KX1 #1740 - The first 100 QSOs

[James Kearman]

I built KX1 #1740 last month but waited until I had accumulated some
experience to discuss it. With 100 QSOs in the log, I think I'm ready to
let the cat loose. My comments will be most useful to people thinking
about buying one.

Why KX1?
I live in a condo so I can only put up antennas at night, but I live
near a nature preserve with lots of trees. I wanted the portability of
the KX1, as opposed to features found in the K1, which was too big for
my purposes

Options?
I got 'em all, 80-30, paddle, ATU

Assembly
Went together pretty easily. I merged the 80-30 mods into the original
construction with no difficulties. I was shorted one RFC (pays to have a
junkbox) and one RFC was supplied in mini rather than micro size but I
made it fit. The instructions were very good. For the 80-30 mod part,
having the instructions point to the correct area of the board, as is
done in the main assembly manual, would have been helpful. But the radio
worked first time and that's what counts. I spent a long time building
it because my eyesight is getting poor and I didn't want the heartache
of making a mistake. There is some close-quarter work involved in
installing the 80-30 upgrade. Be prepared to take longer than you expected.

Before I got my kit I read every KX1 post to the Elecraft reflector for
the previous year, and downloaded and studied the manuals. I strongly
recommend anyone planning to build an Elecraft kit do the same. I knew
in advance where I might run into trouble (such as a wire that can go
astray on the little board that comes with the 80-30 upgrade), and
gained the confidence to build the 80-30 mod right in, testing on 40 and
20 M first, then adding the 80-30 main board and testing on 80 and 30 M.
I built the ATU first, so that when the radio was finished I didn't have
to wait to put it on the air. I work slowly but that doesn't mean I'm
patient. :)

Performance - General
I use a 1.4 AH gel cell in the field, and get >4 W out on all bands. The
receiver has a low enough noise floor that I can hear band noise on all
bands, though I sometimes wish for a little more audio gain to pull out
the weaker signals. I use and recommend MDR earbuds, which are much more
sensitive than some cheaper ones I hd.

Performance - Specifics
Most of my contacts have been made on 20 and 40 M. Lately, for field use
I've only been on 20 M, using a ground plane hanging from a branch, so
the base is about 8 feet (2.5 m) off the ground, three sloping radials,
fed through a coiled-up RG-58 balun. The SWR is 1.1 in the middle of the
band, don't need the tuner. This antenna outperforms the inverted vee I
tried first.

I've worked 30 countries on 20 M with this setup in a month, including
such juicy stuff as ST2R, EL2DX (who answered my CQ on 14060!), 3XD2Z
and 6V7F. I worked 6V7F in a pileup that required using the RIT to work
split, which is hard work, and it took me about 15 minutes to get
through. The west coast of Africa is a chip shot from my South Florida
location, but I'm not complaining. Oh, and K2HYD/HR9, whom I found
calling CQ on 14060. He was running a KX1, too!

I've also used the rig at home on 40 M, with an inverted vee. On 40 at
night, strong signals blow past the filter and things get a little more
difficult, but that's not the environment for which the radio was
designed. I have worked TA3D, 3DA0PM and SU9FL on 40 with the rig, and
3DA is farther from here than Japan. I will work a JA with it on 40
eventually, it's a matter of staying up late enough. I've also used the
KX1 from home in a couple of sprints.

Today I tried a random length of wire on 30 M from the park, to get an
idea of what might work on an upcoming trip to England, Holland and
France. I thought the higher angle radiation might get me more US QSOs
but domestic activity on 30 seems light. I did work MI0SRR and G0RTN
just before sunset, so even funky antennas will bring in DX sometimes.
Too bad I have to be out of the park by sunset, and it's a half-hour
walk back to my car.

The random length of wire was a little long for 30 M. Even though I
added bypass capacitors to the ATU as recommended by Wayne, it went
haywire a couple of times. I will make sure to keep the antenna shorter
in future, or use a better counterpoise. But this was intended to be a
worst-case kind of setup, something like I might encounter in a city
park on the trip.

I've used all the features on the rig, and there are a bunch. Once you
get a little practice you can quickly change keyer speed, jump in and
out of RIT, or do any other necessary operation. I haven't done much
SWLing, but I have listened to WWV a few times to get a feel for
propagation. I have yet to make a QSO on 80 M, been too busy on the
other bands.

I plan to swap in a set of rechargeable Lithium-Ion batteries for the
trip, but the 1.4 AH gel cell has worked very well for an afternoon's
operating. The battery, radio, headphones, paddle, clock and power cord
fit in a cheap pencil case from Walgreen's. My balun is wrapped on the
cover for a stack of CD-RWs, and other antenna bits and pieces go inside
the cover, which sits on top of the pencil case in my knapsack. Add a
folding stool and a bottle of water and I'm ready to work some DX.

I wasn't sure how I'd like the KPD1 paddles, but they are actually very
good. I use a Bencher paddle at home and have no trouble going back and
forth. I rest the rig on my knee, and having an integral paddle really
makes it convenient to use. That was a great idea!

Wish List
I'd like better filter skirts for when I can use a better antenna, but
understand you can only squeeze so much into the little box. A bit more
audio would be nice but my hearing isn't as good as it used to be -- too
many Jethro Tull concerts in my youth. I'm going to wish for the high
bands pretty soon, but understand there's no way to get there with the
existing DDS. I guess I'll have to go back to the bench and build
something -- what a concept. Oh, one last thing. I never got a chance to
call N8S, the Swains Island DXpedition, because whenever I heard them on
20 they were working a 7-kHz split, and the KX1 RIT only covers plus or
minus 5 kHz. But that's the only pileup in which I faced that problem. A
dual-range RIT would be neat to have, though.

Tips
Do the 80-30 mod simultaneously only if you can stay active on the kit,
so you can keep track of what you're doing. Doing it separately, later,
is not a big deal, and might save you some grief.

Use MDR or other sensitive earbuds.

The suggested Pomona BNC-to-Banana-Jack adaptor is okay, but having the
antenna tied directly to the radio is not always convenient. Resonant
antennas are better, if possible. I have a BNC-to-alligator-clip cable
that I prefer to the Pomona adaptor for random wires, because it
provides some slack and moves the connection point away from my hand.
It's more to carry, but worth considering if you have space in your pack.

I bought an MFJ-107B LCD 24-hour clock. I slipped the clock part out of
the aluminum stand and put mating pieces of hook-and-loop fastener on
the bottom of the clock and the top of the KX1, on the right side. So
now I don't have to do mental gymnastics to calculate UTC (my mind is
going, Dave, I can feel it), and I can still hold the radio in one hand.
I'm right handed. If you're left handed, mount the clock on the other side.

Summary
The KX1 is neither cheap nor inexpensive. The quality is very good, but
you pay for what you get. I had to think about it for 3 years before I
finally pushed the button. Having the park to operate from made the
difference. This is not the optimum radio for a home station, but it
wasn't supposed to be. For a portable CW radio, however, I don't think
you can do any better. The receiver will let you hear other QRPers down
in the noise, and I get many compliments on the quality of the
transmitted signal. For the types of antennas you're likely to use
afield the receiver is more than adequate. I've been able to work a lot
more DX on 20 during the last month than I ever expected. Thanks to
having the KX1 I am able to spend many more hours on the air every week,
without demolishing my sleep schedule or stumbling around in the dark
hauling up antennas. And I'm looking forward to operating from Europe. I
wouldn't consider taking a much larger radio on the trip, but it will
fit in my attache case, so I can demonstrate it to the nice lady at the
airport.

Someone on QRP-L just asked about classic QRP radios. I don't know if
the KX1 has been around long enough to be considered a classic, but it
will be. It's an amazing piece of technology, designed in the USA, no
less. If your budget is a little tight, consider the basic radio and the
paddles. You'll be glad you got them. You'll have to make resonant
antennas, but you only need a single support for a ground plane or
inverted vee. The 40 and 20 M bands will keep you busy for a long time,
and you can add 30, or 80 and 30, plus the ATU down the line. My only
question is, if there are more than 1740 KX1s out there, why have I
worked only one other KX1? Get 'em on the air, folks! I still need 24
states.

Jim, KR1S
Author, "The DXCC Handbook," coming soon from ARRL


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