Preamplifier; Attenuator - Icom IC-7700 Instruction Manual

■ Preamplifier

P.AMP
The preamp (P.AMP1 or P.AMP2) cannot be used
while the digital selector is activated.
Also the preamp is automatically disabled when the
digital selector is turned ON.

■ Attenuator

ATT
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]
preamp OFF, preamp 1 ON or preamp 2 ON.
➥ Push and hold [P.AMP]
preamp function OFF.
For all HF and 50 MHz bands
P.AMP
1
High-gain preamp for 24 MHz band and
P.AMP
above (Available for all HF and 50 MHz
2
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 elec-
tromagnetic 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 an-
tenna (such as small loop, a Beverage antenna or a
short Yagi antenna).
The attenuator prevents a desired signal from being
distorted when very strong signals are near the de-
sired frequency or when very strong electromagnetic
fields, such as from broadcast stations near your lo-
cation.
➥ Push [ATT]
(MF4)
tor 6 dB, 12 dB, 18 dB or attenuator OFF.
➥ Push and hold [ATT]
tenuator function OFF.
6 dB
ATT
attenuation
6dB
12 dB
ATT
attenuation
12dB
18 dB
ATT
attenuation
18dB
5-9
several times to set the
(MF3)
for 1 sec. to turn the
(MF3)
several times to set the attenua-
for 1 sec. to turn the at-
(MF4)
5