Category Archives: Portable

Morse Code, New Products, News, Portable, QRP, QRP Radios, Reviews

The (tr)uSDX QRP transceiver: My initial impressions after a CW POTA activation

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I mentioned in a previous post that I placed an order for a (tr)uSDX kit with roWaves in February. My order was placed for a third production run kit and I assumed I would receive it sometime in March 2022.

Later that month, I discovered that DL2MAN announced AliExpress would sell both kits and fully-assembled versions of the (tr)uSDX. I used the link from DL2MAN’s website and ordered a fully-assembled unit.

My thinking was that I would receive the kit first, build it, then test the performance by comparing it with the factory-assembled unit. These units are so dang affordable I felt like I could splurge for both.

roWaves order on hold

I recently discovered that my (tr)uSDX kit had been placed on hold due to issues that popped up in the first and second kit group buys via roWaves.

Evidently–and someone can correct me if I’m wrong here–the first and second production runs kits had a component issue that equated to lower output power. In addition, Josh (KI6NAZ), reports that the early group orders had no boot loaded and the MCU was DOA.

I’ll patiently wait for roWaves to sort this out. I’m not in a huge hurry at this point because, frankly, my available time to build a kit has come and gone. The next few months, I’ve a lot of plans, travels, and projects to work through.

Fully-assembled (tr)uSDX

Much to my surprise, the assembled (tr)uSDX arrived Monday and I picked it up when I was at home on Tuesday of this week.

I was only home one night, but managed to do some quick testing.

I soldered Anderson Powerpole connectors on the supplied power cable pigtails. Next, I hooked the (tr)uSDX up to my variable power supply and a dummy load.

A quick test showed that I was getting about 3 watts of output power with about 13-13.2 volts, 3.25 watts at 13.8 volts, and 2 watts of power with 9-10 volts. This is lower than the expected 5 watts of output power @ 13.8 volts. The current consumption in receive however was about 60 mA even at 9 volts. That’s slightly below the published specs.

I honestly had no time that evening to play radio, but I took a moment to hook up the (tr)uSDX to my skyloop antenna just to check the audio quality in SSB.

As luck would have it, the first station I heard on 40 meters was a POTA activator in Ohio. He was calling CQ, so I couldn’t help but reply. I pressed the PTT button on the (tr)uSDX, spoke into the internal mic,  and he came back immediately with a 5×8 report. My meter was showing a max of 2 watts output power–the heavy lifting, of course, was done by the antenna.

This gave me a very good initial impression!

(tr)uSDX POTA Activation

The following morning, after running a few errands and carting my kids to some appointments, I left the QTH for a couple nights of travel.

I just couldn’t help but pack the (tr)uSDX and attempt a park activation en route. My goal was to see if it had enough positive receiver characteristics to be a proper POTA/SOTA portable rig–the feature set is comprehensive for a $135 radio.

I stopped by South Mountains State Park and paired the (tr)uSDX to an EFHW my buddy Steve (MW0SAW) kindly built and sent me. [Steve–I’m loving this antenna! Thanks again, OM!]

I made a video of the entire activation and will soon post the field report. I’ll push this video to the front of the line, but with my internet bandwidth, it might still be a few days before I can post it. Because of this, I thought I’d go ahead and share some of my experience with the (tr)uSDX in case you’ve been thinking of purchasing one.

(tr)uSDX pros

This little radio design has a lot going for it.

The chassis is very compact–perhaps the size of two Altoids tins stacked on top of each other. The encoder does protrude–in fact, it’s nearly as deep as the radio chassis. It’s not that the encoder is particularly tall, it’s just that the (tr)uSDX is so wee.

The radio has all of the CW adjustments you’d typically find in a compact field transceiver and even sports QSK (there’s also a semi QSK setting) with no relay noise. I assume it uses PIN diode switching.

(tr)uSDX Cons

Unfortunately, I did find a few negatives. The reviewer in me automatically gives the (tr)uSDX wide berth and a lot of forgiveness: we’re talking about a $135 transceiver here. I don’t think anyone is under the impression this would be a stellar performer.

In my opinion, the biggest negative is the (tr)uSDX audio. This little rig has a very high noise floor–perhaps S5 or S6.

The internal speaker is very modest and mine is incapable of producing audio at a level that is workable in the field where there are ambient noises like wind, water, conversations, birds, etc. The audio sounds decent when working a strong station, but weak stations are extremely hard to hear. If you turn up the volume on my unit beyond level 14, the audio simply squeals. I need to tinker with the volume control more.

Since the audio was so weak, I hooked up my Sony digital audio recorder to the (tr)uSDX headphone jack and made a separate audio recording for the upcoming activation video.

The headphone audio is louder, but there’s also a lot of noise in the audio amplification chain–again placing the (tr)uSDX noise floor around S5 or S6.

I was fully expecting the (tr)uSDX receiver to overload and it does. The variable filter helps and narrowing it makes the audio sound more pleasant in CW, but it doesn’t stop adjacent signals from bleeding through. Honestly, though? I could live with this and just use the filter between my ears if the audio was simply cleaner.

I also discovered that my unit needs alignment: the frequency display is off by 1.6 kHz in CW mode on 40 meters. I’ve put this on my to-do list–after all, this is a project radio meant for hands-on tweaking. I’m good with that.

One final point and minor quibble: the OLED display is very difficult to read outdoors. It’s superb indoors, but outside any sunlight or reflection simply wipes it out. To read the display I had to cover it with my hand.

The activation was a success: I worked 11 stations in 20 minutes or less, but I’m sure there were weaker signals out there I missed because they were simply buried in the (tr)uSDX’s noise floor.

I liked the (tr)uSDX keying, and I love the form factor, but I’m not sure I’ll ever use this radio again–configured as it is now–during an activation. For casual contacts, it could still be fun.

A little (tr)uSDX grace

I mean…$135 right?!?

The (tr)uSDX is an open source project and truly pushes the boundaries of what one can achieve for $135–again, even much less for the kit version. Frankly, I’m in absolute awe that any transceiver can be made below the $150 price point; especially a multiband, multimode transceiver.

The (tr)uSDX is an experimenter’s radio and I plan to dig into this little unit and see if there’s anything I can do to lower that noise floor. My hope is that the CPU or display may simply need better grounding or isolation. My time is limited at the moment, but I will open into this radio in the next few weeks.

In fact, eventually completing the kit build will give me an opportunity to explore the components and connections in much better detail.

I do know that my unit also seems to have the power output issue that some of the roWaves kits have. I can’t achieve anything better than 3.25 or 3.5 watts output at 13.8 volts. It should be about 5 watts at 13.8 V.

I would welcome your suggestions especially if you’ve built the (tr)uSDX kit or if you’ve put your assembled (tr)uSDX on the air and found that it had much better audio characteristics.

Field Reports, Morse Code, News, Portable, POTA, QRP

“The Elecraft AX1 antenna is just a dummy load!” Really? Let’s test that!

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Like a lot of QRPers, I love a good challenge.

Maybe it’s just in the nature of those of us who love QRP.

We get a small thrill out of seeing what we can accomplish with less.

AX1 Doubts?

On the morning of February 7, 2022, I received an email from a subscriber in South Carolina who had placed an order for a new Elecraft KX2 and an AX1 antenna package.  He picked this particular combination because he wanted the most simple and easy-to-set-up field radio system for impromptu CW POTA activations and a little random QRP fun.

He mentioned that, at his age, mobility is a bit of an issue and even though he knew a wire antenna would be more effective, deploying it while walking on uneven ground just wasn’t in the cards. The AX1 was a much more manageable and packable system. Plus, as he said, “I’m not going out to work DX. I just want to play and have fun.”

Only a week after placing his order, he was having buyer’s remorse which prompted his message.

He explained that he had exchanged emails with a friend in his radio club who told him he’d made a foolish mistake and that the AX1 was completely ineffective as an antenna and would only lead to disappointment. His friend said [direct quote here], “I owned [an AX1] for a month and was never able to make a single contact. It is really good at being a dummy load and nothing more! This thing shouldn’t be marketed as an antenna. It doesn’t work.”

I pointed out that I’ve used the AX1 numerous times in the field and have yet to be disappointed.

Before I used the AX1, I too, was very skeptical but after actually using it (instead of simply theorizing about it) I found it’s one of my most valuable antennas for a quick and fruitful activation. I pointed him to this playlist that includes all of my AX1 activations on YouTube. In all of these activation, I’ve limited myself to 5 watts as well even though the antenna can handle a full 10 or 15 watts from the KX2 or KX3.

I told him I’d been planning to pair the AX1 with my Mountain Topper MTR-3B and, it turned out, that very day a small window of opportunity opened in the afternoon. I told him we could both see how the AX1 might perform with three watts of power, especially since he’d planned to use 10 watts with his KX2.

As I’ve mentioned in the past, my motto is less theory, more practice!

We’d put the “dummy load theory” to the test! Continue reading “The Elecraft AX1 antenna is just a dummy load!” Really? Let’s test that! →

Antenna Tuners, News, Portable, QRP

Richard recommends the Phoenix QRP Pocket Transmatch

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Many thanks to Richard (M0RGM) who writes:

Hi Thomas,

Hope this email finds you well, and thanks for all the recent blog updates and videos.

Like many other QRP ops we sometimes need an ATU or matching unit. For a while I’ve been looking for a small compact unit for use with my QCX-mini, MTR-3B and TX-500. I was sorely tempted by the Emtech ZM2, but they are quite expensive over here in England, especially as I’m awaiting delivery of a Venus SW-3B!

After much research I stumbled on the Phoenix Transmatch sold by Kanga Products. Paul, the proprietor, sells quite a range of quality QRP goodies. Having purchased the assembled device (work gets in the way of construction these days), I can say that this is a really good lightweight model that suits my purposes fully. No, it doesn’t have the tuning range of the ZM2, but I rather hope my antennas are not too far out of resonance!

For size comparison, see the attached photo taken whilst playing in the sunshine….

For anyone interested, the web details can be found at https://www.kanga-products.co.uk/ourshop/cat_1750054-QRP-ATUs.html

I have no connection with Kanga other than being a satisfied customer!

Regards,

Richard M0RGM

Thank you for sharing this, Richard. I love the size of Phoenix Tranzmatch–I was not familiar with it. It would be a great additon to pretty much any field kit. I see you also have the N6ARA paddles–I think they’re great!

It also sounds like you, too, have a QRP radio addiction. I hope you realize there’s no cure, so don’t fight it! 🙂

Thanks again for sharing this, Richard. 

Antenna Tuners, Antennas, Field Radio Kits, Grab And Go, Portable, Portable Power

Brent’s updated review of the CQHam TB Box

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Many thanks to Brent (VA3YG) who writes:

Hi Thomas, hope you’re well.

Just a short message to bring you up to date on the performance of the new equipment.

In a nutshell, it’s brought me back to my old faithful friend, the FT-817. I bought my FT-817 20 years ago and it’s served me flawlessly all these years. It’s not the best at everything but it’s a perfect QRP shack-in-the-box.

The TB Box makes the little Yaesu a pleasure to use. The tuner tunes my 43’ vertical and K6ARK end fed random wire from 80-10 for the vertical and 40-10 for the ef random wire.

The battery tray slips out to reveal 6 Panasonic 18650 cells. The battery life is exceptional even with the 817 set on 5 watts. I’m just now in the process of topping the batteries up.

Attached are a couple pics of my operating situation today….it was such a nice day out on the driveway. I have a telescopic pole attached to the RV and strung the 41’ of wire up. Also, a closeup of the battery tray and one of the cells.

I can whole heartedly recommend this piece of gear to supplement an FT-817/FT-817ND/FT-818ND.

Loving it!

72/73,
Brent VA3YG

Very cool! Thank you for sharing the update, Brent! I’ll admit that I like the “old school” simplicity of this power and trans match system.

Click here to check out the CQHam TB Box on eBay. (partner link)

New Products, News, Portable, Portable Power

Bruce discovers roWaves ROW-PDS-0X USB-C to 12V converter boards

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Many thanks to QRPer contributor, Bruce, who writes:

Hi Thomas,

I have been on a several-year journey to get to the point where all my portable electronics can be powered or charged via USB or USB-C. Gone are the days when I would have to lug around multiple chargers (or lots of spare batteries) in my travels.

Unfortunately, radios have been the holdout. I know that some people have played with USB-to-12v converter boards, with varying levels of success. I recently came across these dongles sold by the Romanian company roWaves Technologies:

Click here to check it out.

I just received a DS-02 (for FT817) and a DS-04 (for IC-705). I can now charge my 2m HT and marine VHF handheld using a USB-C charger or battery pack. I can now charge/run my IC-705 at 12v from the same source.

I have yet to explore how much noise these adapters generate. Even if just used for charging, they’re a great addition to my travel kit.

Probably not SOTA gear, but a nice addition to any ham’s travelling kit.

Bruce

Wow! Thanks for the tip, Bruce! I love how compact these are and it’s certainly a huge bonus that they can charge the internal batteries on your rigs. That alone, as you say, is huge because it can cut down on the amount of accessories needed during radio travels.

Let us know how well this works for you over time, Bruce. I’m curious if others have tried this USB to 12V converters–please comment!

Click here to check it out at roWaves.

Antenna Tuners, Articles, Field Radio Kits, Grab And Go, Kits, News, Portable, QRP, QRP Radios

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

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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 →

Field Reports, Morse Code, News, Portable, POTA, QRP

Amazing Fun with 3 Watts: Pairing the MTR-3B, T1, Speaker Wire, and a 9V LiFePo4 battery at South Mountains

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I’ve been spending more time with my Mountain Topper MTR-3B (“Tuppence”) recently and have been thoroughly enjoying this little radio’s companionship.

Since I made a dedicated ultra-compact field kit for the MTR-3B, it has also been even easier to toss it in my backpack and take it on little field adventures. The field kit is truly a grab-and-go and even includes a throw line and weight.

On Friday, January 28, 2022, after a total of six individual park activations during the previous two days (a POTA RaDAR run and my first 2020 Antenna Challenge activation) driving back to the QTH I thought, “surely I can skip doing an activation today.”

That quickly turned into, “Wait a minute…I’ve got enough time to fit in both an activation and a hike!”

So I made a quick detour off of I-40 to visit the Clear Creek access of South Mountains State Park.

South Mountains State Park (K-2753)

I pulled into an empty parking area; not really a surprise on an early Friday afternoon. In addition, I figured many were out grabbing bread and milk since winter weather was in the forecast.

I decided to do my activation first, then pack up and take the full kit on a hike. Continue reading Amazing Fun with 3 Watts: Pairing the MTR-3B, T1, Speaker Wire, and a 9V LiFePo4 battery at South Mountains →

Field Radio Kits, Field Reports, Morse Code, News, Portable, POTA, QRP

POTA RaDAR Run Final Activation: Testing the new MTR-3B field kit at Tuttle Educational State Forest

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On January 26, 2022, I fit in multiple park activations in one day as a RaDAR (Rapid Deployment Amateur Radio) run. My hope was to activate four or five sites between 14:00 – 21:30 UTC.

Here are the field reports and videos of my first four activations:

The next park in my run (#5) was Tuttle Educational State Forest and it was the final park in this modest RaDAR run!

I packed up the gear at Johns River Game Land in a matter of three minutes, popped it all in the car, then drove 8 minutes to nearby Tuttle Educational State Forest which, at this point, almost feels like a home away from home.

Tuttle Educational State Forest (K-4861)

As I pulled into the Tuttle parking lot, I found my buddy Max (W4GZ) activating the park from his truck. It was no surprise finding Max here since I had just worked him Park-To-Park (P2P) from Johns River next door.

Max delivered some precious cargo: some more of his mom’s homemade QRP pickles!

“Them’s QRP pickles!”

Max continued to activate Tuttle from his truck while I set up my station. Continue reading POTA RaDAR Run Final Activation: Testing the new MTR-3B field kit at Tuttle Educational State Forest →

Field Reports, Morse Code, News, Portable, POTA, QRP

POTA RaDAR Run Activation #4: A “wham bam” activation at Johns River Game Land

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On January 26, 2022, I fit in multiple park activations in one day as a RaDAR (Rapid Deployment Amateur Radio) run. My hope was to activate four or five sites between 14:00 – 21:30 UTC.

Here are the field reports and videos of my first three activations:

The next park in my run (#4) was either going to be my last activation, or second to last depending on my available time.

After visiting with my buddy, Hamilton, at his ceramics studio in Morganton (read about that in the previous report) I looked at the time and decided I could fit in a very quick activation of Johns River Game Land (#4) en route to Tuttle Educational State Forest (#5).

I made up my mind en route that I’d use my fastest-to-deploy combo: the Elecraft KX2 and Chameleon CHA MPAS Lite.

I really wanted to be in and out of the site within a 20 minute window. That’s actually very doable as long as I could rack up at least ten contacts in 10-15 minutes. Some days, propagation can make that a tall order, though!

Johns River Game Land (K-6916)

Johns River actually has a number of access points and, frankly, none of them are exactly “bucolic.” Other than the river itself which is beautiful and the main access point for the river which is well-maintained, most of the game land parking areas are filled with litter.

I chose a parking area for this activation which has, in the past, looked like a dumping ground. I was pleased when I pulled into the parking lot this time to find it much cleaner (no old refrigerators or sofas dumped at the far end of the lot) but then again the snow on the ground was likely hiding quite a bit of litter! My philosophy is to always leave a site cleaner than I found it, but Johns River often has so much littler, I could spend a week picking up trash.

After doing a very short intro for my activation video, I set up the Elecraft KX2 and MPAS Lite antenna in a matter of two minutes.

Gear:

On the air

I started calling CQ POTA (with my fingers crossed!) on 40 meters and was very pleased that chasers were out and about!

I worked my ten contact in 9 minutes and then went QRT! Woot!  Here’s the log sheet:

In this short activation, there was actually a P2P with Max (WG4Z) who was just up the road at Tuttle Educational State Forest. We were definitely working each other via ground wave.

The contacts were flowing so well, that I wanted to stay on the air a bit longer, but I knew to fit in Tuttle and a hike, I really needed keep moving. As soon as I worked my ten, I hopped off the radio.

While I like putting more contacts in the log–especially when they’re flowing so freely–it was actually kind of fun to validate this activation in somewhat of a “sprint.”

QSO Map

Here’s what 5 watts and the MPAS Lite yielded in nine minutes on the air:

Activation video

Here’s my real-time, real-life video of the entire activation. This must be one of the shortest activation videos I’ve ever made:

Click here to view on YouTube.

Thank you

Thank you so much for reading this short report and coming along with me on this RaDAR run! I’ll be posting Park #5–Tuttle Educational State Forest–soon where I catch up with Max (WG4Z) and we work park-to-park once again.

As always, I’d 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 truly appreciate the support.

These are crazy times we’re living in these days (at time of posting). I wish all of you good health, safety, and peace–especially our good friends in Ukraine.

Let’s all treat each other with kindness and respect this week as we remember that all we’ve got on this old planet is each other.

I hope you get some time to play radio this week!

72,

Thomas (K4SWL)

Field Radio Kits, News, Portable, QRPers

Steve is QRV in the Swiss Alps

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Steve (MW0SAW) and I were recently exchanging emails and he has kindly allowed me to share a few photos and details of the QRP field kit he has taken on holiday:

I’m currently in Switzerland (ski holiday)–I did bring the Venus SW-3B. I was very surprised to get 2 USA stations last weekend with 4-5 watts in the ARRL CW contest.

Only a couple of Europeans today. But it’s all fun and I did have a lovely morning ski so can’t complain lol.

My gear:

Steve
HB9/MW0SAW

Wow, Steve! I would love to be in Switzerland right about now. I’ve got a bucket list item to journey there someday (in summer months) and activate at least 10 summits. Having lived in Grenoble, the Alps always feel a bit like home.

I love how compact your setup is and obviously the K6ARK EFHW is doing the trick if you’re making contacts State side with QRP and during a contest competing with the big guns!

Hmmm…I’m now thinking I might grab a second Maxpedition Fatty Pouch. I just checked and Maxpedition still has the “buy one, get one free” deal on their website.  The link above goes to Amazon (hence the affiliate link which my site auto-converts) because pricing is typically best there, but I believe you get an even better deal at present going directly to the source; especially if one could use two pouches!

Thanks again, Steve, for sharing your field kit photos and notes!