Elecraft KPA100 Shield Upgrade - Manual

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L E C R A F T
K P A 1 0 0
S H I E L D U P G R A D E I N S T R U C T I O N S
Rev. B, Feb. 10, 2004
NOTE: An additional upgrade to the KPA100 was recently
made available (KPA100MDKT). This upgrade allows the
KPA100 to tolerate higher SWR before limiting power (2:1
vs. 1.5:1), and is highly recommended.
This upgrade improves grounding of the KPA100 shield, reducing RF
coupling between the KPA100 and the K2 RF board. This is especially
important when load SWR is high.
Also included is a shield for the KPA100 speaker, which will prevent the
speaker magnet from having any effect on the K2's VCO relays, located
directly below the speaker when the KPA100 module is installed.
The kit should include the following items:
(1) Replacement KPA100 shield E100137
(3) Spring clip E980058
(4) 4-40 x 3/16" panhead screw (1 spare) E700015
(4) 4-40 hex nut (1 spare) E700055
(4) Split lock washer (1 spare) E700004
(2) Solder lug E700062
(1) Speaker shield E980087
Sandpaper E850090
Turn off the K2. Remove the KPA100 module (six screws) and unplug
all interconnecting cables. Save all of the hardware.
Lay the KPA100 assembly upside down on a soft cloth, with the rear
panel facing you.
Remove the original KPA100 shield, which will no longer be needed.
Save all of the hardware.
Orient the new shield as shown in the illustration on the back of this
instruction sheet (top view). The top and back edge views show the proper
orientation of the spring clips, which will be installed in the next step.
Install spring clips on the shield at the locations identified by the
letter C. As shown by the dotted lines, the clips should be installed on the
bottom side of the shield. Use 4-40 x 3/16" black pan head screws, 4-40
nuts, and split lock washers. The lock washers go between the nuts and
the spring clips.
Each clip should be perpendicular to edge of the shield, and
extending beyond the edge by about the amount shown. If necessary,
loosen the hardware slightly and adjust the positions of the spring clips so
that they closely match the drawing. Then re-tighten the hardware.
Place the shield assembly onto the KPA100. The three spring clips
on the shield should face downward (toward the KPA100 PC board). The
spring clip in the rear should be touching bare metal at the inside of the
rear panel. When the shield is aligned with its standoffs, this clip should
be slightly compressed.
Secure the shield with the original hardware (4-40 x 1/4" pan head).
Locate the speaker shield. Remove the backing from the self-
adhesive pad inside the shield (Figure 1). Install the shield over the
speaker magnet, keeping it approximately centered.
Shield
Adhesive
Backing
Figure 1