Replacing one of the KX3’s encoders

While operating on DM/BW-852 I encountered an issue with the Keyer/Mic- encoder of my KX3. A detailed description can be found here: Link

Elecraft support confirmed the encoder being the root cause :

„We […] do know that extreme temperature changes, more typically found with the KX2 and KX3, may cause shorter life spans for them.
The most common failure mode we see with the encoders is that the viscous damping material used in the shafts will leak out onto the encoder itself, which in turn, causes them to fail or skip as the encoder is turned.


KX3 Go Box

Having played with the KX3 for a couple of weeks I wanted to try it outdoor. But hiking comprises a certain risk for the equipment: Humidity from rain and snow, vibration and shock from other items in the rucksack can cause harm to the rig. The first attempt with bubble wrap basically worked, but was not to my complete satisfaction. A box was needed!

I searched the web for availalbe solutions (which are quite a few) and found Tom’s great Go Box: – the most professional one I found.

However, I had something different in mind: The Go box should look understated in order not to attract thieves on a stay on a camping site. It should also be as light as possible. By accident I tripped over an old first aid box, big enough for the KX3.


With a few pieces of foam and some glue the protective padding was made.


The KX3, a short power cable, earbuds and the Palm Pico Paddle fit nicely into the box.



[2018-04-02]: Removed the foam in the lid to overcome the VFO-A encoder issue (see description below).

[2020-05-01]: Added a check list in the lid and a cavity for pencil and pencil sharpener in the foam.

KX3 Go Box

VFO-A encoder issue:

From time to time, while turning the dial, I noticed that VFO-A seems to get stuck at a certain position. The frequency reading in the display „jumps“ back several 10 Hertz then moves on and „jumps“ back again  This can happen several times. Suddenly the failure disappears and the VFO works as intended.

This video from KC9W describes exactly my situation:
One explanation is that the old version of encoder is responsible for this behaviour. But taking a close look revealed that my KX3 already has the new encoder version. (Link to ELECRAFT’s KX3 VFO Encoder FAQ). Other possible explanations for this weird behaviour suggest excessive mechanical stress to the encoder.

When opening the Go Box, I found that the VFO-A knob leaves a mark in the foam in the lid. Possibly, if compressed that much, the foam transfers pressure to the VFO-A knob and the encoder.

As a counter measure I removed the foam from the lid. Now there is some space between lid and VFO-A knob even if the lid is closed. Instead, I put a large piece of foam on top of the bezel. If the lid is closed the foam will be compressed and keeps the KX3 in its place. But it no longer applies any pressure to the VFO-A knob.
In order to finally solve the encoder issue I had to replace the encoder.