ELECRAFT KX3 - Calibration Procedures; Reference Frequency Calibration; Method 1: Automatic Tuning Calibration; Method 2: Manual Tuning Calibration

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Calibration
Most calibration steps are performed at the
factory for both kit and assembled KX3s.
There is one exception: If you install a KXFL3
roofing filter during KX3 kit assembly, or install
one in a factory assembled KX3 after initial
purchase, you’ll need to perform the Receive
Sideband calibration step (pg 32).
Viewing tech-mode menu entries: To view the
menu entries used during calibration, hold ME N U ,
then rotate OF S / VF O B to locate the TECH
MD menu entry. Use VFO A to change the
parameter to ON.
To unlock the parameter for a tech-mode menu
entry: Hold KH Z until you see the lock symbol
( ) turn off (about 3 seconds).
Reference Frequency
Using the calibration procedure below, you can
achieve accuracy of better than +/- 1 ppm.
This procedure requires a stable signal generator, or
an on-air signal at a known frequency, such as
WWV at 5, 10, or 15 MHz. The carrier of a
commercial AM broadcast station can also be used.
During the procedure, you’ll have a choice of
two methods for adjusting the reference frequency:
(1) automatic tuning, or (2) manual tuning.
Method (2) may be slightly more accurate but
requires “zero-beating” of two signals, which some
operators may find difficult to do.
 Select CW mode by tapping MO DE .
 Hold ME N U. Rotate O F S / V FO B to find
the DUAL RX menu entry. Set it to OFF, then
exit the menu.
 If you’re connecting a signal generator to the
antenna jack, set PW R to 0.0 watts to avoid
accidental damage to the generator.
 Use direct frequency entry (pg. 10) to set VFO
A to the exact frequency of your signal
generator or on-air signal source. This will also
switch the KX3 to the required band.
 Set AF gain for a comfortable listening level.
You should be able to hear a carrier.
 Method 1 (automatic tuning): Hold C WT .
The upper half of the S-meter becomes a tuning
aid, with the CW T icon turned on. This enables
the auto-spot function to be used below.
Method 2 (manual tuning): This method
requires manually matching the pitch of the
received signal to the CW sidetone pitch using
SP O T . To prepare for this, you may need to
increase sidetone volume. See pg. 12.
 Locate the I/II icons (right end of the filter
passband graphic). If function II is selected, tap
PB T I / II to select function I (bandwidth).
 Rotate the P BT I /I I control to set the
bandwidth to 0.30 kHz (BW 0.3 0).
 Tap P BT I /I I to switch to function II (shift).
 Rotate the P BT I /I I control until the filter
passband is centered in the filter graphic.
 Hold ME N U, then rotate OF S / VF OB to
locate the REF CAL menu entry.
 Hold KH Z for about 3 seconds to unlock the
parameter (shown on VFO A).
 If you see only 7 digits, tap R AT E .
 In case you decide to restore the factory setting,
write down the full 8-digit parameter value:
_________________ .
 Method 1 (automatic tuning, CWT on): Tap
SP O T to auto-spot the signal. The REF CAL
parameter value should automatically move up
or down a small amount. When it finishes
moving, the bar directly beneath the CW T icon
should be turned on as shown below. The
reference will then be closely calibrated.
50
100
2
3
SWR
RF
CWT
S1
3
5
7
9
Method 2 (manual tuning, CWT off): Tap
SP O T and manually adjust the REF CAL
parameter using VFO A until the received
signal pitch matches the sidetone pitch. Adjust
for zero-beat.
 If you have difficulty with this procedure, or if
you’re not sure that it worked correctly, set the
parameter value to its original value (recorded
above) using VFO A.
 If you have adjusted the REF CAL value more
accurately, write down the new value (8 digits)
here for future reference: ______________ .
 Exit the menu by holding M E N U .
 Save your configuration using KX3 Utility.