Att - Yaesu FTdx5000 Series Operating Manual

C
Even with the IPO function on, extremely strong local signals or high noise can still degrade reception. In such situations,
you can use the [ ATT ] button to insert 6, 12, or 18-dB of RF attenuation in front of the RF amplifier.
VFO-A ATT Setup
Press the [ A ] button to activate VFO-A receiver (The
[ A ] button will glow red).
Move the [ ATT ] knob up or down to set the desired
attenuation level of the VFO-A receiver, per the chart
below.
Attenuator is Off
OFF:
6 dB: The incoming signal power is reduced by 6
dB (Signal voltage reduced by 1/2)
12 dB: The incoming signal power is reduced by 12
dB (Signal voltage reduced to 1/4)
18 dB: The incoming signal power is reduced by 18
dB (Signal voltage reduced to 1/8)
The selected attenuation level will be indicated in the
ATT column of the Block Diagram Display.
To quickly restore full signal strength through the At-
tenuator circuit, press the [ ATT ] knob in briefly to re-
store the ATT display to the "OFF".
[ ATT ] Knob [ A ] Button
A :
If background noise causes the S-meter to deflect on clear frequencies, move the [ ATT ] knob until the S-meter drops to
about "S-1". This setting optimizes the trade-offs between sensitivity, noise, and interference immunity. Also, once you
have tuned in a station you want to work, you may want to reduce sensitivity further (or add more attenuation) by moving
the [ ATT ] knob to a greater setting. This reduces the strength of all signals (and noise) and can make reception more
comfortable, important especially during long QSOs. When looking for weak signals on a quiet band, you will want maxi-
mum sensitivity, so the IPO should be disabled and the [ ATT ] knob should be set to "OFF" by pressing the [ ATT ] knob. This
situation is typical during quiet times on frequencies above 21 MHz, and when using a small or negative-gain receiving
antenna on other bands.
Page 52
F

ATT

VFO-B ATT Setup
Press the [ B ] button to activate VFO-B receiver (The
[ B ] button will glow orange).
Move the [ ATT ] knob up or down to set the desired
attenuation level of the VFO-B receiver, per the chart
below.
Attenuator is Off
OFF:
6 dB: The incoming signal power is reduced by 6
dB (Signal voltage reduced by 1/2)
12 dB: The incoming signal power is reduced by 12
dB (Signal voltage reduced to 1/4)
18 dB: The incoming signal power is reduced by 18
dB (Signal voltage reduced to 1/8)
The selected attenuation level will be indicated in the
ATT column of the Block Diagram Display.
To quickly restore full signal strength through the At-
tenuator circuit, press the [ ATT ] knob in briefly to re-
store the ATT display to the "OFF".
[ ATT ] Knob [ B ] Button
FT 5000 O
DX
M