for 1 second to turn ON theAttenuator.• “ATT” appears on the display when the Attenuator is ON.➥ Push P.AMP ATT (C) to turn it OFF.✔ About the “P.AMP2” preamplifierPreamp 2 is a high gain receive amplifier. When it isused in the presence of strong electromagnetic fields,distortion sometimes results. In such cases, use ei-ther the “P.AMP1” or “P.AMP OFF” setting.Preamp 2 is most effective when:• Used on bands above 24 MHz and when signals areweak.• Receive sensitivity is insufficient when using low-gain antennas, or while using a narrow band an-tenna (such as small loop, a Beverage antenna or ashort Yagi antenna).About the Preamplifier and Attenuator switching procedurePush or hold down P.AMP ATT (C) to switch the Preamplifi er and Attenuator, as shown below.Hold downPushATT ONPushP.AMPOFFP.AMPONPushATT ONP.AMPOFFP.AMP1ONP.AMP2ONP.AMP ATTP.AMP ATTP.AMP ATTHold down P.AMP ATTP.AMP ATTPush P.AMP ATT• HF/50 MHz frequency bands• 144/430 MHz frequency bandsPreamp and attenuatorP.AMP ATTP.AMP ATT