[Elecraft] KX3 ATU problem

[Bill Frantz]

Thanks Brian. I worked with Gary at Elecraft support who was a 
big help in shooting the problem. Your message was also an 
important clue, and maybe knowing about my problem will help you 
with yours.

I ended up taking out the 2M board and the ATU board and the KX3 
worked. I added in the ATU board and it still worked. When I put 
the 2M board in, the problem became intermittent. (GRRRRR!) I 
finally got it so I could poke at one corner of the 2M board and 
make the problem appear and disappear.

It appears that my problem was being caused by having the 
antenna coax for the 2M SMA connector touch a toroid on the ATU 
board. The 2M board installation instructions warn about 
allowing that to happen. Just moving it caused the problem to 
appear and disappear. I'm hoping I have cured the problem, but 
time will tell.

73 Bill AE6JV

On 6/19/18 at 9:30 AM, brian.waterworth at gmail.com (Brian 
Waterworth) wrote:

>Hi Bill,
>
>I too suffered from issues as you are now with my KX3.  Into a dummy load I
>was getting high SWR numbers.  I have been so busy at work that I haven't
>had the time to find the fault, but what does seem to work for me is not to
>tighten the case bolts too tightly.  Looser is better, but not so loose
>that the rear legs are flopping about.  When I relieve the tightness on
>these bolts, SWR values always settle around 1.0-1.2 depending on the
>antenna.  Too tight and SWR jumps up to between 3-15.  This sounds to me
>like a bad ground somewhere.  Just haven't had the time to investigate.
>
>Another time that I had the types of SWR you are observing (25+, even 45+
>for me), a few years ago, I had to send the KX3 back to Elecraft and they
>repaired something.  I am not at home now so I can't recall specifically
>what they repaired.  The prevailing theory of the issue was perhaps a
>static discharge from the antenna during the winter months when I connected
>the KX3 one day.  This was my first experience with static discharge in the
>antenna system, assuming that was the problem that fried one of the
>components in the KX3.  Again, can't recall which component (actually a
>surface mount chip on one of the larger components), but it needed to be
>replaced.
>
>regards,
>Brian
>VE3IBW
>
>On Mon, Jun 18, 2018 at 8:42 PM Bill Frantz <frantz at pwpconsult.com> wrote:
>
>>Thanks for reminding me to look at dumb things.
>>
>>Yes, the BNC was pugged into the tuner board. Note that the
>>radio has been working well for a while. I ran FT8 in New
>>Hampshire using it in April/May. The most recent venture into
>>the inside was to pull the batteries to recover from a hung
>>firmware load. That load worked after getting other programs and
>>the PX3 out of the way.
>>
>>73 Bill AE6JV
>>
>>On 6/18/18 at 5:29 PM, ghyoungman at gmail.com (Grant Youngman) wrote:
>>
>>>Probably a dumb question, but did you unplug the jumper from
>>>the BNC connector to the main board and plug it into the tuner board?
>>>
>>>Grant NQ5T
>>>K3 #2091, KX3 #8342
>>>
>>>>On Jun 18, 2018, at 8:04 PM, Bill Frantz <frantz at pwpconsult.com> wrote:
>>>>
>>>>AE6JV

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