35
FT-891 Advance Manual
Tools for Comfortable and Effective Reception
RF Gain (SSB/CW/AM Modes)
The RF Gain control provides manual adjustment of the receiver RF and IF stages gain,
to accommodate the noise and signal strength conditions at the moment.
1. The [
RF/SQL
] knob should, initially, be ro-
tated clockwise, so that the minimum S-Me-
ter indication is not deflected. This is the
point of maximum sensitivity.
2. Counter-clockwise rotation of the [
RF/SQL
]
knob will gradually reduce the RF system gain.
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As the [
RF/SQL
] knob is rotated counterclockwise to reduce the gain, the minimum
S-meter reading will rise. This indicates that the AGC voltage being applied to the
receiver is increasing (this causes a reduction in receiver gain).
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Rotating the [
RF/SQL
] knob control to the fully counter-clockwise position will
essentially disable the receiver, as the gain will be greatly reduced.
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Reception frequently can be optimized by rotating the [
RF/SQL
] knob slightly counter-
clockwise to the point where the “stationary” S-meter indication is set just about the
same as the incoming noise level. This will reduce the RF gain to find a level of
improved signal to noise ratio.
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The RF Gain control, along with the IPO and the Attenuator 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. Also, the IPO generally 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 to fully optimize performance.
ATT (Attenuator)
The Attenuator will reduce all signals (and noise) by 12 dB, and it may be used to make
reception more pleasant under extremely noisy conditions.
1. Press the [
F
] key repeatedly, to find the
“FUNCTION-1” list screen.
2. Rotate the
MULTI
function knob to select
“ATT”.
3. Press the
MULTI
function knob.
The ATT will turn on.
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To set the ATT to “OFF”:
1. Press the [
F
] key repeatedly, to find the
“FUNCTION-1” list screen.
2. Rotate the
MULTI
function knob to select “ATT”, then press the
MULTI
function knob.
3. Press and hold the [
F
] key for one second to exit the “FUNCTION-1” list screen
and resume normal operation.
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The ATT function may be assigned to the [A], [B] or [C] key. Refer to “Changing the
function assigned to the [A]/[B]/[C] keys” in the FT-891 Operating Manual.
