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 TUNE 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 TEST. This forces all
bands to use the KXV3’s transverter output
jack, and outputto be limited to 0-1.5 mW.
Set power to exactly 1.00 milliwatts (0 dBm).
Hold TUNE; output power should be about 1
mW.Then tap XMIT to exit TUNE.
Repeat the above procedure on 80-6 m.
Set CONFIG:KXV3 back to NOR.
Tap MENU to exit the menu.
Reference Oscillator
The K3’s reference oscillatoris a TCXO, 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 reference calibration,
allow the transceiver to warm up at room
temperature for about 15 minutes (cover on).
The TCXO can be calibrated using an accurate
frequency counter (Method1), or by zero-beating
the sidetone against a reference signal (Method 2).
The accuracy of the 1 ppmTCXO 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.
Method 3 could also be used with the 5 ppm
oscillator. However, improvement in accuracy is
not specified in this case, andthe user must first
determine the TCXO’s frequency at two or more
temperature points using Method 1 or 2.
Method 1 (Frequency Counter):
Locate the CONFIG:REF CALmenu entry. (If
the menu entry name is REF xxC, tap 1 to
change it to REF CAL).
Connect a frequency counter with +/-1 Hzor
better accuracy to J1 on the reference oscillator
module. Measure the exact frequency in Hz.
Using VFO A, set the REF CAL parameterto
match this frequency. Then exit the menu.
Method 2 (Zero-Beating):
Select CW mode. Set W IDTH to about 2.8
kHz. (A wide filter passband is necessary since
you may need to move the REF CAL parameter
a significant amount.)
Tunethe K3 to a strong broadcast station or a
known-accurate reference signal. Use the
highest-frequency source you can (e.g. WWV
at 10, 15 or 20 MHz).Set the VFO to the
specifiedfrequency of the signal.
Using MON , 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).
Tap SPOT to enable the sidetone.
Adjust the REF CAL frequency until the
sidetone is zero-beated with the signal. Asyou
approach the correct frequency, you’ll hear an
undulating “beat note” between the signals. The
slower the beat note, the closer they are.
Cancel SPOT and exit the menu.
Method 3 (1 ppm TCXO Option):
Locate the CONFIG:REF CALmenu entry.
Tap 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.
Tap MENU to exit the menu.
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