Tag Archives: QCX-Mini

Guest Post: Lake Thunderbird (K-2792) with a homebrew transmitter!

Activating (sort of) Lake Thunderbird (K-2792) with a homebrew transmitter

Sam Duwe WN5C

When I dove into radio a couple years ago a few sub-hobbies caught my attention: QRP, portable ops, CW, and homebrew. Of course, these all fit nicely together, but in my mind there was a huge leap between soldering an unun and a building a radio. But why not try? What’s the worst that could happen by melting solder and then sitting at a picnic table? This is how I built a simple transmitter and kind of activated a park.

The Michigan Mighty Mite

Nearly everyone has heard about the Michigan Mighty Mite (MMM), a QRPp transmitter popularized by the Solder Smoke blog. There are countless YouTube videos and posts across the internet. It’s very simple: a single transistor, a variable cap, a coil, a crystal and some resistors and a cap. Supposedly one can get up to half a watt of output (I couldn’t). But with a small purchase from Mouser one can oscillate. That seemed pretty cool.

I hadn’t touched an iron until I started playing radio. But I’ve been drawn to homebrew projects. I built a regenerative receiver last year which was very rewarding. I’ve also put together kits (a QCX mini and a TR-35). But my dream has always been to construct a transmitter/receiver combo, or a transceiver. I thought a good place to start was the MMM.

I built the transmitter based on the common schematic for the 40-meter band. The MMM is crystal controlled but I opted to solder in a socket and buy a handful of crystals, so I have the luxury of operating on 7056, 7040, and 7030 kHz. I made a few other improvements, too. The first was to build a low pass filter to attenuate harmonics. Second, although I haven’t finished it yet, the switch on the right will be to choose between multiple crystals. And third, I added a BNC jack to connect a receiver, with a transmit switch. When not in use the transmitter will dump into a dummy load. This receiver switching idea was lifted from the design of the MMM that QRP Guys produces.

When I tested the transmitter at home the best I could get with my charged Bioenno 3 Ah battery was about 300 mW output. The filter is reducing things somewhat, but maybe I need to look into a different transistor or rewind the coil. But I was able to get a 339 signal report from Illinois (no sked) in the midst of distance lightning crashes, so I had a little confidence going forwards. School is out for me this summer, so I decided to head to the park. Continue reading Guest Post: Lake Thunderbird (K-2792) with a homebrew transmitter!

CQ From Latvia with Love

CQ From Latvia with Love

by Leo (DL2COM)

A completely under-prepped SOTA & WWFF activation which turned out to be perfect

In preparation for a tough conversation a good friend once told me: “You know what, just walk into the fire. If you have bad news to deliver, don’t sugar coat it and do it right away. You’ll be fine.” 

“Just walk into the fire.” I believe this can be applied to many other situations in life. While I would consider myself to be well-prepared on most trips, hikes and activations and getting a lot of joy out of optimizing my kits I try to stay open-minded. Imagine the things you would miss out on if you wouldn’t be spontaneous or only do things while fully prepared and 100% safe – even if it means taking risks.

On the road back to Riga
The QCX-Mini silently drying after a successful activation

Last Wednesday, I kind of walked into the fire. Not fire as in fire-fire but fire as in Latvian winter storm. In general this wouldn’t be such a big deal had I brought the right clothes, gear and shoes to my short business trip to Riga.

Due to very strict luggage restrictions I could only bring one small backpack for three days. Inside I had enough room for a laptop, washbag, spare clothes and the compact QCX-Mini Kit I built for exactly these occasions. I was wearing sneakers and jeans. At this point I had not planned a specific activation but I wanted at least to be able to operate YL/ & /p maybe 30 minutes from a nearby park – not a problem if you can jump right back into the warm hotel afterwards.

My rental car rocking summer tires in Winter (yes, I was driving veeeeeeery slowly)

During our stay, my schedule for Wednesday morning freed up so I decided to try activating one out of only three SOTA summits in Latvia: YL/YL-003. It turns out this summit is also located within WWFF territory YLFF-0007 about a 1,5h drive from Riga. Big Thanks to Val (YL2SW), Latvia’s WWFF manager, for assisting me with local rules and processing my log. A quick look at the weather forecast showed freezing temperatures, 90% chance of snow, heavy winds and overcast. Many of you will understand why a SOTA&WWFF combo in a rare country could be a small reason not to use the hotel’s sauna on a day like that. Sometimes things just need to get done.

Summit watchtower
The majestic watchtower on YL/YL-003

I got up early the next morning and was very happy to be able to grab a Bolt rental car from the street and get going quickly. The drive went by without issues up to a point just about 3km away from the mountain (well, 1-pointer hill I should say). The roads were completely covered in snow so I could barely see where I was driving. Latvia is a rather flat country but here it started to get a bit hilly and the tires were certainly not cut out for that. Continue reading CQ From Latvia with Love

Testing a new QCX-Mini Field Kit built in an Evergreen 56 Watertight case

In early November, I happened up a new waterproof case called the Evergreen 56. As with Pelican cases, it’s waterproof and also made in the USA. Like Nanuk cases (that are also waterproof and made in Canada) Evergreen cases have a built-in locking mechanism to keep the latch from accidentally opening during transport.

I thought the price for the Evergreen 56 at $28 US was fair and in-line with the Pelican 1060 and Nanuk 903 which are similar in size. I grabbed one made of a clear material with one radio in mind: my QCX-Mini!

There are a number of color options available for this Evergreen case, but I like the clear polycarbonate one because it makes it so much easier to see what’s inside (for a quick gear check) but also to confirm that no one part of the kit is being pressed too hard inside the case after the lid is sealed.

After receiving the Evergreen 56, I was very pleased with the quality–again, on par with what I would expect from Pelican or Nanuk.  It is incredibly solid and the seal is watertight.  The Twist Lock Latch (see above) is easy to operate and the case comes with two “keys” for adjusting the inner lock.

The Evergreen case has a soft egg crate-like rubber boot interior as opposed to the pick foam material you’d typically find in a water tight case. The case also has a hammock-like rubbery webbing on the inside of the lid that can be used to organize smaller contents (I knew instantly I’d use this to hold the antenna!).

The QCX-Mini fits in the Evergreen case perfectly–this was no surprise–but I was eager to see if my other station components could also fit. Note that I didn’t buy anything specifically to be used in this case; I used components I already owned. I could minimize the contents even further if I used a smaller battery, antenna, and key.  Here are the components of the first version of the QCX-Mini Field Kit: Continue reading Testing a new QCX-Mini Field Kit built in an Evergreen 56 Watertight case

A Few Field Radio Gift Ideas for Less Than $100!

I received an email from a reader’s spouse asking about gift ideas for the holidays and beyond; ideas that could not only be used this month, but also tucked away for the future. They weren’t looking for the obvious things like a transceiver–they were looking for accessories that might enhance their significant others’ field radio fun.

Being the enabler I am, I was happy to oblige and, in fact, decided to turn my reply into a post (since it quickly turned into a very long email) with their permission. For obvious reasons, I’m keeping their ID secret! 🙂

Here’s a rather random sampling of things that came to mind. I tried to limit this to items that retail for less than $100 US. Note that some of these product links are affiliate links:

A quality LiFePO4 battery

Being a QRPer, I don’t need a large battery to enjoy hours of radio fun per charge. My favorite battery chemistry is LiFePO4 due to its weight, safety, shelf life, and recharge cycles (which is in the thousands as opposed to hundreds).

For me, a 3Ah battery is more than enough capacity to keep my QRP radios on the air for 3-5 activations per charge (depending on length of activation, etc.).

I’m a big fan of Bioenno batteries. Their customer support is excellent. You can purchase their 3Ah 12V battery for $64.99 US including the charger. If you already have a charger, the battery alone is $49.99. Click here to check it out.

If your significant other likes to push 100 watts, consider a larger capacity battery. I also have a 15Ah Bioenno battery for this purpose, though it exceeds the $100 gift price threshold). Click here to check it out.

A very affordable Li-Ion rechargeable battery


One of the most affordable rechargeable battery packs for the QRPer in your life is the TalentCell Rechargeable 12V 3000mAh Battery Pack. This pack typically costs around $30 US and is sometimes even less expensive.

This little pack is great because it will not only output 5V to recharge USB devices, but it also outputs 12 volts which is brilliant for QRP radios like the Elecraft KX series, TX-500, FT-817/818, Mountain Toppers, Penntek TR-35,  Venus SW-3B, and many others. I actually now pair this with my QCX-Mini. The battery comes with the charger and standard barrel connectors on the included DC cord which fits Elecraft and Penntek field radios among others.

This is a small battery, so can only be paired with efficient QRP radios.

While I don’t consider this a high-quality solution like a Bioenno battery, it is insanely useful and affordable. Click here to check it out.

Morse Code Keys!

I could easily write a series of articles about Morse Code keys. That’s not what you’re looking for, though, right? You want some quick suggestions. Here is a sampling of some of my sub $100 favorites listed in alphabetical order.

If your budget is flexible, you might also consider these paddles which are still less than $200:

Okay, so if you don’t mind pushing more than $200, I highly recommend any key made by the amazing Begali family. Their Simplex paddle was my first set of paddles and I still use them today. I plan to buy their Traveler next year. They’ve a massive selection of models and styles. Continue reading A Few Field Radio Gift Ideas for Less Than $100!

Jay discovered that his first CW POTA activation wasn’t scary at all!

Many thanks to Jay (W1ASP) who, last week, sent me a note about his first POTA CW activation. I asked if he’d consider writing up a short field report about his experience to share with others and he was happy to do so. Thank you, Jay.


Halloween POTA

by Jay (W1ASP)

Halloween doesn’t have to be scary.

I set out to Bear Brook State Park (K-2643) for my first CW POTA activation.

Bear Brook is relatively close by, its the largest state park in New Hampshire with over 10,000 acres. There’s camping, hiking and biking trails along with an archery course and plenty of swimming and fishing areas.

I didn’t give it much thought about what day it was, just that I had the time to do an activation and it was nice out, what a perfect opportunity to break in the newly assembled kit.

I decided on a spot next to the water and as luck would have it there was a picnic table right there. I took out my gear, set up and proceeded to tune around and listen. The band seemed pretty quiet. I wasn’t sure if I’d get enough QSO’s in to make it an official activation. I decided on 14.038 MHz, I sent QRL? I then held down the memory button, took a deep breath and hit it again to transmit: CQ POTA DE W1ASP

I waited a second or two and used the memory keyer once more, again nothing. I went to the POTA website on my phone and added my activation.

The memory keyer was used for a third time, I noticed a message pop up on my logging app, the Reverse Beacon Network spotted me. It wasn’t too long after, the first call came back to me!

I was nervous and fumbled a bit here and there but once I took my time I was fine, sending their call back and TU UR 599 599 NH BK. I cheated a little and left the CW decoder enabled. I wanted to be sure I had the call correct as I logged my 13 QSO’s. (I swear the 13 wasn’t intentional.) for my first CW park activation! I only realized that it was Halloween while walking back to my truck.

I thought to myself, “that wasn’t scary at all.”

Once I decided that, as an activator I’m in charge of the QSO, I relaxed and it was a lot of fun. I may have made a few mistakes but everyone was patient with me. I later received an email from another Ham in Delaware. He was using the same radio, and referred to them as the perfect “picnic portable radio” we emailed back and forth a few times and I look forward to hearing him on the air again soon.

 

The week before, I finished building my second QCX Mini. The first kit I built was for the 30 meter band around this time last year, this second one is a 20 meter version. I love these little radios, there’s something about these little transceivers that I just can’t seem to put them down.

I took my time making sure it was working properly, I hooked it up in my shack and I had my first QSO with another POTO activator in Maryland just over 400 miles away.  To say I was excited is an understatement!

I planned on putting together a kit about a month ago for POTA and eventually SOTA with the QCX Mini as the radio. I decided on using a small pack, I wanted it to be a self contained kit that had everything I needed to do an activation and nothing extra.

I keep the wire and radios together,  and depending what band I choose to operate on is the one I pack. I’m considering a third kit; maybe a 10m version? I threw the EFHW matching transformer in the bag along with a notebook, mechanical pencil and a battery pack I put together using four 3.2v LifePo batteries. The paddle I’m currently using is a stainless paddle I found on online with a mini CW paddle for backup and set of folding headphones.

I’m looking forward to my next park, this was a great experience. I wanted to learn CW since I became a Ham in 2016, that’s another story of what got me into Ham Radio in the first place.

Leo’s complete QCX-mini field kit and ZM-4 manual tuner kit

Many thanks to Leo (DL2COM) who recently reached out after watching my livestream with Josh at HRCC on the topic of QRP/CW portable. 

Leo shared some photos of a complete radio kit he built around the QCX-mini along with a ZM-4 ATU kit he also recently built. Leo has kindly agreed to share these on QRPer.com.

Leo notes:

Attached is a photo of my ultra light kit.

It consists of a QCX-Mini 20m version (self-built), K6ARK EFHW, Palm Radio Pico Paddle, Eremit 2Ah LiFePo battery, headphones and a few cables.

I usually also carry a small arborist kit and if there is still room also the 6m mast from Sotabeams, depending on what I think will work best.

I chose a hard case and went for the Peli 1060 Micro. It has room for everything I need and it could easily hold a bit of RG316 coax in addition (even more if I chose to shorten the 30m arborist line).

The main benefit for me is that I really don’t have to worry at all about what’s inside – compared to a soft pouch. So I can just shove it into my backpack or glove box and forget about it since this configuration is a lot more rugged and water proof – while being slightly heavier. Continue reading Leo’s complete QCX-mini field kit and ZM-4 manual tuner kit

SOTA & POTA with the QRP Labs QCX-Mini and Packtenna EFHW on Flat Top Mountain

When I head out the door to activate a summit, if it involves a long hike, I reach for one of my super compact QRP transceivers like the Mountain Topper MTR-3B, Elecraft KX1, or KX2. If you’re carrying your entire station and all of your hiking provisions in your backpack, it’s best to keep the load as light and compact as possible.

I purchased the single-band QRP Labs QCX-Mini last year specifically with Summits On The Air (SOTA) in mind. My QCX-Mini is built for 20 meters which tends to be my most productive SOTA band.

The QCX Mini has a rugged, utilitarian feel: basic controls, two line backlit LCD display, and a sturdy aluminum enclosure. It’s super compact.

One of the first things I did was build a dedicated field kit around the QCX-Mini. Everything–save my throw line–fits in my Spec-Ops Op Orders pouch:

After the QCX-Mini’s insane debut on Mount Mitchell in November, I was eager to hit the field with it again.

A window of opportunity opened on the morning of Thursday, December 9, 2021, so I packed my new Spec-Ops EDC backpack with the QCX-Mini kit and drove 1.5 hours to Flat Top Mountain off of the Blue Ridge Parkway near Blowing Rock, North Carolina. Continue reading SOTA & POTA with the QRP Labs QCX-Mini and Packtenna EFHW on Flat Top Mountain

My QCX-Mini Field Kit

So I just finished putting together a dedicated, compact field kit for the QCX-Mini. I’m planning to do a SOTA activation tomorrow, if the stars align. Hopefully, they’ll align!

Everything in the photo above, save the throw line bag, fits in my Spec-Ops Brand Op Order Pouch.

QCX-Mini Field Kit Contents:

One of the newest products in this kit is my high viz 2mm x 50M Marlow throw line. I learned about this throw line from Mike (W4MAF)–thank you, Mike! It is much less bulky than standard poly throw line and fits in my Tom Bihn small travel tray. We’ll see how well it works tomorrow. First impressions from having used it at the QTH once was very positive.

Again, with any luck I’ll have this kit in the field tomorrow on a summit. If you’ve nothing better to do, look for me on the SOTA Watch spots page!

SOTA Report: New QCX-Mini, new Packtenna EFHW, and pileup insanity on Mount Mitchell

Do you know what it’s like when you have a new radio and you can’t wait to take it to the field?

Yeah, me too!

Even before I received my QCX-Mini in October 2021, I already knew where I’d take this pocket-sized, single-band QRP CW transceiver for its first field activation: Mount Mitchell (W4C/CM-001).

Mitchell is the highest summit east of the Mississippi river and only about 6 miles from my QTH as the crow flies.  I had yet to activate Mitchell this year for SOTA although I have activated it for POTA/WWFF several times. As I’ve probably mentioned in the past, Mount Mitchell park is my “happy place.” Our family loves this site and we visit it frequently to hike in the spruce-fir forest.

On the morning of Wednesday, November 3, 2021, I realized I had enough room in my schedule to swing by Mount Mitchell for an activation, so I quickly assembled my SOTA pack around the QCX-Mini. Continue reading SOTA Report: New QCX-Mini, new Packtenna EFHW, and pileup insanity on Mount Mitchell

QCX-Mini: Quick Recap of Mount Mitchell activation

First of all, thank you to everyone who tried to hunt me this morning while I activated Mount Mitchell Summit and Park!

When I posted an announcement about the activation this morning, I didn’t expect much of a response due to the short notice. I don’t typically announce my activations, but the Mitchell SOTA activation was a special one for me because it’s my favorite NC park and also fairly local (well, as the crow flies from the QTH).

This was a “welcome back to winter conditions” SOTA activation and I knew it would be in advance.

The drive to the summit, starting around 1,000M ASL (3,000′) was in heavy, heavy fog. The ceiling was low and I thought perhaps the summit would peak through, but I was wrong. It was also foggy on the summit and about 33F (0.5C) per my car.

It was a gorgeous site though as the summit was covered in rime ice.

There were maybe two other visitor cars in the park–after all, most go to Mitchell for the views and there were none this morning.

I found a nice spot in the woods well within the activation zone, but not at the observation deck on the summit.

Pile-ups

I’m not sure if I called CQ more than twice with the QCX Mini before I was slammed with a steady pile up with many stations from Europe.

The QCX performed well and obviously the PackTenna 20M EFHW did as well, but the little amplified speaker connected to the QCX-Mini struggled with the variation in signals and tones. It sort of fell apart on me and after logging, perhaps, 30 stations, I switched out with the KX2.

If you chased me and I wasn’t able to copy you, my apologies. It was tough to hear signals via that little speaker–everything simply blended together.

I’ll be writing a full report in due time once I have the video uploaded in a couple weeks, but suffice it to say, 5 watts and a wire worked this morning. Here’s the QSO Map:

Click to enlarge.

The QSO map doesn’t include a number of stations on the west coast either.

A struggle for K4SWL

My hands were a wee bit stiff as they dealt with the cold/damp conditions, so my fist was (as I had predicted) rather sloppy. 🙂

I was also struggling to type in callsigns correctly into the HAMRS app on my phone and that certainly messed with my rhythm handling QSOs.

This was my first cold activation since March. I’ll get back into winter mode soon and toughen up again!

The little speaker, combined with so many contacts zero-beating me, turned into a 5-7 second long  steady tone in the pile-up.  I seriously contemplated running split to spread everyone apart, but I’ve never seen that done with POTA or SOTA so didn’t attempt it.

Seasoned SOTA CW activators would’ve certainly found the pile-up much more manageable.

When I went QRT, I happened to turn on my HT and had the SOTA simplex frequency locked in. Two second after turning on the HT I heard KN4LRO on Round Mountain (W4T/SU-029) and worked him S2S. My first VHF S2S!

The SOTA/POTA/WWFF activation was AMAZING fun, though. One of my favorite SOTA activations to date. Again, I made a video of the activation and will write up a proper field report within the next couple of weeks.

As I left the park, I found it odd that I was the only visitor there. As I approached the front gates (again, in heavy fog) I saw why: they had closed the park and were only allowing people to leave, not enter.

I felt pretty darn lucky to snag Mount Mitchell this morning.

I’ve said this before, but Mount Mitchell is truly my special, happy place.

Speaker suggestions?

In the meantime, I’d love your suggestions and links to proper, capable amplified portable speakers. I need something much better to pair with the QCX Mini, MTR3B, and KX1.