[Elecraft] KX3 sluggish keyer

[AA4BQ]

The problem, according to my own experience, is that the ground in
intermittent. Each paddle arm is the ground that makes contact with each
standoff. Without a good grounding, the contact action between the set screw
and the standoff is sometimes hit or miss. The reason the ground is
occasionally weak is because the contact with ground by each keying paddle
is designed to be via the pivot pins of each paddle arm. They are
independent and sometimes intermittent grounding occurs. This results is
missed dots or dashes (dits/dahs) being keyed. There are some solutions
outlined on the web whereby one does a little soldering of two small wires
to ground and then screw down the opposite ends of said wire under the heads
of each countersunk screw head on each respective paddle arm. (These screw
heads are the spring retainer screws.)

I developed another reliable solution whereby no soldering is required. (I
am good at soldering but the miniaturization of the solder pads here are
very delicate. I feel sure warranty issues come to mind as well. ) A great
alternative is to provide backup grounding. 

To do so, 

1. Disassemble as if changing springs.

2. The spring is coated for durability and anti-corrosion. So, on each end,
place the spring opening (each end alternatively) on a micro file (or very
fine emory board) and remove just the coating on the ends that contact the
arms.

3. Delicately, use a small screwdriver or tool to remove the paint where the
spring contacts each arm. Take your time. The paint is durable. Just remove
an amount about the size of a lock washer. This will, in effect connect each
paddle arm together.

4. When disassembling the key, you removed three allen screws. The heads of
these screws fit into a recessed hole. At the bottom of that recess, you
will need to remove the paint there as well. You need only do one but I did
all three to be sure. 

5. Reassemble the keyer.

This mod resulted in 100% keying. The original reliability was dependent on
the pivot arms of each paddle independently. This mod increases the
reliability by transferring a good ground (via the spring) over to the arm
that may be intermittently ungrounded. This method is still statistically
less than 100% over time, but whereas I was getting keying errors regularly,
they have completely disappeared. 

Happy keying.

73,
Bill, AA4BQ





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73,
Bill - AA4BQ
Jupiter, FL.
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