Category Archives: SOTA

Field Radio Kits, Guest Posts, Kits, News, Portable, POTA, QRP, QRP Radios, SOTA, Videos

A Strong Case for the (tr)uSDX: Jamie’s Perspective

11 Comments

Readers, there’s a bit of a backstory to this guest post by my friend Jamie (AA4K). During the W4SOTA campout in October 2023, Jamie showed me his favorite field radio: the (tr)uSDX. I’ve used the (tr)uSDX for a couple of activations, but I’ll be honest—I haven’t exactly shown it a lot of love. I’ve even complained about its audio and receiver performance in the past. Jamie, on the other hand, really enjoys using his and makes a solid case for it as a field radio.

Jamie showing me his (tr)uSDX during the W4SOTA campout.

I asked if he’d be willing to write a guest post for QRPer, and he agreed (eventually!). When I saw him at Hamvention this year, he told me the article was ready—and in true form, he sent it to me via Winlink… using his (tr)uSDX.

A Case for the (tr)USDX

by Jamie (AA4K)

Introduction

There are many factors that must be considered when choosing a field radio. How big and heavy is the radio? How hard is it to repair or replace the radio if it becomes damaged or lost? How hard is the radio to operate? How power-efficient is the radio? Does the radio have the desired/required modes and features? Of course, the most fundamental question is, “Does the radio work?” I will try to answer these questions as I lay out… a case for the (tr)USDX as perhaps an almost perfect field radio.

The last two contacts on this page were with my friends Carlos (KB4CO, now AE2W) and Thomas (K4SWL).

How big and heavy is it?

The first question is an easy one. Aside from small home-brew radios such as K6ARK’s “Choking Hazard”, there isn’t a smaller or lighter commercially available radio out there that I am aware of. The (tr)USDX measures 112 x 61 x 50 mm (I trimmed the encoder post and used a lower profile knob), and weighs 5.3 oz, or 151 g. The next closest currently available commercial radio is perhaps the QRP Labs QMX. This radio is very comparable in size (110 x 64 x 38 mm) and cost, but it does weigh more at 7.3 oz, or 207 g. The more rugged metal case probably plays a big part in the weight difference.

(tr)USDX with a modified case I designed to use the radio as the antenna winder.

How hard is it to replace or repair it?

The (tr)USDX is often sold as a kit for about US$86 (+$20 for the case) [QRPer affiliate links]. Any repairs should simply involve desoldering affected components and replacing, or possibly just updating the firmware. I am a relative noob when it comes to kit building and this kit is honestly not very difficult to build… about one day. The instructions and support videos provided by the hardware developer, Manuel DL2MAN, are very thorough. I learned a lot about radios from building the kit. If you have no interest in kit building, the assembled radio can currently be purchased from Amazon for US$138, complete with a case. Whether purchased as a kit, or already built, the band pass filters on the radio board will need to be tweaked to get the most out of your radio.

How hard is it to operate?

The (tr)USDX only has 4 buttons including the rotary encoder: Menu, Encoder, Enter, and PTT. The Menu and Encoder cover the majority of the adjustments, and most of the time I don’t use the Enter and PTT buttons. The PTT functions only as a ptt or cw key depending on the mode (yes, if your key breaks mid activation, you have a built-in backup key). The single-layer menu system is simple to scroll through, and the most commonly used items are near the front of the menu.

The most challenging aspect of operation for some people is the tiny OLED screen which gets obliterated in bright light. Reading glasses do help, although when you become familiar with the menu are not as important. I would love to see a version with an e-ink display and, more importantly, a push-button wheel rotary encoder (to remove the protruding knob).

How power-efficient is it?

This radio sips power. I tested the radio I built using a LiFePO4 battery that supplied 13.56v. The current draw on receive is 66.1 mA, and 570 mA on CW keydown into a dummy load. A properly tuned (tr)USDX delivers about 5w on each of the five bands when fed ~12v. A set of three 18650s in series will provide the proper voltage and power the radio through many activations.

Does the radio have the desired/required modes and features?

The (tr)USDX is not for princesses. It is a minimalist’s radio. But if you start from the perspective of an ultralight backpacker who has to justify every gram in their kit, this radio checks all of the boxes. It is a five band radio (Low, Classic, and High band models available). It is capable of doing voice, cw and digital modes. Thanks to a beta update from the firmware developer, Guido PE1NNZ, this radio will interface with a computer without requiring a soundcard. One of my favorite features of the radio is the built-in SWR meter. With the SWR feature enabled in the menu, just put the radio in CW mode and press the PTT to find out if your radio is happy with the current antenna arrangement.

This photo was taken while sending the text of this article via Winlink to Thomas, K4SWL.

Does the radio work?

Although my total activation count is nowhere near as high as many of you, I have used the (tr)USDX for a majority of my successful POTA (156 as of this writing) and SOTA (72 as of this writing) activations. My confidence in this little radio was demonstrated when I used it on an ATNO activation of Admiralty Island National Monument (US-4537) in Alaska.

Conclusion

One reason why I like to participate in SOTA and POTA is that it gives me an opportunity to practice field radio deployment and operation with the goal of being ready to communicate anywhere and anytime. This level of readiness means that I have the necessary equipment with me all the time. For me, the (tr)USDX is my EDC (every day carry) radio. It can bounce around in my backpack (in its protective case, of course) and be ready to deploy if needed. If it were to get lost or broken, I can fix or replace it easily. And I find it to be easy enough to use with the understanding that it isn’t a luxury radio.

The author at ~11,000’ in Uncompahgre National Forest.

Video

Click here to view on YouTube.

(tr)uSDX Winder Case:

Click here to download the print file for Jamie’s the modified (tr)uSDX case.

Antennas, Guest Posts, How To, News, Portable, POTA, QRP, SOTA

Build a Linked End-Fed Half-Wave Antenna with Bluetooth-Remote Band Switching!

19 Comments

A Remote Control Antenna Link

by Dave (KO4YLZ)

Like so many other SOTA activators, I’m constantly tweaking my gear to optimize it for all the variables we encounter in the mountains. One of my main antennas is, of course, an EFHW. Paired with my KX2, I generally get sub-1.6:1 SWR on 40, 20, 15, and 10. However, 30m has an unacceptably high SWR. I considered switching to a multi-link EFHW, but hopping up to change links to chase an inadvertent S2S on another band is inconvenient, especially when the link for low bands is generally well beyond my reach and requires lowering the antenna.

To fully optimize my EFHW I decided I needed to come up with a way to add a “remote” link for 30m. After a couple of design iterations, I came up with the light-weight and compact remote antenna link shown/described below. The version described here is not my final one. While this “pill bottle” version is still quite small, I’d like to reduce the size even further.

Let’s start with the end…

Here’s the final product. It weighs under 1 oz. and is ~2.5” long. I have included a complete parts list at the end of the article.

My design considerations were:

  • Small and light
  • Range of at least 75 ft.
  • Reasonable battery life
  • Waterproof
  • Durable
  • Able to withstand the current at the 30m position on the antenna
  • Doesn’t adversely impact antenna performance on other bands
  • Easy to connect and disconnect from the antenna

Executive Summary

For those in a hurry, here’s a summary description of the remote antenna link. It consists of a very, very small remote control Bluetooth relay powered by two CR2032 batteries (user supplied). A set of contacts (either normally open or closed) lead from the relay to male and female 2mm bullet banana connectors in the cap of the pill bottle. Two matching bullet banana connectors at the antenna plug into the remote control link.

To operate, you simply open the bottle, switch on the batteries, re-install the cap, extend the antenna, and plug the bullet banana connectors at the antenna into the opposite pair embedded in the cap of the pill bottle. When you are ready to operate, you just push the remote button. When the remote button is pushed, the relay opens or closes thereby making or breaking the link and physically shortening or lengthening the antenna. Below is a picture of both sides of the mini-relay (antenna wire not shown)

The relay can run on 3.5-12 volts and can handle 1A. The included 1-button transmitter sends a signal (455mHz) to the relay and either opens or closes a set of contacts depending on how the user programs the relay.

Wiring It Up

I won’t bore you with a detailed written explanation…it’s a pretty simple build. Below are a simple wiring diagram and a series of photos with build details [click images to enlarge].

Making It work

The relay has three operating modes: latched, momentary, and toggle. Because I wanted the 30m link to be normally connected when the relay is in standby waiting for a signal from the remote control and open and stay open when I pressed the remote button, I had to reprogram the relay. Programming is accomplished by turning the unit on, then putting a 22ga wire jumper between the two “programming dots” and then pressing the remote button until the LED on the relay board flashes the number of times specified in the instructions for the operating mode you want.  The instructions are not very clear, so I recommend connecting the unit to your VOM in continuity mode to figure out the button/LED flashing sequence that corresponds to how you want the relay to behave.

Testing

The unit is rated for 1A so, to be sure I wasn’t going to blow it up when I transmitted with 10 watts, I used ChatGPT to produce a very nice graph showing the current at the 30m position on the antenna for each band when transmitting with 10W. Here’s the graph. Luckily, the maximum current at the 30m position (~43’) is .6A at 7.062 MHz.

I tested the unit on my KX2 by setting my operating frequency and then putting the KX2 tuner in bypass mode and pressing the button on the remote control; Ding…the SWR jumped immediately to the expected pre-determined (and acceptable) SWR value for the 30m band!

The unit draws 7mA when in standby and 32mA when the relay is energized. Assuming 40 minutes of operating off of the 30m band (relay not energized) and 20 minutes on the 30m band (relay energized), I calculated that approximately 17mA would be drawn from the two CR2032 batteries. Given that a CR2032 battery has a capacity of 220mAh, they should provide about 12 hours of operation.

Any questions, please comment.
Dave – KO4YLZ

Parts List

Note: The Amazon links above are affiliate links that supports QRPer.com at no cost to you.

Antennas, Field Reports, Guest Posts, Homebrew, How To, Portable, POTA, QRP, SOTA

Experimenting My Way to the POTA Kilo Award

8 Comments

by Thomas (DM1TBE)

Some time before Easter I noticed that I am close to 1000 QSOs at my favourite place at the “Kalte Feld”, a POTA and SOTA activation zone and would soon qualify for the POTA Kilo Award. I like the Kalte Feld for the quiet, spacious area with a hut that is vending traditional basic food and beverages – which in Germany usually means good beer and different sausage types (and other stuff – to be fair). I already wrote some articles about the history of the area and my activations.

The conditions at the activation zone are quite good. I have made 2 activations there with more than 100 QSOs (and many smaller), so I thought it should not be too difficult to complete the required QSOs in one day.

DAY 1

The weather for the Easter weekend was expected to be one of the first warm and sunny days this year. So, on Easter Sunday, I headed to the area to get the last missing 49 QSOs for my POTA Kilo Award. Easter hiking has a centuries long history in Germany. This and the nice weather made the area quite crowded. The close airfield for gliders was busy and the whole time while operating there they were in the air above.

The barbecue places and outdoor seating around the mountain hut were busy but happily the bench some meters away that I am normally using, was still available.

I wanted to start with an end-fed half-wave antenna for the 20m band, tied to a 10 meter (33 ft) fiberglass mast. This is a very easy and quick to deploy antenna and I like it, especially if there is not too much space for antennas with a larger footprint. Since it’s a straight vertical, it also has a higher chance for DX contacts – when the conditions allow that. The antenna is Open Hardware and you can find further details on GitHub.

The mast was tied to the bench and the antenna was raised. Besides the comfort, the possibility to tie a mast to it is the second reason why I am always looking for benches.

The conditions were far from being perfect, and it took me 40 minutes to get 18 CW QSOs on the 20-meter band. Switching to SSB wasn’t a big help either, and I soon gave up with only 3 additional SSB QSOs in the log.

I had brought another antenna with me that I wanted to try. The 10 meter (33 Ft) fiberglass mast also has the perfect height for a ¼ wave vertical on the 40-meter band. So I cut 5 wires to a length of about 10 meters (33 ft) and connected 4 of them together at one end with a cable lug and attached another cable lug to the vertical element.

I then used the basis of the JPC-7 antenna for the coax plug and for connecting the vertical element and the radials. There are a lot of articles and videos about ¼ wave vertical antennas. But the information is usually about either elevated and resonant radials or random length ground radials. I wanted to have resonant radials, but I could not be bothered with carrying all the stuff nearly 2 miles to a summit for elevating 4 x 10m (33 ft) wires, so I simply left them on the ground.

My idea was to try a full size vertical for the 40 meters band with resonant radials that still is portable and fits to my existing equipment.

The SWR was quite nice being close to 1.0 : 1 at the CW portion of the band, so I started operating.

The conditions were similarly difficult as on the 20-meter band. It took me 25 minutes for another 18 QSOs.

As it became increasingly cloudy, I checked on my mobile and saw that rain was approaching fast. Since I had roughly 2km or 1.5 miles descent ahead of me, I stopped abruptly with just 10 QSOs short of the POTA Kilo Award.

A bit disappointed, I called it a day.

DAY 2

I could not leave the missing 10 QSOs for long. The very next day, Easter Monday, was a public holiday in Germany. And as the weather started nice, I again made my way to the activation zone. Continue reading Experimenting My Way to the POTA Kilo Award →

Articles, Field Reports, Guest Posts, Mobile, News, Portable, POTA, QRP, SOTA, Travel

From the Badlands to Mesa Verde: QRP Across America’s National Parks

18 Comments

Activating on the Road:  National Parks

by Brian (K3ES)

This article continues my series from our 2024 road trip across the United States (Six Weeks and 7300 Miles:  Activating on the Road).  I hope to wrap up the series with one last article soon.  In this report, I will cover the six National Parks (NPs) that we visited during our trip.  I activated five of them for the Parks on the Air (POTA) program using CW mode at 5 watts.  A previous report on Stealth Activating with the KX1 Antenna System provided activation details for three of the parks (Badlands NP, Yellowstone NP, and Grand Canyon NP), so I will not reproduce activation details here, but I will include more of Becky’s pictures.

Each of these NPs is spectacular in its own right, and also distinctly different from each of the others.  We were able to see some of the sights, but by no means had enough time to do them justice.  In fact, as we completed our drive through Yellowstone NP, Becky and I committed ourselves to going back again and spending much more time to see its wonders.

As I reflect on our visits to NPs on our trip, it occurs to me how beneficial it was to buy an Annual America the Beautiful National Parks and Federal Recreational Lands Pass before we left on our trip.

The pass costs $80 for a year, and generally covers the admission of one vehicle and its occupants.  We were able to save on admission costs several times over, making this one of the best NP values going.  Having now completed 62 trips around the sun, when we next visit NPs, I am eligible for an even better value, the $80 Senior Lifetime America the Beautiful Pass.

Badlands NP

The first NP we visited on our trip was Badlands NP in South Dakota.  We spent a couple of nights and days based nearby in the town of Wall, so we were able to take two drives through the park.  There is a stark transition from rolling plateau north of the park to the spectacular peaks and canyons of the badlands.  Rapid erosion has been shaping the terrain for about 500,000 years with the Cheyenne and White Rivers cutting their way through the terrain.  The resulting landscape is both beautiful and severe.

While visiting the park, we were privileged to see a variety of wildlife.  We saw a number of bison, ranging from small herds grazing in fields along the road, to an individualist who took a liking to the taste of grass beside one of the overlook parking areas.  There were also bighorn sheep and pronghorn antelope wandering other parts of the park.  There was abundant bird life, from a disoriented prairie chicken that accepted water from concerned visitors, to birds of prey soaring high above.  Becky particularly enjoyed the frenetic activity of the residents of Roberts Prairie Dog Town.

This bison had no problem napping in the middle of the Prairie Dog Town
This prairie chicken appreciated shade and water in the parking lot

During our visit, we stopped at an overlook parking area for Becky to take pictures of the spectacular scenery, including the aforementioned bison.  While she was doing this, I took the opportunity to do a stealth activation of the park, which is documented in an earlier Field Report here on QRPer.com, linked as K3ES:  Stealth activating with the AX1 Antenna System.

I managed to catch the photographer in action during a lull in my activation
Of course, Becky caught me in action, too

Yellowstone NP

We knew when planning our trip, that we would not have time for a proper visit to Yellowstone NP.  In fact, we intended to hold off on visiting until we had time for a dedicated trip.  But throughout our drive, Becky kept searching the available maps for opportunities and possibilities.  As we traveled through Montana, she noticed that we could fit in an abbreviated trip through Yellowstone and Grand Teton NPs if we adjusted our route.  Consequently, we found ourselves spending the next night in Gardiner, MT, just outside the north entrance to the park. Continue reading From the Badlands to Mesa Verde: QRP Across America’s National Parks →

News, Portable, POTA, SOTA, Travel, Websites

Planning an Activation Rove? Michael recommends Ham-Map.com

6 Comments

Many thanks to Michael (OK7SE) who writes:

Hello Thomas.

Michal (OK1SIM) has put together an online map that might be useful for activation planning. You might want to check it out:

https://ham-map.com/

I usually activate “what’s available,” so I like that I can generate a map that aggregates SOTA, POTA, GMA, and WWFF for a target place (e.g., when I go to Austria for a trip) so I can see what’s nearby my accommodation, etc.

Fine-tuning the map results

Click on the icon with three bars in the upper left corner and select your country. Then, you can select the activities you are interested in (WWFF, SOTA, POTA, etc.).

Then click the “Rebuild Map” button and the map will show you all of the activation entities you requested.

In order not to overload the application, you can either select WWFF for the whole world (which is the default) or various activities, but only for one country at a time, which is usually enough for trip planning.

If I am around country borders, I open two Firefox windows and have two countries at once that way.

72s,
Michael OK7SE

Thank you so much for sharing this resource, Michael. We’ve mentioned Ham-Map in the past, but it’s clear that it has only grown more comprehensive over time. It’s an incredible tool, and we owe a big thanks to our friend OK1SIM for creating and sharing it with the ham radio community!

Field Radio Kits, News, POTA, QRP, SOTA

Field Radio Kit Gallery: N5YCO’s Lightweight CFT1 SOTA Kit

4 Comments

Many thanks to Corey (N5YCO), for sharing 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.

CFT1 Field Kit

by Corey McDonald (N5YCO)

I thought I would supply the field kit that I use for my CFT1. I prefer SOTA activations when I can, so my kit is on the lightweight minimal side.

All of the 3d printed parts are carbon fiber PETG for strength.

Not pictured: Small log notebook, SOTABeams Carbon6, guy ring and lines.

My kit consists of the following:

Note: All Amazon links are affiliate/partner links that support QRPer.com at no cost to you.

72,

– Corey N5YCO

Guest Posts, How To, News, POTA, QRP, Skills, SOTA

K5KHK: POTA Spotting via Low Earth Orbit

8 Comments

Many thanks to Karl (K5KHK), who shares the following guest post, which initially appeared on his ham radio blog:

POTA Spotting via Low Earth Orbit

by Karl (K5KHK)

For way too long, I have had the “Working from 200 different units” awards dangling in front of my face: I was at 197 unique parks activated. Only three more! Sunday 11/3/24 was a beautiful day with nothing else to do, so I was planning to hit the road. I needed three parks that I had not yet activated and I wanted them to be relatively close to each other.

A while ago, a created software that takes my activation stats from the POTA site and marks entities in New York with different colors and symbols based on there type and if I had them activated or now. I looked at the map and found the three closest entities that would not require “special equipment” like a boat.

The first one on the list was Honeye Creek Wildlife Management Area – US-9032 – followed by Honeye Inlet Wildlife Management Area – US-8642. These two are close to each other. My third planned park was about an hour away from the second stop: Rattlesnake Hill Wildlife Management Area – US-8626.

On the Road

I got on the road a little later than planned – this was the day after changing the clocks back to standard time and I wanted to have plenty of daylight left.

At the first stop, everything went smoothly. I put up my 31ft Jackite mast with the 30.5ft random wire going to a 9:1 LDG Unun and a 1:1 LDG choke. The coax then goes to a LDG AT-200Pro II tuner and my Yaesu FT-857D dialed down to 5W. This is my standard configuration when I am operating from the car.

This was my first outing with a new key: The Putikeeg Mini straight key.

I started by looking for active spots on 40m and found one, a minute later, I had KD3D in the log. I looked for a free frequency, spotted myself and finished with 13 contacts in my log about half an hour later.

After a 10 minute drive, I set up at my second location. The little wrinkle in my plan here was that I had no cell coverage to spot myself. My last spot from the earlier park was less than 30 minutes ago, so if I would have called CQ without a new spot, I would have been re-spotted at my previous park. Not what I wanted.

There are of course ways to get spotted without cell service. APRS over HF is an option, SOTAMate via FT8 will work as well, but I wanted to try something new…

Satellites to the rescue!

The recently released iOS version 18 came with a new feature: Apple has supported making emergency calls via low earth orbit (LEO) communication satellites since the iPhone 14, but until recently, this was reserved for contacting emergency services. With iOS 18, this feature was extended to text messages – both SMS and iMessages. Continue reading K5KHK: POTA Spotting via Low Earth Orbit →

Articles, News, POTA, PSK, QRP, SOTA

2025 Plans: Less About Goals, More About the Journey

4 Comments

Last week, we recorded an episode of the Ham Radio Workbench podcast. Our main topic was Winter Field Day, but we also discussed our plans for 2025—not just workbench projects but our overall goals and what’s on the calendar.

Lately, I’ve been so focused on the present and immediate future (sorting out post-storm property repairs, etc.) that I hadn’t really taken the time to think about our bigger plans.

I may tweak this list over time, but here’s what’s on my mind so far:

Projects:

  • A proper, thorough shack purge: I really need to cut a lot of the detritus out of my QTH radio space.
  • Attend at least four hamfests with N3CZ as vendors to help accomplish the first point!
  • Use PSK-31 and other digital modes more frequently.
  • Finally build that QCX+!
  • Develop our Swannanoa Valley GMRS network and grow the user base through public information sessions.
  • Spend more time QRPp and experiment with antenna choices: I do love playing radio with one watt or less!

Where I plan to go:

  • The Charlotte Hamfest 
  • RARSfest (timing for this one is always tricky for me, but I’ll do my best!)
  • Four Days in May
  • Hamvention 2025 (I’ll be at the Ham Radio Workbench table with the crew)
  • A multi-week family trip this summer (possibly a road trip or something further afield by air—it all depends on my daughters’ summer studies schedule).
  • WCARS Hamfest (if we’re in the country)
  • The W4 SOTA Fall Campout

I’d love to attend Ozarkcon, but that weekend is a tough one—perhaps if I skip RARSfest, I could make it. I’d also love to attend the Huntsville Hamfest, but I suspect it’ll conflict with university move-in dates for my daughters.

A true bucket list item is Messe Friedrichshafen, but unfortunately, the date this year conflicts with another commitment.

What I’m looking forward to:

  • Checking out the new Yaesu FTX-1F (I paid to reserve one with DX Engineering)
  • Ham Radio Workbenches On The Air (coming in March—details will be announced soon on the HRWB website).
  • Getting back into SOTA (Hurricane Helene really set me back here)
  • Taking my vintage Swiss Army Rucksack to the field!
  • More camping! Depending on the car we choose to replace the Subaru Forester, I may or may not get to use my awesome C6 rooftop tent

I may add more to this list, but you might notice there are no numerical goals—for example, specific targets for POTA or SOTA activations. This year, we’re still focusing on getting back on our feet. Maybe next year, I’ll set goals in that regard.

You might also notice that I don’t have any active goal of growing my YouTube channel’s subscriber base. Indeed, I never have. Honestly, my philosophy has always been that people who enjoy my channel will find it organically. What makes my channel so fun for me is not worrying about subscriber numbers, channel metrics, or stats.

Following the YouTube algorithm often leads to stress, clickbait, and compromising one’s vision. It also creates a certain sameness among channels, which I’m just not interested in. I love the community around my channel and am happy to let it grow naturally.

Thank you for making this QRPer community such an amazing one!

How About You?

I’d love to hear what your plans and projects are for this year. Please comment below!

Field Radio Kits, Field Reports, Guest Posts, News, Portable, POTA, QRP, SOTA, Travel

Snow, Sand, and Solar Storms: Tim’s New Year’s Eve Radio Adventure

3 Comments

New Year’s Eve Sand Dune SOTA & POTA

by Tim (W8TMI)

My wife and I head to Northern Michigan over the New Year’s holiday almost every year. It’s a nice way to wrap up the year and the busy holiday season. Most of our friends and family obligations are met, and we can spend time unwinding and exploring the wonderful things that Michigan has to offer.

This year was no exception. We found a nice place to stay in Frankfort, Michigan. Several breweries, eateries, coffee houses, hiking trails, miles of shoreline, and a local bookstore made this an ideal location for a few days with nothing pressing to accomplish.

Being a ham, I always take a peek around to see what POTA and SOTA entities may be nearby wherever we end up staying. I was in luck, there was a SOTA within a POTA just north of where we were staying. Along the Sleeping Bear Dunes National Lakeshore (US-0767) is Empire Bluffs sand dunes (W8M/LP-019). This was too much to resist.

Sleeping Bear Dune National Lakeshore

As the plans firmed up around our timeline and bookings, my mind began to imagine the activation. I am well versed in POTA activations and have many tricks to overcome beaches, snow, lack of picnic tables, lack of trees, and many other things that can come my way. My mind began to question if I had the right gear to make this happen and I began to plan for a setup that could be deployed and operated in harsh conditions with little assistance from the environment around me.

I have learned from my previous experiences on the sand dunes of the Great Lakes that  conditions can be challenging. I knew I would more than likely face snow on the ground, new snow in the air, wind, cold temps, sand, narrow dune peaks, local vegetation, and the challenge to hike all of my gear to the spot. Now it was time to take what I had and turn it into the SOTA/POTA setup that could get the job done.

The antenna would be the GabilGRA-7350  [QRPer.com affiliate link] with three 13’ radials deployed out as far as I could get them. Gabil recommends setting the antenna to the general resonance area marked on the coil and using a wide range tuner to finish the job. I have found this to be true, especially analyzing the antenna on the soil in my backyard where I can get a 1:1 SWR match versus the sandy beaches of Lake Michigan.

Gabil GRA-7350, spare whip, and three 13′ counterpoises attached via 2mm banana plugs

I chose the CFT1 as my radio. It covers the bands that I would more than likely operate and with the Tufteln face cover it weighs around 8 oz.

20 meters being the primary band because with the wind and cold, I knew speed would be paramount. For the tuner and battery, I chose the mAT-10 ATU and the Talentcell 3000 mA Li-Ion [QRPer.com affiliate link]. Finally, the N0SA M7 iambic paddle.

CFT1, mAT-10 tuner, Talentcell battery, N0SA M7, Rite in the Rain book and pencil

To bring this kit together in a way that I could operate standing up, I needed some kind of bag or pouch to wear that would allow access to the tune button on the tuner, the volume and VFO on the radio, ability to log, and key without having to hold on to the paddle. As a fly fisherman I thought about a sling pack or a chest pack, but neither would work with any of my backpacks I planned to haul the antenna.

My friend Erik (WS3D) recommended a waist pack. At first glance I wasn’t sure this could meet my needs. Off to the local shopping center I went to see if I could find some options that could accommodate my SOTA kit. After going into five different stores that had some forms of waist packs, my local athletics sporting goods store had one that I thought might work with some minor modifications.

It was small, which meant it could easily fit into the backpack I planned to use. Once I got home, I was able to stuff each component into one of the several pockets provided on the pack. The question remained: how do I key without holding the paddle?

Following the tip provided by N0SA who designed and made the M7, Velcro attached to the bottom of the key would allow adhesion to the pack. I was able to purchase some of the “loop” material from JoAnn and got to work with my sewing machine. A small 2”x3” portion on the right side of the pack would allow for right hand keying while I kept the logger in my left hand. Keeping my right hand free to operate the message functions, volume, and VFO of the radio if needed.

Outdoor Gear fanny pack with sewn on hook and loop patch

I had a kit and a plan, now to get to it. Continue reading Snow, Sand, and Solar Storms: Tim’s New Year’s Eve Radio Adventure →

Field Radio Kits, News, Portable, QRP, QRP Radios, SOTA

Field Radio Kit Gallery: Pedro’s (tr)uSDX Field Kit

3 Comments

Many thanks to Pedro (PP2PB), who shares the following article about his portable field radio kit, which will be featured on our Field Kit Gallery page.

Pedro’s (tr)uSDX Compact and Affordable Field Kit

by Pedro (PP2PB)

Here’s my new kit.

This kit weighs just under 1,2kg and has phone and CW operations in mind. I might add some cables for digital modes, but I haven’t tested this rig with digital modes, just yet.

The (tr)uSDX was bought assembled with the LO bands RF board, and I assembled the HI RF board myself. I got Adam’s alternative case printed out for easy band switching and did a minor mod to the RF boards soldering a Zener diode reverse polarized as a high SWR protection.

I also added a USB port to the battery pack because the (tr)uSDX can operate with around 0,5W directly from USB and that’s a great way to test for SWR and fine tune the antenna without stressing the finals.

The manual antenna coupler is also my creation and even though it doesn’t appear on the exploded view it does fit in there no problem (it was added after I took the pictures).

Gear List:

72 DE PP2PB