ELECRAFT K3, Руководство пользователя

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49
High Power (50 W) TX Gain Calibration
This applies to the K3/100 only. Use the same
procedure as shown for 5 watts, but set power to 50
W, and use a 50-W dummy load. The
TU N E
power
output indication should be about 50 watts.
Calibrate TX gain at 50 W on ALL bands.
Milliwatt TX Gain Calibration (KXV3)
This applies only if you have the KXV3 option.

Switch to 160 m.

Set
CONFIG:KXV3
TE S T . T his forces all
bands t o us e t he KXV3’ s t r a ns ver t e r ou t pu t
jack, and output to be limited to 0-1.5 mW.

Set power to exactly 1.00 milliwatts (0 dBm).

Hold
TU N E
; output power should be about 1
mW. T hen tap
X MI T
to exit TUNE.

Re peat the above proce dure on 80-6 m.

Set
CONFIG:KXV3
back to NO R .

T ap
ME NU
to exit the menu.
Reference Oscillator
The K3’ s r e f er e nce os ci l l a t or
is a T CXO, or
temperature-compensated crystal oscillator . It is
normally calibrated at assembly time or by the
factory. There are two types: 5 ppm and 1 ppm.
Before attempting re fe rence calibration,
allow the transceive r to warm up at room
tempe rature for about 15 minutes (cove r on).
The T CXO can be calibrated using an accurate
frequency counter (
Me thod 1 ), or by zero-beating
the sidetone against a reference signal ( Method 2 ).
The accuracy of the 1 ppm T CXO can be improved
to better than 0.5 ppm by entering supplied
calibration data (
Method 3 ). Be sure to keep the
data sheet that was supplied with the oscillator.
Me thod 3 could also be used with the 5 ppm
oscillator. However, improvement in accuracy is
not specified in this case, and the user must first
determine the T CXO
’ s f r equency a t t wo or mor e
temperature points using Method 1 or 2.
Method 1 (Frequency Counter):

Locate the
CONFIG:REF CAL
menu entry. (If
the menu entry name is REF xxC , tap
1
to
change it to
REF CAL
).

Connect a frequency counter with +/- 1 Hz or
better accuracy to J1 on the reference oscillator
module. Measure the exact frequency in Hz.

Using VFO A, set the
REF CAL
parameter to
match this frequency. Then exit the menu.
Method 2 (Zero-Beating):

Select CW mode. Set
W ID TH
to about 2.8
kHz. (A wide filter passband is necessary since
you may need to move the REF CAL parameter
a significant amount.)

T une the K3 to a strong broadcast station or a
known-accurate reference signal.
Use the
highest-fre quency source you can (e.g. WWV
at 10, 15 or 20 MHz). Se t the VFO to the
spe cifie d fre quency of the signal.

Using
MO N
, set the sidetone monitor level
to roughly match the volume level of the
received broadcast or reference signal.

Locate
CONFIG:REF CAL
. (If the menu entry
name is
REF xxC
, tap
1
to select
REF CAL
).

T ap
S P O T
to enable the sidetone.

Adjust the
REF CAL
frequency until the
sidetone is zero-beated with the signal. As you
appr oac h t he cor r ec t f r equency, you’ l l hear a n
undul at i ng “bea t not e” bet ween t he s i gnal s . The
slower the beat note, the closer they are.

Cancel
S P O T
and exit the menu.
Method 3 (1 ppm TCXO Option):

Locate the CONFIG:REF CAL menu entry.
T ap
1
to change the name to REF xxC .

Locate the calibration data sheet, which shows
frequency vs. temperature over a wide range.

For each data point, tap
2
(down) or
3
(up) to
select the temperature, then use VFO A to set
the specified oscillator frequency in Hz.

T ap
ME NU
to exit the menu.