Yaesu FTDX5000 CAT BOOK, Operating Manual

Page: 54 / 148

Page 52 FT
DX
5000 O
PERATING
M
ANUAL
ATT
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
ˆ Press the [ A
] button to activate VFO-A receiver (The
[
A
] button will glow red).
ˆ
Move the [
ATT
] knob up or down to set the desired
attenuation level of the VFO-A receiver, per the chart
below.
OFF OFF OFF OFF OFF
: Attenuator is Off
–6 dB 6 dB 6 dB 6 dB 6 dB
: The incoming signal power is reduced by 6
dB (Signal voltage reduced by 1/2)
–12 dB 12 dB 12 dB 12 dB 12 dB
: The incoming signal power is reduced by 12
dB (Signal voltage reduced to 1/4)
–18 dB 18 dB
18 dB 18 dB
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.
VFO-B ATT Setup
ˆ Press the [ B
] button to activate VFO-B receiver (The
[
B
] button will glow orange).
ˆ
Move the [
ATT
] knob up or down to set the desired
attenuation level of the VFO-B receiver, per the chart
below.
OFF OFF OFF OFF OFF
: Attenuator is Off
–6 dB 6 dB 6 dB 6 dB 6 dB
: The incoming signal power is reduced by 6
dB (Signal voltage reduced by 1/2)
–12 dB 12 dB 12 dB 12 dB 12 dB
: The incoming signal power is reduced by 12
dB (Signal voltage reduced to 1/4)
–18 dB 18 dB
18 dB 18 dB
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.
A
DVICE
:::::
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 OFF OFF OFF 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.
ˆ 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”.
ˆ 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”.
[A] Button [ATT] Knob [B] Button [ATT] Knob
C
ONVENIENCE
F
EATURES