Category Archives: Portable

Hams, Morse Code, News, Portable, POTA, QRP

CW saves Leo’s POTA activation during a low battery warning!

5 Comments

Many thanks to Leo (DL2COM) who writes:

Thomas,

Today was crazy: when I woke up I thought it would be a good idea to attempt a first activation of DA-0171 in central Berlin after dropping off the kids at day care. So I grabbed my KX2 bag and jumped on my bike.

Shortly later I arrived at the park and pulled up my 40-10m EFHW and started calling CQ on SSB 40m.

It took me about 30 mins to realize that the KX2 was regulating the power down to 5W since both the internal and the external 4Ah battery I took with me were nearly dead.

I had one QSO with a German station and felt I wasn’t really heard anywhere. Then my KX2 started showing “low batt”.

It’s funny because attempting an activation isn’t really what one would call a very important thing, but I do develop quite an ambition if I have decided to get it done. So my only chance was using CW even though I am all but ready for that.

Having read your article about auto-spotting and watched many of your videos including POTA QSO style I didn’t think long and started calling CQ POTA on 20m.

OMG what followed was just amazing!

Fortunately I didn’t run into a classic pileup which would have been super overwhelming for me, but instead about every 2 minutes someone would reply to my call and in a very patient fashion – including one P2P QSO with an operator from Italy.

So all in all I completed 13 QSOs on a “low batt” warning of my KX2.

CW literally saved by butt and I am a very happy person. Without your work for the ham radio community this would not have been possible. So many thanks again.

On a different note: Last weekend (kit building seminar with the club) I had my first DX QSO. It was K3LU who picked up my call from my KX2 and a random wire 9:1 Unun antenna (L-Shape on a mast) with 28 and 17ft legs. I had to sit down and open a beer not able to do anything for about an hour but smile. Such a motivating event and I am happy he was such a great operator instantly QRSing with me and repeating his call. I am in touch with him and looking forward to receive his QSL card which will probably go in a frame.

I also finished the TR-35 and must say I am super impressed. It runs very quietly and the reduced concept is something I really appreciate. When will you take it into the field?

All the best & 73s de Leo (DL2COM)

Oh wow, Leo! I love this–thank you so much for taking the time to share your experience.

First of all, thank you for the kind comments–I’m honored to have even played a minor role in your CW activation. In truth, this is all chalked up to your determination and bravery! I’m guessing what you discovered is what I discovered during my first CW activation: not only is it not as bad as I had imagined, but it was actually fun and got the adrenaline pumping! 🙂 

I’m now happy to know that when I hit the Low Battery warning on my KX2, I still have some time left! In truth, the KX2 is so efficient, I’ve made six individual CW 5 watt activations on one charge of the internal battery without even hitting the low battery warning. 

Again, this story just makes my day. CW is such a fabulous, efficient, and magical mode! Good on you for diving in, OM!

I also think it’s brilliant that you worked Ulis (K3LU). You couldn’t have worked a better op for your first CW contact–he’s the real deal and a wonderful fellow. Not only that, but he has some amazing QSL cards!

And the TR-35? I couldn’t agree with you more. I did an activation with the TR-35 last Friday so a video and field report is forthcoming!

Thank you again, Leo! I hope others share their experience hitting CW for the first time (hint, hint!). 

Field Reports, Kits, Morse Code, New Products, News, Portable, POTA, QRP, QRP Radios, Reviews

Video: Taking the new (tr)uSDX QRP transceiver on a CW POTA activation!

13 Comments

As I mentioned in a post published three days ago, I’m now the proud owner of a (tr)uSDX QRP transceiver.

The (tr)uSDX has been a much-anticipated QRP transceiver for those of us who love playing radio in the field.

What’s not to love? It sports:

  • Up to 5 watts output power
  • CW, SSB, FM, and AM modes
  • A built-in microphone
  • Five bands: 80, 60, 40, 30, and 20 meters
  • A super compact and lightweight form factor
  • An open-source hardware and software design
  • Super low current consumption in receive
  • A super low price of roughly $89 US in kit form and $143 US factory assembled (via AliExpress, but there are numerous other group buys and retailers)

Frankly speaking, this sort of feature set in such an affordable package is truly a game-changer. Back when I was first licensed in 1997, I could have never imagined a day when a general coverage QRP transceiver could be purchased for under $150 US. The price is almost unbelievable.

My initial impressions

On Wednesday, March 30, 2022, I took the (tr)uSDX to the field to attempt a Parks On The Air (POTA) activation. I had only taken delivery of the (tr)uSDX about 15 hours beforehand and had only had it powered up for a total of 30 minutes the previous day. Most of that time, in fact, was checking the power output at various voltage settings into a dummy load. I did make one totally random SSB POTA contact shortly after hooking the radio up to my QTH antenna.

I knew that taking the (tr)uSDX to the field and making an activation video might not be the best idea having had so little time to play with the radio and get to know it in advance, but then again, I was simply too eager to see how it might perform.  That and I always believe there’s value in sharing first experiences with a radio. Continue reading Video: Taking the new (tr)uSDX QRP transceiver on a CW POTA activation! →

How To, Morse Code, News, Portable, POTA, SOTA

How to use the Reverse Beacon Network (RBN) for automatic POTA and SOTA spotting

39 Comments

If you’ve read my field reports or watched any of my activation videos, you’ve no doubt noticed that I rely very heavily on automatic spotting  via the Reverse Beacon Network (RBN) for both POTA (Parks On The Air) and SOTA (Summits On The Air).

I’ve gotten a lot of questions about how to use the RBN functionality for both SOTA and POTA, so thought I might clarify (in very basic terms) how the system works and how you can take advantage of it.

Note: CW and Digital Modes Only

Keep in mind that Reverse Beacon Network spotting only works with CW and some digital modes.

I, personally, have only used it for CW activations.

The system does not currently recognize voice transmissions (although as voice recognition becomes more accessible and effective, I wouldn’t be terribly surprised if something like this is offered in the near future!).

Here’s how the RBN works

The RBN is essentially fueled  by a global network of volunteer receiving and decoding stations that feed information into the RBN spotting system. This system is running 24/7 and recording spots constantly.

This is what the RBN spots search results look like using my call at time of posting.

If I hopped on the air right now and made at least two generic CQ calls with my callsign–barring any abnormal propagation–the RBN would no doubt collect my information and spot me automatically to their network.

Click here, for example, to see all of the times the RBN has spotted me recently. Click here to search for your own callsign on the RBN.

To my knowledge, the RBN is a completely independent resource and not directly affiliated with POTA, SOTA, WWFF, or any other contest or activity. Continue reading How to use the Reverse Beacon Network (RBN) for automatic POTA and SOTA spotting →

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

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

42 Comments

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!

25 Comments

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

10 Comments

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

8 Comments

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

9 Comments

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

4 Comments

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

3 Comments

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 →