ELECRAFT K2 - Page 3

4 MHz Oscillator Calibration PLL Reference Oscillator Range
Test
Plug the frequency counter probe into P6 (Control board).
Connect the probe tip to the PLL reference oscillator test
Set up the K2 internal counter as described for
4 MHz
point, TP3 (left-front corner of the RF board, near U4).
Oscillator Calibration
(at left, first three steps).
Using the menu, select
CAL FCTR
, then hold
MENU
a second time to enable the frequency counter. The
counter
If you have an external frequency counter probe connected to
TP3 along with the K2's internal counter probe, disconnect it.
should show a frequency of 12090 kHz +/- 30 kHz. If it is
0000.00,
When you’re in frequency counter mode, the
BAND +
and
changing rapidly, or out of range, you could have a problem with
BAND -
switches can be used to check the range of the PLL
the counter probe or the PLL Reference Oscillator.
reference oscillator. First, tap
BAND +
and write down the
frequency
Use one of the following methods to adjust C22 on the
Control board (listed in order of preference):
reading below (typically about 12100 kHz). Then tap
BAND -
and
 Connect a calibrated external frequency counter probe to
TP3,
write down this frequency reading (typically 12080-12090 kHz).
without removing the K2's internal counter probe. Adjust
C22
Ref. High Freq. Ref. Low Freq. Range (kHz)
____________ ____________ __________
until the K2's reading matches the external counter's reading.
Subtract the lower frequency reading from the higher reading.
 Alternatively, you can use a calibrated short-wave or ham-
band
The range must be between 9.8 and 13 kHz (if not, see
Troubleshooting). Tap
M E N U
to exit
CAL FCTR
.
receiver. Set the receiver for LSB or USB mode. Connect a
short length of wire to the receiver's antenna jack, and lay the
end near the 4 MHz crystal on the K2 Control board. Find the
oscillator signal on the receiver. Tune the receiver to 4.000
MHz, and adjust C22 until you hear a zero-beat (pitch = 0 Hz).
 If you don't have a counter or receiver, leave C22 set at its
mid-point for now. You can improve the calibration later using
a calibrated signal generator or an on-air signal, such as WWV
(at 10.000 MHz).
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