22
Special VFO B Displays
The KX3 can continuously display time of day or
one of several operational parameters on the VFO B
display. To access these displays, tap D IS P , then
rotate the
OF S / V FO B control.
The available special displays are listed below.
24-hour time obtained from the real-time-clock
on the KXBC3 option module. If a KXBC3 is
not installed, the time since last power-on will
be displayed. To set the time, use the TIME
menu entry. You can also set an alarm time
anytime in the next 24 hours using the ALARM
menu function. This may be useful as a
reminder of a contest or operating schedule.
The alarm will turn the KX3 on if it occurs
when power is off.
Supply voltage. If you have an internal battery
pack installed in addition to an external supply,
the voltage shown will be the greater of the
two. This and the next three parameters stay
visible even in transmit mode, so you can check
key-down conditions.
Supply current. Typical receive-mode current
is 0.15-0.2 amps (150-200 mA). It will be
higher with the backlight, preamp, or isolation
amp on, or when using the internal speaker.
Transmit current is typically 1-2.5 A.
Power amplifier (PA) temperature. The PA
temperature will rise gradually as you transmit.
The KX3 automatically reduces power if the
PA temperature is too high.
Synthesizer (OSC) temperature. This
parameter is used by the KX3 to adjust the
synthesizer (or oscillator) frequency as
temperature varies. If the ambient temperature
is very low, it can take several seconds for the
reading to stabilize, during which some drift in
the oscillator frequency may be observed. A
few degrees of additional temperature rise is
also normal during transmit.
Audio Signal level (AFV). This display shows
the approximate level of the KX3’s audio
output, prior to the AF gain control (in other
words, the AF gain control has no effect on the
reading). The reading will vary with preamp
and attenuator settings as well as the RF gain
control. AFV is normally used in conjunction
with the dBV function (at right).
Relative audio signal (dBV). This display can
be used to measure receiver sensitivity or
gain/loss of various stages, or compare two
signals. To use it, first select AFV (described at
left) and allow the voltage reading to stabilize.
(This may not be possible with modulated or
rapidly changing signals.) Once the signal
appears stable, select dBV. You should now see
a reading of around 0 dBV (see Glossary)
relative to the last AFV reading. If you change
the setting of the preamp or attenuator, you
should see this reading change. However, it
may not change as much as you expect unless
you turn AGC off using the AGC menu entry.
(Be sure to turn AF gain down before
turning AGC off, as the signal may become
very loud.) Measurement of receive sensitivity
(MDS) requires a calibrated 1-µV signal source
such as an Elecraft XG1/2/3. These sources
include instructions for measuring MDS.
Extended Single Sideband (ESSB)
An increase in SSB voice bandwidth may improve
fidelity and reduce listening fatigue. However, this
also increases signal bandwidth, and is not
appropriate for use when bands are crowded.
ESSB receive
The KX3’s normal SSB receive bandwidth is about
2.8 kHz. This can be widened by using the PB T
control. In voice modes, function I is low-cut and
function II is high cut. Tap the control to select
function I or II, and rotate it to adjust the passband.
ESSB transmit is set up as follows:
Locate the TX ESSB menu entry. Tap 1 to turn
ESSB on, then use VFO A to select the desired
transmit bandwidth. The + icon will turn on in
the mode area of the LCD.
ESSB, AM, and FM have separate TX EQ from
regular SSB, allowing you to optimize the
transmit passband for these wider-bandwidth
modes. See the TX EQ menu entry for details.
You may wish to assign the TX ESSB menu
entry to a programmable function switch if
you’ll be turning it on/off frequently.
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