Category Archives: Portable

W2AEW’s Trapped EFHW Antenna Tutorial: Building a Smaller, More Versatile Solution for Portable Operations

Many thanks to Alan (W2AEW) for the following guest post:


Trapped EFHW antenna story (it’s all Vince’s fault)

by Alan (W2AEW)

One of my favorite antennas to use for POTA activations is a 40m EFHW wire.  When properly tuned and deployed, it can be used on 40, 20, 15 and 10m without the use of a tuner (although, I really don’t mind using a tuner when I need to).  Most of my activations are on 40 and 20m, so those bands are covered easily.  It can be used successfully as a sloper, an inverted vee, or a combination of these (whatever the trees or support structures allow).  It is efficient, inexpensive to build, lightweight and effective.

There are a few downsides to this antenna.  The first is that it is approximately 68 feet (almost 21 meters) long.  That’s a lot of wire to get in the air.  Some POTA sites just don’t have that much room or support structures to effectively use this antenna.  Another downside is that it doesn’t naturally support operation on the 30m band, another favorite of mine.

A few weeks ago, I watched a video from my friend Vince VE6LK entitled: “Discover the secret ingredients to build a trapped EFHW antenna”. This piqued my interest…

The video introduces a design for a 40/30/20m trapped EFHW.  The fact that it covers the three bands I use the most, and would be shorter than my trusty full-sized 40m, and give me 30m to boot, got me excited to learn more.

Vince used a pair of traps (30m and 20m) that are offered in kit form by Tim Sherry, N7KOM.  Here is a link to kit on Etsy.

Image Source: Tim Sherry, N7KOM

These are exclusively for use at QRP power levels – perfect for my application.  I placed my order immediately after watching the video.  The build instructions are very detailed, including how to tune the traps, which is critical in getting the antenna to work.

Image source: SparkPlugGear

He also used a 49:1 UNUN from SparkPlugGear.  I’ve had one of these in my POTA kit for a while, but only used it occasionally.  This was another good reason to proceed with this antenna build.

Of course, you could also use the QRP UNUN kit from KM4CFT that I made a video about earlier this year.

I created a video that showed how to assemble and tune the traps.  Tuning can be a little tricky, and then stabilizing the turns/spacing to preserve the tuning is critical – not hard, just takes a bit of patience.

With the traps built and tuned, the next step would be to build and tune the antenna itself.

I was able to find the time this weekend to do just that, and make a video of the process.

Details of the resulting wire segment lengths are in the video.  It is important to note that if you decide to build this antenna, your wire lengths will likely vary from mine.  Several factors will effect the resulting lengths (details of the UNUN used, the trap construction, etc.).  My video goes through the process I used to build, tune and test the antenna.

“The proof is in the pudding” as they say.  It was time to actually run a POTA activation with this antenna.  The overall length of the antenna was about 43 feet (about 13.1 meters), which is about 2/3rds the length of the 40m EFHW.  This opens the possibility of using my 12 meter Spiderbeam mast (video review) as a support rather than just relying on a tree branch.

The weather here in NJ has been oppressively hot and humid with heat indexes over 100F, so I opted for a morning activation, before the heat really built up.  The intent was to get some contacts on all three bands, even though 20m probably wouldn’t be very active.

I setup at my “home” park – Washington Rock State Park, US-1635.  I decided to setup the Spiderbeam mast as the support for the new antenna:

The rig was my trusty KX2 with the BamaTech TP-III paddles:

I only had about an hour to dedicate to operating before the family activities for the day, so I figured I’d start on 40m and get most of the “ten” there first, then move on to pick up a few on 30m and 20m.

I was able to put 14 contacts in the log, under “so-so” band conditions, which at least a few on each band, several of which were park-to-park contacts.

Here’s the map of the “reach” that the new antenna had during this short activation:

Overall I am quite pleased with the antenna’s performance.  The near ideal band coverage for my typical activations, and the ease of deployment compared to the full-sized 40m EFHW make this antenna a great addition to my POTA kit.  I suspect it will get a lot of use!


Resources:

The Write Stuff: My pencil/paper weatherproof logging combo!

If you’ve followed my field reports in the past couple of years, you’ll know that I predominantly use Rite In The Rain notepads and mechanical pencils.

When I first started my POTA journey in 2019, I would print out log sheets for each activation just like I did during the National Parks On The Air program in 2016. It was a very inexpensive and organized way to manage all of my written logs.

Over time, though, I made a shift to small pocket-sized notepads (Moleskine, Moji, Mead…) basically any pad that took up less space and could remain in my QRP field kits.

Rite In The Rain

After a couple of moisture mishaps with Moleskine pads (which, by the way, I otherwise love) I decided to completely shift to using Rite In The Rain spiral-bound notepads.

I resisted doing this for a long time because Rite In The Rain pads aren’t cheap; they typically cost about $6-$7 US each, but they are made in the US and are very high quality. They don’t smudge or smear.

My father-in-law is a retired professor of Botany and the bulk of his research time was (literally) in the field–in the mountains of western North Carolina. He’s always been a huge fan of Rite In The Rain and we often purchased these for him as gifts.

I switched to Rite In The Rain and haven’t regretted it. Yes, they’re pricier than all of the previous options I’d used, but they are insanely durable, can survive getting wet, and they hold quite a lot of my 45-60 minute POTA and SOTA activations! One pad will typically last me several months.

There are two sizes of pads I use:

(Left) 3×5″ and (Right) 4×6″ Notepad

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The 3×5″ sixe easily fits in my Pelican 1060 case

I find that both sizes work well. I tend to use the larger 4×6 size most of the time, but I love the 3×5 size because it fits in some of my smallest field kits including the MTR-3B SOTA kit I highlighted last week.

When you use a Rite in the Rain pad, it will hold up in the rain if you are using any pencil, or one of their pens which has a special ink that bonds to the paper permanently.

I use mechanical pencils when I log, although I plan to start using pens more often only because it makes it easier for my YouTube video subscribers to read my logbook as I write (pencil can be more difficult to read from the camera angle, depending on reflection, etc.).

Mechanical Pencils

This is an area where (being fully transparent here) I can geek out a bit (understatement alert).

I’ve always had a place in my heart for mechanical pencils. It dates back to my high school years when I took drafting classes. These were the days when drafting desks, pencils, T-Squares, triangles, and templates were tools of the trade (CAD was just becoming accessible to students).

I found mechanical pencils to be an amazing piece of engineering and, while I couldn’t afford a lot of them, I would spend my hard-earned money to buy them. To me, visiting our local drafting store was like a trip to the toy store.

But I digress…

In the field, performing a POTA or SOTA activation, I don’t look for the same precision I needed in drafting class. Quite the opposite–I’m looking for durability and reliability.

Wooden pencils, to be clear, are both of those things and will serve you well in the field. What I love about mechanical pencils is that their leads are consistent when writing and there’s no need to pause and activation to sharpen them. Just click and keep going.

There are currently three mechanical pencil models I use.

My wife recently gave me a uni Core Keeps Sharp Mechanical Pencil as a gift. She did so after reading a comment from one of my readers (I had no idea she even read QRPer–I’ve got to be careful what I say around here!). 🙂

What makes this particular pencil unique is that it rotates the lead as you use it. This keeps the line looking sharp since the lead doesn’t wear to one side.

So far, I love it. This one has a .5mm lead, which is small–I tend to prefer .7 or .9mm because they’re more durable. Expect to see this in activation videos soon.

Next is the Zebra Mechanical Pencil, Del Guard, 0.7mm. This particular pencil lives in my MTR-3B SOTA field kit. The Del Guard has a double spring mechanism that acts as a shock absorber when you write.  If you apply a little too much vertical or angled pressure, it absorbs the energy thus saving your lead from breaking.

I find it works really well, in fact. I tend to have a heavy hand when I write in my log books and I find I have less lead breakage in the field.

Finally, the mechanical pencil I’ve adopted as my primary SOTA and POTA pencil is the amazing GraphGear 0.9mm 1000.

This pencil is the most durable mechanical pencil I’ve ever used.

Bruce (KO4ZRN) introduced this to me when he joined me on a SOTA activation of Craggy Dome a couple years ago. This pencil is incredibly strong. In fact, I’ve even used it in woodworking and carpentry projects to mark cuts on wood.

At this point, I think I probably own about six of these GraphGear pencils and I couldn’t be happier.

Video

I actually made a short (for me) video about my notepads and pencils:

Click here to view on YouTube.

Again, you don’t need anything fancy…

If you’re not into waterproof paper and mechanical pencils, just use what you have to log.

I remember once using the back side of an envelop and a pen I found in my car to log a NPOTA activation–it worked perfectly! I even remember another NPOTA activation using a pen to log and running out of ink, so I used the pen to log in the dirt on the ground. I only copied three or so more contacts then took a photo of the ground. (I can’t recommend this, but point is, practically anything can be used for logging!)

I just find that when I do something on a regular basis, I’m willing to invest in tools I love using. I feel they serve me well in the end.

How do you log?

I’m curious how you log. I know that a large percentage of POTA activations never write a thing on paper logs–they simple log directly to an app on their phone, tablet, or laptop.

I prefer making a paper copy of my logs, then taking a photo of them when the activation is complete. I worry less about my app crashing, phone running out of power, and, frankly, I just find the process of logging more fun on paper. Furthermore, rain can disrupt touch accuracy on capacitive touchscreen devices, making logging difficult in wet conditions.

I’m curious how you log in the field. Please comment!

Thank you

Thank you for reading this post!

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 not a requirement, as my content will always be free, I really appreciate the support.

Have a brilliant week and I hope you run out of paper due to the number of contacts you must log!

Cheers & 72,
Thomas (K4SWL)

Where the Heck is the POTA Babe?

by Teri (KO4WFP)

Okay. Y’all haven’t heard much from me lately and may be wondering, “What the heck is the POTA Babe up to?” Actually, a lot!

Earlier this year, I asked QRPer readers for suggestions as to parks to visit for a summer POTA trip to either North Carolina and/or Virginia. I appreciate all the suggestions I received. In evaluating the time I have and that I’ll be driving by myself, I have opted to visit North Carolina. I’ll be on the road for eight days mid-July camping with Daisy. I hope to activate ten to eleven parks as well as successfully complete four SOTA activations. It is a lot to bite off but then I enjoy being challenged.

I originally planned for a twelve-day trip but decided to nix the second week near the Charlotte area due to obligations at home. I am bummed at missing out on those parks. (Thank you Bob K4RLC for the recommendations in that area.) However, now I’ll have those parks to activate on a future trip.

Preparing for this trip is no slap-dash endeavor. At least not for this POTA Babe. As I mentioned in the articles of my last trip to southwest Georgia, I am tweaking my camping equipment as well as how I organize and access those items.

An item I’ve added is a fan because camping in July might be a bit toasty, even in western North Carolina. My partner Glenn W4YES came across a helpful video on the CheapRVLiving Youtube Channel discussing USB-charged devices. The Koonie 8” rechargeable fan was mentioned. As it received favorable reviews on Amazon and I can charge it using my Jackery, it is now in my arsenal for summer camping.

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Koonie USB-charged 8″ fan

I also added an ultralight shelter I may use on a summit or for POTA in general. While researching summits to activate, I came across a picture on the SOTlas website and reached out to that op as to information about the tarp he was using for shade. Patrick WW4D introduced me to Mountain Laurel Designs, a company that makes ultralight shelters (tarps and tents). They aren’t inexpensive, but then I’ve learned to purchase good quality where I can. In a shelter, good quality counts.

I purchased the Trailstar. It can be used as a tent or a shelter. Before the trip, I need to seal the seams. What I didn’t realize until the other day is that I will also need to cut the guylines as well as figure out what knots to use in securing the guylines to the stakes included. Then I have to learn how to set it up using my hiking poles. The learning never ends, does it?

I couldn’t believe how light the Trailstar is having never experienced a shelter like it. It will be a welcome addition to my SOTA backpack since it weighs hardly anything.

The Trailstar by Mountain Laurel Designs. source: Outdoor Gear Lab

I’ve also undertaken re-waterproofing my tent. Sierra Designs sent me instructions and information about the products they recommend which I ordered. I thought to myself “how hard could it be to re-waterproof a tent?” Those of you who have done this know it is a time-consuming process! You have to remove the old waterproofing substances before applying the new ones. The substances used for waterproofing fabric are meant to not come off easily, especially after being on there for 30 years (the age of my tent). I’ve spent more time in the bathtub scrubbing and smelling rubbing alcohol than I care to admit. However, when this process is finished, my tent and its rainfly will be clean and good to go for another eight years or so.

waterproofing products for tent and rainfly
Washing tent with unscented detergent and ammonia
old waterproof coating to be scrubbed off
section of tent floor with new coat of waterproofing barrier

I am also researching how to do a SOTA activation. I’ve found quite a few helpful videos on Youtube and plan to reference them in a future article. For my pack, I am using a Six Moons Designs ultralight pack (the Flight 30 Ultra) I purchased about four years ago. As it was not being used, I’ve been employing it as my POTA pack for several months now.  Given I’ll be hiking to activate summits, I need to rethink what I’ll take in the pack since, in addition to ham gear, I’ll need emergency supplies one should take when hiking.

While preparing for this trip, I’ve had a new addition to my shack that is sharing my focus as of late. Nearly two years ago, I ordered a Frattini Magnetic Evolution bug. I didn’t hear anything further for the longest time and figured it wouldn’t ever arrive. Then, about four weeks ago, Alberto Frattini sent me an email the key was ready and, oh by the way, was I still interested in it? You bet I was! “The Frattini” (as I call it) is now in my shack and I am resuming my pursuit of the Straight Key Century Club’s (SKCC) Triple Key Award. (When I’m not scrubbing the tent, mind you.) My fist is a work in progress but what a great challenge!

my Frattini Magnetic Evolution bug
Hummer on the Frattini plate – a nice touch given my POTA Babe logo also has a hummingbird on it

My goal is to run at three speeds eventually – 16, 20, and 25 wpm. Right now I am concentrating on 16 wpm as that is a good speed for SKCC QSOs. At that speed, I am more relaxed and the more relaxed I am, the better I can focus on making my characters correctly with good spacing. My goal with the Frattini is that the dits and dahs be proportional and timed well enough it doesn’t sound like I am using a bug. With continued practice off and on the air, I will eventually get there.

One thing I’ve found that helps is having either Word List Trainer up and running or my Morserino in the shack. Just like a choir conductor will play a note on a pitch pipe for a choir, I’ll play the letter “o” at 16 wpm to get that dah cadence in my head before I get on the air. Eventually, I’ll fall into that rhythm naturally at that speed but in the meantime, I find that trick extremely helpful with my timing of the dahs.

If you’d like to hear my bug fist (a work in progress, mind you), click on the video link here to access it on Youtube.  Also, if you’d like to follow my progress on earning bug QSOs for the Triple Key award, check out the goals section on my QRZ page.

Well, there you have it – my ham radio related doings since my southwest Georgia POTA trip. For those interested in hunting me while I’m in North Carolina, I will not release my itinerary in advance for safety reasons. However, Glenn or I will schedule my activations each morning so keep an eye out on the POTA and SOTA Watch pages beginning July 14 if you are keen to work me and support the trip.

I am a little nervous about the trip.  I’m going to be out of my comfort zone and sure to make mistakes. However, this is how we learn – making mistakes. This is a part of ham radio and such a trip – the unknown! Who knows what I’ll learn and discover along the way. I hope to work many of you that week and look forward to sharing with you those adventures on QRPer.com after my return. But before I leave next Sunday, I plan a POTA activation Monday, July 8 to get my head back in the game. What park will I pick? Stay tuned…

Deep Dive: My Mountain Topper MTR-3B Watertight SOTA Field Kit

Last week, in response to a reader’s question here on QRPer.com, I was reminded that I hadn’t yet made a video specifically about my Mountain Topper MTR-3B SOTA field kit.

Yesterday, I made a short video (see below) where I show what I pack in my MTR-3B field kit and why I choose to house it in a Pelican 1060 case.

First, let’s look at a list of the gear, then I’ll talk about what went into my choices, and I’ll link to the video.

Gear:

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Self-Contained Watertight Field Kit:

Optional Gear for SOTA/POTA:

Design Choices

Here’s the philosophy behind my design choices in this kit:

Pelican 1060 Case

I chose to house this field kit in a Pelican 1060 Micro Case even though, at one pound, it weighs more than the typical pouch I also use for small field radios. The Pelican, however, protects the entire radio kit as it’s fully watertight and crush-proof. If I trip while fording a creek or fall and land on my pack, the Mountain Topper will be safe. Yes, there’s a mass/weight cost, but I feel it’s very minimal for the protection it offers.

Counterpoise-less End-Fed Half-Wave

When I build the K6ARK EFHW antenna kit for my MTR-3B, I chose to make it without a counterpoise. Even though the antenna would be more efficient with a dedicated counterpoise and less prone to the effects of body capacitance, I feel like the benefits of this design outweigh the compromises. For one thing, leaving off the counterpoise saves space inside the Pelican case. In addition, by designing the antenna to attach directly to the MTR-3B’s BNC port, there’s no need to include a feedline, thus saving quite a bit of space.

So far, I’ve been very impressed with how forgiving this antenna has been and, most importantly, with how well it has performed.

N6ARA SWR Meter

I include the N6ARA MiniSWR  in my field kit to give me some peace of mind if my antenna deployment is compromised (for example, if the trees on a summit are too small, etc.). Since my MTR-3B version has no built-in SWR metering, I feel this is a meaningful addition tot he kit.

Throw Line and Weight

At least 90% of the summits and parks I activate here in western North Carolina have trees. To me, no field kit is truly sufficient unless I include a throw line and weight. I find that the Marlow KF1050 Excel 2mm Throwline is small, lightweight, and effective—-25 meters is enough to deploy any wire antenna I’d carry on a SOTA activation.

Many SOTA ops use a small sack that they place stones in to act as a throw weight for their line. This is very clever because you don’t have to pack in that extra 8 ounces on the roundtrip hike. Still, I like the convenience of a throw weight that’s designed to glide through tree branches with ease–especially if the tree is dense. If I were to do a multi-day SOTA backpacking trip, I’d probably use an empty throw sack instead of a dedicated weight.

Rechargeable 9 Volt Battery Packs

I love these 9V rechargeable batteries. It’s hard to believe that the MTR-3B can complete 2-3 typically SOTA activations on one charge! Then again, the MTR-3B uses something like 18ma in receive? That’s crazy low current consumption. These batteries are super lightweight and the particular brand I use has never produced any RFI (I’ve read that some others can). What’s best is that I can recharge these easy via a USB-C cable.

The MTR-3B will operate on nine volts, which yields three watts of output power.

Helinox Chair and Kneeboard

Yes, these are luxury items. I know many SOTA ops who are quite happy to sit on the ground and balance their radio on their leg. Perhaps it’s my age, but I don’t like doing this anymore because my legs tend to fall asleep and I lose feeling in them if not careful.

My Helinox Zero chair weighs 1 lbs 2 oz (509 g). I feel like it’s weight and mass well-spent. Since I record activation videos, the chair also gives me a much better position for my camera angle (bonus!).

My Tufteln/N0RNM kneeboard is an essential part of my SOTA kit. I never leave without it. The chair and kneeboard combo gives me the flexibility to set up anywhere, anytime. I love it.

Video

Here’s a video showing the breakdown of my Mountain Topper MTR-3B SOTA field kit:

Click here to view on YouTube.

Thank you!

 

Thank you for reading my field kit post and watching the video! I hope you enjoyed it.

As always, 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 not a requirement, as my content will always be free, I really appreciate the support.

If you’d like to see loads more field kits, check out our field radio kit gallery!

Thanks for spending part of your day with me!
Cheers & 72,
Thomas (K4SWL)

Friedrichshafen: Christian and Andrea’s Multi-Country POTA Rove

Many thanks to Christian (IX1CKN) who shares the following field report:


Friedrichshafen: POTA Across Borders

by Christian (IX1CKN)

The Friedricshafen fair is one of the most interesting events for its social aspects, where you can finally put a face to colleagues whose voices you’ve only ever heard. Among the various OM (radio amateurs) I met this year was Gabriele IT9RGY, a flagbearer of the Italian Contest Club. When he recognized Andrea IW0HK and me, he said, referring to our respective SOTA/POTA activities: “You two are the real deal.”

I found that to be a very powerful statement, and I am grateful to him for it. Personally, I try to document each outing to capture the sensations it gave me, but also in the hope of inspiring someone. Andrea is more succinct than I am (if we were all the same, the world would be boring), but his spirit is identical. Parks on the Air (POTA) is a state of mind. It was no coincidence that, being in Germany for the Hamradio Messe, we had planned a series of activations.

Our schedule was tight and ambitious, and just completing it was a source of happiness, but there’s more to tell. In Germany, dinner time isn’t synchronized with Roman schedules. So, on Friday evening, after leaving the restaurant (for dinner with the Summits On The Air group) at 20:23, I looked at Hotel-Kilo and said, “If I go to bed now, I’ll digest in a week; let’s go activate a reserve!”

The easiest option in the area (after a disastrous experience last year in DE-0156, the park in the town center hosting the fair) was DE-0766, the Seewald Landscape Reserve. It’s near the FRN airport (and thus not far from the fairgrounds), in a fully bucolic setting. A narrow road cuts through meadows, with footpaths and bike paths leading into a wooded area.

We parked the car in one of these spots. It took only a moment to set up the vertical antenna in the field, but the presence of a swarm of mosquitoes as big as F-18 Hornets advised us to operate from inside the car to save our skin (literally).

Andrea turned on the KX-3 (10 watts would be our fixed power for this trip), and the 14 MHz calls began. Right away, a very strong IZ3QFG Dario (just 380 km from us) answered, highlighting an unusually short skip.

We logged 20 QSOs in 30 minutes… Many were from Italy (Spartaco from Grosseto at full scale, Mauro I1JQJ always active, and Beppe I1WKN a constant), with two “park to park” contacts. A classic for many OMs in the area, but also a great mood booster and a tasty appetizer for the next day… Continue reading Friedrichshafen: Christian and Andrea’s Multi-Country POTA Rove

Construction Notes: VO1DR Monopod Antenna Mount

Many thanks to Scott (VO1DR) who shares the following guest post:


Construction Notes – VO1DR Antenna Mount for Camera Monopod

by Scott Schillereff,  VO1DR

Further to my article about radio during trip to Portugal, a number of readers asked for details on how I mounted my whip antenna system to my camera monopod for /P use.  Here are some photos and notes on this.

General notes:

  • This is a “straight-through” design.  Just direct connections from the BNC center pin to whip (via brass nut), and BNC housing to radial connector.
  • This is not a cook-book construction article, rather just a show-and-tell of how I built mine.  You can use what you have on hand to build something similar.
  • I suggest you start with your telescoping whip, so you know the size and threads for mounting bolt.
  • You could use any type of connector for the radial (wingnut, knurled nut, spade lug, alligator clip, whatever you like).  I prefer banana jacks since a) I can push in the radial banana plug fast, b) the plug is a weak release point (pulls apart if someone walks into the radial), and c) I can easily attach additional radial wires, if desired.
  • Use a strong case (metal clamshell or cast aluminum work well).  With the whip extended, there can be substantial forces (bending moment) from wind or handling. A tiny plastic case would be fractionally lighter but might fail.
  • For size, the one I used (25 x 25 x 50 mm; 1” x 1” x 2”) is about as small as I would go.  It needs to have a big enough footprint to sit firmly on a camera mount fitting.
  • Use high heat (e.g., Weller 100-140 W solder gun) when soldering the center pin wire to the brass whip mounting nut.  Solder the wire to the brass nut before you epoxy the nut.
  • I custom made the white plastic insulating bushing (where whip screws in). This was from a nearly-right bit from my junk box.  You can be creative here.  You could also epoxy on short piece of close-fitting, thick-walled PVC pipe around the outside of the whip mounting hole as a supporting sleeve to give some lateral support to whip when it is screwed in.
  • Dry-fit everything (before epoxying) to make sure nothing touches that shouldn’t and you can screw in the camera nut and whip fine.  Test proper continuity of center pin and radial connections to BNC fitting.  Once glued, there’s no going back!
  • For surfaces to be epoxied (metal nut sides and bottom, insides of mounting case), slightly roughen with sandpaper or jewellers file, then clean with isopropyl alcohol and Q-tip.  This will increase adhesion and strength.
  • Use good-quality, high-strength, long-cure epoxy (e.g., JB Weld), not el-cheapo 5-minute epoxy from the Dollar Store.  LET THE EPOXY COMPLETELY CURE BEFORE MESSING WITH IT!  Just walk away from it for a day… (your patience will be rewarded).

Figure 1 – VO1DR Antenna Mount, clamped onto top of monopod.  Coax goes to BNC on left; whip screws into top; raised radial connects by banana plug on right

Figure 2 – Antenna mount unclamped from top of monopod.  The black plastic fitting (at right, with wedge-shape) fits into slot on platform at top of monopod (at left) and clamps in with cam arm.  Large steel screw attaches wedge fitting to antenna mount case. Ruler shows scale of things.

Figure 3 – Antenna mount case (right) unscrewed from camera mount fitting.  Steel screw is standard camera mount size (1/4-20 thread size).  Black silicone cap keeps dust out of BNC connector.  If your camera mount does not have a detachable wedge fitting (like the one on the left), you would simply screw the camera mount screw directly into the bottom of the antenna mount case.

Figure 4 – Top of monopod dissembled to show (clockwise from top): black monopod tube with telescoping whip stored inside (stainless steel with 10 mm brass mounting bolt), antenna mount case, detachable camera mount fitting, and round top plate of monopod.  For my monopod, I had to remove one tiny screw and apply gentle torque to break a weak glue joint of this round piece on top of the monopod leg.  It remains a snug hand fit (no screw needed).

Figure 5 – Fully assembled whip antenna mount with wiring.  Radial (blue wire) with tie-off cord (yellow) at left; RG174 coax (5 m) at right.  Whip is only ever screwed in hand-tight.  Deploying in the field, I first tie off the monopod to something (park bench, picnic table, fence, tree), then screw the collapsed whip into the antenna mount and clamp mount on top of monopod, then plug in radial and tie the yellow cord off to something (straight out at 2 m height or slope down to ground anchor), and finally connect the coax to the rig.  When all in place, I carefully raise the whip (slowly, with two hands to reduce bending forces).  Take-down is all in reverse.

Figure 6 – Detail of antenna mount case.  Case is 50 mm x 25 mm x 25 mm aluminum clam shell box with square metal end plates.  These end plates are screwed in to hold the two halves together.  White plastic bushing provides additional lateral support for the whip when it is screwed in.  The bushing is glued to outside of case with CA (Krazy) glue.

Figure 7 – Inside of antenna mount case.  On left, a ¼-20 steel nut is epoxied to inside of case with strong JB Weld epoxy.  In main case, a 10 mm brass nut is epoxied to inside of case with an insulating washer beneath.  This brass nut connects to the whip and is “hot”, so must be insulated from the black aluminum case.  Yellow wire connects center of BNC to brass nut (soldered).  Black wire connects ground side of BNC to radial banana jack.  Use plenty of epoxy; there is a lot of force exerted on the steel and brass nuts.

Figure 8 – Detail of inside of case.  Note separation of banana jack solder post and edge of 10 mm brass nut.  Solder yellow wire to nut before epoxying in nut.

Hope you find this useful.  Just use what you have on hand and some ingenuity to make yours!

Best 72, Scott  VO1DR

QRP SOTA: Lee pairs the KH1 and MPAS 2.0 to activate High Willhayes (G/DC-001)

Many thanks to Lee (M0VKR) who shares the following field report and video:


SOTA CW Activation on High Willhayes Dartmoor

by Lee (M0VKR)

It was an overcast and breezy morning when wife Joanne and myself Lee, M0VKR set out on our latest SOTA (Summits on the Air) activation adventure. Our destination was High Willhays, the highest point in Devon UK – SOTA G/DC001, Dartmoor is well known for its rugged beauty and challenging terrain.

We parked the car a short distance up the road from the army camp, slung our packs over our backs and set off. The gravel tracks leading to the summit stretched out before us and took a winding path through the moorland.

A few sheep and cattle grazed in the rough grass as we made our way upwards on the gentle slope. It was a breezy morning and we had had rain a short while earlier. Despite the weather our spirits were high, and we were eager to reach the top and get on the air with the Elecraft KH1.

In my pack was my now trusty Elecraft KH1 and an MPAS 2.0 vertical antenna, with the KX3 as backup, a reliable setup for such expeditions. I’m pretty sure I could halve the weight in my pack, but as it’s not a huge walk to the summit I don’t mind ferrying the extra gear to the top. The weather, though overcast, was adding a touch of drama to the landscape, and the breeze kept us cool as we trekked upward.

Joanne, ever the supportive partner, helped carry some of the cooking equipment and victuals and she kept the mood light with her cheerful conversation.

After a brisk hike, we reached the summit of High Willhays. The view, even under the Grey sky, was breathtaking. Rolling green hills and expansive moorland stretched out as far as the eye could see.

I set about preparing the station, using the MPAS 2.0 vertical antenna, which is quick to deploy and ideal for the variable conditions we faced. Despite the less-than-ideal propagation conditions, I was determined to make the activation a success.

Although the MPAS in vertical form isn’t very efficient on 40, I prefer to take advantage of the quick setup that it offers, one of these days I will look at adding a top section to make 40 more efficient, perhaps as a sloping inverted L or something similar, more reading of the manual required!

With everything set up, I made the first call on the 40m band. My Friend Matt MW0KAX answered, he was essentially line of sight from Wales, so his signal was strong. That was the first and last contact on 40m. I changed to 20 meters, where the MPAS was more efficient for the little KH1 and it was able to breathe a bit easier. The tuner in the KH1 is nothing short of amazing, and quite happily tuned 40 meters in a few seconds.

The static crackled, and for a moment, there was silence. Then, a faint reply came through. The thrill of making that first contact was palpable. It still amazes me every time I make those first few contacts that QRP does work, even with a compromised antenna system. Despite the challenging conditions, My limited skill, Plenty of luck and the reliability of the equipment began to shine. All the equipment I was using was off the shelf, I hadn’t made a single thing myself, maybe one day.

One by one, contacts started to come in. Each short QSO contact was a small victory, a testament to perseverance and the joy of ham radio. It is necessary to persevere as a newer CW operator and use QRP power levels and poor propagation conditions. It’s non-negotiable after driving for 2 hours, and a 4km hike that we go home empty handed. I logged each contact meticulously, my excitement growing with every successful connection. Joanne watched on slightly bemused but very supportive of the hobby, sharing in the triumphs that each contact brings and providing much-needed encouragement.

By the end of the activation, We had made several QSOs. While the propagation conditions had been far from ideal, the activation was undeniably a success. We had achieved what we set out to do: connect with fellow hams across the airwaves from the summit of High Willhays for a SOTA activation.

As we packed up our gear, the breeze picked up, and the clouds began to clear slightly, offering a glimpse of blue sky. The trek back down was filled with reflections on the day’s achievements and plans for future activations. We both felt a deep sense of accomplishment. We had braved the elements, navigated the challenging RF conditions, and emerged victorious.

This activation, like many before it, was a reminder of the joys of ham radio, CW and QRP operation and the adventure it can bring. For me and my wife Joanne, High Willhays would always hold a special place in our memories, not just for its height, but for the heights that we reached together on the airwaves.

Activation Video:

Take care and Speak soon, 72,

Lee M0VKR

Tabletop QRP POTA: A Father’s Day Getaway to Mount Mitchell State Park

When our family needs a change of scenery without a long drive, Mount Mitchell State Park is our go-to destination. I’ve mentioned before that it’s my “happy place” here in North Carolina. Mount Mitchell is only about 6 miles from our home as the crow flies, but it takes about 50 minutes to drive there, and it’s not in the direction of any of our usual destinations. Heading up the Blue Ridge Parkway and watching the flora change with elevation makes it feel like a proper getaway.

On Sunday, June 16, 2024, we wanted just such a getaway, as my wife and daughters were treating me to some Father’s Day fun. After visiting my father-in-law in the hospital in the early afternoon, we drove to Mount Mitchell.

Mount Mitchell State Park (US-2747)

Sundays on Mount Mitchell tend to be busy, especially in the summer. However, on this particular Sunday, it was rainy, foggy, and there were storms in and around the area.

Weather like this never bothers us on Mount Mitchell, as it can shift in an instant, as long as thunderstorms don’t intrude.

As soon as we arrived, I grabbed my radio bag from the car and found an empty picnic shelter. I’d been hoping for a free shelter since it was raining, and fortunately, we got our pick!

One of the first things I did after dropping off my pack was to tie Hazel to a picnic table because she was laser-focused on a chipmunk she saw run up a tree next to the shelter. That dog drives chipmunks and squirrels crazy, I’m sure.

My wife and daughters dropped off some art supplies at one of the shelter tables, then went on a short hike while I performed my POTA activation.

Note that Mount Mitchell is also a SOTA summit, but the picnic area is not within the activation zone. I could have easily gone to one of my go-to SOTA spots on the summit and knocked out a SOTA activation quickly (only four contacts are needed), but I wanted to save that for another day. Plus, being in the shelter meant that I could have a nice leisurely, dry activation!

I brought along my Penntek TR-45L and planned to pair it with a random wire antenna for the activation. However, since the weather was iffy—again, my primary concern was any thunderstorms that might sneak up on us—I decided to skip the wire antenna and go tabletop instead.

Fortunately, my Elecraft KH1 lives in my EDC bag at all times, so I set it up for tabletop mode.

New Tufteln KH1 Right Angle Adapter

KH1 “tabletop mode” gave me the perfect excuse to try out an accessory my friend Joshua (N5FY) sent me: his version of a KH1 right-angle antenna adapter.

You might recall that I have used the Elecraft KH1 adapter in previous activations and I think it works brilliantly. The first version of Elecraft’s adapter had one issue: the parts would fall apart if you weren’t careful with how you attached it to the KH1.

Joshua designed his right-angle adapter with captive components so that it’s all in one piece and can’t come apart.

I should note here that Elecraft actually updated their right-angle adapter design so that it also has captive components as well—so you have two choices! I’ll use the new Elecraft adapter in a future video and field report.

Joshua’s Tufteln design works really well (it’s also less expensive than the OEM adapter), and I like that it’s bright red, which means I’m less likely to leave it in the field!

Gear:

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On The Air

I assumed that 20 meters might be the most productive band that afternoon, so that’s where I started calling CQ POTA after snagging a Park-to-Park with K9NUD. Continue reading Tabletop QRP POTA: A Father’s Day Getaway to Mount Mitchell State Park

WN5C: Notes from a homebrew POTA adventure

Many thanks to Sam (WN5C) who shares the following guest post:


Notes from a homebrew POTA adventure

Sam (WN5C)

I recently wrote about the homebrew transceiver I built to operate on a month-long trip through the American Southwest. Upon arriving back in Oklahoma here’s the final outcome: 27 days, 40 parks, and 669 QSOs. I honestly can’t believe that the rig went the distance, or that I made so many contacts on 2 watts or less!

The priority of this trip wasn’t radio, though. I’m an archaeologist and I’m starting a new research project that marries my historical interests with my love of two-way communication. In short, I’m studying the effects of how communication technology aided the American colonization and transformation of the western United States around the turn of the twentieth century. This means I walked and mapped single-wire telephone lines strung up in pine trees in northern New Mexico (used to connect fire lookouts with Forest Service ranger stations), a fascinating story of dramatic changes in land management. I also visited heliograph (sun-mirror signaling) stations established in southeastern Arizona by the U.S. Army Signal Corps in 1886 to assist in apprehending Geronimo.

Working Fort Bowie NHS (US-0815) in Arizona. The peak in the distance, Helen’s Dome, had a heliograph station on top. From the fort telegraph lines would have connected remote operations to the rest of the Army’s 1880s communication network. Next time I’m climbing up on top!

I look forward to relocating and studying the artifacts from more of these heliograph sites (mostly on remote peaks) to reconstruct this communication network and understand the lives of both the soldiers and the Apache, and how this novel surveillance system altered the battlefield. Based on the artifacts I’ve seen so far there are many cans of Army-issued proto-Spam and beer bottles surrounding the signaling station where American Morse Code would have been sent and received via flashes of sunlight. The original Field Day?

But back to radio. I covered a lot of ground and activated parks in Oklahoma, Texas, New Mexico, Arizona, Utah, Colorado, and Kansas.

The POTA sites that I activated (click image to enlarge).

At some locations I was camping so I was able to do multiple long activations and work the lower bands well into the evening. These were some of my favorite moments of the trip, being the only spot on the POTA app and leisurely working with no time or weather-based worries. It also gave me a chance to hear callsigns I was unfamiliar with, essentially exploring a new area of the country.

Working closer states after hours on 30 and 40 meters at Colorado NM (US-0918).

For other times, due to time constraints or weather (thunderstorms or that it was unbearably hot), I got my 10 contacts and moved on. Sometimes I packed the equipment for a long hike, often carried it from the car to a picnic table, and a few times deployed my antenna and operated from my vehicle.

Not every activation was a grand adventure. Sometimes, like here at Rocky Mountain Arsenal NWR (US-0226) in Colorado, I worked from the passenger seat in the car.

Every activation was memorable in its own way. I worked folks from 44 states, five Canadian provinces, and an unforgettable contact from Italy.

A map of the contacts I made (not including those in northern British Columbia, Alaska, and Italy).

The radio held up surprisingly well. Aside from it looking like a Dalí painting as the 3D printed box continued to deform in the heat, and some hot glue remelting, the electronic components worked as they should. I look forward to printing a stronger case and making some upgrades going into the fall. I do now have a real respect for the engineering that goes into designing field radios, especially those that are thrown into a pack!

Setting up a portable shack on Vail Pass in the White River NF in Colorado (US-4410). This was near the end of the trip, the plastic case was looking pretty bad.

After I began feeling less anxious about the homebrew radio (it kept turning on!) I could start focusing on the trip itself: an amazing POTA adventure with an often-uncooperative sun. Here’s a few themes I noted. Continue reading WN5C: Notes from a homebrew POTA adventure

VO1DR Portable in Portugal: Coffee, Cobblestones and Contacts!

Many thanks to Scott (VO1DR) who shares the following guest post:


Coffee, Cobblestones and Contacts – Portable in Portugal

by Scott Schillereff, (VO1DR), St. John’s, NL, Canada

On a recent trip throughout Portugal (May 29 – June 12), I operated /P QRP CW at five locations, with varying success.  Here are some details and pictures that you might find interesting.

Portugal and /P sites

Figure 1 shows a map of Portugal and the five locations where I operated.  On this trip, we were on the move a lot, so radio was tucked in here and there when I found some free time.

Figure 1 – Portugal and operating locations. 1 Lisbon, 2 Faro (Algarve region), 3 Foz do Duoro (near Porto), 4 Funchal (Madeira island; off coast of Morocco), 5 Monte Estoril (coast west of Lisbon).

QRP gear

I was packing the following gear in a small compartmented zip bag:

  • ATS-V5 CW transceiver for 15, 12, and 10 m (small-run kit from Steve Weber, KD1JV; fits into lid-less Altoids tin).  My max P(out) was 1.7 W on 15 m rising to 2.3 W on 10 m.
  • Homebrew whip antenna system.  2.54 m telescoping whip on top of a 2 m camera monopod; raised radial (coiled up to preset lengths to resonate on each band); no ATU; directly wired via 5 m of RG174 coax to choke at rig.
  • Homebrew common mode choke – RG174 coax threaded through five FT37-43 toroids and coiled around a larger unknown ferrite core (scavenged from TV).
  • Homebrew resistive SWR bridge – common design to null out an LED at low SWR; max tuning SWR 2:1; switchable in and out of Tx circuit; direct BNC connector to rig
  • 30,000 mA-hr Lithium-ion battery– car jump-starter; lightweight (284 g); 15V and 5V no-load outputs; 15V output through voltage controller to rig.  One charge did entire trip.
  • Homebrew Voltage Controller – simple design based on LM317T regulator and small V-A display (see article in SPRAT #195, p.24).  Vin max 40V; Vout 1.2-37V; Iout up to 1.5A.
  • Homebrew single paddle key, made with popsicle stick inside a plastic screw-top vial.

I chose a whip- versus a wire-based antenna system because I anticipated setups on hotel balconies, beaches or in city parks, not “off in the woods”.  Wire antennas are certainly more portable and could be taken in carry-on without worry, but might be more noticeable during setups in city parks.  Wire antennas are also not much good on beaches or balconies (without distant anchor points).  I wanted to be less conspicuous, and didn’t need to worry about weight.

Air travel with radio gear

I put all my QRP gear and antenna in my checked bag and had no trouble anywhere.  I added a note in English and Portuguese stating that this was amateur radio gear for hobby use, and included a copy of my Canadian licence. I probably could have taken the works in carry-on, but I was a bit uncertain about the metal monopod and whip (might be perceived as a weapon) so I just checked it all.

1. Lisbon Old Town

Due to a *two-day* travel disruption on the way to Portugal (thanks to Air Canada at Toronto Pearson airport; another story), we only had one night in Lisbon. Our hotel was a four-storey concrete and steel building in a narrow street. Our 3rd storey room had two little balconies about 3 m apart, with metal rails. To test the waters, I mounted the monopod and whip on one balcony and tied off the radial to the other balcony. The antenna impedance match was fine but, either due to band conditions, night time, or metal in the buildings, all three bands (15-10 m) were dead. Not a single signal; not even the ghoulish drone of digital signals; a total bust. Not a great start, but things improved later – read on!

Figure 2- Tram on steep street in Lisbon Old Town, close to our hotel

2. Faro (Algarve Region)

We travelled by wonderful inter-city Portuguese train to Faro in the Algarve.  Faro is a hub city in this sun-drenched and slow-moving southern region of Portugal; a region where everyone seems to be in second gear, and quite content there. Being a coastal city, I had hopes of good propagation.  Our schedule meant I could only play radio at our hotel late one afternoon. I set up in a quiet corner of a concrete-walled, 2nd storey courtyard with an open roof.  The top of the whip extended ~1 m above the concrete wall, but the radial was deployed entirely within the courtyard.  An improvement on the air – I could hear a number of stations, mainly on 15 m, and worked LY2NK (Lithuania, 3,119 km).  I was amazed at what 1.7 W and a whip antenna with a single raised radial could do!

Figure 3 – Walking street in Faro, 5 min from our hotel.
Figure 4 – Boats at Ilha da Culatra, on day trip out of Faro

3. Porto and Foz do Duoro (“mouth of the Duoro”)

We travelled on a delightful high-speed train (complete with coffee and snacks trolley down the aisle!) up to Porto in the north of Portugal.  Porto has a much different vibe than the Algarve.  A more working-class, energetic, commercial feel, and steeped in the wine- and port-making industry along the picturesque Duoro River. The Duoro Valley is a huge viticulture region and, yes, they still stomp grapes with bare feet on harvest day (don’t worry – in the making of port, fortification with 60% alcohol (aguardente) abruptly stops sugar fermentation and kills every living microbe in the batch!).

One afternoon, we took a clattering electric tram from downtown Porto west to Foz do Duoro, a seaport town 6 km away where the Duoro R. empties into the Atlantic.  After an espresso in an outdoor café, I set up the radio in a city park adjacent to the ocean – monopod lashed to a park bench and a radial tied off to a palm tree.  Figure 5 shows my park bench set up with a sea wall and Atlantic in the distance.  In QRP radio, as in real estate, “localização, localização, localização”!  Conditions were great here and I worked these stations on 15 m:  TM56JO (France; 1,087 km); HA0DD (Hungary; 2,476 km); OU5U (Denmark; 2,146 km); LY2PX (Lithuania, 2,903 km); and 9A2N (Croatia, 2,119 km).  Very exciting! And, again, passers-by  took no notice.

Figure 5 – Radio set up on park bench, Foz do Duoro, Portugal. View west to Atlantic Ocean in distance.
Figure 6 – Detail of my radio set up. Clockwise from L to R: paddle key in clear plastic vial; blue floss container with volume control for ear buds; ATS-V5 rig (green cover) in bottom of Altoids tin; oltage controller in bright blue Altoids tin; Li-ion battery pack (black rectangle); common mode choke (red sleeve); resistive SWR bridge (silver top with LED). Zippered back for this gear is immediately to right. The whip collapses to about 14 in and fits inside the camera monopod for transport.

4. Madeira

Air travel is fairly cheap within Portugal, so we detoured to Madeira, an autonomous Portuguese island in the Atlantic ocean ~1,000 km southwest of Lisbon.  The main city (Funchal) is about even with Casablanca on the Moroccan coast.  Madeira is a very rugged volcanic island with its highest point (Pico Ruivo) 1,862 m (6,109 ft) above sea level.  We were based in Funchal and toured around to see the sweeping vistas, mountain-scapes, and steep coastal cliffs. Continue reading VO1DR Portable in Portugal: Coffee, Cobblestones and Contacts!