Category Archives: Antennas

Elecraft KX2 and AX1: Seriously…how effectively can such a compact field kit work?

On September 20, 2021, I had a full day planned in town. It was one of those days where my few errands and appointments were spread out across the day in such a way that driving back home between appointments made no sense. I knew I might have a bit of time to kill.

The big appointment holding me in town was recall service work on my Subaru that would take most of the day. The dealership reserved a loaner car for me.

That morning, I cleaned out my car (removing a couple of radios and antennas) and I packed a backpack with the supplies I’d need for the day; water, sandwich, laptop, and (fortunately) my Elecraft KX2 and AX1 antenna.

I would take this pack with me in the loaner car as I ran my other errands.  I remember thinking that there was  likely no possibility of doing an activation–it was rainy and I knew even getting set up at the service center might take an hour. I packed the Elecraft gear nonetheless. (Never leave home without a radio, I say!)

That morning, I drove to the Subaru dealership and–long story short–the service work had to be cancelled. While I wasn’t happy that I’d made the early morning trip to the dealership for nothing, this did essentially free up a good portion of my morning to play radio. Even though I had my own car for the day, I had completely emptied it of radio gear, so the KX2 and AX1 were truly all I had. Continue reading Elecraft KX2 and AX1: Seriously…how effectively can such a compact field kit work?

New Chameleon Pocket Antenna Series

FYI: I just received this announcement from Chameleon Antennas. They will be sending some samples of these antennas for me to test in the field.

(Source: Chameleon Antenna)

INTRODUCING THE CHA POCKET ANTENNA SERIES – PRE ORDER

The CHA Pocket Series are a series of single and multi-band HF antennas that can literally fit in your pocket when not in use. There are THREE models available: a 40-6 Meter Off- Center Fed Dipole (OCFD), 40 Meter Dipole, and a 20 Meter Dipole.

This series of antennas are designed for ultra-light (all are 7 oz. or less) low power (QRP) portable operation. When running low power, an effective antenna is essential to actually making contacts – these are full-size antennas with full-size performance, but built with lightweight materials and miniaturized components. They were designed to complement the exciting new lineup of lightweight, battery operated, HF portable transceivers.

STARTING TO SHIP AT THE BEGINNING OF SEPTEMBER 2021

Click here to check it out at Chameleon.

Click here for the user guide.

Please note that Chameleon is a sponsor of QRPer.com!

 

Anatomy of a Field Radio Kit Part 1: Basic components and advantages of going QRP

The following review was first published in the June 2021 issue of The Spectrum Monitor magazine:


Part 1: Anatomy of a field radio kit

by Thomas (K4SWL)

Whether it’s the ARRL Field Day, Winter Field Day, a QRP contest, or, more likely, a Summits On The Air or Parks On The Air activation, I look for any and every excuse to hit the field with my radios.

Most of my on-air time is in the field. While I enjoy operating from the shack, I’ve discovered I especially enjoy operating in the great outdoors.

Besides being a fan of hiking, camping, and the great outdoors generally, I also am particularly fond of radio field gear. I like portable transceivers, portable antennas, battery packs, and all of the accessories that make field operation efficient and enjoyable.

I appreciate the emergency communications skills I’ve developed in the field, too. Should the need (or opportunity) arise, I now keep a complete field kit packed and ready to go at all times, and can even deploy all of it within just ten minutes. In my early days of ham radio operation, I might have easily spent thirty minutes setting the antenna, alone…especially on Field Day, with folks watching me struggle to untangle wires and cables, followed by the undoubtedly entertaining attempts I made to put a line into a tree to deploy the antenna. But after deploying a variety of antennas hundreds of times now, I find that––while I’m still not perfect––I finally have a bit of skill and the process of tossing up a line is becoming much swifter and smoother.

Confessions of a pack geek

The Red Oxx C-Ruck loaded and ready for the field!

If I’m being honest with myself, I admit: I also simply get a thrill out of kitting out my field packs, as well as organizing and tweaking them over time. Yes, (don’t judge me!) I actually like packing up my field gear.

I think my passion for organizing and packing gear goes back to a former career when I lived in the UK, Germany, and France, and was required to travel throughout Europe frequently. Originally inspired by travel guru Rick Steves, I’ve always appreciated the footloose feeling of having all of my travel gear in one lightweight pack. I don’t like checking in luggage, but love the freedom of grabbing my backpack and skipping the baggage claim carousels. And I also like knowing that, even though my gear is compact, it contains everything I need.

I’ve become something of a “less-is-more” traveller. Two years ago, for example, I traveled for one week using what Frontier Airlines classifies as a “personal carry-on.” My Tom Bihn Stowaway pack, which only measures 14.0″ (w) x 9.4″ (h) x 8.1″ (d), carried everything I needed for a conference, including my own presentation gear.

My Tom Bihn Stowaway personal carry on convertible pack with everything I needed for a one week trip including a conference.

Packing for that trip was great fun as it really challenged me to decide what was essential and what was not. My iPad doubled a computing and presentation device, for example, but I also packed a small flashlight and a mini first aid kit, which I felt were important. Of course, I also carried a small portable Shortwave/AM/FM radio and my Yaesu VX-3R handheld…also vital, as I can’t leave home without radios!

Getting started with a field kit

Putting together a field radio kit is so similar to packing for travel: you must first do an assessment of what you need, starting with the basics––then organize it, pack it, and test it.

In my world, this is a very deep topic. We’re going to break down this topic into two parts.

This article, Part 1, we’ll dive in:

  • first, going over the obvious components of a basic field radio kit;
  • second, discussing the benefits of going low-power (QRP) if that appeals

In Part 2, we will:

  • look at variations of kits based on activity, and finally
  • review what I consider the “golden rules” of a good field radio kit

The basics of a field radio kit

First, let’s go over the basics of your field kit, considering that that these primary components will dictate your bag, pack, or case size.

A transceiver

The lab599 Discovery TX-500

Since I’m a bit radio obsessed, I have a number of QRP transceivers I like to take to the field.  But if you have selected one transceiver you plan to dedicate to field work, or simply have only one transceiver, period, you can build a kit around it (and see my note below about “modular” kits). If budget allows, you might consider buying a radio specifically for field use, so it can always be packed and ready to go.

There are a number of transceivers on the market that are designed with field use in mind. Some are compact, power-stingy CW-only QRP transceivers that might only operate on three ham radio bands, while others are 100-watt general coverage transceivers that even have built-in antenna tuners––there’s a wide range of options.

Look for field-friendly, built-in options like:

  • CW and voice-memory keying;
  • SWR and power meter readings;
  • a battery voltage indicator;
  • low current consumption;
  • the ability to lower power to at least one watt;
  • an internal battery option; and
  • an internal antenna tuner option

And the more such options are already built into your field rig, obviously, the less separate accessories you’ll need to pack and keep track of in the field, which is a good thing.

The Elecraft KX2 has a built-in ATU, battery pack, and even attachable CW paddles!

Some of my favorite field-ready general-coverage transceivers currently in production are:

  • The Elecraft KX2 A full-featured, inclusive, and compact 80-10 meter transceiver that’s truly a “Swiss-army knife” of field operation (see November 2016 TSM review)
  • The Elecraft KX3 Benchmark performance, wide array of features, and compact design
  • The lab599 Discovery TX-500 Military-grade engineering, weatherproof, spectrum display, and benchmark current consumption for a general-coverage radio (see October 2020 TSM review)
  • Mission RGO One Top-notch performance, 50-watts out, and excellent audio (see November 2020 TSM review)
  • The Yaesu FT-817/818 Rugged chassis, 160-6 meters, VHF and UHF multi-mode, both BNC and PL-259 antenna inputs
  • The Xiegu X5105 Affordable, 160-6 meters, 5 watts output, built-in ATU, and built in rechargeable batttey
  • The Xiegu G90 Affordable, relatively compact rig with built-in ATU, color screen with spectrum/watefall, good audio, and 20 watts of output power (see August 2020 TSM review)
  • The Icom IC-705 Benchmark performance, a multitude of features, exchangeable battery packs, 160-6 meters, VHF and UHF multi-mode, D-Star, GPS, WiFi, Bluetooth (see February 2021 TSM review)
  • The Yaesu FT-891: Affordable relatively compact radio with detachable faceplate, 100 watts output, and excellent audio (see November 2017 TSM review)

And if you’re primarily a CW operator, you’ll have some incredibly compact radio options like the CW-only Mountain Topper MTR-3B or 4B, or the Elecraft KX1 (used).

An important side note for field contests: if you plan to use a field transceiver in an event like the ARRL Field Day and/or another popular radio contest, make sure you choose a transceiver that can handle tightly spaced signals in an RF-dense environment. This is not the time to pull out a lower-end radio with poor receiver specifications. Use Rob Sherwood’s receiver test data table as a guide.

An antenna––and a means to deploy/support it

The CHA LEFS sloper

This particular topic, alone, might warrant a three-part series of articles. So, to keep the scope of this article realistic, let’s just say that you should build or buy an antenna that can comfortably handle the wattage you’re pushing into it in all the modes that you operate, considering that some 100-watt SSB-rated antennas might melt or arc if you run 100 watts CW or FT8.

I would suggest you consider having at least one resonant antenna, like an end-fed half-wave (EFHW) that might cover 40 and 20 meters without the need of an antenna tuner to match the antenna impedance to your rig.

Some of my favorite portable antenna systems?

I’m a big fan of Chameleon Antenna for their ease of deployment and benchmark build quality. Their prices range from $145 for the Emcomm III random wire, to $550 for their MPAS 2.0 vertical antenna system. These prices are near the top of the market, but Chameleon antennas are all machined and produced in the US and the quality is second to none. These are antennas you might well pass along to the next generation, meaning, really heirloom-worthy kit!

Packtenna 9:1 UNUN Random Wire
The PackTenna 9:1 UNUN

PackTennas, likewise, are pricey for such a compact product, but they are also beautifully engineered, lightweight, and designed for heavy field use. PackTenna produces an EFHW, 9:1 UNUN random wire, and linked dipole models. They’re some of the most compact field antennas on the market that can still handle as much as 100 watts of power output.

My Wolf River Coils “TIA” vertical antenna

Wolf River Coils verticals are affordable, compact, and resonant––thus an ATU isn’t needed. It will take some time to learn how to adjust the coil during frequency changes, but they work amazingly well. I have the WRC Take It Along (TIA). Their antennas are designed to handle 100 watts SSB, 50 watts CW, or 20 watts digital.

The EFT Trail-Friendly

Vibroplex sells a number of compact field portable antennas and is the manufacturer of Par End Fedz offerings. I’m very fond of the EFT Trail-Friendly and the EFT-MTR.

The MFJ-1984LP EFHW packs a lot of performance for the price

MFJ Enterprises also has a few portable antennas in their catalog, and it’s very difficult to beat the price and performance of their antenna gear. I have their $50 EFHW antenna (the MFJ-1982LP) and love it.

The Elecraft AX1 attaches directly to the BNC port on the KX3 and KX2.

I’ve also had tremendous fun with the uber-compact Elecraft AX1 antenna. Unquestionably, it’s the most compact and quickest-to-deploy antenna I own. It’s designed to pair with the Elecraft KX2 and KX3 using the optional internal antenna tuner.

There are a number of other antenna manufacturers who cater to portable operators. For example––although I’ve not yet had the opportunity of testing their antennas––SOTAbeams is highly regarded among SOTA enthusiasts.

Short on cash? No worries; you can build your own! In fact, until 2016, I had never purchased a field antenna; I built all my own. EFHW antennas and random-wire antennas are no more than a carefully-wound coil, a female antenna connector, an enclosure or mounting plate, and some wire. Some of the most active field operators I know homebrew all of their antennas. It’s easy, affordable, and fun!

In fact, some antennas are no more than a bit of speaker wire matched with a good ATU.

A power source

A 3Ah Bioenno 12V LiFEPo4 powering my LD-11 transceiver

I’ll keep this point brief because we recently covered the topic of batteries in detail in our previous feature.

Make sure you choose a battery that is sized appropriately for your transceiver power output. I will say that I’m a huge fan of LiFePo4 rechargeable batteries for their voltage range, lightweight design, and longevity. Being primarily a QRPer, I typically use 3 to 4.5 amp hour batteries as they’ll carry me through as many as three or four activations without needing to be recharged. For longer field deployments, or when I’m powering my 100W KXPA100 amplifier, I’ll use my 15 aH Bioenno LiFePo4 pack.

I use my 15Ah Bioenno LiFePo4 pack for QRO transceivers

Again, check out our Portable Power Primer for a deep-dive into the world of portable power.

A key, mic, and/or computing device

It should go without saying that you need to pack these, but I have gone to the field with operators who forgot their key or mic and asked if I had a spare.

Keys are fairly universal, but keep in mind legacy transceivers often want a ¼” plug while newer rigs typically accept an ⅛” plug. Microphones, however, vary in port type and pin configuration based on the manufacturer and model. You could damage your mic or rig if you plug in a multi-pin mic that was designed for a different transceiver. Most mics that use a ⅛” plug are universal. Still, check before you plug it in if using an after-market or non-OEM mic.

Of course, choose a key, microphone, or boom headset that’s compact and rugged so that’ll be easy to pack and will stand the test of time.

I also always pack a set of inexpensive in-ear earphones. These can dramatically help with weak-signal interpretation.

Also, if you plan to operate a digital mode, you’ll likely need some sort of computing device. Even though I rarely operate digital modes in the field, I often pack my Microsoft Surface Go tablet in case I change my mind.

My Microsoft Surface Go tablet

In addition, I like logging directly to N3FJP’s Amateur Contact Log application directly in the field to save time submitting my logs later. Soon, I’ll be using the new HAMRS field log on my iPhone.

Speaking of logging…

A means of logging

I like compact notepads like Muji and Rite In The Rain for field use.

As simple as it is, it’s very important to take at least some paper and a pencil for logging your contacts. I like using small, pocket-sized Muji notebooks (affiliate link) for logging, and if the weather is even a little questionable, I’m a huge fan of getting my contacts down in Rite In The Rain mini notebooks (affiliate link) or notepads using a good old-fashioned pencil.

I like logging to paper and sometimes simultaneously logging to my Microsoft Surface Go. I have completed phone-only field activations where I only logged to my Surface Go tablet: in those cases, I snap a photo of my N3FJP call log, just in case something happens to my tablet between the field and the shack! Having endured enough technology failures, it gives me peace of mind to have at least one other backup.

Keep in mind that when you’re activating a park or summit, the folks calling you are relying on you to submit your logs to the appropriate programs so that they can get credit for working you. Many times, this might also help their awards for a state, county, or grid square. Always submit your logs after an activation even if you didn’t make enough contacts to validate the activation (POTA requires 10 contacts, SOTA requires 4 logged). It helps other folks out.

A pack or case

If you have a field radio kit, you’re going to need a means to organize and contain it for transport. There are at least three types of systems used for field kits.

A backpack or soft-sided case

My GoRuck BulletRuck is a brilliant SOTA pack

Since I enjoy the option of hiking with my radio gear, I love using backpacks. Although I’ll speak to this more next month in “Part 2,”, I choose quality packs that have at least one waterproof compartment and are comfortable to carry on long hikes. I also try to look for packs with Molle or some sort of external strapping so that I can attach portable antenna masts or even my hiking poles to the exterior of the pack.

A waterproof case or flight case

Ruggedized, weatherproof cases come in all sizes. This Pelican 1060 can house my entire KX1 radio kit.

Many field operators who want extra protection for their gear––especially when they don’t plan to hike or carry their gear long distances to the operating site––like hard-sided cases. I have built field radio kits in waterproof Pelican cases and appreciate knowing that I could drop my kit in a whitewater river, and it would likely survive the adventure unscathed. If you are one of these operators, look for quality watertight cases from brands like Pelican and Nanuk with interiors lined in pick foam padding that allows you to perfectly accommodate and safely protect your radio and accessories.

Portable ready-to-deploy cases

Although this option is almost outside the scope of this article, many emergency communications enthusiasts love having their gear loaded in rugged, portable––often rack-mounted and hard-sided––cases that they can simply open, hook to an antenna, and get right on the air. These systems are often the heaviest, least “portable,” and less suited for long distance hikes, but they’re often completely self-contained, with all of the components, including the power, hooked up and ready to go on a moment’s notice. While a system like this would be impractical for many Summits On The Air sites, it could be ideal for a park or island activation where you’re never that far from your vehicle.

Optional: Antenna cable

An ABR Industries RG-316 cable assembly

This doesn’t sound like an option, but it’s true.  I’ve often operated my Elecraft KX3, KX2, and KX1 without a feedline at all: I simply attached two wires to a BNC binding post, and connected that to the radio. It makes for a super-compact setup.

Even an 8-12 foot feedline can make it easier to configure your operating position in the field. If you want to keep the feedline as low-profile as possible,  especially if you’re operating QRP, consider investing in a quality RG-316 feedline terminated with the connector that fits your radio and antenna.

Optional: Antenna Tuner/Transmatch

A portable ATU with RF-sensing like the Elecraft T1 will give you an amazing amount of frequency agility. I’ve been known to use the T1 to tune my CHA Emcomm III random wire antenna on 160 meters..

Again, this topic could easily warrant a multi-part series of articles, but I’ll sum this one up in a nutshell: while I love (and even prefer) using resonant antennas that require no antenna tuner, I almost always carry a radio with a built-in ATU or an external portable ATU like the Elecraft T1 or ZM-2.

Why? Because an ATU will give you a certain amount of frequency agility or freedom. If I’m using an antenna that’s resonant on 40, 20, and 10 meters, but there’s a contest that day and the bands are incredibly crowded, I might use the ATU to find a match on 30 meters or 17 meters, thus finding a little refuge and space to operate. Also, sometimes antenna deployments aren’t ideal––due, for example, to site limitations such as dense vegetation that may alter the antenna deployment and thus its resonance. An ATU can at least keep your transceiver happy with the SWR when your resonant antenna might not be perfectly resonant.

But the main reason I carry it? A portable ATU gives you operational flexibility.

QRP or QRO?

I have operated QRO in the field with my KXPA100 amplifier on Field Day.

Its good to keep in mind that many of the station accessories listed above need to be matched to the output power of your transceiver and modes you use.

Many ham radio friendships have been placed in jeopardy over the question of either using QRP (low power) or QRO (high power) for field operations. This is a shame. Some operators have very strong opinions, but the truth is, there is no right or wrong answer.

In the spirit of full disclosure, I operate 97% of the time at QRP power levels––in my world, this means five watts or less. Personally, I enjoy the challenge of low-power operating.  But I also appreciate the portability QRP gear offers.

The wee Mountain Topper MTR-3B

Speaking pragmatically––and this fact really isn’t open to debate––QRP and lower-power transceivers and accessories tend to be more efficient, more compact, and lighter than their higher-power siblings.

Most of my QRP transceivers weigh anywhere from two to five times less than their 100-watt equivalents. If you’re operating mobile (from a vehicle or camper/caravan, for example), an eight to twelve pound difference might not be a big deal. But the moment you’re hiking several miles to a mountain summit, weight becomes an important factor.

QRP transceivers have modest power requirements: everything from battery, to antenna, and even to tuners, are smaller, lighter, and more compact.

When operating QRP, you don’t have to worry as much about RF coming back to the radio from, say, an end-fed antenna. If I’m pushing over 20 watts into an end-fed half wave or end-fed random wire, I’ll likely want an in-line RF choke to keep some of that energy from affecting my transceiver or giving me an RF “tingle” when I touch the radio chassis or my key. Too much RF coming back to the transceiver can also affect things like electronic CW keying. But at five watts? I don’t worry. This is almost a non-issue, unless your transceiver happens to be very RF-sensitive indeed.

And even though I’m predominantly a QRPer, I definitely do pack radios like the 50-watt Mission RGO One and occasionally my Elecraft KX3 and KXPA100 100-watt amplifier, especially for an event like Field Day where my club is operating at higher power. I simply size up my gear appropriately. Again, this is especially important with your antenna, feed line, ATU, and battery selections.

If you primarily activate parks and are never far from your vehicle, it’s quite easy to accommodate a 100 watt transceiver like an FT-891, for example. Of course, if you wish to operate low-power and save your battery, simply turn down the output power. If you plan to hike a lot with your gear, then get your mind around QRP!

Stay tuned for Part 2!

In Part 2 we’ll dig into some of the details, looking at different approaches to field radio kits and some guidance and suggestions based on my real-life experience (read: operating mistakes).

Click here to read Anatomy of a Field Radio Kit Part 2.


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Hike and Talk: Non-Resonant vs. Resonant Antennas and should you buy an ATU?

I had a topic on the mind as I made my way back to the trailhead after a SOTA activation recently.

I get a lot of questions from readers and subscribers about resonant vs. non-resonant antennas and whether or not an ATU is a good or bad thing.

If you know me, you’ll know that I tend to lean towards qualitative research; meaning, I like to base my opinions on first-hand observations rather than laboratory or textbook explanations. Part of the reason is I’m not an engineer, so specifications and performance stats don’t influence me–I don’t understand them half the time–rather, I base my opinions on trying or field testing.

The proof is in the pudding, right?

So with the topic of antennas and ATUs on the brain, I decided to turn on the action camera and do an unscripted video on the trail as I hiked back to my car.

This video is essentially stream of consciousness: I won’t blame you if you skip it.

With that said, if you manage to stay awake for the whole video (congratulations in advance) I’m curious what your thoughts are so please consider leaving a kind comment!

Thank you & 73,

Thomas (K4SWL)

Dan’s clever chalk line homebrew EFHW antenna

Many thanks to Dan (KQ8Q) who writes:

Hi Tom,

I discovered something you might have an interest in for your wire antenna deployment. Years ago when I was a building contractor, we used chalk line for floor layout. It has a very high tensile strength and is very light weight. After reflecting on this, I recently bought a 100’ spool of braided 1 millimeter chalk line and used it for a field deployment. I attached my “throw weight” to it and easily launched it about 60’ into a tree. You can see it in the attached photo holding my homebrew EFHW to my Jeep.

This link is what I used: Tajima PL-ITOL 100 ft .04″ Bold Braided Replacement Chalk Line New | eBay

Click here for full parts list (PDF)

The magnet wire was scavenged from a HUGE transformer from a neighbor’s discarded light fixture.

Lug Nut Throw Weight: left hand threaded from a 1966 Plymouth Fury

I did the new installation for him and he gave me the old one. I promptly disassembled it and collected miles of 14 and 20 gauge magnet wire 😊!

I haven’t added the capacitor to this antenna yet because it is sufficiently resonant and broadbanded on 40, 20, 15, and 10 Meters. I did some testing with the capacitors though on my previous build which was the PVC tube EFHW transformer. I believe I may have sent you a photo of that in a previous message. It too was resonant in the same places, but adding the capacitor smoothed and widened the acceptable SWR range.

The attached photos are my complete antenna assembly: matching transformer (49:1), 65.5’ speaker wire, 100’ braided 1MM chalk line, and throw weight (epoxy filled lug nut with short paracord pigtail).

Compact and lightweight.

Dan/ KQ8Q

I love this, Dan! I also like how self-contained and compact it is. What a professional job, too, with heat shrink, proper connection points and tie-offs.

Brilliant work!

Do you have an antenna or radio project you’d like to share on QRPer.com? Contact me!

How to pack a compact Arborist Throw Line Storage Bag

Since last year, I’ve become a bit of an arborist throw line evangelist.  Arborist throw lines have made my wire antenna deployments so quick and easy compared with using monofilament fishing line or more complicated systems.

Since purchasing this arborist throw line last year, I’ve never looked back. The throw line never gets caught in tree branches, it’s reusable hundreds of times, and with it I can easily snag branches 50’+ above the ground to hang my wire antennas.

When I purchased my first arborist throw line, I also purchased this folding throw line packing cube:

It has a huge opening, is stable on the ground, and makes for an incredibly quick deployment and pack-up.

While the cube folds into a compact triangle, it’s a little too bulky for backpacks I use during SOTA and other trailside activations.

A smaller throw line storage bag

A few months ago, I purchased a second throw line for backpacking and this compact Weaver Leather throw line storage bag (note: Amazon affiliate link).

If I’m being honest, I was very skeptical about how easily this bag would work in the field. One of the reasons my throw line storage cube works so well is the opening is large allowing the line to deploy without tangling. Packing up is so fast because the line can be flaked back into the cube in a matter of seconds.

Before purchasing, I was afraid the compact throw line bag might get tangled when being stored in such a small stuff sack. I was really concerned packing the line in the storage bag might take too much time.

I purchased the the throw line bag and a new throw line from Weaver.

At home, I did a full break-in of the new throw line (attaching it to a tree, stretching it to full length, then pulling it for enough tension that some of the bend “memory” is removed). Then I attempted to simply stuff the line in my throw bag–it took ages, because the whole idea of a throw line is that it doesn’t easily tangle. The line wanted to “spring” from the bag as I tried stuffing it in.

A much better way: The “Figure 8” stuffing method

After a field activation this spring, I received a game-changing tip from one of my subscribers and I hope they step up to take credit! (Update: it was NW3S!–thank you!).

When stuffing the line back in the bag, wind it on your hand using the figure 8 method. I wind almost all of my lighter-weight cables and antenna wires in a figure 8 so that they deploy without getting tangled. I’ve been doing this for years and it works brilliantly.

I’d never thought about using this method on the arborist throw line. I was amazed with how effectively it worked.

Video demo

I made a short video (thank you for requesting this, Scott!) to better demonstrate how I pack my throw line storage bag now:

This method works amazingly well and I can usually pack the entire line within one or two minutes.

Again, I’m incredibly grateful to the subscriber who first suggested this method!

Field Report: Let’s build a super simple antenna on-site and activate this park!

Until 2016, I had never purchased a commercial field antenna; I built all the ones I had ever used.

These days, I take a number of commercial antennas to the field and use them in my real-time videos and I really enjoy deploying and using them. My buddy Eric (WD8RIF) reminded me, though, that I hadn’t actually used a homebrew antenna in ages. He was right!

You see, while I believe commercial field antennas can be incredibly durable and compact, it’s important to note that antennas are one of the easiest components of an amateur radio system to build yourself. They require only the most simple of tools and are very affordable. And the best part? They can perform as well as those that are available commercially.

I also get a great deal of pleasure out of building things.

A simple goal

I’ve mentioned in previous posts that I often set a little goal that runs in the back of my mind for each park or summit activation I make.

On Monday, June 14, 2021, I made a simple goal: buy my antenna wire en route to Lake James State Park, build the antenna on site, and complete a valid Parks On The Air (POTA) activation.

A very simple antenna

I also decided to employ my Xiegu X5105 since 1.) it’s one of the most affordable general coverage QRP transceivers I own and 2.) it has a built-in antenna tuner (ATU).

One of the cool things about having an ATU is that, if it has the matching range, you can allow it to do the “heavy lifting” in terms of matching impedance.

Although I’d never put the X5105 to the test, I suspected its internal ATU would have the matching range to forgo building a 4:1 or 9:1 transformer and simply pair it directly with a random wire.

All I would need was a 28.5 foot length of wire for a radiator, at least a 17 foot length for a counterpoise, and a BNC to binding post adapter.

The antenna would benefit from multiple 17′ counterpoises, but I really wanted to keep this setup dead simple to prove that anyone can build an effective field antenna with a very minimum amount of components.

Even though I have plenty of wire lying around the house to build this simple antenna, I wanted to pretend I had none to prove that any wire would work.

And to add just a wee bit more challenge, I also limited myself to shopping for antenna wire between my home and the park without making a serious detour from my route. That really limited my options because there isn’t much in terms of commercial areas between me and Lake James State Park.

The wire

As I left the QTH, I decided that the best spot to shop was a Walmart in Marion, NC. It would only be a four minute round-trip detour at most.  I had a hunch that Walmart would even have speaker wire which would be ideal for this application.

In my head, I imagined I would have at least three or four choices in speaker wire (various gauges and lengths), but turns out I had a difficult time finding some at Walmart. We live in such a Bluetooth world, I suppose there isn’t much demand for it these days. A store associate helped me find the only speaker wire they had which was basically a 100 foot roll of the “premium” stuff for $17 US.

While I would like to have paid a fraction of that, in the end it’s not a bad price because once you separate the two conductors, you have double the amount of wire: 200 feet.

Although the frugal guy in me cringed, I bit the bullet and purchased their speaker wire. To be clear, though, I could have found another source of wire in that Walmart, but I preferred speaker wire for this application. And $17 to (hopefully!) prove a point? That’s a deal! 🙂

Lake James State Park (K-2739)

Once I arrived on site, I found a picnic site I’d used before with some tall trees around it.

Here’s how I prepared the antenna:

First, I cut 28.5 feet of the speaker wire from the roll and split the paired wires so that I’d have two full 28.5 foot lengths.

Next, I stripped the ends of the wire and attached banana jacks I found in my junk drawer. Although these aren’t necessary as the binding post adapter can pair directly with the wire, I though it might make for a cleaner install. In the end, though, I wasn’t pleased with the connection to the radiator, so dispensed with one of the banana jacks on site, and later dispensed with the other one as well. The connection is actually stronger without the banana jacks.

I then deployed the 28.5 radiator with my arborist throw line, and laid the other 28.5 half on the ground (the ground of this antenna would pair with the black binding post, the radiator with the red post).  I only needed 17 feet of counterpoise, but once it couples with the ground, I don’t think any extra length makes a difference (although less than 17 feet likely would).

The antenna was essentially set up as a vertical random wire with one counterpoise.

I then plugged the BNC binding post adapter into the rig, hit the ATU button, and was on the air.

It’s that simple!

My new speaker wire antenna in all its glory.

Gear:

On The Air

I’ll admit: I was a bit nervous putting this antenna on the air. Although I felt the X5105 ATU *should* match this antenna, I had no idea if it actually would.

Fortunately? It did.

At this point, if you don’t want any spoilers, I suggest you watch my real-time, real-life, no-edit, no-ad, video of the entire activation (including buying and building the antenna!).

Click here to watch the video.

Otherwise, scroll for my activation summary…

I was very pleased that the X5105 found a match on the 40 meter band.

I started calling CQ in CW and validated my activation by logging 10 stations in 13 minutes.

Honestly: it doesn’t get much better than this.

I logged three more stations on 40 meters CW, then moved up to the 30 meter band where the X5105 easily found a match.

I worked one station on 30 meters before heading back down to the 40 meter band to do a little SSB. I logged three SSB stations in five minutes.

Mission accomplished!

In the end, I logged a total of 17 stations including a P2P with K4NYM.

Not bad at all for speaker wire!

After the activation, I tested the X5105 ATU by trying to find matches on other bands–I was able to find great matches from 60 meters to 6 meters. Most impressive!

X5105 battery

You might recall that I attempted to deplete my X5105 internal battery at my last (rather long) activation of Lake Norman State Park.  I wasn’t able to deplete the battery at that activation, but I finally did at this one.

All I can say is that I’m incredibly impressed with the X5105 internal battery.  This was my fourth activation from one initial charge on May 16.  The battery lasted for 20 minutes, taking me well beyond the 10 contacts needed to validate this park. I’ll now consider taking the X5105 on a multiple SOTA summit run!

Short Hike

Even thought the heat was intense and the humidity even more intense, I decided to take in a 2 mile hike post-activation. I snapped a few shots along the way.

This is the Christmas Fern which derives its name from a few characteristics: its resilience to early season snows maintaining a dark green color beyond Christmas, and because folks believe its leaves are shaped like Santa’s boots or even Santa on his sleigh.

Improvements

I’ll plan to add more counterpoises to the speaker wire antenna as I know this will only help efficiency.

In addition, I’ll plan to build even more antennas with this roll of speaker wire. If you have some suggestions, feel free to comment!

Thank you for reading this field report!

Cheers,

Thomas (K4SWL)


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G4USI has fun testing the matching ability of the Xiegu X5105 ATU

Many thanks to Stephen (G7VFY) who shares the following article posted on G4USI’s blog:

Xiegu ATU’s – just how good are they?

Preamble: Based on some social media comments, let me say at the outset that: a) I know that the ATU does not tune the antenna, but provides a good match to it; b) resonant antennas are more efficient; c) that you can tune a dummy load; d) just because you can tune something doesn’t make it an effective radiator. I do know these things. This post is intended as a bit of fun and to see just how much of a mis-match this ATU can handle to press objects into service as an antenna, even a very inefficient one. Please don’t take it too seriously!

Ask any Xiegu owner of the X5105, G90 or the XPA125B linear amp, and they will all tell you that they have great auto-tuners. Well, I own a X5105 and recently was lent a G90 for review for Practical Wireless. I decided to put the ATUs to the test using my X5105.

But what challenge to give it? Well, how about trying very, very long and very, very short antennas? What about metal gates, a cow shed roof, the framework of a polytunnel and a stock trailer?

Read on to find out how it really performs.

Click here to continue reading…

I love G4USI’s philosophy with this fun experiment: see if it’ll match, then see if you can get spotted!

Xiegu ATUs certainly have a wide matching range–so do the Elecraft KX series ATUs. Indeed, having a super capable trans match means that you don’t necessarily need an extra inline transformer to make matching a non-resonant wire easier.

And I see why G4USI mentions that there’s a difference between a good SWR and efficiency. It’s an important note because, yes, dummy loads will yield perfect SWRs!

Many, many moons ago, I used to participate in a fun contest where the idea was to make as many contacts as possible from not-so-standard antennas. The rules of the contest really pushed the operator to metal objects that, in no way, resembled an antenna. They didn’t allow electric fences or even gutters, if I recall correctly.

One year, I remember loading two identical small trampolines and my in-law’s house. I think I ran them QRP with my Elecraft K2 and used a ZM-2 manual tuner to match them. I’m sure they weren’t efficient, but it worked! I made several contacts with other contest stations and it was amazing fun!

Have you ever had success with a non-traditional antenna? Please comment!

Pairing the Chameleon CHA LEFS with the Discovery TX-500 at Table Rock Fish Hatchery

Last time I visited Table Rock Fish Hatchery–this activation–it was a struggle to get the ten contacts I needed for a valid activation. Propagation was horrible that day, making it a proper struggle.

On Thursday, May 20, 2021, I thought I’d go back to the fish hatchery for another try! I really like the site: it’s open, has lots of trees, and the staff (and neighborhood dogs) are all very friendly.

My not-so-QRP diesel truck!

Thing is, as I drove to Table Rock, my buddy Mike informed me that propagation took a nose dive. Earlier in the day, it had been reasonably stable, but he noted that POTA activators were struggling in the afternoon and the propagation numbers were in the dumps.

There’s a beautiful little creek next to the picnic area.

My secret weapon: The Chameleon CHA LEFS

Shortly after I posted my “unboxing” video of the lab599 Discovery TX-500, Carl at Chameleon Antenna made a comment on my YouTube channel that he was going to send me their CHA LEFS (Lightweight End Fed Sloper) wire antenna since it’s resonant on 40, 20, 17, 15, 12 and 10 meters. In many ways, it’s ideally suited to pair with the TX-500 since this transceiver lacks an internal ATU. Side note: there is a cool project in the works called the DIY599 that adds a 60 watt amp and ATU to the TX-500 . 

I had only recently received the CHA LEFS and had not yet taken it to the field. Table Rock was the perfect opportunity.

When I know in advance that propagation is poor, I try to make my portable set up as efficient as possible, so that’s when I 1.) make sure I pull out a resonant wire antenna and 2.) use a wire antenna with longer radiators. The CHA LEFS fits both of these bills.

The CHA LEFS has a 63 foot radiator made of 20 gauge PTFE antenna KEVLAR wire. The winder has a large efficient transformer to match impedance, and there is an inline coil to make the most of the 63′ radiator. They also include 50′ of Micro 90 paracord.

 

Like all Chameleon antennas I’ve used, it’s built to military specs.

Table Rock Fish Hatchery (K-8012)

Table Rock is ideally-suited for a long-ish sloping wire antenna, too. The site has tall trees and open spaces that make stretching out the sloping radiator quite easy. Just watch those power lines!

The CHA LEFS takes longer to deploy that end-fed antennas with a feedpoint near the ground. I find it quicker to deploy, however, than dipoles.

I deployed the LEFS by first stretching out its radiator wire in the direction I planned to deploy it.

Next, I connected the coax feedline to the SO-239 on the LEFS winder and stretched it in the opposite direction of the radiator. Why do this? It helps keep the radiator and coax from twisting together as I raise the winder/feedpoint into the tree.

This is not a difficult antenna to deploy as one person. Of course, if you have a helper, it’ll go even faster (I’ve yet to convince Hazel to help me with antenna deployment).

I had launched the arborist line quite high into a tree at the picnic table where I planned to operate. I was able to elevate the LEFS feedpoint/winder about 47′ into the tree.

I used the supplied paracord to attach the radiator to a nearby branch. The end of the sloper was perhaps 6 feet off the ground (if memory serves).

Gear:

On The Air

Knowing how poor conditions were from real-life K8RAT observations, I didn’t expect to actually validate my activation by logging the required 10 contacts. As I stated in my activation video, I was fully prepared to walk away with three or four contacts–I didn’t have a few hours to burn on an activation. I was simply happy to play with a new antenna, the TX-500, hang with the local canine welcome committee and enjoy the fine weather.

First, I hopped on 40 meters and discovered the LEFS provided a perfect 1:1 match on 7063 kHz. Very promising!

Next, I started calling CQ and the Reverse Beacon Network functionality of the POTA spots page must have quickly auto-spotted me.

Within 13 minutes, I logged six contacts! I was impressed. Mike (K8RAT) was in that first six contacts and he later told me it was one of the strongest signals he’d ever heard from me at a POTA activation. He asked what I was using as an antenna that day and said, “it was working!”

Next, I moved to the 30 meter band and worked K8RAT again (a rarity on 30 meters!) along with four other stations.

I ran out of time, so called it quits with 11 stations logged.

I did not expect to not only walk away with a valid activation, but to have completed it in such short order.

QSO Map

Here’s the QSO Map of my contacts all made with 5 watts of power:

Video

Here’s my real-time, real-life, no-edit video of the entire activation. Next time I take the LEFS out, I’ll try to remember to include setting it up:

Loving the CHA LEFS!

Talk about good first impressions!

As Carl suggested, I’m going to keep the CHA LEFS tucked away along with my PackTenna EFHW in the Discovery TX-500 pack.

When conditions are poor, I’ll spend the modest amount of extra time deploying this fine antenna.

The only CHA LEFS criticism I noted–and it’s a minor one–is that the in-line trap/coil isn’t very low-profile and takes a little attention to make it fall in the right spot when reeling the antenna up post-activation. Seriously. A minor criticism and I’m guessing Chameleon has a reason for it being on the large size–likely for power handling reasons.

Field Day is coming up, and I think I’m going to make the CHA LEFS one of Team Baklava‘s main antennas (Team Baklava = my buddy N3CZ and me!).

As for the CHA LEFS, I highly recommend it!

Max’s simple MFJ-1984 EFHW antenna winder mod

Many thanks to Max (WG4Z) who writes:

Thomas, my MFJ 1984MP arrived today so looking forward to using a resonant antenna with my 705 but also have the LDG Z-100Plus tuner as a back up.

I’ve seen many antennas that have a winder built in allowing the user to wind in a figure eight fashion. It might help keep the kinks down.

I have fashioned a cord winder for the MFJ 1984 EFHW Antenna. It is a winder made for electrical drop cords and comes in a 3 pack at Lowe’s. Very inexpensive solution for adding it to the MFJ antenna with a couple of zip ties. I’m set to go works some POTA with an efficient antenna. Thanks for your videos deploying the MFJ antenna in the field.

Thank you for sharing this tip, Max! I like how you can so easily secure the antenna to the extension cord winder with cable ties.

While I couldn’t find the three pack link on the Lowe’s website, here’s a link a single winder ($3.48).