Yaesu FTdx5000MP, Руководство по эксплуатации

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Page 18 FT
DX
5000 O
PERATING
M
ANUAL
F
RONT
P
ANEL
C
ONTROLS
& S
WITCHES
[
ATT
]
Switch
Move this knob up or down to select the degree of
Attenuation to be applied to the receiver input.
Available selections are “–6 dB”, “–12 dB”, “–18 dB”,
or “OFF”. The selected attenuation level appears in
the ATT column of the Block Diagram Display.
A
DVICE
:
Press this knob in briefly, to quickly turn the at-
tenuation level off.
The Attenuator may be used in conjunction with
the [ IPO
] switch to provide additional gain reduc-
tion when an extremely strong signal is being re-
ceived.
[
IPO
] (
I
NTERCEPT
P
OINT
O
PTIMIZATION
)
Switch
Move this knob up or down to select the optimum front
end characteristics of the receiver circuit. Available
selections are “AMP 1”, “AMP 2”, “IPO 1”, or “IPO
2”.
Normally, IPO is set to “AMP1”. If you want to in-
crease the sensitivity, use “AMP2”. When set to
“IPO1”, the IPO performance of the receivers is im-
proved. When set to “IPO2”, the RF preamplifier is
bypassed, yielding direct feed to the first mixer. As a
result, the IPO is improved more.
A
DVICE
:
Press this knob in briefly to quickly select the
“AMP1” IPO setting.
“IPO 2” can not be selected for VFO-B.
[
R.FLT
]
Switch
Move this knob up or down to select the bandwidth of
the first IF Roofing Filter. Available selections are “300
Hz”, “600 Hz”, “3 kHz”, “6 kHz”, “15 kHz”, or
“AUTO” (“300 Hz” and “600 Hz” are available only
in VFO-A. The “300 Hz” filter is optional, except in
the MP version). The selected bandwidth appears in
the R.FLT column of the Block Diagram Display.
A
DVICE
:
Press this knob in briefly to quickly select “AUTO”.
Because the roofing filter is in the first IF, the pro-
tection it provides against interference is quite sig-
nificant. When set to “AUTO”, the SSB bandwidth
is 6 kHz, CW is 3 kHz, and FM/RTTY are 15 kHz.
However, on a crowded SSB band, you may wish
to select the 3 kHz filter, for the maximum possible
interference rejection.