FT-2000
Operating Manual
Vertex Standard Co., Ltd.
52
LSB/USB/PKT 6kHz
CW/RTTY
3kHz
When the Roofing filter mode is set to “AUTO” and the Noise Blanker is turned On,
the Roofing Filter bandwidth will automatically be set to 15 kHz, as this setting
provides the most effective noise blanking. However, you still may override the
automatic setting, and select a more narrow Roofing Filter. Noise blanking may be
compromised, however, with a tighter Roofing Filter in the line.
Terminology: A “Roofing Filter,” as its name implies, places a “Roof” over the receiver’s
IF system bandwidth. This “Roof” protects the circuitry downstream from the first
mixer from interference, just as a roof on a house protects the contents from rain and
snow.
Interference Rejection (Signals within 3 kHz)
CONTOUR Control Operation
The Contour filtering system provides a gentle perturbation of the IF filter passband,
so as to suppress or enhance certain frequency components modestly, so as to enhance
the natural-sounding received signal.
1. Press the [CONTOUR] button. The Contour characteristic will appear in the
display to confirm that the Contour filter is engaged.
2. Rotate the [CONTOUR] knob to achieve the most natural-sounding audio
reproduction on the incoming signal.
3. To cancel Contour tuning, press the [CONTOUR] button once more.
Advice:
The Contour filter effects to the Main band (VFO-A) only.
The Contour filter’s level (either nulling or peaking) may be adjusted using Menu
item “089 rdSP CNTR LV.” The factory default setting is –15.
The bandwidth over which the Contour filter effect is applied may be adjusted
using Menu item “090 rdSP CNTR WI.” The factory default setting is 10.
When the optional DMU-2000 Data Management Unit is connected, the Audio
Scope (on the “Oscilloscope” page) is particularly useful when adjusting the Contour
control. Not only can you see the effect of the notch/peak of the Contour system, but
you also can see the position of the notch/peak with respect to frequency
components of interest on the incoming signal. You may then observe (on the Audio
Scope) the effect of the Contour control while listening to the effect on the signal,
and this will help build your intuition on how best to use Contour tuning in the
