Elecraft K1 - Manual (Page 14)

E
LECRAFT 13
Cut two 3/4" (19 mm) bare wires (use component leads).
Referring to Figure 4-1, insert bare wires into the grounding
holes provided near X1 and X2. Fold each wire over the top of the
crystal and solder it on top. Keep soldering time below 5 seconds at
a time; if it takes longer, your iron may not be hot enough, or your
iron tip may not be making good contact with the crystal can.
Solder and trim the wires on the bottom of the board.
X2 X1
Figure 4-1
Install the ceramic resonator, Z1, to the right of U1. (The
ceramic resonator looks like a capacitor with three pins, and can be
oriented in either direction.) Limit soldering time to 2 or 3 seconds
on each pin to avoid altering the oscillation frequency.
Locate the eight 1-µH slug-tuned inductors, and make sure
they are all
have a red stripe or are labeled "T1050".
Install the inductors at L1 through L8, pressing each one down
as far as it will go. They have five pins, plus ground tabs, and can
only be installed on the board one way. Solder the inductors.
At the left and right ends of the board you’ll find two short
jumper locations, each labeled with a ground symbol ( ). Use
component leads to make 3/4" (19 mm) U-shaped wires for each
jumper (Figure 4-2). Solder the jumpers on the bottom of the board,
with the top of the U-shape approx. 1/4" (6 mm) above the board.
Top side
Figure 4-2
Identifying Toroid Cores
Several toroidal inductors are used in the K1, including four on the
Filter board. It is important to use the correct type of core. This
can be determined from the color and size.
The cores used on the Filter board are type T37-6. The T identifies
an iron-powder core. The number following the T specifies the
outside diameter in hundredths of an inch, in this case 0.37 inches
(9.4 mm). The suffix (-6) refers to a specific mix of iron powder,
which uses a particular color, in this case yellow.
Later in assembly you'll encounter ferrite cores, for example type
FT50-43. In this part number, FT identifies the core as ferrite, and
50 is the size (0.50", 12.5 mm). The suffix (-43) identifies the type
of ferrite used, although all ferrite cores are dark gray in color. All
ferrite cores used in the K1 are of the -43 type.