Yaesu FT-950, Руководство по эксплуатации, Страница: 55 / 132

Page 53 FT-950 O
PERATING
M
ANUAL
RF G
AIN
(
SSB/CW/AM M
ODES
)
The RF Gain control provides manual adjustment of the gain levels for the receiver RF and IF stages, to account for noise
and signal strength conditions at the moment.
1. The [ RF GAIN
] knob should, initially, be rotated to
the fully clockwise position. This is the point of maxi-
mum sensitivity.
2. Counter-clockwise rotation of the [ RF GAIN
] knob
will gradually reduce the system gain.
A
DVICE
:
ˆ As the [ RF GAIN
] knob is rotated counterclockwise
to reduce the gain, the S-meter reading will rise. This
indicates that the AGC voltage being applied to the
receiver is increasing (which causes a
reduction in re-
ceiver gain).
ˆ Rotating the [ RF GAIN
] knob control to the fully
counter-clockwise position will essentially disable the
receiver, as the gain will be greatly reduced. In this
case, the S-meter will appear to be “pegged” against
the right edge of the analog S-meter scale.
Q
UICK
P
OINT
:
ˆ Reception frequently can be optimized by rotating the
[
RF GAIN
] knob slightly counter-clockwise to the
point where the “stationary” meter indication is set just
about the same as the incoming noise level. This set-
ting ensures that excessive gain is not being utilized,
without so much gain reduction that incoming signals
cannot be heard.
ˆ The RF Gain control, along with the IPO and the At-
tenuator features, all affect the system receiver gain in
different ways. The IPO generally should be the first
feature engaged when dealing with a high noise level,
or a crowded, high-level signal environment, the IPO
generally should be the first feature engaged, if the fre-
quency is low enough to allow the preamplifier to be
bypassed. Thereafter, the RF Gain and Attenuator fea-
tures may be employed to provide precise, delicate
adjustment of the receiver gain to fully optimize per-
formance.
[RF GAIN] Knob
I
NTERFERENCE
R
EJECTION