page 49
MARK-V FT-1000MP Operating Manual
Use the BANDWIDTH buttons and then the SHIFT
and WIDTH controls to suppress interference. Their
use varies somewhat from mode to mode.
When you are ready to retune to a new frequency,
you may wish to return the SHIFT and WIDTH con-
trols to their default positions (center detent). The
WIDTH control can also be turned counter-clock-
wise to reduce the IF bandwidth more gradually,
and then the SHIFT control can be turned left or
right from center to shift the center frequency lower
or higher, as depicted in the drawing.
For digital modes, the wider bandwidth selections
are fine for tuning around, but the 500 or 250 (Hz)
bandwidths will generally give the best copy with
narrow shifts. If you have the RTTY and PKT menu
selections set to match your TNC/terminal unit (see
page 55), you should not need to adjust the SHIFT
O
PERATION
D
EALING
WITH
I
NTERFERENCE
control at all, and the WIDTH control should only
be adjusted with a great deal of care (to avoid los-
ing the contact). See the section on digital modes
in this manual for more details.
For 300-baud packet, use the 500 (Hz) bandwidth
and keep the WIDTH control centered; the SHIFT
control may require fine tuning either side of center
for optimum copy of weak signals. Experiment with
the SHIFT setting on a busy packet channel, and
then note the optimum setting for all future HF
packet operation (it will be the same unless you
replace your TNC or recalibrate the input tones).
Note
- except during extreme QRM conditions, the
WIDTH and SHIFT controls should be left in their
center (detent) positions when tuning the receiver
to a new frequency. This will provide the best fidel-
ity and easiest tuning.
C
LARIFIER
(R
X
/T
X
O
FFSET
T
UNING
)
The three CLAR buttons near
the lower right corner of the front
panel, and the control just above
them, are used to offset either the
receive, transmit, or both fre-
quencies from their settings on
the main display. The three small
numbers in the center of the dis-
play (just to the right of the main
frequency display) show the cur-
rent Clarifier offset. The Clarifier controls on the MARK-
V FT-1000MP are designed to allow you to preset an
offset (up to ±9.99 kHz) without actually retuning, and
then to activate it with the Clarifier’s RX and TX but-
tons.
Perform the following steps, if you like, to familiar-
ize yourself with the Clarifier controls:
r
Without pressing any of the Clarifier buttons, rotate
the CLAR knob back and forth while watching the
small center display. Notice that the small digits
change, indicating the preset Clarifier offset (which
hasn’t been
applied
to the Tx or Rx frequency yet)
while the main display remains unchanged.
r
If you press the Clarifier TX button, “CLAR”-“TX”
appears below the smaller offset display, and if you
press the PTT you will see the Tx frequency shift by
the amount of Clarifier offset.
r
If you press RX instead, notice that “RX”-“CLAR”
appears and the frequency offset is applied and the
display shifts to the offset receive frequency accord-
ingly. Press the PTT switch, and notice that the
Advice on QRM Reduction
transmit frequency remains the same as the origi-
nal frequency display when the receive Clarifier is
on. You can reset the offset to 0.00 kHz at any time
by simply pressing CLEAR.
r
With the RX Clarifier active, the center tuning marker
just above the main frequency display moves to the
right or left as you change the offset by rotating the
CLAR knob. Also notice that the main frequency
and the Clarifier offset displays change together.
r
Now press the Clarifier CLEAR key and observe
that the offset is cleared to zero, and the Main VFO
frequency returns to what it was originally.
The Clarifier is commonly used when you are in
contact with a station whose transmitter drifts (or per-
haps you didn’t have him quite tuned in when you called
him). You don’t want to change your transmitting fre-
quency, as that would force him to retune - you just
want to adjust your receiver.
Another application for the Clarifier is in a casual
DX pile-up situation, where the DX station is listening
in a “Split” mode (but listening “UP 5” or a similar split
of less than 10 kHz). In this case, you leave the main
receiver on the DX station’s frequency, then use the
RX Clarifier to tune the pile-up area, listening for the
station currently in QSO with the DX station. When you
find that station, you can switch the TX Clarifier On
and the RX Clarifier Off; you will now be receiving back
on the DX station’s frequency, but you will be transmit-
ting on the frequency where the DX station probably is
still listening. See the discussion on page 56 regarding
the use of the SPOT control for CW spotting; it speeds
up the above process significantly.
