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.

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 encoder issue

While operating on DM/BW-852 I encountered an issue with the Keyer/Mic- encoder of my KX3. For about a minute it wasn’t possible to change the keyer speed. Luckily the speed was set to a reasonable value (20 wpm). Then, maybe by touching the knob differently, it worked again.
A couple days ago, when preparing the activation, I had the same issue while trying to reduce the KX3’s output power. I pushed the button (the display showed 10 W) and turned the knob. The reading went down to 9.8 and stayed there regardless of any further turning. I switched to „keyer speed“ by pushing the knob (which actually worked) and tried to change the keyer speed to no avail. Then I switched back to output power and turned the knob again: the encoder did not work. Even after switching the KX3 off an on, it remained in this state.

Next I opened the KX3, took out the CP- board and did some resistance measurements at the back side of [Z4]. Now the encoder seemed to be working again. After assembling the KX3 everything worked smoothly.

It looks like the encoder has an issue. But before I replace it (or even all four of them) I asked the experts at ELECRAFT for a confirmation. The reply arrived within a few hors (!)

„Hi Roman,
Thanks for the contact.  To your questions on the KX3 encoders, we have received reports of some encoders losing some of the damping fluid that is embedded into the shaft and sleeve.  These are sealed but can leak.  When this happens, some of the fluid will get into the optical encoders and cause the symptoms you are seeing.
Generally, we recommend all 4 be replaced at the same time to save having to do them individually.  We do this with the K3 and K3S encoders in much the same way.
The KX3 encoder is Elecraft part #E640018 at $2.08 each.“

The encoders are already ordered and will be replaced as time permits. Thanks ELECRAFT for the fast support!

DM/BW-852 – Herrenwald – 910m


April 2, 2018  12:00 – 13:30 UTC
Sunny, approx. 10°C, few clouds
Walking time 20 min. up, 15 min. down

Rig: KX3 / 10W, 2200mAh LiPo, Palm Pico Paddle
Ant: End Fed Half Wave Dipole with Traps (40m – 30m – 20m) on a 8m wooden tower

4 CW QSOs on 20m, 3 CW QSOs on 30m, 40 CW QSOs on 40m, 5 CW QSOs on 60m



Participated in the Multi/ Single HP class with the team of DD1A. Conditions were OK if you accept that we are close to the bottom of the cycle. 10m didn’t open at all and 15m opened only briefly on both, Saturday and Sunday afternoon.
On Sunday afternoon 20m was in excellent shape and we enjoyed a good rate for several hours. Stations from the North and West showed the typical „fluttery“ signal – sweet music in a DXer’s ear 😉


CQ WW 160 CW

Since 2015 I made serious attempts to participate in this contest in the QRP class.

To my big surprise I ended up 2nd place in Germany/ QRP in 2015. With no dedicated Rx- antenna and moderate effort I reached 46,617 points with 261 QSOs whereof 39 were mults and 2 had been with W/VE.

In 2016 I put more effort in (but still no proper Rx- ant) and ended up 2nd place in Germany/ QRP again. This time with 63,210 points (327 QSOs, 1 W VE/ and 41 mults). There were some issues with the interface to the KX3 during the first night, forcing me to use the PC only to log the contacts. All QSOs were hand made.

Finally I built a shielded loop and tried again in 2017. This time 1st place in Germany/ QRP with 86,296 points (425 QSOs,  1 W/VE and 45 mults).


Delta Loop for the 20m band

A delta loop antenna is not particularly suitable for SOTA. It requires much more space than a vertical and the set-up is more complicated.
Nevertheless I’d like to show this design here because sometimes space (and weight) don’t matter and a low take off angle is welcome. One possible scenario could be the VK/ZL/JA <> EU S2S event.

Delta Loop on HB0/Li-004, Augstenberg, 2359m a.s.l. during our DX-pedition to the Principality of Liechtenstein in September 2013. DL4AAE worked many JA’s on 20m with 100 Watts output power.  Note: the horizontal wire has been attached to the pole in order to avoid sagging.