Category Archives: QRP Radios

Replies from the Ergonomics vs. Performance poll

Yesterday, I posed the following question and asked for your input:

“Which aspect of a QRP radio holds more importance for you: its ergonomics (ease of use, comfort, display, size, etc.) or its performance (receiver test data, dynamic range, etc.)?” 

Thank you to everyone who participated in my recent quickie poll, which has now closed. There were so many interesting points in the feedback. Here are the results from the 252 votes cast within a 20-hour window:

In essence, a slight majority preferred ergonomics, with 57.1% of respondents indicating it as more important, while 42.9% favored performance.

As I mentioned in my previous post, I’m well aware that this question paints with broad brush strokes. There’s not a give-and-take between the two: an investment in the user interface typically doesn’t mean performance is going to suffer. Indeed, I would say most of our modern transceivers sport decent ergonomics and decent performance.

If anything, the relationship between price and performance plays a proper tug of war. Even that’s nuanced, though!

I also received a number of comments and messages from readers who pointed out that my survey was flawed because it didn’t define what I meant by ergonomics and performance carefully enough. I agree that this wasn’t a carefully considered and properly worded poll.

That said, the way I wanted to present this was more like an informal raise of hands–something I often ask for during radio club presentations.

Selection of Comments

The comments from readers were excellent and what I would expect to hear from people who’d raised their hands in a club meeting.

Here are snippets from a few of them, (for all of the comments, click here):

From Scott (KK4Z):

A tricky question. I actually prefer a balance between ergonomics and performance. If you have a good performing radio with mediocre ergonomics, it might not be used to its full potential. A radio with good ergonomics and mediocre performance might be used to its full potential which may be above a good radio with poor ergonomics.

From Mark (NA4O):

My assumption is that performance would have to be good enough for the radio to be in the running. Likewise, ergonomics would have to be good enough for it to be considered usable.

From Nick (KC0MYW):

As I consider the radios that I have and have used and which ones I like better and why, I think that the performance of the radio can almost be considered an ergonomic characteristic with regard to how comfortable and easy the radio is to operate. While a radio with poor ergonomics is not a lot of fun to operate, a lower noise floor and smoother QSK can add as much to the enjoyment level as an easy to access RIT control.

From William (KR8L):

Difficult to say… Since my field operations are very casual affairs I suppose performance is a secondary consideration, although I don’t think I’d enjoy doing a POTA activation with my HW-8.

Ergonomics can be very important — for example, although my FT-817 performs well enough, the number of button pushes and knob twists required to change the keyer speed (or just about any other setting) can be very annoying.

The well thought out controls of my KX2 make it my favorite for field operating, but then it’s a good performer too.

From Brian (K3ES):

Tough question. I will say ergonomics, but what I really mean is easy access to the features I need. I don’t necessarily need contest grade performance, but I do rely on features like a tuner, cw speed adjustment, vfo, etc.

From Emily Clark:

I pick performance for a few reasons: I do contest QRP at times (most recently ARRL RTTY Roundup). I like the filtering, the clarity of the screen, the true FSK for RTTY, and the ability to put an IF spectrum out into N1MM+. I only have wire antennas, and with the AH-705 I virtually do entire contests on my 80m OCFD.

From Michael (N7CCD):

If taken to the extreme on both options, I think I would have to choose performance. I would rather operate a radio that can handle QRM (overloaded front end, etc.) with confusing menus, than the opposite. If not taken to the extreme, then I may choose ergonomics…

From Mark (W8EWH):

Ergonomics for me because I, like many, have many field portable radios and as I cycle between them I need to be able to use them without the need to consult a user manual or waste time fumbling around a menu system looking for a particular feature or setting.

From Shawn (WS0SWV):

Performance! As a retired design engineer, I learned that good design addresses the performance needs of the user(s) in an intuitive manner. If it is cumbersome or overly complex then users will tend to migrate away from it. Some communities have specific ergonomic requirements and for QRP field radios I would argue the primary ones are size, weight, current consumption there are others depending on mode of operation like keyer memories and narrow filters for CW but those are the big ones.

From Wlod (US7IGN):

Different people have different preferences and ideas about ergonomics and performance. It’s important to find a balance, or better yet, have different radios for different tasks.

From Andrew:

Ergonomics is nice, but without performance … it has no use, imagine a coffee mug; it may be hyperergonomical, but then it has a hole at the bottom…

From Dick (K7ULM):

Interesting question. It is interesting how the ergonomics of the KH1 over shadows the performance of the KX2 for some use cases. In some uses the KH1 is definitely the the choice due to its ergonomics. For other radios of its size it will be chosen because of performance and ergonomics. The specific use case is the controling factor IMHO. Performance slightly over ergonomics, generally for me, kind of?

My thoughts?

If there was one comment that reflected my thoughts most closely, it would be this one from John (AE5X):

There’s a lot of overlap between these two characteristics. Too little of one undoes the effectiveness of the other.

I find that most radios do have “good enough” performance (barring an outright flaw or deviation from legal requirements), therefore I pay attention to ergonomics more than to lab numbers of dynamic range and other electronic specs…if I need lab equipment to discern whether or not my radio’s performance is acceptable, it’s acceptable. I don’t like buried menus for commonly-used features.

John’s right. We’re lucky these days in that most of our modern QRP field radios have acceptable performance for our field activities like POTA, SOTA, IOTA, QRP Contests, and some even have the chops for the RF density of, say, Field Day.

If performance is acceptable, I tend to give more weight to ergonomics because it’s important to me that the radio be fun to use.

What makes this show of hands a hot mess, when we look at it under the microscope, is the fact that both ergonomics and performance are nuanced. Herein lies the challenge I find in writing radio reviews: I believe it’s important to explore those nuances so that the review can inform a potential buyer (who might not share my same point of view) in a meaningful way. Sometimes it’s difficult to do that within a print publication’s word count.

Closing thoughts…

As we often say, there is no “perfect” radio that will please everyone, so I think it’s important before we make a purchase decision that we’re realistic with ourselves and understand what we actually value.

Here’s one real-life example–outside the world of QRP transceivers–I’ll share from a friend who, sadly, is now Silent Key. Since I can’t ask for his permission, I won’t mention his name.

Back in 2010, he came to me for advice on buying an SDR (Software Defined Radio)–a PC-connected black box receiver.

Even though not that long ago, keep in mind this was still during the infancy of modern, high-performance, SDRs and most of the options were going to set you back $1,000 or much more. In other words, a substantial investment.

This friend was an avid SWL DXer and was considering an SDR that, at the time, had a slight performance edge over popular SDR models from manufacturers like Microtelecom, RF Space, and WinRadio. I’m not going to call out this SDR by name either, but I’m sure some of you can guess which one I’m referencing.

This particular SDR had fabulous receiver characteristics on paper, but it was well known that the proprietary PC application that controlled it was a bit of a nightmare to use.

My friend purchased it. I tried to help him set this SDR up and learn how to use some of the basic functions and features, but we both found it a struggle. The GUI (graphic user interface), one could tell, was likely designed by the hardware engineer, not someone with experience creating usable software applications, also, unlikely someone who was a DXer or SWL.

He ended up selling this SDR after having owned it for less than a month. He agreed that the performance was brilliant, but hated using the app that controlled it. In the end, he purchased the venerable Microtelecom Perseus and absolutely loved it.

Rob’s advice

This topic of our personal preferences is such a deep one; I think I might put together a club presentation, exploring some of the nuances.

Speaking of presentations, if you’ve never seen Rob Sherwood’s excellent presentation exploring transceiver performance, I highly recommend you check this one out. Rob will be the first to tell you that modern transceivers tend to perform so well that the operator should give weight to ergonomics and usability.

Also, consider listening to this episode of the Ham Radio Workbench podcast when Rob was the guest.

Cast Your Vote: Ergonomics vs. Performance – What Matters Most in a QRP Field Radio?

I’m in the midst of writing several radio reviews, and this process always brings up a few inherent dichotomies.

For example—and the point of this quickie poll—some operators seek, first and foremost, a radio with brilliant performance specs. This is especially the case when we’re talking about contest-grade, pricey transceivers. Dynamic range, sensitivity, filtering, and blocking? Yeah, those are looked at very carefully by contesters and DXers.

On the other hand, for some, a radio’s performance is less important than how enjoyable the radio is to actually operate. Are the ergonomics well thought through so that common tasks are easy to perform? Is the display easy to read? Is the encoder weighted correctly? Is the radio compact but useable, etc.?

Even though field radios are typically not thought of as “contest-grade,” many of them have superb contest chops and receivers that can handle RF-dense environments with ease (I’m thinking about my KX3 with roofing filter here).

However, some radios might lack precision filtering and a contest-grade receiver architecture but are designed with field use in mind interface-wise. The Elecraft KX1 and Penntek TR-45L come to mind, although there are many more. Both have great receivers, actually, but the designers obviously placed an emphasis on user a user interface that is field-friendly. I find both such a pleasure to use.

What’s your opinion?

I recognize fully that I’m painting with broad brush strokes here—there are so many other variables in evaluating a radio. I’m sure most of us want a good balance of both performance and ergonomics.

But if pressed for an answer, where do you fall? What do you give higher priority: performance or ergonomics?

If you’d like to cast your vote, please consider participating in the poll below:

A Slimmed-Down Solution: My first POTA activation with the Penntek TR-45L “Skinny”

You might recall a recent POTA activation where Jonathan (KM4CFT) joined me at the Vance Birthplace K-6856 US-6856–?

Jonathan used my Penntek TR-45L for his portion of the activation, and I was pleased he got to spend some time with this magnificent CW machine. You might also recall that it still had a buzz in the speaker audio–something inside the radio was vibrating.

KM4CFT working the TR-45L in late December 2023.

I tried to track down the buzz as Jonathan operated by tightening some of the screws holding on the speaker grill (yeah, I’m sure that was annoying, and he’ll think again before activating with me in the same space–!). I knew, though, it was something inside the chassis that was vibrating with audio.

As I also mentioned, my TR-45L was a prototype unit (I helped Beta test it)–it had a couple of mods and wasn’t exactly representative of the upgraded production model.

John (WA3RNC) at Penntek reached out to me after I published my recent field report and video; he offered to upgrade my TR-45L to the production chassis which would sort out the buzz. I was most grateful, of course!

He then asked if I would be interested in checking out the TR-45L “Skinny,” which is essentially a TR-45L in a much skinnier chassis. The Skinny model lacks the ATU and battery options but is lighter weight and more portable. I mentioned to John that I’d like to purchase one, actually. Since John was interested in sponsoring QRPer, we ended up working out a barter (at full market price) for ad space. I love this arrangement, actually, because I was going to approach him about sponsorship at some point anyway.

The Skinny!

Now keep in mind that the TR-45L is one of my favorite CW radios. I love the audio, the receiver characteristics, and the “Apollo era” aesthetic. I think it’s one of the best-looking and best-sounding radios on the market.

The Skinny is just like the bigger TR-45L, just roughly half the depth. I did have concerns that the audio wouldn’t be as good since the acoustic chamber would be smaller, but turns out, I had nothing to fear. The Skinny’s audio is on par with its bulkier sibling.

There was no learning curve with the Skinny because 1.) it’s identical in operation to my TR-45L and 2.) Penntek radios have super simple interfaces, and almost every function has a top-level direct control.

Zebulon Vance Birthplace (US-6856)

On Tuesday, February 27, 2024–the day after receiving the TR-45L Skinny–I packed it up and took it to the Vance Birthplace for its inaugural POTA activation!

That day, I had about 90 minutes to enjoy an activation, and I was looking forward to spending time with the new Skinny.

Vance was a great choice that day because the weather was moody; it was gusty, rainy, and I knew their picnic shelter would provide excellent cover.

The Skinny (in its padded bag), the MC-750 and my ABR cable assembly.

The TR-45L Skinny, unlike my original TR-45L, has no internal Z-Match ATU, nor does it have an internal battery. In fact, there’s no room for either in the Skinny, so it’s not even an option.

I paired the Skinny with my Chelegance MC-750, which is a resonant antenna when deployed correctly, so there was no need for a matching device. I supplied power via one of my 3Ah Bioenno LiFePO4 batteries.

Setup was simple and easy!

Gear:

Note: All Amazon, CW Morse, ABR, Chelegance, eBay, and Radioddity links are affiliate links that support QRPer.com at no cost to you.

On The Air

I hopped on the air with the intention of working 20 and 17 meters. Continue reading A Slimmed-Down Solution: My first POTA activation with the Penntek TR-45L “Skinny”

The Index Labs QRP Plus: Any fans out there?

I recently acquired an Index Labs QRP Plus transceiver (more on that in a future post!).

This little rig was produced in the mid to late nineties and, to my knowledge, was one of the first 160-10 meter, field-portable, general coverage QRP transceivers on the market. The only other one I can think of was the Ten-Tec Argonaut II, but please correct me if I’m wrong on this point.

QST ad from 1995 courtesy of WD8RIF.

I’m just curious if anyone here ever owned one and what they thought of it? Please comment!

Field Radio Kit Gallery: W4JL’s Venus SW-3B and “Sporty Forty” Vertical

Many thanks to Dave (W4JL) who shares the following article about his portable field radio kit which will be featured on our Field Kit Gallery page. If you would like to share your field kit with the QRPer community, read this post Continue reading Field Radio Kit Gallery: W4JL’s Venus SW-3B and “Sporty Forty” Vertical

Pedestrian Mobile POTA Hunting: Pairing the KH1 and N6ARA’s Tiny Paddle Plug

On Sunday, March 3, 2024, I had a couple of errands to run in downtown Asheville and also had to pick up my daughter.

I ended up having about 40 minutes to kill and, since I had my Elecraft KH1 field kit packed in my EDC bag, I thought it might be fun to fit in a little radio time.

Since I was downtown, the only viable POTA site to hit would be the Thomas Wolfe Memorial–you might recall my activation there last year–but technically, the park was closed. It is an urban park in the middle of Asheville, and there are no gates to keep people from walking across the grounds, but still, I’d feel better activating with permission from the staff first. (I’m pretty sure they’ll grant that permission, by the way.)

Instead of activating, I decided to do a little POTA hunting.

I parked at the spot where I planned to meet my daughter and grabbed my KH1 field kit.

Upon opening it up, I remembered that I had put N6ARA’s new KH1 TinyPaddle Plug Adapter in the M40 case!

My good friend, Ara (N6ARA), designed a small 3D-printed adapter that allows his TinyPaddle Plug to fit the KH1 securely. He sent me (free of charge) this new key/adapter to evaluate.

The adapter is a super simple design that works with the TinyPaddle Plug (not the TinyPaddle Jack).

I hadn’t used this new adapter in the field yet–I only very briefly tested it at the QTH a couple of days prior.

I mentioned last year, shortly after the KH1 was introduced, that I expected a number of 3rd party paddles to start appearing on the market. Since the interface with the KH1 is a standard 3.5mm plug, it does open the door to 3D-printed designs and experimentation. Admittedly, it’s a small space to fit in a paddle, but it’s doable.

I believe N6ARA was actually the first non-Elecraft paddle I used on my KH1 because his TinyPaddle Plug will fit it natively. That said, the new KH1 adapter makes it a proper secure fit–the way it should be!

Side Note: The OEM Elecraft KH1 paddles (the KHPD1s) are now in Revision 2, and all KH1 owners (who received the original paddles) will get version 2 paddles eventually via Elecraft for free.

The original KH1 paddles have a green circuit board.

I haven’t received my Rev 2 paddles yet, but I know I will before long. It’s my understanding that the Rev 2 paddles have a much better feel, and keying is more accurate.

Still…it’s brilliant that Elecraft used a standard jack so that we hams can design our own paddles if we like.

The TinyPaddle Plug

Ara’s TinyPaddle design is super simple, and while he originally designed the TinyPaddle to be a back-up option, I know a number of hams who use the TinyPaddle as their main field key.

If you’d like to hear more about the TinyPaddle and Ara (N6ARA), I’d encourage you to listen to this recent episode of the Ham Radio Workbench podcast when he was our guest. He’s such a brilliant fellow.

Park Lot Pedestrian Mobile

Again, I can’t stress how cool it is to have a radio that allows you the flexibility to hit the air pretty much anywhere, anytime.

The KH1 is so quick to deploy, low-impact, and low-profile.

It’s as conspicuous as holding a transistor radio with a telescoping whip. So far (it’s still early days, let’s be honest here) no one has seen me with the KH1 and asked me if I’m a spy. I can’t count the number of times I’ve been asked this over the years of POTA activating!

POTA Hunting vs. Activating

Even though both activities–hunting and activating–are a part of the same program, they are very different animals. Continue reading Pedestrian Mobile POTA Hunting: Pairing the KH1 and N6ARA’s Tiny Paddle Plug

Elecraft KH1 Tabletop Mode: The new KHRA1 Right-Angle Adapter makes for a super-portable POTA machine!

It’s funny how sometimes one small accessory can have a huge impact on a field radio kit.

When I first learned about the Elecraft KH1 (basically, the day I was invited to join the volunteer testing group), I felt like Elecraft had designed my ideal QRP radio. The KH1 is super compact, weighs 13 oz completely loaded, covers my favorite bands, and has features I would expect in much pricier radios. It reminded me of my beloved KX1, but even more portable with more features.

The KH1 caters to handheld or pedestrian mobile operating–at least, that was the overarching design objective. It accomplishes this amazingly well. It’s so easy to operate handheld, and there’s nothing else quite like it on the market. I suspect that when others copy the design (I’m sure they’re already doing so–!) it won’t be as versatile, functional, and lightweight.

At the end of the day, though, I feel like I’m only using the KH1 pedestrian mobile about 30% of the time I have it on the air. Of that 30%, I’d say that only 10% of the time I’m pedestrian mobile while activating, and 20% of the time I’m doing little impromptu radio sessions in parking lots, ballparks, while visiting family, and even on my own mountain property.

While handheld operating is simply a game-changer, I knew I wouldn’t do this 100% of the time with the KH1. It’s for this reason that my very first bit of proper KH1 feedback to Elecraft, well before I had my hands on a prototype, was that a right-angle adapter for the whip antenna would truly round out the KH1’s field prowess.

This would basically give my KH1 the same functionality of my beloved KX2 and AX1 antenna combo, but in an even more portable package.

Turned out, Elecraft already had a right-angle adapter on the design board!

Fast-forward to present day…

Last week, Elecraft sent me a prototype of the right-angle adapter to test and evaluate. They’ve given it the model number KHRA1.

Full disclosure: Elecraft also gave me permission to post a video and article about this new accessory even though (at time of publishing) it’s not even showing up on their website. I will, however, link to it here as soon as Elecraft makes it available. This is an item I would otherwise have tested in private–thanks, Elecraft!

The KHRA1: Small accessory, big impact!

Illustration Source: Elecraft KHRA1 Instruction Manual

The KHRA1 is a simple adapter. Other than metal attachment hardware, most of it is lightweight and 3D-printed from a durable material (I assume the same material they use in the KH1).

Attaching it to the KH1 is very easy.

First, you unthread the large metal thumb nut from the KHRA1. You will need to hold together the remaining KHRA1 components (legs and attachment bracket) so that they don’t come apart before you attach them to the KH1. This is actually pretty easy to do, but users should know to follow the KHRA1 instruction sheet. If these parts fall apart in the field, it might require a bit of searching the ground for the pieces.

You simply thread the large thumb nut onto the KH1’s whip antenna antenna port, then thread the rest of the KHRA1 bracket/legs onto the large thumb nut.

Check out Elecraft’s illustration:

I then position the KHRA1 legs as shown above, then tighten the KHRA1 adapter so that everything is secure.

It’s super simple to do, and you can see this process in my activation video below.

Speaking of an activation…

On Saturday, March 2, 2024, (yes, only two days ago) I had my first small window of opportunity to squeeze in a POTA activation and test the KHRA1.

That day, my daughters and I had a number of errands to run, then a three-hour round-trip drive to pick up my wife. We were on a very tight schedule, but I had a 30-ish minute window of opportunity to fit in some POTA radio therapy.

I set my sights on the easiest-for-me-to-hit POTA site on the Blue Ridge Parkway: the Folk Art Center.

Amazingly, I discovered that morning, that the KHRA1 fits in my Pelican M40 Micro case along with my KH1, whip, counterpoise, key, spare N6ARA key, and earphones.

With the KHRA1, this means my M40 field kit can do both pedestrian mobile and tabletop operating. Woo hoo!

The weather that morning was simply glorious. A very wet front swept through the previous day leaving behind clear skies and warm temps. Frankly, it was a bit odd activating without wearing a jacket or hoodie.

Gear:

Note: All Amazon, CW Morse, ABR, Chelegance, eBay, and Radioddity links are affiliate links that support QRPer.com at no cost to you.

On The Air

Setting up was quick and easy, even though this was my first time using the KHRA1 in the field.

I hopped on the air and started calling CQ. Once spotted (for some reason the RBN auto-spotting feature wasn’t working again), the contacts started flowing in.

I worked a total of 18 contacts in 16 minutes. It hardly gets better than that for a CW activation!

I had to call QRT after my 18th contact. Even though I had a 30-minute window to POTA, nearly 14 minutes of that was taken up with my intro and summary for the activation video.

I called QRT with a small pileup still in place. I really hate doing that, but I had a schedule to keep!

QSO Map

Here’s what this five-watt activation with a 4′ telescoping whip antenna looked like when plotted out on a QSO Map:

Activation Video

Here’s my real-time, real-life video of the entire activation.  As with all of my videos, I don’t edit out any parts of the on-air activation time. In addition, I have monetization turned off on YouTube, although that doesn’t stop them from inserting ads before and after my videos.

Note that Patreon supporters can watch and even download this video 100% ad-free through Vimeo on my Patreon page:

Click here to view on YouTube.

A super-portable, low-impact POTA machine!

The KH1 works amazingly well as a tabletop radio when combined with the KHRA1 adapter.

At the end of the day, the KHRA1 is a very simple piece of hardware, but it effectively transforms the KH1 from a handheld radio to a tabletop.

Of course, I’ve used the KH1 numerous times with wire antennas in a tabletop configuration (I’m a massive fan of wire antennas) but the ability to use the 4′ whip antenna and internal KH1 loading coils means that I can operate anywhere I have a surface.

As I mentioned in a previous post, in some cases, low-impact, and low-profile are key to positive park relations.

Herein lies the thing I love about my KX2/AX1 pairing as well. It’s just with the KHRA1, the KH1 makes for an even smaller, lighter-weight field kit.

Any negatives? The only one I’ve come up with is that the KH1 is so lightweight that I realize I need to carry a small piece of shelf liner (something like this) to provide the KH1 with a bit more grip on a slick park table, especially those composite ones.

Again, I will update this post when Elecraft announces KHRA1 pricing and availability.

Thank you

I still can’t believe the entire kit fits in this small case. Even when I put the KHRA1 thumb screw on backwards!

Thank you for joining me on this quick little tabletop activation!

I hope you enjoyed the field report and my activation video as much as I enjoyed creating them!

Of course, I’d also like to send a special thanks to those of you who have been supporting the site and channel through Patreon, and the Coffee Fund. While certainly not a requirement as my content will always be free, I really appreciate the support.

As I mentioned before, the Patreon platform connected to Vimeo make it possible for me to share videos that are not only 100% ad-free, but also downloadable for offline viewing. The Vimeo account also serves as a third backup for my video files.

Thanks for spending part of your day with me!

Have an amazing week ahead and play some radio!

Cheers & 72,

Thomas (K4SWL)

QMX – From Kit to Field!

by Matt (W6CSN)

The Radio

The QMX by QRP Labs is a five band, multi-mode radio introduced by Hans Summers G0UPL at FDIM in 2023. The QMX is the next logical step in the radio development journey at QRP Labs, bringing together the innovative approach to FSK modes like FT8 from the QDX and the CW performance of the QCX series. This is all done in same enclosure as the QCX-Mini which is not much larger than a deck of playing cards.

Size of the QMX compared to standard deck of playing cards.
The QMX is about the size of a deck of cards.

The keen observer will notice that the QMX also sports a built-in microphone which, along with associated circuitry, supports future introduction of voice modes by way of firmware update. Other notable features include SWR metering with protection as well as solid-state “PIN” diode T/R switching, plus the option for “high band” coverage of 20 through 10 meters in addition to the original 80m-20m version.

Most hams have, at one point or other, forgotten to throw the antenna switch, adjust the tuner, or even connect an antenna before transmitting. The SWR meter and protection really sets the QMX apart from earlier QRP Labs radios. There are plenty of sad tales on the QRP-Labs forums from QCX or QDX users that “smoked” the BS170 mosfet finals in a moment of operating into a badly mismatched load. It’s remarkably easy to do, ask me how I know!

The Build

Based on experience with the QCX-Mini and having put together several QDX’s, I admit to being hesitant to starting assembly of this radio. The level of integration in the QMX as a multi-band, multi-mode unit is probably the highest yet to come out of QRP Labs. The components that were merely small in earlier radios are absolutely tiny in the QMX, specifically the LPF toroidal cores. The main board, internal switching power supplies, display, and controls board are all sandwiched together in a tight fit for the custom enclosure.

photo showing a partially completed circuit board
Most of the electronic components installed on the main board.

The build started with a slow and methodical approach of doing a little bit each day and working in the morning when my mind was fresh and there was good light on my workbench, a.k.a. the dining room table.

The first “disaster” happened when performing the factory recommended modification to Revision 2 boards shipped in 2023. The mod calls for a protection diode to be installed across a SMD mosfet. Several leaded 1N4148 diodes were available in my “junque” box so I attempted to carefully fit one of these in the right position on the board. While soldering the diode in place I managed to lift C508, a microscopic .1uF SMD capacitor, clean off the board!

photo of circuit board with modifications
The suggested modification adding a protection diode.

Given the tools at my disposal, there was no way I was going to be able to get that capacitor back into place. Therefore, I grabbed a standard through hole .1uF cap and painstakingly got it connected in the right place, verified by lots of continuity testing.

Once finished with all the electronic components on the main board, I was feeling pretty cocky and also the completion of the project was more clearly in view. The cautious and methodical approach gave way to a faster build pace, which directly lead to the second “disaster.” While installing the headers that connect the main board to the display board, I failed to CAREFULLY READ THE ASSEMBLY MANUAL and soldered the male pin headers where I should have installed the female sockets!

This misstep might have ended the project right then and there if I had not at some point in the last year bought a proper desoldering tool. This is not an expensive automatic vacuum pump powered solder re-work stations, but rather a heating tip and manually actuated solder sucker built into one tool. Twenty-two unsoldered connections later, we were back on track. Continue reading QMX – From Kit to Field!

Field Radio Kit Gallery: K4ZSR’s Xiegu X6100 Field Kit

Many thanks to Zach (K4ZSR) who shares the following article about his portable field radio kit which will be featured on our Field Kit Gallery page. If you would like to share your field kit with the QRPer community, read this post


K4ZSR’s Xiegu X6100 Field Kit

by Zach (K4ZSR)

My primary portable radio station is based around the Xiegu X6100. This was the first HF transceiver I bought after getting my ticket, and I have taken it on well over 100 POTA and SOTA activations across ten countries. Over time, I have learned what does and does not work for me and my operating style, and my field kit now has exactly what I need.

I have used several different packs to hold my portable radio gear, but my current favorite is this Quechua NH Escape 500 from Decathlon (I bought mine in Romania, but you can order them online). While designed as a laptop bag, this pack has all the features I need to carry for radio gear: full-opening main compartment, padded laptop/tablet sleeve, waist belt, good internal organization, and extra room. My field kit always stays in this bag, unless I am going on a long hike or camping.

The heart of this field kit is a fully self-contained station in a semi-hard side case (meant for a portable projector). As long you have a tree or other antenna support, everything you need is in this case. I always have more equipment with me, but this is the bare minimum. Two modifications I made to make the kit smaller was replacing the stock mic coil cable with an ultra-slim CAT 6 cable, and making a 6-inch power cable.

Gear

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  1. LTGEM Hard Case
  2. SP4 POTA/SOTA Paddles
  3. Xiegu X6100
  4. Panasonic Earbuds and Moleskine Cahier notebook
  5. K6ARK 20w EFRW Antenna (laser-cut winder, 26g PTFE wire)
  6. GPS/GLONASS Receiver and USB cables for digital modes
  7. Bioenno 3Ah Battery
  8. “QRP” sized Weaver 8oz bullet throw weight with braided fishing line
  9. 10ft RG-316 Feedline

Since I do no always have a tree handy, and you should never be without at least two antennas, I always have a mast and an antenna accessory pouch with me as well.

Gear

  1. DIY spike base, tent stakes, and guy lines for mast
  2. K4ZSR 20m EFHW “Credit Card” antenna
  3. SOTABeams Carbon-6 Mast
  4. Solognac medium organizer pouch – purchased in Europe
  5. Miscellaneous antenna gear (compass, wire ties, extra stake, bungee cord, carabiners, etc)
  6. 80m extension for 6-band EFHW
  7. K4ZSR 6-band EFHW (40-10m, with 30 & 17m links)

Adding my Microsoft Surface Go 2 tablet for logging and running WSTJ modes, and my field kit comes in at just over 9 lbs (ignore the scale, the tablet case was empty in this picture).

If I am going to be operating in an accessible and open area, I may bring my vertical whip antenna system. This is one of my newest additions, I assembled this antenna over Christmas 2023. I wanted a ground mount system for a 17 ft whip antenna, but I needed it to pack down relatively flat to be able to carry easily in a back pack. My solution was a modular base designed like a pedestal mount used for soccer flags. Even in somewhat soft ground, this base is incredibly stable despite the small size of the ground spike.

Gear

  1. Wolf River Coils 17’ SS whip
  2. 25ft RG-8X coax
  3. Tent Stakes
  4. Wolf River Coils Sporty 40 coil
  5. Faraday cloth
  6. K4ZSR ground spike vertical antenna mount

Assembled, the mount is inserted into the ground until the disk makes firm contact. The spike and the 3/8-24 mount are removable for packing, and the aluminum boss has 4mm holes for inserting banana plugs to ground the faraday cloth, or to attach ground radials.

Here is the antenna system assembled and in use at K-2949, Harpeth River State Park.

My true passion for amateur radio is portable operations, and as I add to my collection my field kits will grow and evolve. The most important lesson I have learned operating portable is to have simple, durable kit that you are very familiar with. That way when the situation is different than expected, or conditions change, you are prepared to adapt and overcome.

73, de K4ZSR

Field Radio Kit Gallery: N7KOM’s Pocket HF Go Kit

I couldn’t believe my eyes when I saw it or held it – just how small this kit is. Tim (N7KOM) and I met up in December 2023 when I was on a trip in the Pacific Northwest and he and I stopped for a lunchtime activation.

Tim’s ENTIRE kit for mountain-top activating less his mast and the 9V battery seen in the background. It’s a stark comparison to my KX3 Go-Kit.

His kit is super light and small. I’ll let Tim take up the description from here:


A Pocket HF Go Kit.

by Tim (N7KOM)

There are few pleasures in life more satisfying than making QSOs on a thin wire tuned for a half wave.

One of my favorite radios is the classic MTR3B. At 9.8cm x 6.5cm x 2.4cm it is truly a pocket radio. Everything I need to get on the air fits into an Amazon external Harddrive case. Here’s a breakdown with weight measurements:

  • MTR-3B – 126 g
  • 9V Li-Poly USB-C rechargeable battery + power plug – 29 g
  • K6ARK 3D printed paddle and 3.5mm cable – 22 g
  • Earbuds + external volume control knob – 26 g
  • Trapped EFHW on an RCA connector (matching the radio’s connector) tuned for 20m/30m/40m. 28-32 ga wire on a 3d printed winder. – 42 g
N7KOM’s ultra-lightweight HF Kit

As is, it weighs a total of 323 grams or 0.7 lbs. Add in a lightweight 9 foot mast from ali-express and I have everything I need to make contacts. I could even string the wire on some bushes or the ground if I was really in a pinch.

Other notes

I could reduce the weight and packability further by using shorter cables on the earbuds/volume control as well as the paddle cable.

The antenna winder is a K6ARK 3D printed winder printed at around 70% size.

A 41 g external speaker may also be added to the kit, but it does not fit in the HDD case and must be carried separately.

Here is a video tour of the kit on YouTube:


So there you have it folks -323g of portable HF kit everything included! Check out Tim’s YouTube page or his Microlight QRP Traps on Etsy for your next QRP outing.

Tim’s field kit is now featured on our Field Kit Gallery page. If you would like to share your field kit with the QRPer community, read this post

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