Elecraft K2 Owner's Manual - Manual (Page 47)

46
E
LECRAFT ®
Using the Calibration Functions
Scroll the menu until you see CAL OFF. This is the entry point into
the calibration sub-menu, which you’ll be using during alignment.
Enter EDIT mode by holding
E D I T
as before, moving the underline to
the OFF parameter. Then turn the VFO knob to see the various CAL
functions, including FCTR (frequency counter), CUR (transmit
current limiting), tPA (KPA100 temperature calibration), S LO /
S HI
(S-meter calibration), FIL (crystal filter configuration), and
P L L (VFO calibration).
Once you select a CAL function, holding
E D I T
again activates the
function. The selected CAL function remains active until you tap
M E N U
again, which returns you to the menu. Another tap of
M E N U
returns you to the normal K2 display.
In the following section you’ll activate the CAL FCTR (frequency
counter) function. For now, just tap
M E N U
once or twice to return to
the normal display.
Frequency Counter Probe Assembly
In the bag labeled MISCELLANEOUS you’ll find the
components for the frequency counter probe (Figure 6-14). These
components include a 10 pF axial-lead capacitor, two crimp pins, a 2-
pin housing, and a 1-pin male connector (probe tip).
Cut a 7" (18 cm) length of RG-174 cable and carefully remove
1/2" (13 mm) of the coax jacket from each end. Be careful not to nick
the braid.
Separate the braid from the center conductor at both ends.
Remove 1/4" (6 mm) of insulation from each center conductor. At one
end, cut the braid off completely right at the coax jacket (a ground
connection will not be needed for frequency measurements). The braid
should be twisted into a fine bundle at the other end.
Solder crimp pins onto the center conductor and shield at the
housing end of the cable. Solder quickly, so that the heat from
soldering does not melt the center insulator of the coax and cause a
shield-to-center short.
Insert the pins into the crimp housing as shown in Figure 6-14.
They should snap into place. Each crimp pin has a small tab on the
back that latches into a hole in the housing.
Trim the leads of the 10 pF axial-lead capacitor down to 1/4" (6
mm). Solder one end to the center conductor of the coax cable.
RG-174 Coax,
7” (18cm)
Crimp housing
Probe
tip
10pF
Heat-shrink tubing (2 layers)
Figure 6-14
Solder the probe tip to the other end of the 10 pF capacitor.
Slip a 1" (2.5 cm) length of the larger size heatshrink tubing onto
the probe tip components. Shrink the tubing using a heat gun. (You
can also use a soldering iron, but avoid melting the tubing.)
Add a second, identical length of heatshrink tubing on top of the
first, then shrink it. This strengthens the assembly.
Plug the frequency counter probe assembly into P6, which is at
the far left end of the Control board (as viewed from the front of the
transceiver). The connector can only be plugged in one way.