Split Frequency Operation; Diversity Reception - Yaesu FT-1000 Operating Manual

4, Operation - Using Sub Vfo B
Otherwise, the two vfos will share the same antenna
and frontend bandpass filter, and so should be tuned
fairly close to each other for maximum sensitivity (that
is, within 500 kHz or so at low frequencies, or within
several MHz at higher frequencies). Although you may
be able to receive on, say, 21 and 28 MHz at the same
time, you may find the sub receiver signal attenuated.
The RX MIX control adjusts the audio balance be-
tween the two receivers. To really take advantage of
dual reception, you will want to connect the AF OUT jack
on the rear panel to an external stereo amplifier, or
stereo headphones to the PHONES jack, and set the PHONE
switch in the top access panel to either the mix or the
st(ereo) position. Compare these two positions with
the RX MIX control set at 12 o'clock and both vfos tuned
to signals, to select your preference. With headphones,
the st position completely separates the two channels
(main in left channel, and sub in right), while the mix
position gives you some audio from each channel in
each ear, but with the one channel emphasized in one
ear, and the other emphasized in the other ear, resulting
in a kind of "3-D" spatial audio effect.
If you have connected the AUX (high impedance)
input of an external stereo amplifier to the AF OUT jack
on the rear panel, the front panel AF and RX MIX controls,
and the PHONE switch in the top access panel, will not
affect your audio. Instead use the controls on your
external amplifier.
Note that the RF GAIN, SHIFT, WIDTH, NOTCH, APF and
AGC functions do not affect the sub receiver (AGC
decay rate is automatically selected according to
mode).
We'll return to discussing some special applications
for dual reception in a minute, but first lets look at split
operation.
Split Frequency Operation
Typical split operation is performed by receiving on
the main vfo (A) or a memory channel, and transmit-
ting on the sub vfo (B). The special case of FM repeater
operation uses some features of its own, and is des-
cribed in the box on page 28.
To activate split receive/transmit operation, just
press the SPLIT button. SPLIT appears in a box at the left
edge of the display, and the orange TX LED above the
sub vfo tuning knob lights. With the FT-1000, we re-
commend that you always activate the dual receiver
feature when working split, as this allows you to mon-
itor your transmit frequency on the sub vfo (while
receiving), as well as the main vfo receiving frequency,
so you don't accidentally "step on" somebody.
page 30
Note: For split operation with a separate antenna, you
do not need the BPF-1 . In fact, if you have the BPF-1
option installed and you want to use a separate receiving
antenna for split operation, you will have to set things
up differently from that described on the previous page
for dual reception on separate antennas:
¢ The receiving antenna must be connected to the
RX ANT phono jack on the rear panel (not the jack on
the BPF-1).
¢ Internal switch $1001 on the RF Unit must be set to
the R ANT position.
* Press the RX ANT switch on the front panel (so its LED
is On).
Keep in mind that only the main ANT jack can be
used for transmission. During split frequency opera-
tion, since the sub vfo (B) determines the transmitting
frequency, and since only the main ANT jack is used for
transmission, the BPF-1 option is inoperative.
Diversity Reception
This is one of the most exciting types of operation
offered by the FT-1000, which is capable of several
types of diversity reception: sideband diversity recep-
tion of AM signals, bandwidth diversity reception of all
modes except FM, and antenna diversity reception of
all modes (this last requires the BPF-1 option, and of
course, two antennas).
Sideband Diversity Reception of AM Signals
In this mode, you receive a single AM signal
through the two receivers in the FT-1000, each receiv-
ing the opposite sideband. Skywave-propagated sig-
nals often show considerable phase distortion in this
mode, but it gives you a view of the entire passband,
from which you can then select the best sideband for
listening (or for SWL dxing, you may want to listen to
both sidebands at the same time, to get the best copy).
On groundwave signals, where the phase of the side-
bands is likely to be the same, there is an interesting
sense of depth to the signal.
To tune in a signal using this mode, you should have
stereo headphones connected to the front panel PHONES
jack, or an external stereo amplifier connected to the
rear panel AF OUT jack.
¢ Set the main vfo to either LSB or USB mode, and
tune precisely for zero beat on the desired signal.
* Press the A> B button below the main tuning knob to
copy this mode and frequency into the sub vfo.
* Press the mode button to select the opposite side-
band for the main vfo (A).
¢ If using headphones, set the PHONE switch in to top
access panel to the st position.