Using The Sub Receiver - ELECRAFT K3S Owner's Manual

Using the Sub Receiver

The KRX3A option adds an independent, high-
performance sub receiver to the
to monitor a second frequency, using different
bandwidths or modes. Diversity receive is possible
if the main and sub receivers use different antennas.
Dedicated Sub Receiver Controls
Tapping turns on the sub receiver (and
S U B
icon). VFO B then controls the sub's frequency, and
also serves as the TX frequency during SPLIT.
You should leave the sub off when not in use.
This turns off the -3 dB passive splitter used when
the sub shares the main receiver's antenna path.
Holding turns on diversity receive (pg. 40).
D I V
The kHz decimal point of VFO A flashes as a
reminder. VFO A controls both the main and sub
frequencies in diversity receive, but VFO B remains
independent so it can be used as the SPLIT transmit
frequency.
VFO B can be linked to VFO A even in non-
diversity mode; see CONFIG:VFO LNK.
SUB AF gain normally sets the sub's volume
SUB AF can be used as a
level. Alternatively,
main/sub balance control (see
).
AF
With stereo headphones or dual speakers,
you'll normally hear main on the left and sub on the
right. CONFIG:L-MIX-R selects various alternate
combinations of main/sub audio mixing.
CONFIG:SPKRS must be set to
stereo speakers; otherwise, set it to
SUB RF gain normally sets the sub receiver's
RF GAIN level. If this knob is assigned to main/sub
squelch (CONFIG:SQ MAIN), then RF gain for
main/sub is controlled by the main RF gain control.
BSET: Additional Sub Receiver Settings
Normally, filter controls,
apply only to the main receiver. To change these
settings for the sub receiver, first hold
A will show , and the S-meter will show the
B S E T
sub receiver's signal level. After you've made the
desired sub receiver changes, tap
to exit .
B S E T
B S E T
Preamp 2 can be used with the sub receiver, though
there are some limitations (pg. 45). The sub
receiver's switchable attenuation is fixed at 10 dB.
K3
. It allows you
S
S U B
CONFIG:SUB
if you use
2
.
1
, , , etc.,
P R E A T T N M O D E
. VFO
B S E T
or hold
A / B
The sub receiver's band cannot be set
independently unless CONFIG:VFO IND is set to
Y E S . If it's set to N O , you'll see = M A IN when
during B S E T , and the sub receiver
you tap
B A N D
band will be set the same as main.
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 (see pg. 43).
When using
B S E T
sub between
M A I N
AUX input). When
icons show which antenna the sub is sharing
R X
with the main receiver. When
these icons will all be off (if CONFIG:KRX3 is set
for ) or will show the non-TX ATU
A N T = B N C
antenna, or (if KRX3 is set for
1 2
Shortcut: If you're not in
quickly switch the sub between
holding
R X A N T
ANT on/off for the main path.)
The AUX antenna must be well-isolated
from the transmit antenna to avoid damage to
the sub receiver. If keying activates the sub's
carrier-operated relay (heard as a click) keying,
try relocating the AUX antenna.
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
If CONFIG:VFO IND is set to
the sub receiver to a different band from main.
Hold , then tap
B S E T
sub receiver's band. If you only use band-
independence for the sub occasionally, you may
want to assign VFO IND to a programmable
function switch (pg. 23).
If the two receivers are sharing the main
antenna path, putting the sub receiver on a
higher-frequency band than main may result in
signal loss in the sub. This is due to sharing of the
main receiver's low-pass filters. If you select an
incompatible band combination, the K3
displays
U S E A U X
receiver signal loss, use the sub's AUX input.
39
, you can tap to switch the
A N T
(shared) and (the sub's
A U X
is in effect, the
M A I N
is in effect,
A U X
A N T = A T U
mode, you can
B S E T
and
M A I N
. (Tapping turns RX
R X A N T
, you can set
Y E S
up/down to select the
B A N D
S
as a warning. To avoid sub
- and
1 2
).
by
A U X
briefly