ELECRAFT K3, Руководство пользователя

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37
Using the Sub Receiver
The KRX3 option adds an independent, high-
performance
sub receiver to the K3. Sub receiver
installation is covered in the KRX3 manual.
You can use the sub receiver to monitor two
different frequencies or bands, using different
bandwidths or modes.
Diversity receive is possible
if the main and sub receivers use different antennas.
Dedicated Sub Receiver Controls
S U B
turns the sub receiver (and S UB icon) on.
Turn the sub re ceive r off when not neede d.
This bypasses the main/sub antenna splitte r,
improving main re ceive r sensitivity by 3 dB.
VFO B co
nt r ol s t he s ub’ s f r equency, a nd i s al s o t he
T X frequency during SPLIT (see details at right).
Holding
SU B
links the VFOs, allowing diversity
receive (details at right). VFO A is the master,
moving both VFOs in tandem. VFO B can be offset
from VFO A, or set equal to it by tapping
A B
.
SUB AF
gai n s e t s t he s ub’ s vol ume l evel . Wi t h
stereo headphones or dual speakers, you'll hear the
sub on the right and main on the left. Otherwise
main and sub receiver audio are added together.
SUB RF gai
n nor mal l y s e t s t he s ub r ecei ver ’ s
RF GAIN level. If this knob is assigned to main/sub
squelch (
CONFIG:SQ MAIN ), then both main and
sub RF gain are controlled by MAIN.
BSET: Additional Sub Receiver Controls
Normally, receive controls such as SHIFT and
WIDT H, as well as the
MO D E
control, apply only
to the main receiver (VFO A). To change sub
receiver settings (VFO B), hold
B S E T
. VFO A will
show
BS E T
, and the
S-meter will show the sub
receiver's signal level. Tap
AN T
to select the
sub rec
e i ve r ’ s a nt e nna ( de t a i l s a t r i g ht ) .
Some controls, including
B AN D
,
P R E
,
ATTN
,
N B
, and
NR
cannot be set independently for the
sub receiver unless CONFIG:VFO IND is set to
Y E S
. I f i t ’ s s e t t o
NO
, you’ l l s e e
= M AI N
when
using these controls during
BS E T
.
T ap
A/ B
or hold
B S E T
again to exit
BS E T
.
Sub Receiver Antenna Selection
The sub receiver gets its RF input either from the
main receiver (sharing ANT 1-2 or RX ANT IN), or
from its auxiliary antenna input. (Also see pg. 40.)
During BS E T , you can tap
AN T
to switch the sub
between
M AI N
(shared) and
AUX
( t he s ub’ s AUX
input). When M AI N is in effect, the 1 - 2 and RX
icons show which antenna the sub is sharing with
the main receiver. When
AUX
is in effect, these
icons will all be off (if
CONFIG:KRX3
is set for
AN T= BNC ) or will show the non-transmit AT U
antenna,
1
or
2
(if KRX3 is set for
ANT= ATU
).
The s ub r ecei ver ’ s AUX a nt enna mus t be wel l
-
isolated from the main (transmit) antenna to avoid
activatin
g t he s ub r ecei ver ’ s car r i er
-operated relay.
Using the AUX input for the sub receiver
slightly improves sensitivity of both the main and
sub receivers because the splitter is not used.
Sub Receiver Band Independence
Using
B S E T
, you can set the sub receiver to a
different band from main (using
B AN D
) if
CONFIG:VFO IND is set to
Y ES
.
If the two receivers are sharing an AT U
antenna, putting the sub receiver on a higher band
than the main receiver may result in signal loss in
the sub receiver due to the shared low-pass filters.
To a voi d t hi s , us e t he s ub r ecei ver ’ s AUX i npu t .
SPLIT Mode with the Sub Receiver
During split (
S P LI T
), VFO A is the receive
frequency and VFO B the transmit frequency. If the
sub receiver is on, you can listen to both receive
and transmit frequencies, making DXing more
conveni e nt . You can s et up t he s ub r ecei ver ’ s
filtering independently using
B S E T
.
Diversity Receive
Diversity receive can improve signal copy during
fading (QSB). A separate antenna must be used for
t he s ub r ecei ver ( AUX; s ee above ) . You’ l l al s o
need to link VFO B to VFO A by holding
S U B
.
For best results, use identical crystal filters and DSP
settings on the two receivers. (Elecraft can provide
5-pole crystal filters with matched offsets on
request. 8-pole filters are already matched.)