Tag Archives: QRP Labs QCX-Mini

The QRP Labs QCX-mini CW Transceiver

by Scott (KN3A)

I have been a fan of QRP operating since I got licensed in 1983. The sticker in the picture is a joke a good friend who is not into CW or QRP, so I include it in my field pictures.

My interest in ham radio had reached a point I was getting away from the hobby. In 2020, I learned about Parks on the Air (POTA) and Summits on the Air (SOTA). I got hooked on activating parks and summits, and now I mostly do QRP CW, much like Thomas Witherspoon, K4SWL does.

Over the past year, I’ve been refining my antennas and radios in the field. I have different radios and antennas for different reasons, and to just mix it up a bit. Occasionally, I will take my IC-7100 or IC-7300 out into the field with my Bioenno 20aH battery, if I’m not planning to hike or go far from the parking lot, or if the bands are just not cooperating.

Back in November 2020 I had my left knee replaced so I had lots of down time and made an important purchase for field activities – an IC-705. It is fantastic and does everything I want it to do without a lot of wires. I’ve also owned and sold within the past 18 months a Yaesu FT-891 (which I sold when I got the IC-705) and had both the Xiegu G90 and X5105.  I would expect one day to get another FT-891 as it has amazing filtering and pulls in weak CW signals better than any radio I’ve owned. The G90 and X5105 are okay, however I was not impressed with the G90 from the start for out in the field. There were just too many wires in order to set up and use with my portable laptop computer if I was taking that along.

The X5105, which I had high expectations for, disappointed me in the fact that storing and using CW memory keying is not user friendly. The nice thing about that radio is, no microphone, no problem, I had some success using the 5105 and got great audio reports.

I’ve been looking ahead to my projected retirement and hopes of through hiking the Appalachian Trail in 2026. Although the IC-705 is an excellent field radio, all mode, VHF/UHF/D-Star/HF/6 meters, I already know for a 7 month hike from Georgia to Maine, it will just be too bulky in my backpack. I have heard really good things about the QCX-mini, however I’m an appliance operator and not good with kit building and soldering.

I saw there are options to purchase an assembled QCX-mini, so I decided to check out a 40 meter radio. It took about 2-1/2 weeks before it arrived at my QTH on Saturday afternoon. I hooked it up to one of my HF antennas in my yard  used for my IC-7300 that was resonant on 40 meters. I had to use my Heil headset in order to hear the audio, plugged into the 3.5 mm jack. I used my CWMorse paddle and tuned around the band. I called CQ several times before finally I heard WA0USA in Palm Beach, FL calling CQ. I called him and got a 579 report and he was a solid 599. We chatted for about 10 minutes, and he was running a kW while I was using 5 watts. It felt good to know that I was being heard.

Sunday morning I had time to go activate a local park (K-1418) before some afternoon commitments. I had also recently purchased a link dipole for 20/30/40 meters off eBay from N9SAB. I had tested this antenna out a couple of times last week, so I wanted to pair it with the QCX-mini. I went with little expectations about the little mini, so I also packed my IC 705 just in case I needed it to complete my 10 contacts to have a successful activation. To my surprise, I spotted myself on the POTA page, and in 45 minutes I had a total of 26 QSOs in my HAMRS log! It was amazing and I think I found the perfect combination for true lightweight, portable operations.

I was so impressed with this activation that last night I ordered the 20 meter QCX-mini! These can be ordered from qrp-labs.com and they have a lot of other kits available as well. The kit itself is $55, and I opted to have it assembled ($45) and purchased the enclosure ($20).

This little radio is very user-friendly. I was able to easily access the menus, customize it to my liking, including the paddle, preset frequencies, several stored CW memories, and was on the air calling CQ Saturday evening without seeking out the instructions.

I had mentioned previously about my disappointment with the Xiegu X5105 and not being able to easily store and recall memories. Not a problem at all with this little radio. I enabled the decoder feature just to test it out, and it decodes better than the G90 or X5105, including very weak signals. The size is a fraction of the size of the X5105 and total weight for everything, including the Bioenno 12v 3aH battery is less than 2 pounds and it all stores very nice.

These quick videos were taken this evening before storms hit; that’s why you will hear lawnmowers in the background. I wanted to first show a demo of the receive decoder and how well it decodes even weaker signals:

My biggest complaint about the X5105 was how the memory was next to impossible to use. I do a quick demo how to access a stored message and send it over the air. I also have it set to repeat every 6 seconds:

I did make a couple of changes to the radio setup. I did not like having to use the headset, so I went on Amazon and purchased a mini portable 3 watt mobile phone speaker line-in speaker with 3.5mm audio interface (affiliate link). That cost under $15 and works extremely well. It has a built in charger that plugs into a micro-USB to charge the battery when not in use. I also have a cell phone holder that fits perfectly on my Neewer stand I purchased several months ago for my IC 705, and it sits nice and firm on the table. I may not take that to the field if I’m doing a lot of hiking.

Here are some other details about the QCX-mini from their website:

The Optional enclosure is black anodized extruded aluminium, very sturdy and elegant. The enclosure size is 95 x 63 x 25mm without protrusions. The top and side panels are drilled and cut to match the QCX-mini with laser-etched lettering. The enclosure includes four self-adhesive feet.

Special portable-friendly features:

  • Small size: 95 x 63 x 25mm enclosure (plus protusions)
  • Low current consumption (for example 58mA receive current, with 12V supply and display backlight off)
  • Low weight, 202 grams
  • Sturdy extruded aluminium enclousre
  • All-metal BNC short connector, bolted to enclosure

List of features: 

  • Easy to build, two-board design, board with main circuit and connectors, display panel board with LCD; all-controls board-mounted on a press-out sub-board. No wiring, all controls and connectors are board-mounted
  • Professional quality double-sided, through-hole plated, silk-screen printed PCBs
  • Choice of single band, 80, 60, 40, 30, 20 or 17m
  • Approximately 3-5W CW output (depending on supply voltage)
  • 7-14V recommended supply voltage
  • Class E power amplifier, transistors run cool…
  • 7-element Low Pass Filter ensures regulatory compliance
  • CW envelope shaping to remove key clicks
  • High performance receiver with at least 50dB of unwanted sideband cancellation
  • 200Hz CW filter with no ringing
  • Si5351A Synthesized VFO with rotary encoder tuning
  • 16 x 2 yellow/green LCD screen
  • Iambic keyer or straight key option included in the firmware
  • Simple Digital Signal Processing assisted CW decoder, displayed real-time on-screen
  • On-screen S-meter
  • On-screen real time clock (not battery backed up)
  • Full or semi QSK operation using fast solid-state transmit/receive switching
  • Frequency presets, VFO A/B Split operation, RIT, configurable CW Offset
  • Configurable sidetone frequency and volume
  • Connectors: 2.1mm power barrel connector, 3.5mm keyer jack, 3.5mm stereo earphone jack, 3.5mm stereo jack for PTT, 3.5mm stereo jack for CAT control,  BNC RF output
  • Built-in test signal generator and alignment tools to complete simple set-up adjustments
  • Built-in test equipment: voltmeter, RF power meter, frequency counter, signal generator
  • Beacon mode, supporting automatic CW, FSKCW or WSPR operation
  • GPS interface for reference frequency calibration and time-keeping (for WSPR beacon)
  • CAT control interface
  • Optional 50W PA kit
  • Optional aluminium extruded cut/drilled/laser-etched black anodized enclosure

Just a quick note on the link dipole. It is well made and I had a 1:1 SWR on the CW part of the band, which is perfect. I did put the IC 705 to work when I attempted to work a couple of SSB stations on POTA, and at 7.235 the SWR was only about 1.3:1, so minimal loss. Check out the N9SAB antennas on his eBay site. His shipping is very quick. I took a picture of the balun with the included choke in the package I purchased, and the second picture is the link between the 20 and 40 meters. It works great.

I mentioned my goal about hiking the Appalachian Trail in 2026. I’m sure there will be other multi band mini size radios available by then and I’m hopeful QCX will have one in 5 years for me to use. My goal is to activate summits along the way while taking breaks from the hiking, or at night before calling it an evening. Since I’ll be on the A.T. I’ll also have lots of opportunity to activate POTA as well. Most thru hikers are not hams and they are always concerned about no cell phone coverage. I won’t have that issue and I’m confident I’ll be able to be in touch with other hams throughout the journey.

Thank you once again Tom for allowing me to post on QRPer. I think I finally have a QRP radio that you have not tested or purchased yet. I hope your readers find this short article useful.

73

Scott – KN3A


Scott Lithgow (KN3A) is a regular contributor on QRPer.com. Click here to check out his previous posts.

Video: QRP Labs QCX-mini 5W CW transceiver–now available to order

Hans at QRP Labs has just posted a video of the new QCX-Mini 5 watt transceiver kit. It looks like another thoughtful design:

Even though I’ve yet to build my QCX+ (!!!), I just ordered the QCX-Mini. This little kit will be a challenge for me–even though all of the SMD components are pre-populated, it’s still a tight board and requires some fancy toroid work!

Still, I’m buying it to support QRP Labs’ work and because I love the challenge of building kits. This one is awfully cute and I’m pretty sure I’ll use it to claim a summit!

My entire QCX-Mini kit with enclosure set me back $86.99 US with shipping and tax included. How could I resist? (Don’t answer that, please.)

Click here to check out the QCX-Mini product page.