Rf Front End; Using The Vrf (Variable Rf Front-End Filter) - Yaesu FTdx5000 Series Operating Manual

A I
DVANCED NTERFERENCE
The FT 5000 includes an unmatched array of RF selectivity-enhancing features. Please study the following material
carefully, to understand the many interference tools and techniques completely.
U
SING THE
The VRF system is a high-performance RF front-end preselector that has a high Q factor and low insertion loss. VRF
provides outstanding rejection of out-of-band signals, it can also significantly improve receiver performance when located
near other transmitters, such as a contest or DX-pedition station. The FT 5000 VRF system affects the 1.8 - 28 MHz
amateur bands only.
VFO-A VRF Setup
Press the ( VFO-A )[ VRF ] button. The button will glow
red, and the " " icon will appear at the FLT col-
umn of the Block Diagram Display. The VRF system
will be engaged and centered on the currently operat-
ing amateur band. The ( VFO-A )[ SELECT ] knob will
now function as the VRF adjusting knob.
You may rotate the ( VFO-A )[ SELECT ] knob to
change the VRF system tuning, relative to your oper-
ating frequency.
A :
You may observe the relative skew of the VRF sys-
tem in the SUB DISPLAY- . window.
After moving the passband of the VRF system
manually, you may re-center it on the current Ama-
teur band by pressing the ( VFO-A )[ CLEAR ] but-
ton.
To switch VRF off, press the ( VFO-A )[ VRF ] button
until the " " icon shows "
umn of the Block Diagram Display; this confirms that
the VRF circuit has been removed from the incoming
received signal path.
Page 54
-S
UPPRESSION
VRF V
ARIABLE
" in the FLT col-
( VFO-A )[ VRF/µ-T ] Button
[ CLEAR ] Button
( VFO-A )[ SELECT ] Knob
F
EATURES
RF F - F
RONT END
VFO-B VRF Setup
Press the ( VFO-B )[ RX ] button to engage Dual Receive
operation. The button will glow green.
Press the ( VFO-B )[ VRF ] button. The ( VFO-B )[ VRF ]
button will glows red, and the "
at the FLT column of the Block Diagram Display. The
VRF system will be engaged and centered on the cur-
rent operating amateur band. The ( VFO-B )[ SELECT ]
knob will now function as the VRF adjusting knob.
You may rotate the ( VFO-B )[ SELECT ] knob to
change the VRF system tuning, relative to your oper-
ating frequency.
A :
You may observe the relative skew of the VRF sys-
tem in the SUB DISPLAY-
After moving the passband of the VRF system
manually, you may re-center it on the current Ama-
teur band by pressing the ( VFO-B )[ CLEAR ] but-
ton.
To switch VRF off, press the ( VFO-B )[ VRF ] button.
The " " icon shows "
the Block Diagram Display; this confirms that the VRF
circuit has been removed from the incoming received
signal path.
FT 5000 O
DX
:
RF F E
ILTER
" icon will appear
window.
" in the FLT column of
( VFO-B )[ VRF ] Button
[ CLEAR ] Button
( VFO-B )[ SELECT ] Knob
M