FT-950
Operating Manual
Vertex Standard Co., Ltd.
49
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.
IF Noise Blanker (NB) Operation
The FT-950 includes an effective IF Noise Blanker, which can significantly reduce noise
caused by automotive ignition systems.
1. Press the [NB] button momentarily to reduce short-duration pulse noise such as
from switching transients, automobile ignitions and power lines. The “NB” icon
will appear in the display to confirm that the Narrow-NB is operating. Press and
hold in the [NB] button for two seconds to reduce longer-duration man-made pulse
noise. The “NB” icon will blink for five seconds, and thereafter will appear
continuously, to confirm that the Wide-NB is operating.
2. Adjust the Noise Blanker level via the Menu item “067 RGEN NB LVL” to the
point where the offending noise is best reduced or eliminated, if desired. See box
below for details.
3. To end Noise Blanker operation, press the [NB] button once more. The “NB” icon
will turn off, confirming that the Noise Blanker is no longer in operation.
Advice:
The Noise Blanker operation will be memorized independently on each VFO stack
of the VFO-A and VFO-B. However, the Noise Blanker level is in common.
When the Roofing filters mode is set to “AUTO” and the Noise Blanker is turned
“ON”, the Roofing Filter bandwidth will automatically be set to “15 kHz”. The
Roofing Filter may be changed to a narrower selection, as described previously,
although Noise Blanker operation may be compromised somewhat when using a
narrower Roofing Filter.
Adjusting the Noise Blanker Level
1. Press the [MENU] button to engage the Menu mode.
2. Rotate the [SELECT] knob to select Menu item “067 RGEN NB LVL.”
