Category Archives: Antennas

Beautiful POTA activation at Brunswick Town/Fort Anderson and Afternoon in Southport!

On Wednesday, July 10, 2024, my wife and I were in the middle of a week-long stay in Wilmington, North Carolina, while our daughters attended residential programs at NCSU and UNCW.

That particular day, we couldn’t decide what to do because the weather was fickle! Temperatures and humidity were high, fueling a constant string of isolated thunderstorms rolling over Wilmington and the Cape Fear River area. Every hour or so, a new storm would roll past.

Heather suggested I fit in a POTA activation, and, of course, I loved the idea. I just didn’t want to play radio anywhere near thunderstorms.

We decided to drive south to one of my favorite coastal towns in North Carolina: Southport. Based on the weather radar, it looked like we could drive to Southport on the west side of the river, then return via the Fort Fisher Ferry on the east side, potentially avoiding most of the isolated thunderstorms moving north along the coast.

After stopping in Leland for supplies, we made our way to Brunswick Town/Ft. Anderson State Historic Site, directly across the Cape Fear River from where I’d activated the previous day at Carolina Beach State Park (US-2722).

En route, we drove into a thundershower with rain so intense that most cars on the road turned on their hazard lights and slowed to a crawl. Visibility was nil.

Fortunately, the heaviest rain only lasted 10 or so minutes, and by the time we were two minutes from the park entrance, it had slowed to a drizzle. As we parked at the visitor’s center, it had all but cleared up.

Brunswick Town/Ft. Anderson State Historic Site (US-6834)

Brunswick Town/Fort Anderson State Historic Site is unique in that it offers a blend of colonial and Civil War history along the beautiful Cape Fear River.

Founded in 1726, Brunswick quickly grew into a bustling port town known for exporting naval stores. However, the town was burned by British troops in 1776 and never rebuilt, leaving behind ruins for visitors to explore today.

During the Civil War, Confederate forces constructed Fort Anderson atop the remnants of Brunswick. The fort’s earthen walls and impressive gun emplacements now stand as a reminder of the region’s strategic importance during this turbulent period.

Visitors can explore the colonial foundations and Civil War earthworks, while enjoying the river waterfront.

There’s also a visitor’s center with exhibits detailing the area’s rich history.

I was pleased to spot a picnic area on the opposite side of the parking lot from the visitors’ center. This would allow me to set up close enough to the car that if another storm approached, I could pack up quickly.

First, I introduced myself to the staff and asked for permission to activate. I was confident they would grant it, as this site had been activated 39 times already (mine would be the 40th).

The two park rangers inside were incredibly kind and accommodating. My wife and I ended up speaking with them about history for nearly 30 minutes. I also gave them more insight into the POTA program and asked if activators were following their rules. Fortunately, they gave a very positive report. NC State Historic Sites protect both the archaeology of the site and the natural resources, so I always ask for permission to activate because some sites have restrictions about putting lines in trees or stakes/spikes in the ground. Fortunately, this was not an issue at the picnic area.

Setting up

Since weather was iffy and since Heather and I wanted to spend the rest of the afternoon in nearby Southport, I decided to pair my Elecraft KX2 with my AX1 antenna.

This also gave me a chance to try out a new 3D-printed bipod that my friend Mike (KE8PTX) sent me.

This Bipod consists of a 3D-printed clip and knob designed by Adam (K6ARK) and two legs designed by Mike.

I was really amazed at 1.) how easy it was to attach the clip to the antenna’s BNC base and 2.) how incredibly stable this Bipod felt even compared with the OEM bipod.

Thank you, Mike (and Adam)!

With the radio set up, I was ready to activate!

Gear

Note: All Amazon, CW Morse, ABR, Chelegance, eBay, and Radioddity links are affiliate links that support QRPer.com at no cost to you.

On The Air

I assumed 20 meters would be the best place to start and, frankly, I hoped it would be productive enough to cap off my activation in short order so that my wife and I could continue our travels.

Unfortunately, propagation was not compliant. Continue reading Beautiful POTA activation at Brunswick Town/Fort Anderson and Afternoon in Southport!

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:

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

Experimenting during Field Day 2024

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

Video: Mike shows just how quickly he can deploy the Explorer mast

Many thanks to Mike (KE8PTX) who shares the following video as a follow-up to his previous post about the new Explorer POTA 20 telescoping mast (which I have on order via GigaParts).

In this video, Mike shows just how quickly he’s able to deploy the Explorer using his 3D-printed tent stake holder:

Click here to view on YouTube.

Mike compares the new Explorer POTA20 with the venerable SOTAbeams Carbon 6 Mast

Last week, I ran into my good friend Mike (KE8PTX) at Hamvention, and he was bursting with excitement over a new product he’d just purchased: the Explorer POTA20 Carbon Fiber Mast at GigaParts.

Mike is a massive fan of the SOTAbeams Carbon 6 telescoping pole and has been through two of them over the years he’s been doing field radio work. He told me that the new Explorer POTA20 is even better than the Carbon 6.

I don’t think Mike knows it yet, but after his recommendation, I ordered an Explorer mast—it’s backordered, so it’ll be a month or two before it ships.

Mike took this photo of his mast from a POTA activation this morning. You can see the mast left of the dead tree.

Mike is also a brilliant designer and has made a 3D-printed tent stake holder that fits on the end of both of these poles. He told me that these 20′ carbon fiber masts are so lightweight that there’s no need for guying the pole, even in fairly windy conditions. His simple tent spike is all that’s needed to hold a carbon fiber mast in place.

Videos

In the following video, Mike compares the Carbon 6 with the new Explorer mast and speaks to the utility of using a tent spike to secure the mast:

Thank you, Mike, for sharing this video and the tip about the new Explorer mast!

Again, it’s currently backordered at the time of posting, but you can place an order at GigaParts. The price is $79.95 plus shipping.

Gordon’s Simple AM-801 Alligator Clip Mod

Many thanks to Gordon (KF5JWL) who writes:

Tom,

I’ve been thinking about this for a while and finally tried it.

I attached an alligator clip to the AM-801 [window antenna mount] so it could be used to connect a counterpoise. Turns out alligator clips (at least the Mueller version I had lying around) have a toothy clip part at one end and a banana jack or socket at the other end. I didn’t want to go down the Google rabbit hole to find out if this is standard on all alligator clips. The clip also has a 6-32 threaded hole between the two ends so I drilled a clearance hole (using a #28 drill) in the AM-801 near the edge and attached the clip with a stubby 6-32 screw.

My trusty automatic center punch apparently failed to make a significant impression in the AM-801 so my drill bit wandered somewhat and the resulting hole was not exactly where I wanted it but I was still able to connect the alligator clip.

73,

Gordon KF5JWL

Thanks, Gordon! That’s a clever addition to the AM-801. Thank you for sharing it with us.

Testing the Tufteln AX1 Support: Late-Shift POTA with Vlado in Pisgah National Forest

On Tuesday, February 13, 2024, one of my daughters had a dress rehearsal for A Midsummer Night’s Dream. The venue where the cast meets is a good 45 minutes from my QTH, and if I didn’t have POTA fever, I’d have to find something to do to burn four hours of time.

Since I do have POTA fever, I see these windows of waiting around as an opportunity!

An opportunity to spread the POTA fever, even.

On that particular Tuesday night, my dear friend Vlado (N3CZ) didn’t have any plans, so I invited him to join me on a short, late-shift activation. The idea was that he’d perform an activation, then we’d go grab dinner at a restaurant in Mills River.

Pisgah National Forest (K-4510) and Game Land (K-6937)

Quick note about park numbers: As of the time of publishing this article, we’re still using the “K” prefix for US parks. Tomorrow (March 20, 2024), all US park prefixes will change to “US.” Pisgah National Forest, for example, will be US-4510 starting tomorrow. Today, it’s still (barely!) K-4510, so that’s what we’ll use.

We drove to the Sycamore Flats Picnic Area where I performed a number of late-shift activations in February. What I love about the site is that it’s rarely busy (especially at dusk and into the evening), there are numerous spots to set up, and it’s pretty convenient to the Shakespeare venue.

Tufteln AX1 Antenna Stand

I’d mentioned to Vlado in advance that I was going to test “a new antenna support system.” I think he might have assumed I was packing a large tripod with a 1/4 vertical or something similar, so it was fun to pull out the AX1 and  Tufteln AX1 Antenna Stand!

Vlado, like me, loves compact radio gear, and I knew he’d never used the Elecraft AX1 before, so I was looking forward to showing him just how capable of an antenna it is for POTA, even on 40 meters.

That day, it had been pretty gusty, and in the evening hours, while a little calmer, it was still a tad windy. I thought it would be the perfect opportunity to pair the AX1 with Joshua’s AX1 stand because it’s much more stable than the AX1 bipod in windy conditions.

Source: Tufteln.com

The stand consists of two parts: a base and an antenna sleeve. The sleeve screws into the base, and the AX1 simply slides into the sleeve. The height is perfect for the KX2’s BNC (indeed, it works with a number of radios). The stand will also accommodate the AXE 40M coil.

Source: Tufteln.com

When attached to the KX2, it makes for a very stable base. You can even use it as a stand-alone antenna support for the AX1.

Joshua has had this stand in his Tufteln product line for over a year, but I don’t think I’ve actually used it during an activation that I’ve also filmed.

New Mics!

Speaking of filming, this activation with Vlado gave me an opportunity to test my new DJI wireless mics. The system comes with two mics so both Vlado and I used them.

I filmed the activation, but in truth, was doing this more or less to test the mic audio. I believe I mentioned early on that this video might not ever be published.

In the end, I decided to publish it–the audio was quite good, and the wireless mics cut down on the wind noise dramatically.

Gear:

Note: All Amazon, CW Morse, ABR, Chelegance, eBay, and Radioddity links are affiliate links that support QRPer.com at no cost to you.

N3CZ: On The Air

My goal was to get Vlado on the air and give him a taste of POTA using the AX1 and 40M coil. I hadn’t planned to activate–since we were grabbing dinner afterward–but I did end up activating after the UTC day changed.

Without realizing it, I actually put a lot of pressure on Vlado.

He started his activation at 18:42 local (23:42 UTC). That meant, in order to log a valid POTA activation on February 13, he needed to log at least ten contacts in 18 minutes (using the AX1!).

Keep in mind that Vlado is a contester and DXer (also, very much a QRPer!). He’s used to operating CW at insane speeds when needed. In fact, he’s always one of the top people (if not the top) in the CW speed test at the W4DXCC contesting and DX conference.

I suggested he operate around 20 words per minute.

He started calling CQ POTA, and the first few contacts came in pretty slowly. I was getting nervous that I might have unintentionally made Vlado’s first POTA activation one that wouldn’t be valid.

Then the pace started picking up. (Whew!)

He ended up logging a total of 10 contacts in 12 minutes! Woo hoo!

Here’s his QSO Map, showing what the AX1 pushing 5 watts for twelve minutes can do:

Next, we decided that I would, indeed, perform a quick activation.

I spotted myself on the POTA site and started to call CQ, then it hit me: it was 23:58 UTC. If I worked one contact in that two minutes, it would be considered an activation on February 13 of only one contact.

Instead, we waited for a little over a minute for the UTC day to change!

I ended up working a total of 24 contacts in 21 minutes. Woo hoo!

Here’s my QSO Map:

And here are our logs:

Activation Video

Here’s my real-time, real-life video of the entire activation.  As with all of my videos, I don’t edit out any parts of the on-air activation time. In addition, I have monetization turned off on YouTube, although that doesn’t stop them from inserting ads before and after my videos.

Note that Patreon supporters can watch and even download this video 100% ad-free through Vimeo on my Patreon page:

Click here to view on YouTube.

What fun!

I always enjoy hitting the field with Vlado.

Since this quick little activation, he’s been out there hitting POTA sites regularly.

He hasn’t seen the doctor yet, but I’m positive he caught POTA fever. It’s incredibly contagious.

Also, the Tufteln AX1 stand worked perfectly in the wind. I’m going to keep this tucked away in my pack alongside my second AX1 to pair with a wide variety of radios.

Thank you!

Thank you for joining me during this activation!
I hope you enjoyed the field report and my activation video as much as I enjoyed creating them!

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.

As I mentioned before, the Patreon platform connected to Vimeo makes it possible for me to share videos that are not only 100% ad-free but also downloadable for offline viewing. The Vimeo account also serves as a third backup for my video files.
Thanks for spending part of your day with me!
Cheers & 72,
Thomas (K4SWL)

Let’s Give it a Go: Pairing the Elecraft AX1 and Emtech ZM-2 Manual ATU

Last month, I received a comment and question from Gordon (KO4AYC) here on QRPer.com:

“I am curious if anyone has used the AX1 with the AXE1 40 meter extender and tuned this antenna for 40 meters using the Emtech ZM-2 tuner?”

For the life of me, I couldn’t remember if I’d tried this combo before.

The ZM-2 ATU is a simple manual antenna tuner that you can purchase either as a fun-to-build kit or fully assembled and tested.

I’ve owned my ZM-2 for many years, and I believe every QRP field operator should have one. They do a brilliant job of matching random wire antennas and taking your resonant antenna to a non-resonant band. Being a manual ATU, they require no power source. If you’d like to read a quick tutorial on tuning the ZM-2, read this previous post.

I figured the easiest way to answer Gordon’s question was to give it a go!

The AX1 does require a counterpoise, so before hitting the field, I did check to make sure there was continuity between the shield of the ZM-2’s BNC connector and the black binding post when the ZM-2 was switched to “GND” for coax antennas. Fortunately, there was! I loved this idea because it meant that no matter the radio, I knew I’d have an easy connection to ground for the AX1 counterpoise.

Blue Ridge Parkway (K-3378)

On Wednesday, February 21, 2024, I grabbed the ZM-2, AX1, and AXE 40M coil (since Gordon specifically asked about 40M) along with my Yaesu FT-818ND. It was time to see just how effectively the ZM-2 might match the AX1.

I store my AX1 in this Maxpedition pouch (see link in gear section below).

Upon arrival, I began setting up the station.

Even though it was approaching 2:00 PM locally, I wanted to see if the ZM-2 would match the AX1 (with AXE coil) on 40 meters first. I didn’t expect a lot of activity on that band so early in the afternoon, but I figured I could hopefully work a couple of stations.

I attached the AX1 directly to the ZM-2 antenna port and deployed the whip and 40M counterpoise.

It was a bit gusty, and I quickly realized that the AX1 might topple over in the wind. To secure the antenna, I used the handle of my GR1 backpack. It was a semi-effective arrangement (actually, the handle sort of pulled the antenna toward the pack, which wasn’t ideal either–I eventually removed it).

In calm conditions, I wouldn’t worry about the antenna toppling over; the ZM-2 provides enough of a base that it’s stable. In the wind, though, you’ll definitely need to secure the ZM-2/AX1 combo to keep it from being blown over.

My plan was to start on 40 meters, then also hit 30, 20, and 17 meters. This would give me an opportunity to see if the ZM-2 could match the AX1 on multiple bands.

Side note: I can’t remember if I mentioned this in a previous field report, but one sad bit of news for me is that there’s a new source of QRM at the Folk Art Center. It’s likely coming from the VA medical complex next door, but it raised the noise floor to at least S5 on most bands. This will make it more difficult for me to work weak signals from this particular POTA site.

Then again? My buddy Alan (W2AEW) recently pointed out to me that compromised antennas like the AX1 don’t feel the effects of local QRM as a higher-gain antenna would. I’d been thinking the same thing.

Gear:

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On The Air

I hopped on the air and started calling CQ POTA on the 40-meter band. I worked one station quickly (thanks, W5GDW) and then silence. I didn’t expect 40 meters to be active this time of day, but I didn’t think it would be completely dead either.

I checked the POTA spots page and discovered that the connection to the Reverse Beacon Network was down. Even though I scheduled the activation, the system hadn’t spotted me.

Once spotted, I worked three more stations in quick succession.

I didn’t hang around on 40 meters. Continue reading Let’s Give it a Go: Pairing the Elecraft AX1 and Emtech ZM-2 Manual ATU

POTA by Lantern Light: One Activation in Two Days with Two Antennas!

On Friday, February 9, 2024, I had an opportunity to do an extended Late-Shift POTA activation in Pisgah National Forest. I couldn’t pass that up!

Once again, one of my daughters had a casting call and a Shakespeare performance that opened up an activation window from about 17:00 – 20:00 local (22:00 UTC – 01:00 UTC).

If you’ve followed my POTA activities for a while, you’ll note that multi-hour activation windows are very much a rarity. More often than not, I’m squeezing activations into 30-60 minute windows of time as I go about my work and family duties.

Pisgah National Forest and Game Lands

The closest POTA site, once again, was Pisgah National Forest (K-4510) and Pisgah Game Lands (K-6937). There are so many sites to choose from within Pisgah; it’s always a difficult decision in terms of picking a location.

In this case, I decided to stay a little closer to mobile phone service just in case my family needed to reach me during that time. I chose the Sycamore Flats picnic area and was happy to see that the picnic shelter was available.

I thought it might be fun to set up two antennas since I had so much time. For the first part of the activation, on 20 meters, I would deploy the Chameleon MPAS Lite vertical.

For the second part (the following UTC day), I would deploy my MM0OPX 40-meter end-fed half-wave as I knew 40 meters would be much more active after sunset.

EFHW Deployment

Since sunset was approaching, I deployed my MM0OPX EFHW first because it’s much easier to deploy a wire antenna in a tree when it’s still light outside.

Side note: I mention in the activation video that a good headlamp (like my Fenix) makes working in the dark quite easy. I’ve deployed wire antennas after sunset with headlamps before–it’s quite doable–but I still prefer using a throw line when there’s still sunlight. It’s just easier (for me, at least) to judge distance.

I deployed the EFHW in a tree and in the brush between two pathways. While it would have been easier to deploy it on a path, I always try to deploy my wire antennas in a way that hikers and other park guests wouldn’t easily walk into them–especially at dusk when even high-visibility line colors are difficult to see.

Chameleon Carbon Fiber Tripod

The second antenna deployment was my Chameleon MPAS Lite vertical, and this activation gave me an excuse to test the new Chameleon carbon fiber portable tripod.

In January, Chameleon sent me a box with a few of their smaller accessories/promotional items. I plan to give away everything, save the tripod, in an upcoming QRPer giveaway.

I’ve been eager to test the tripod because it’s lighter and easier to transport (in my SOTA pack) than the stainless spike that comes with the MPAS Lite antenna system. This tripod will also come in handy when operating at parks that don’t allow stakes in the ground. Continue reading POTA by Lantern Light: One Activation in Two Days with Two Antennas!