Tag Archives: Guest Posts

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.


Scott – KN3A

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

Guest Post: Field Day – 200 QSOs with a Flashlight Battery

The PowerFilm LightSaver (Image: PowerFilm Solar)

Many thanks to Jim Cluett (W1PID) who has kindly allowed me to share this recent post from his website:

Field Day – 200 QSOs with a Flashlight Battery

June 2021

by Jim Cluett (W1PID)

Field Day was an experiment this year. I operated for nine hours using a 5V 18650 battery and made 200 QSOs before calling it quits.

I operated on the deck with an MTR 4-B designed by KD1JV. The antenna was an 88 foot doublet up about 45 feet. I used the ZM-2 tuner. For power I used the PowerFilm LightSaver. This is a 5 watt roll-up solar panel that charges a 3.7V 18650 battery rated at 3.2 Ahr. The battery inside the Powerfilm product is commonly used in flashlights. The combination of the rig and the power supply is crucial.

The MTR rigs will operate from 6 to 12 volts. The Powerfilm puts out 5V to a USB socket. The secret ingredient required to bring the USB voltage up to the operating voltage of the rig is a Baofeng USB charging dongle. This device takes a 5V input and outputs 10.3 volts… perfect for the MTR transceiver. With this voltage the MTR puts out a little less than 3 watts.

The PowerFilm LightSaver is designed to charge cell phones for hikers and campers. It weighs only about 5 oz. and rolls up into a tiny package. Any USB 5V cell phone charging battery could be used with the Baofeng dongle.

This year my whole station operated on 5V. I used a Samsung tablet for logging.

In New Hampshire it was cloudy for most of Field Day, but fortunately the amorphous solar panel provides some charging even when it’s cloudy. I’m guessing that after 9 hours of operating the battery was down to about half capacity. The beauty of this system is that one could operate indefinitely with moderate sunshine.

I’ve been experimenting with this setup during hikes and bike rides for the last couple of months with a view to using it for Field Day. This year’s emergency exercise proves that it is viable for an extended grid-down power outage.

Click here to check out Jim’s website!

What a brilliant challenge and test for Field Day, Jim! Thank you for allowing me to share it here on QRPer. Also, a hat tip to Eric (WD8RIF) for bringing this article to my attention!

Guest Post: “German spies are eavesdropping on you!”

Many thanks to my friend Ollie–an SWL in Germany–who shares the following guest post:

German spies are eavesdropping on you!

I recently made the first all-night listening sessions at the German North Sea coast for this year. On the night of June 10th/11th I picked up 2 POTA SSB activations over here and I thought you guys might find it mildly interesting what that sounds like here. 🙂 Condx were just going down from “slightly elevated” to “regular solar minimum” values that evening.

RX was an Icom IC-705, antenna is a 10m/33′ lazy monopole (running 10m wire vertically up a fiberglass pole, no counterpoise, no matching network, balun, flux capacitor, just a wire and pretty conductive ground).

Video: KI5OLV activating K6574 (Lower Neches Wildlife Management Area, TX), around 1:40 UTC

Video: W8CFS activating K-1552 (Warren Dunes State Park, MI), around 23:00 UTC, condx to the stateside were dipping at that time

I don’t know that W8CFS had brought to his park, KI5OLV brought an IC-7100 and was running its 100W into a hamstick antenna on his truck. Nothing to learn from that really, I’m just happy I can hear y’all! 🙂

73s, Ollie

Mike rediscovers radio and POTA “gently reopened the door to an amazing hobby”

Many thanks to Mike (W6MVT) for sharing the following guest post:

Back to Ham Radio for a Year – A Brief Reminiscence

by Mike (W6MVT)

This story will sound like many I have heard over the past year, but I will write it nonetheless as a note of gratitude.

Last March COVID had just restricted our activities and I was wondering how to spend my time. I had received my licenses back in the 80’s. There was a code requirement, there was no internet, no QRZ, no spotting.

Though I enjoyed ham radio very much, family and work took precedence, and the equipment went into storage. I eventually sold it off (who is dumb enough to sell matching Drakes?).

Fast forward to the around 2010, when I knew I would be retiring and might want to get on the air again. I picked up some used equipment and stashed it away without really using it.

Then 2020 arrived and the world changed dramatically. One day, prompted by who-knows-what, I had the bright idea to dust off the gear and hook it up, mostly to see if it even still worked. A makeshift wire in the back yard and a quick listen and there it was – a CQ.

I was actually nervous to answer – it had been that long. It was KE8BKP, who it turns out, was activating a park. I hadn’t a clue what that meant, but I shakily answered. We exchanged reports and he went on the to the next one. I had two immediate reactions. First, I was reassured by that brief, painless interaction. The stuff worked and I could still “do this.” Second, things had changed a great deal since the “old days.” But I researched POTA and SOTA and DX Clusters and all the other magic that now exists.The point is that POTA gently reopened the door to an amazing hobby, one that still fascinates me. I went on to become an active hunter and now a prolific activator.

Since it has been a year now, I felt it important to acknowledge this moment, and to note one more thing. When an activator answers a call, we don’t know the other person’s circumstances. Maybe they are a new – or returning “old” ham. Maybe it took courage to key the mic or pound the key. I have appreciated the manner in which POTA hams enthusiastically help one another improve, learn and in turn help others. Thanks to Jeff, KE8BKP, and all the others since, and to come. And thanks to the many volunteers that keep the program running each day.

73, and be well,

Mike W6MVT

Mike, I couldn’t agree with you more. I think all POTA, WWFF, and SOTA activators are essentially ambassadors for ham radio. We never know what’s happening on the other end and I strongly believe in patience and understanding when answering calls and performing an exchange. It can have a huge positive impact for the person on the other end.

So glad you found Parks On The Air and that you’re enjoying playing radio once again!

Thank you for sharing your story.

Frank builds the EGV+ Three Band QRP CW Transceiver Kit

Many thanks to Frank Lagaet (ON6UU) for sharing the following guest post:

The EGV+ Three Band Transceiver Kit

by Frank Lagaet (ON6UU)

Another EA3GCY kit has seen daylight.  The EGV+ is ready for you all.

It was beginning 2021 I got word a new kit from EA3GCY was ready and distribution could start.  After a successful build of the DB4020 I did not need much time to decide to buy this kit,  a week later the kit arrived at my QTH.  As weather was good I did not start immediately building but then winter kicked in, with snowfall and frost,  perfect time for some quality time and building the kit.

What do you get ? 

The kit has a general coverage receiver from 6 to 16MHz,  it has a keyer built in,  has RIT without limit,  requires only 0.25A on RX and smaller than 2A on TX.  Dimensions are 18x14cm and weight is 0.3Kg.   It is CW only, able to produce 8W on 40 and some 5-6 on 30 and 20.  The kit has an AB class amplifier.   Spurious is below -50DBc.  The receiver is a heterodyne type balanced mixer,  sensitivity is 0.2µV minimum and the CW filter is some 700Hz wide,  the AGC is on audio.   Furthermore the transceiver is equipped with both output for loudspeaker as for a headset or earbuds.

The kit arrived in a brown envelope and in that envelope I found a well-packed packet of plastic bags and the printed board well packed in bubble wrap.  Around that another layer of bubblewrap.  Safe!!

All plastic bags were checked,  all needed stuff was there, super,  well done Javier.

All components were installed in about 10 hours “relax max style”,  if you have built some kits already you can easily do this one,  all elements are far enough out of each other,  the board is not overcrowded at all.  Some attention is needed when soldering the IC’s and display but even that is a piece of cake.   Be careful when installing the SI5351 module.

Winding the toroids,  just follow what is in the manual,  it is not that hard to do,  I don’t understand what many find so difficult.  Just take your time and don’t rush into it.

I got the transceiver up and running quite quick. I didn’t install a speaker in the cabinet but decided to go for a transceiver where no speaker is in. If I want to use it on SOTA or GMA I don’t need the extra weight and can take earbuds with me.  So I installed the speaker connector on the board.

I made connections towards the CW key and CMD push button with jumper cables which fit exactly on the headers Javier supplies,  a little glue to keep them in place is also added afterward.  For easy operation I mounted the CW key connector and CMD pushbutton on the front of the transceiver.

Do to be able to withstand high power nearby stations,  I mounted the EGV+ in a homemade box which is made of printboard.  The box should be a Faraday cage to keep all QRM out.  If you buy a box, buy one in metal.  I added a laminated front and back which make the transceiver look kinda cool.   Now you can also buy a box from qrphamradiokits.


The alignment is done on 40 meters:  crank up the volume and start turning the 2 coils (L1 and L2)to maximum volume.  Be careful to handle these with caution and don’t use metallic screwdrivers.  Connect an antenna after you’ve done that and do the alignment of the coils again for maximum volume.  Find a station on 40 and redo the alignment once more.  You should already have good results now.

P1 Set sidetone level to your liking.

P2 Set the hangtime of the relay after you’ve been on air–fast fingers will need a quick release. Set this to your liking.

P3 Connect a power meter between a dummy load and the transceiver,  set power on 40 to some 8 Watts.   Measure on 30 and 20 meters,  you should find some 6-7W there.  Don’t set the power to full if you want a long life for the final in the transceiver.  Mine is set for 6W on 20,  resulting in some 7.5W on 30 and some 8.4W on 40.  I think I will reduce even more.

P4 Set to max,  it is the RX-attenuator.

P5 Don’t pay too much attention to the signal meter,  mine is set at 6/8 of the potmeter’s range.  It is only an indication.  If you don’t want the S-meter then you can do a start-up sequence with the tuning knob.

These are in fact the alignments you need to do inside the transceiver.  You should also check Xtal calibration and BFO,  these are settings which you need to do in the set-up.  Don’t forget to write all down when you have maximised these settings. If you do a reset, all these values are erased too so be carefull.

The complete CW 3 bander

Well,  you get a 3 band transceiver which you build yourself,  it has RIT and XIT,  has 4 memories on the KB-2 keyer,  speed of CW can be set between 0 and 50WPM and you can set the KB-2 as a beacon which can be handy too.   The EGV+ provides you with 3 bands which are almost for certain insurance for QSOs when going on SOTA,  GMA or POTA.

You may have noticed some resemblance with the DB4020. You are right as some parts are the same on the board.   The designer worked on the same platform to make two completely different transceivers.  The result is twice the fun for kit builders.

I made a box myself since, at the time of ordering, there were no boxes available,  here’s the result.

The naked printboard transceiver.

After adding a laminated front to the trx,  it looks now like this.  You can see it is not made professionally but I like it.

The paper which is between the plastic was first cut out for the display before placing it in the plastics so giving an extra protection to the display.

I have also made a retractable stand for it,  when folded back it is next to the bottom of the transceiver,  when folded out the stand is under the front of the transceiver,  the retractable stand is also made out of printboard.

It’s an easy-to-make stand–take some old printboard and solder it together.   The pictures explain it all, I think.

Meanwhile, I already made a lot of QSOs with this small (16 X 20 X 6 cm) QRP transceiver.   The power out is better than expected and even reduced so all bands are within QRP regulations.

Finally, I’d like to say that I’m not sponsored to make this kit,  I don’t have any ties with the kit producer, nor do I gain money with building it.   If people would like to have this QRP kit built for them I’m willing to help out in populating the board and aligning it.  A ready made box is available with qrphamradiokits.   This also stands for the DB4020 which I made earlier.

The kit comes for 125€ without shipping costs.  Many European countries will have no shipping costs at all.  The enclosure comes for 50€ all included. This means you have a complete 3 band radio for about 200€.  In my eyes, this is a pretty good deal.

Info about the kit can be found here :   Home – Página web de ea3gcy (qrphamradiokits.com)

And here : EGV+ Three band CW – Página web de ea3gcy (qrphamradiokits.com)

Guest Post: Steve builds a DC30B QRP Transceiver

DC30B QRP Transceiver ProjectMany thanks to Steve (KZ4TN) who shares the following guest post:

DC30B QRP Transceiver Project

by Steve Allen, KZ4TN

I wanted to build a lightweight backpackable transceiver I could take hiking and camping. I chose the 30 meter band as it is specific to CW and the digital modes. I am also in the process of building Dave Benson’s (K1SWL) Phaser Digital Mode QRP Transceiver kit for the 30 meter band. Also, a 30 meter antenna is a bit smaller than one for 40 meters and the band is open most anytime of the day.

I sourced the DC30B transceiver kit, designed by Steve Weber KD1JV, from Pacific Antennas, http://www.qrpkits.com. It appears that they are now (10-11-20) only offering the kit for the 40 meter band. The following information can be used for the assembly of most any kit that lacks an enclosure.

Lately I have been finding extruded aluminum enclosures on Amazon.com and eBay.com. They come in many sizes and configurations. I like to use the versions with the split case which allows you to access the internal enclosure with the front and rear panels attached to the lower half of the enclosure. Most of these enclosures have a slot cut into the sides that allow a PCB to slide into the slots keeping it above the bottom of the enclosure without having to use standoffs. The one requirement for assembly is that the PCB needs to be attached to either the front or rear panel to hold it in place.

DC30B QRP Transceiver Project

As the enclosure is anodized, I didn’t want to rely on the enclosure for common ground. I used a piece of copper clad board that I cut to fit the slot width of the enclosure and attached it to the back panel. I was then able to mount the transceiver PCB to the copper clad board with standoffs. This basic platform of the enclosure with the copper clad PCB provides a good foundation for any number of projects. All you have to do is mount the wired PCB on the board, install the components on the front and rear panel, then wire it up.

DC30B QRP Transceiver Project

I wanted to have the choice of a few frequencies to operate on so I searched eBay for 30 meter crystals and found a source for 4 different popular frequencies. I installed a rotary switch on the front panel and added a small auxiliary PCB with two, 4 pin machined IC sockets. This allowed me to plug the crystals into the sockets. I wired the bottom of the socket PCB first using wire pairs stripped from computer ribbon cable leaving extra length. I marked the wires with dots to indicate which sockets each wire pair went to so I could solder them onto the rotary switch in the correct order. It was tight but I always work with optical magnification so I can see exactly what I’m doing. I have used this crystal switching method in the past with good success.

DC30B QRP Transceiver Project

DC30B QRP Transceiver ProjectThe rest of the assembly was straight forward. I find that most kits are well designed and documented, and if you take your time and follow the directions carefully all should go well. The two most common speed bumps seem to be soldering in the wrong component or bad soldering technique. I double check all component values and placements prior to soldering, and I always use optical magnification while working. I inspect each solder joint and look for good flow through in the plated through holes, and make sure there are no solder bridges.

DC30B QRP Transceiver Project

DC30B QRP Transceiver ProjectThe finished product. I bought a Dymo label maker and it works very well for projects like this. I love using these enclosures and they are a leap forward from the old folded aluminum clam shells I used in the past. I could stand on this without causing any damage. Power out is 1-3 watts depending on the DC power in. The receiver is sensitive and the ability to choose from four frequencies is a real plus.

73 de KZ4TN

Steve Allen
Elizabethton, TN

Wow, Steve! What a top-shelf job on this build! I’ll have to look for those aluminum enclosures as well. Beautiful little rig you’ve made there and I think it’s fantastic you’ve a few crystal frequency options! Thank you for sharing!