Tag Archives: Tim (N7KOM)

Accessories, Antennas, Guest Posts, How To, News, Portable, QRP

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

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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:

Antennas, Field Day, Guest Posts, Morse Code, POTA, QRP

Experimenting during Field Day 2024

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by Vince (VE6LK)

Field Day 2024 started out with the best of plans to be spent with the best of friends and ended up totally different – and, unexpectedly, I had a hoot! With my carefully made plan behind me, my new last-minute plan was to run solo for Field Day in the backcountry of Kananaskis Country and bring along my new-to-me Nikon D3400 and lenses and rekindle my interest in (D)SLR photography at the same time as doing some experimentation with radio gear.

I grew up in a home with a scratch-built enlarger and a darkroom, so a love of taking pictures has been with me for a long time. My Father taught me patience to get the shot as he would set up a 120 format bellows camera on an air-triggered remote release to get closeups of chipmunks while we were camping, a process that took hours and yielded excellent results. My Brother, AG7GM, has attempted to instill within me the basics of composition, rule of threes and such and his wonderful skill in editing both stills and live video. While I have plenty of patience, with composition I think I’m fair to middling at best.

Thus photography has always been on my mind.

With a recent sale of a few ham radio related items, I had fun money, so just for fun I started looking [on Thursday before I activated] at used DSLRs and was shocked at how much camera I can get for such a relatively low cost compared to new. I had said once, 25 years ago when I divested out my 35mm kit, that when I could get a DSLR with a 25 to 300mm lens for <$500 I’d jump in… and finally that day is here, even if it means carrying two lenses. Of course, I started looking on the day before Field Day for deals – and scored them too! 🙂 Around these parts, good quality pre-owned consumer grade DSLRs are easily available. I purchased this as much for still photography as for ability in shooting high-quality video for my YouTube channel.

These peaks form part of the border between Alberta and British Columbia to the west

For me, Field Day has always been about the experimentation rather than chasing points. Trying new things. Changing up from the normal way I operate in the field. Comparing, analyzing and making notes as I go.

For example, and as a tribute to Chip Margelli K7JA (SK) after corresponding with his brother David, last year I attempted to wet a piece of string and see if the KX3’s tuner would match it and radiate a signal. Chip was known for many things, among them his proficiency in CW as he demonstrated on The Tonight Show with Jay Leno in 2005. David told me that he and Chip would do crazy and fun experiments like loading up clotheslines and wet string to experiment .. and it fostered a new direction I could take each FD and on some days between. The string experiment was a failure last year but I haven’t given up yet!

This year, I wanted to work with a few different antennas and a Charmast 100W battery pack from Amazon along with a USB-C PD 12v power cable for my KX3 [note: Amazon affiliate links!].

I wanted to know, in no uncertain terms, that the Charmast would or wouldn’t be as quiet as my trusty Talentcell LiFePO4 pack. The Charmast is also used in my field soldering kit with a Pinecil as it delivers USB-C PD. What better way to test this out than to head as far away from noise sources as possible, see the Canadian Rockies in their early summer glory with snow on the peaks, rivers running high (and cold) and the sun in the sky? Just for grins I would ensure that I was in POTA entities while doing Field Day.

Continue reading Experimenting during Field Day 2024 →

Field Radio Kits, Portable, QRP, QRP Radios

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

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

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

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

A Pocket HF Go Kit.

by Tim (N7KOM)

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

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

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

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

Other notes

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

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

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

Here is a video tour of the kit on YouTube:

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

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

[Please note that Amazon affiliate links support QRPer.com at no cost to you. Thank you!]

Field Reports, Guest Posts, Mobile, News, Portable, POTA, Travel, Videos

2,112 miles as AI7LK in the US Pacific Northwest

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by Vince (VE6LK/AI7LK)

As always there are links within the article. Click one! Click them all! Learn all the things! 

In December of 2023, I found myself with a surplus of vacation from my employers, and my Brother who’s move-in date to his new home got suddenly moved forward to just before Christmas. I was able to get time off work and make an epic road trip with POTA stops along the way to both allow me to have some radio fun and to give my body a stretching break. My trip would take me from my home in Alberta, westward through British Columbia, southward into Idaho, Washington, Oregon and I even made it as far as Northern California to see the Pacific before turning around and heading back home.

Along the way, I activated at 14 stops which totaled 21 parks in all after factoring in the 2-fer, 4-fer and 5-fer stops! This was a total of 301 actual QSOs netting 508 after the x-fers were computed in. It was a mix of CW and voice with an average of 21 contacts per stop.

There were many highlights of the trip, and naturally spending time with my brother and his wife were at the top of the list–despite the work of moving into a house–followed by the simply spectacular scenery along the route and the route planning itself. While this trip was decided upon on a Thursday evening and I was on the road the following Monday, I still found about 10 hours to research points of interest along my routes and look for POTA entities that had either not been activated yet or were CW ATNO, having only had a Phone or Digital activation previously. For the most part, these were the stops I targeted as my waypoints.

The Columbia River is nearly a mile wide at Rooster Rock SP

Driving along the Columbia River Gorge on I-84 approaching Rooster Rock State Park felt like driving along the base of the Grand Canyon, given the 1000′ height of the cliffs beside me. Rooster Rock State Park (K-2850), is notable for two reasons. 1 – it’s a 5-fer activation point – my first 5-fer stop ever doing POTA, and 2 – it’s windy as heck as you can see in this short video I took for Charlie W7RTA who told me, via Discord, it would blow [what’s left of my hair] off my head.

Click here for 7 seconds of the Columbia River Gorge wind whipping the hair off my head!

Certainly Rooster Rock was a highlight given it’s the only 5-fer activation I’ve ever done. It was activated two hours after a 4-fer at Willow Creek State Fish and Wildlife Area (K-10646). I only learned about the multiples after chatting with folks on the POTA Discord server.

It was a short drive from Rooster Rock SP to the home of KJ6VU in Oregon City, Oregon. While I’ve worked with George on the Ham Radio Workbench Podcast for nearly three years, I’d never met him in person until this trip. It was such a treat to spend time with him.  George is the creator of the Packtenna that so many of us love to use. As luck would have it, the KJ6VU repeater was due for a replacement and scheduled for the next morning, and I was able to put my skills in racking (installing) repeaters to good use. After we finished the repeater I departed and did some performance testing while southbound on I-5 to test its range.

The repeater crew. L to R: Josh K6OSH, Nick KF7SOM, the Author, and George KJ6VU

Along the way I got to have a coffee break with Nick Smith NT3S who I had met via Discord. Nick can be found activating parks and going overlanding on weekends. Thanks Nick for the time to have a break with you!

Over the next several days I spent time in Grants Pass Oregon assisting my brother and his wife to get moved in. Grants Pass even has a Harbor Freight Tools and I was able to get some shopping done! So as it turns out I wouldn’t be slugging boxes every day and there was a bit of a break during my visit to go out and play radio. I know the POTA program is especially popular in the United States and I’d heard that every entity has been activated at least once, which is very different from here in Canada where many parks are untouched. In my research and thanks to the parks added in the autumn of 2023, there are some in the system that had never been activated. On one Saturday afternoon I was able to visit one of these parks -Cathedral Hills Trail System- and work 72 contacts in under an hour on SSB.

Cathedral Hills Trail System, Grants Pass Oregon
Tall trees at Cathedral Hills Trail System, Grants Pass Oregon

On the following Tuesday, I headed out from Grants Pass to head to California if only to tick off the box on POTA’s website saying I’d activated there. I had no idea that Highway 199 would be so scenic. I activated six entities on this day.

At the end of Highway 199 is Tolowa Dunes State Park (K-1202). The photo at the top of this article is on the dunes and at the coast of the Pacific Ocean near Crescent City CA. Yes, I walked along the surf despite the threatening weather. It also allowed me the luxury to park within the dunes themselves to do my activation with a spectacular view. Continue reading 2,112 miles as AI7LK in the US Pacific Northwest →