Thoughts about the Elecraft KX3

September 07, 2014

Some quick thoughts about the Elecraft KX3.

About a month ago, I ordered an Elecraft KX3, and patiently waited. A lot has already been said about the KX3, but in a nutshell, it’s an ultra-portable, all-band HF SDR QRP transciever. (How’s that for buzzword bingo?) It’s about the size of a brick, and it’s awesome.

Elecraft KX3

Prior to this spring, I had kind of always discounted the idea of both QRP and portable operation. Taking part in the local HF/Aerials in the Park events really opened my eyes to what options are available for operating portable, and I had a blast. To make sure this wasn’t just an “impulse purchase” (the rig is quite expensive), I outlined a number of goals I had for purchasing the rig, and made sure there wasn’t something else I would rather do with the money. Among some of my goals:

  • Be able to operate outside, away from my desk. Go to a park, throw a wire in a tree, and get on the air!
  • Be able to operate HF on trips. Something that wouldn’t involve me sitting on my laptop to pass time.
  • Be able to participate in HF/AITP
  • Having a rig with I/Q out for SDR experimentation

Cost & Options

The base cost of a KX3 without features is $1000 USD. I ended up ordering the radio as a kit, which knocked $100 off the price, and it ended up taking me just a couple hours to put the kit together. There’s no soldering, and most of the assembly is dealing with screws, standoffs and knobs. I went with a few more options on top of the bare radio:

  • KXAT3 automatic tuner - I don’t own an ATU, so this is critical for portable.
  • KXFL3 roofing filters
  • MH3 hand mic

I decided to skip the internal battery charger - I figured I could deal with popping the AA batteries out every once in a while to charge. I have some long-term plans for a LiFePO4 battery, but that will probably wait until next spring.

The options above brought the cost up a bit. I had also originally tried to “cheap out” by skipping the hand mic. You can key the KX3 with the “XMIT” button manually, or use VOX. I’m able to plug a Logitech gaming/computer headset directly into the headphone and mic jacks of the KX3, and run the rig that way. Since I already own a Kenwood TS-590, I attempted to build an 8-pin jack to TRRS (tip-ring-ring-sleeve) 1/8” headphone plug adapter, so I could use my Kenwood hand mic with the KX3. Ultimately, I failed due to the leads in the headphone cable I bought being very hard to solder. Last week, I broke down and just bought the Elecraft brand hand mic.


Top-notch customer support

After assembling my KX3, I had a couple questions - the legs didn’t quite sit at the same position, causing the KX3 to wobble. I also noticed that random LCD segments would light up. I ended up emailing and had a speedy response within 20 minutes! They had even offered to ship me new support legs, which I haven’t taken them up on quite yet.

There’s also a Yahoo user group as well as a general email list.

Great Receiver

I only have a few years of operating HF under my belt, and my experience is a bit limited. Dare I say, it sounds better than my TS-590. I don’t have first-hand numbers to back it up. The KX3 is currently sitting in second place in the Sherwood Engineering rankings, so I’ll trust that they know their numbers :)

I’ve also noticed that the DSP noise reduction sounds subjectively better than my TS-590. I rarely use the NR on my 590, as it sometimes sounds “bubbly”, but maybe I’m using it wrong.

ATU will tune “anything”

As I mentioned above, I didn’t already own an antenna tuner, so I opted to add the internal ATU to the KX3. After using my 590 for a couple years, I grew accustomed to where it would and wouldn’t tune, and therefore, where I couldn’t operate. The 590’s ATU seems to only be able to handle up to a 3:1 mismatch, and gives up with a CW “SWR” sidetone. This meant I couldn’t work 10 or 6m with my antenna, despite it being able to on paper.

The KX3 ATU seems to handle quite a larger range of mismatch, and from what I’ve read it should be able to find a match anywhere up to 20:1! This is a bit ridiculous in practice, but when I hook my KX3 up to my wire antenna in the backyard, I’m able to at least tune on 10 and 6m, as well as 75m.

Other “magic tricks”

There are a couple other cool features that I like, which I’ll eventually probaly write about:

  • CW/PSK/RTTY decode, on-screen.
  • IQ out port, something my TS-590 doesn’t have


After all that praise, I do have a few nitpicks.


This radio wasn’t cheap. On top of that, if I want to go QRO with the rig, the matched Elecraft 100W amp with ATU will run you over $1000! Yikes. I’ve seen other amp kits around $300.

VFO encoder noise on higher bands

I mostly notice this on 10 and 6 meters. There are some steps that can be taken to reduce the noise, and it’s definitely not a deal-killer by any means.

Notch filter is “auto” only.

I can’t twiddle a knob to knock a carrier (or LID ;)) out. Oh well! It still seems to work, but it’s more of a “beat cancel” than a “notch filter”


So far, I’m really pleased with the KX3. I’ve had a number of stateside contacts, and I do have yet to get some actual DX. I will be taking it along to a trip to Manitoba, and I’m excited to use the rig for an extended period of time and see how it holds up.

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