[SCCC] Portable Laptop for Field Use with KX3

[Drew Arnett]

Ah, a topic I am also very interested in and have been working on myself.

I also have used a KX3 in the field.  Yes, the USB CAT cable from
elecraft is readily supported for logging by many applications,
including those that use the rigctld middleware.  A number of options
for keying.  I currently use the K1EL Winkeyer USB.  I have also used
the K3NG arduino keyer if you're into that sort of thing, too.
(cwdaemon or similar programs is a useful middleware like rigctld.)

I've been thinking about contest software, especially in regard to
multiop contest situations.  (Field Day is usually even more
interesting to multi than other contests due to the level of
diversity.  Field Day for me is always portable.  Other contests are
often portable.)

For me, even more important than screen readability, is the keyboard.
As the years go by, the quality continues to diminish versus the gold
standard, the model M.  Turns out, you can still buy the gold standard
NEW at https://www.pckeyboard.com/.  I purchased a lifetime supply for
$1 each out of a surplus store bin years ago.  Don't forget the
ferrite choke on the keyboard cable for the 40m band!

For battery or solar (not genset), I thought running a 40 W laptop
with a KX3 at 5W was a poor match.  (Either more Pb-acid weight or
more LiFePO4 $.)  So, I picked up a Raspberry Pi 2.  (The 2 has the
lowest power consumption per the docs, but way more than enough
horsepower for contest logging.)  With the standard case and standard
non-touch color screen, it's quite a tidy package.  USB keyboard,
keyer, cat don't take up all of the USB ports.  Picked up a Powerwerx
USB Buddy hoping it was lower risk for RFI than non-ham marketed 12 to
5 V DC-DC converters.  The entire lot, less radio, draws 0.4 A off of
a bench 13.8V supply or 5.5 W.  That's a much better match for a 5W
radio running real hard.  I figure 25% CW TX duty cycle as a good
budgeting figure.  (Maybe optimistic on how much time I spend running
as a QRP station, though!)  So, I budget the KX3 itself at about 5W
average.

I think after I switch to 100W portable contesting, having sworn off
QRP after CQP, I'll still find running a 5W logging computer better
than a laptop.  I haven't purchased a gas genset and am seriously
leaning towards battery or battery + solar.  (Panels are so cheap,
they're almost free.)  So, saving 50W will help either in weight or $
for the battery system.

I ran this logging setup during CQP.  Real keyboard.  Real logging
software.  No mouse.  No trackpad to hit with the heel of the palm and
blow window focus.  Enter-send-mode.  Very nice!  The official Pi
display is not an outdoor screen.  I put a cardboard sunshield over
it.  And sat in the shade.  And propped the monitor up so I could be
fairly close.  So long as my T-shirt wasn't lit up by the sun to cause
glare, it was OK in the daytime.  (I think a gooseneck or articulated
mount to hold it up close to my face would be even better.)

A friend gave me a surplus monitor of a kind they used to run in
police cars.  Guaranteed daylight readable.  :-)  Runs of 12V, but I
haven't fired it up to measure the current draw.  That + the Pi setup
drawing as much as a regular laptop but daylight visible would still
be a win.

The real software I ran isn't really good for SS CW.  And I have some
ideas for contest logging software I'd like to try.  So, after CQP, I
embarked on writing my own contest logging software for SS CW.  Turns
out, that month was more than enough time.  I will have zero
complaints about my logging software.  :-)  As a bonus, I now have a
starting point for some of those ideas I want to try.

Don't have to use a Pi to get some of the improvements.  I plugged my
model M keyboard into K6VCRs laptop during Field Day this year.  That
was nice!  With enter-send-mode on and leaning back in the easy camp
chair, that was some lazy relaxed FD contesting.  :-)  Could be
interesting to use a daylight readable screen, too.

If anyone knows of a currently retailed laptop with daylight readable
screen and good keyboard, I'd be interested.  Panasonic Toughbooks?
Something else?

If you're not looking for a real contest logger, but are looking for
something for SOTA, some of the guys are using a nifty tablet based
logging program that is well worth a look.  (I forget the name, but
can check.)

Feel free to ping me off the list if you'd like.

Best regards,

Drew
n7da

> Message: 3
> Date: Mon, 2 Nov 2020 00:46:25 +0000
> From: David Hodge <davidchodge at hotmail.com>
> To: rick darwicki via SCCC <sccc at contesting.com>
> Subject: [SCCC] Portable Laptop for Field Use with KX3
> Message-ID:
>        <BYAPR18MB27114131989A2F7CCF02A778B3100 at BYAPR18MB2711.namprd18.prod.outlook.com>
>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Hello, All.
>
> Does anyone have experience with DC externally powered laptops or tablets for field use?
> I would like to get something that can be powered from a car battery or LiFePo battery, 12 to 14 Volt range.
>
> The corollary question is how to interface it with a KX3.
>
> Transcribing paper logs is getting old.
>
> Thanks in advance for any ideas/leads.
> David N6AN