8
RF Board Assembly
Place the KAT100 RF PC board in front of you, with the
bottom
side
up and the
front edge
facing you as shown in the Parts
Placement Drawing, Appendix B.
On the bottom of the board, along both edges, you'll find
six
locations for
2-D fasteners
. These are used to secure the RF board to
the chassis panels. In the next few steps, just
four
2-D fasteners will be
attached, and the remaining two locations will not be used. Which four
locations to use depends on whether you're building a KAT100-1 or
KAT100-2:
KAT100-1:
Use the two 2-D locations near the front edge, and the
two near the back edge.
KAT100-2:
Use the two 2-D locations near the front edge, and the
two located about two-thirds of the way back. (The 2-D fasteners are
supplied with the EC2 enclosure kit, not the KAT100-2.)
Locate a 2-D fastener and hold it vertically (Figure 1a). Looking
at a side with two holes, note that the holes are offset from the center.
The PC board outlines for the 2-D fasteners have a matching offset,
which will aid in installing them in the next step.
Holes offset
from center
(a)
(b)
Figure 1
Install 2-D fasteners at the four locations identified earlier, on the
bottom
of the RF board. Secure each fastener from the top side of the
board with 3/16" (4.8 mm) pan-head screws (black) and #4 split lock
washers (Figure 1b).
Make sure the 2-D fasteners line up with the edges of the PC
board and do not hang over. If they hang over or do not match their
component outlines, they are installed backwards.
i
The leads on small capacitors are fragile. Do not pull on
the leads or bend them excessively.
Sort all capacitors into groups by physical appearance (size, color,
and lead spacing). Within these groups, sort them by capacitance
value.
Locate the component outline for capacitor C55, on the top side
of the board near the front edge.
Install a 0.1-µF capacitor (labeled "104") at C55. Keep the lead
length as short as possible. (If the leads are pre-formed, the capacitor
may sit slightly above the board.)
Bend C55's leads outward on the opposite side of the board to
keep it from falling out or shifting position. Then solder the capacitor
and trim the leads.
Note:
Components may be soldered one at a time or in groups. Leads
can be trimmed either before or after soldering. After soldering, trim
leads to about 1/16" [1.5 mm] or less in length.
i
If your solder joints are not clean and shiny, your iron
may not be hot enough, or you may be using the wrong type of
solder. These "cold" solder joints will likely result in poor
performance, reliability problems, or component failure. You
may wish to consult our web site for additional soldering
instructions and tool recommendations.
