Vertex Standard FT-1000MP - Manual (Page 50)

Page 48 O
PERATING
M
ANUAL
SHIFT C
ONTROL
The SHIFT control tunes the relative position of the
receiver IF passband with respect to the displayed fre-
quency in all modes except FM. The control is detented
in the center position, which represents the passband
center frequency, which is also the displayed frequency.
Turning the control clockwise raises the passband cen-
ter frequency, while turning the knob counter-clockwise
lowers it.
When QRM is present on both sides
of the tuned station, first adjust the
SHIFT control just to the point where
the interference from one side is elimi-
nated, and then rotate the WIDTH con-
trol in the opposite direction to elimi-
nate interference from the other side. The optimum
settings of these controls depend on the relative signal
strengths of the desired station and the QRM, and re-
quires practice.
When you have activated the IDBT feature by press-
ing the [IDBT] button on the Shuttle Jog, the EDSP
(Contour) filter’s passband offset changes according
to the SHIFT knob setting.
O
PERATION
D
EALING WITH
I
NTERFERENCE
N
OTCH
F
ILTER
After tuning in a desired signal and adjusting the IF
bandwidth and shift, if “heterodyne” interference such
as from a carrier or CW signal occurs, activate the IF
notch filter by pressing the NOTCH button and slowly
adjusting the NOTCH control to null the offending car-
rier. Note that if the interfering carrier is more than about
±1.2 kHz away from the center of the passband, the
notch filter may be unable to null it. In this case, switch
the notch filter off, and readjust the IF bandwidth and
shift so that the undesired carrier is outside of the pass-
band.
IF SHIFT Action
Using IF SHIFT to reduce QRM
The NOTCH feature actually has three operating
modes, involving different combinations of the IF Notch
filter and/or the EDSP Notch filter. You may use menu
selection 2-9 to utilize only the IF Notch (IF NOTCH
selection), the EDSP Notch (Auto DSP selection), or
both Notch filters (SELECT). With Select engaged, any
residual interference getting past the IF Notch will be
eliminated by the EDSP Auto-Notch, and this combi-
nation of filters provides impressive results!
If the SELECT option is chosen, you may need to
watch the S-meter to obtain optimum performance. The
EDSP Auto-Notch will remove the audio from the of-
fending carrier, but in doing so it will also eliminate your
ability to adjust the IF Notch “by ear.” Watch the S-
meter while adjusting the NOTCH control to null out
the interfering signal.
SHIFT/WIDTH Tuning Steps
Rotating the SHIFT or WIDTH control tunes the IF
passband using default 10-Hz steps. If desired, you
can change to 20-Hz steps, which offers a faster
response when turning the control knob. See menu
selection 1-2 to set the default steps as desired.