Preamplifier; Attenuator - Icom IC-R9500 Instruction Manual

■ Preamplifier

[P.AMP]
During 1150–3335 MHz (ANT2) operation, either the
preamplifier or attenuator is activate exclusively.

■ Attenuator

[ATT]
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 sig-
nals.
➥ Push [P.AMP] several times to set the preamp OFF,
preamp 1 ON or preamp 2 ON.
• Below 30 MHz
For all
HF bands
High-gain pre-
amp 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 when strong signal are present,
distortion sometimes results. If this occurs, use the re-
ceiver 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 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 being
distorted by a 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 select the desired at-
tenuator or attenuator OFF.
• During HF bands operation, 6, 12, 18, 24, 30 dB are
available.
• During 30–1150 MHz operation, 10, 20, 30 dB are available.
• During 1150–3335 MHz operation, only 20 dB is avail-
able.
➥ Push and hold [ATT] for 1 sec. to turn OFF the at-
tenuator, when it's ON.
• HF bands
6 dB
attenuation
12 dB
attenuation
18 dB
attenuation
24 dB
attenuation
30 dB
attenuation
5-9
RECEIVE FUNCTIONS
• Above 30 MHz
Only ON/OFF
is available
• 30–1150 MHz
10 dB
attenuation
20 dB
attenuation
30 dB
attenuation
• 1150–3335 MHz
20 dB
attenuation
5