Yaesu FT DX 9000 CONTEST - 2, Руководство по эксплуатации

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Page 53 FT
DX
9000 C
ONTEST
O
PERATION
M
ANUAL
RF G
AIN
(
SSB/CW/AM M
ODES
)
The RF Gain controls provide manual adjustment of the gain levels for the receiver RF and IF stages, to account for noise
and/or signal strength conditions at the moment.
The RF GAIN control (#
) should, initially, be ro-
tated to the fully clockwise position. This is the point of
maximum sensitivity, and counter-clockwise rotation will
gradually reduce the system gain.
P
As the RF GAIN control is rotated counterclock-
wise to reduce the gain, the S-meter reading will rise.
This indicates that the AGC voltage being applied to
the receiver (to reduce the gain) is increasing.
P
Rotating the RF GAIN control to the fully counter-
clockwise position will essentially disable the receiver,
as the gain will be greatly reduced. In this case, as well,
the S-meter will appear to be “pegged” against the right
edge of the analog S-meter scale.
Advice
Reception frequently can be optimized by rotating the RF
Gain control slightly counter-clockwise to the point where
the incoming noise level is just about the same as the “sta-
tionary” meter needle position as set by the adjustment of
the RF GAIN control. This setting ensures that exces-
sive gain is not being utilized, without so much gain re-
duction that incoming signals cannot be heard.
Quick Point
The RF GAIN control, along with the IPO and Attenu-
ator features, all affect the system receiver gain in differ-
ent ways. As a first step in dealing with high noise or a
crowded, high-level signal environment, the IPO gener-
ally should be the first feature engaged, if the frequency is
low enough to allow the preamplifier to be bypassed.
Thereafter, the RF Gain and Attenuator features may be
employed to provide precise, delicate adjustment of the
receiver gain so as to optimize performance fully.
RF GAIN Knob
C
ONVENIENT
F
EATURES