[Elecraft] New KX3 - a few observations, a bug report, and suggestion

Oliver Olsen oliver at oliverolsen.com
Mon Jan 7 01:49:13 EST 2013


Hello,

Just received my KX3 kit this weekend, including the roofing filters and
ATU.  I put it together without any difficulty on Saturday and had it on
air by Sunday morning.  Worked Cuba and BC, Canada on 10 watts SSB from my
QTH in Vermont.   I am amazed at how well the ATU works.  In summary, I am
thrilled - its a great unit!

A few comments from the kit build:

1. I'm really glad that there was an extra bag of screws, washers, etc. -
because some screws and washers were missing from the main bags.  I'm not
sure if the person packing the bags just puts all the stuff they left out
in the "extra" bag, or if it is truly an extra bag, but it definitely was
needed.

2. I meant to write down the exact step, but forgot, so now I'm not 100%
certain which screw appears to be labeled incorrectly in the assembly
manual, but I believe it was flat head screw by the VFO encoder (page 14 of
the assembly manual).  I think it is supposed to be a 1/4" screw, rather
than a 3/16" screw.  I initially put in the 3/16" screw, but then
discovered that I had an odd number of 3/16" screws remaining for a later
step and an extra 1/4" screw.  I concluded that the screw by the VFO should
have been a 1/4" screw, which I changed, leaving me with the correct number
of 3/16" screws for the later step.  But, that logical conclusion may not
hold true given the problems identified in #1 above.  Anyway - something
that the folks at Elecraft might want to double-check.

3. I would be curious to know why Elecraft did not include thermal compound
with these kits - or at least recommend that it be applied to the rear case
where the finals are mounted.  I went ahead and used thermal compound, but
would like to know if there is a specific reason why that was omitted as a
step in the build process.  I have not done any extensive testing, but a
few short QSOs at 10 watts has not pushed the finals higher than 55C temp
yet.  Has anyone else done any comparison with compound vs. no compound?

4. I am very impressed with the quality of the construction and materials
of the KX3.  My only gripe is the quality of the hand-mic.  It works fine,
but it just does not look or feel like it is of high quality.

Now, a small bug report -

Serial Number 3159
Firmware MCU 1.30
DSP: 1.02

Synopsis:  MIC BTN is not automatically set to OFF when in Data Mode,
contrary to what the release notes for MCU 1.12 (7-25-2012) say.

I experimented with some contacts using a few data modes, with an interface
to my laptop.  I had a head-scratcher of a problem with the radio
transmitting as soon as I plugged the audio-out cable from my laptop to the
mic jack.  The manual did not tell me, but I suspected (and confirmed with
a few Google searches) that there was a conflict with the PTT line on the
mic jack and the data cable.  I then learned about the MIC BTN menu option,
which I tried to set to "OFF".  But when I tried turning the VFO knob, it
would not let me change the setting - the unit displayed "n/a".  After a
bit more sleuthing, I found some recent firmware release notes, which notes
that the unit will now automatically set the MIC BTN option to "OFF" when
in the Data A mode.  And here lies the bug - that simply does not happen.
The radio transmits for as long as the cable is plugged in, even when it is
in Data A mode.  And to further frustrate, you cannot change that setting
in the menu when the radio is in Data A mode.  I ultimately was able to
work around this problem by changing the mode to SSB, going back into the
menu, and set MIC BTN to "OFF" - all was OK when I returned to Data A mode,
but of course, I have to remember to change the setting back when I want to
make a SSB contact.

Finally - a suggestion:

The incorporation of the CW decode feature and onboard modems for RTTY/PSK
is a great addition.  It would be nice if you could add a modems for a few
other modes, i.e. weak signal modes like Olivia. Maybe even an SDK that
allows people to write their own modems and upload them to the KX3 (most of
the source code is available in C and open-source - so assuming it can be
ported to whatever you are using for your firmware).

-- 
Oliver Olsen, W1OKO


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