Tag Archives: Field Antennas

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!

Testing the new Chameleon Tactical Delta Loop (CHA TDL) antenna

Chameleon Antenna has sent me a number of their antenna systems to evaluate in the field over the past few months at no cost to me. I appreciate not only the opportunity to test these antennas, but to provide the company with my frank feedback.

As I’ve mentioned previously, Chameleon antennas are military grade and build here in the US (check out Josh’s tour of their factory).  You pay a premium price–compared to imported options–but their gear is built for performance, easy deployment, and longevity.

What has impressed me most about Chameleon gear is how flexible and modular it is. Their antenna systems are adaptable to almost any situation and always built around the idea of emergency communications.

Recently, Chameleon sent me their new CHA TDL or Tactical Delta Loop antenna. This vertical loop antenna has been designed to be portable, and tunable from 3.5 to 54.0 MHz (80-6M), but, as Chameleon points out,  “is most effective on the bands from 10.1 to 54.0 MHz (30-6M). ”

TDL deployment

If I’m being perfectly honest, I wasn’t sure what to expect this antenna to look like–in terms of size–once deployed, so I set it up in the front yard prior to taking it to the field.

Set up couldn’t have been more simple: attach the 17′ telescoping whips to the stainless steel spike (with one whip attached to the Hybrid Micro), extend the whip sections, then attach the loop wire to connect the tips of both whips.

It might have taken me four minutes to set up the TDL on the first go.

This antenna needs a little space  for sure: this isn’t one you could easily deploy in a dense forest, but it has a very flat profile vertically. I can’t think of a single park I’ve activated that couldn’t accommodate the CHA TDL.

I like to try to give gear a fair chance when I do evaluations and thought I’d wait until propagation was at least stable before taking the TDL to the field and making a real-time, real-life video (as I used it for the first time). But, frankly, I’m way to impatient to wait for the sun to play fair! Trial by fire…

Lake Norman State Park (K-2740)

On Monday (March 15, 2021) I packed up the CHA TDL and headed to Lake Norman; one of my favorite parks to play radio.

Gear:

Propagation left much to be desired that afternoon, but the weather was perfect.

I decided to pair the CHA TDL with my Icom IC-705. Since the CHA TDL requires an ATU, I connected the mAT-705 Plus.

NVIS on the low bands

I had no idea what to expect from the CHA TDL in terms of performance, but Chameleon notes that it provides Near-Vertical Incidence Skywave (NVIS) propagation on 40 and 80 meters. NVIS antennas are very popular for the military and for emergency communications since the propagation footprint is much closer to home than it might normally be.

NVIS is also a brilliant option for park and summit activators, especially if they’re activating in an area with a high density of park/summit chasers. For example, if you live and activate sites in the state of Maryland, employing a NVIS antenna might make your site more accessible to the DC metro area, Pennsylvania, Virginia, New York, Delaware, and New Jersey–regions that might otherwise be in the skip zone of your 40 meter signal.

On the air

Operating five watts CW, I started calling CQ POTA on 20 meters and snagged four stations in about seven minutes.

I was very pleased to work a station in California and one in Montana with five watts. (Though I need to check, this might have been my first MT station logged from a park.)

Next, I moved to 40 meters and was very curious if the TDL would provide me with proper NVIS propagation.

It did! One litmus test for me is when I work stations in Tennessee on 40 meters. Typically, I only log TN stations when on 80 meters or when I’ve configured one of my wire antennas for NVIS coverage.

Here are my logs from this 28 minute activation:

Here’s a QSOmap of the activation–the delineation between my four 20 meter contacts and eight 40 meter contacts is pretty evident:

Video

Here’s my real-time, real-life video of the entire activation which also shows how the CHA TDL easily fit in among trees:

In a future video, I’ll show how I deploy the CHA TDL.

Unfortunately, I left my tripod at home, so apologies for the viewing angle as I operated the IC-705.

Summary

This first test of the CHA TDL really couldn’t have gone better.

I was able to easily deploy it on sloping ground, among trees, in a state park, and snag both locals and QRP DX within a brief window of time on the air.  All this, while our local star tried its best to interfere.

In terms of construction, the TDL is what I would expect from Chameleon: military grade.

For park activators and Emcomm purposes, the CHA TDL makes for a convenient, portable NVIS antenna on 40 and 80 meters.

While I have lighter, smaller footprint antenna options for SOTA, I must admit I’m very curious how it might perform on 20 and 17 meters from the summit of a mountain. The idea of being able to rotate the antenna and change the propagation footprint is very appealing. I’ll save this experiment for a summit that doesn’t require hours of hiking, though, and one where I know I can jab the stainless steel spike in the ground (i.e. not on top of a rocky mountain).

Any negatives? When I first deployed the TDL at home, we were having 30+ MPH wind gusts. When the gusts shifted, it did move the antenna. This could be remedied pretty easily by using a bit of fishing line filament to tie off one side of the loop. With that said, I’m not sure I’d configure the TDL as a loop if I expected strong winds. Also, as I mentioned earlier, this might not be the best antenna to pack if you plan to include a multi-hour hike in your activation.

And herein lies the brilliant thing about Chameleon Antennas: If I packed in the CHA TDL and found that winds were strong on site, I would simply configure it as a vertical instead of a loop!

The CHA MPAS Lite vertical

The CHA TDL can easily be configured as a CHA MPAS Lite portable vertical: all it’s missing is a counterpoise wire which you can buy separately from Chameleon or, better yet,  just use some spare wire you have on hand!

Or, you could configure it as a random wire antenna by directly connecting a length of wire to the Hybrid Micro transformer.

That’s the thing about Chameleon HF Antennas: they can be configured so many different ways.

If you’re interested in the CHA TDL, I’d strongly encourage you to read though the user manual: it’s chock full of info and ideas. Click here to download as a PDF.

Next time I take the CHA TDL out, I think it’ll be to a summit where I’d like to see how it might perform on the higher bands with the ground sloping away from the antenna site.

Click here to check out the CHA TDL at Chameleon Antenna ($355 US shipped). 

Icom publishes AH-705 antenna tuner details

Many thanks to Rob Sherwood (NC0B) who notes that Icom has published details regarding their new AH-705 antenna tuner which is designed to pair directly with the Icom IC-705 QRP transceiver.

Many Icom IC-705 owners have been waiting to learn more about the AH-705 before purchasing a dedicated portable ATU for their IC-705. Some of these details may help potential customers make a purchase decision.

Key specifications and features per Icom:

 

  • Covers the 1.8 MHz to 50 MHz bands

30 m, 98.4 ft or longer antenna: 1.8 – 54 MHz, 7 m, 23 ft or longer antenna: 3.5 – 54 MHz
* Depending on operating conditions or environments, the tuner may not be able to tune the antenna.

  • SO-239 antenna connector for 50 Ω antenna such as dipole or Yagi
  • “Terminal connector”, binding post socket adapter supplied for a long wire antenna

  • 2-way power sources using alkaline batteries (2 x AA cells) or external 13.8 V DC*
    * 13.8 V DC should be taken directly from an external power supply, not through the IC-705.
  • IP54 dust-protection and water resistance construction*
    * The connectors should be covered with an adhesive tape or a jack cover to prevent water seeping into the connection.
  • Full automatic tuning, just push the [TUNER] button on the IC-705
  • Latching relays used for saving power consumption
  • 190 × 105 × 40 mm; 7.5 × 4.1 × 1.6 in, 450 g; 15.8 oz* compact design
    * Battery cells are not included.
  • 45 tuner memories

Of course, I don’t have an AH-705 in hand to test yet, so there’s no way I can comment on performance.

Still, I can’t turn of the reviewer inside so I feel I can make some superficial comments assuming the specs don’t change.

Potential positives?

  • Complete integration with the IC-705
  • Could (potentially–?) be permanently mounted outdoors at the antenna feed point as a dedicated remote tuner
  • IP54 dust and water resistant
  • Power from internal batteries and an external DC source
  • It’s an Icom product, so I would expect excellent overall quality

Potential negatives?

  • Maximum wattage is only 10W, which I suppose is okay if you never put an amplifier between the IC-705 and the AH-705
  • Based on Icom specs, the AH-705 is larger than other portable ATUs at 7.5 × 4.1 × 1.6 inches. For example:
  • Some have noted pricing around $350 US price–that’s a premium for a portable ATU considering the Elecraft T1 is $180 assembled and many LDG models are less than $200. Of course, none of those ATUs have an IP54 rating, either.
  • Speculation here, but the AH-705 might only work with the IC-705 or Icom radios with similar ATU commands. One original pre-production prototype image of the AH-705 shows a power switch; the latest images do not. Like the mAT-705Plus, I’m not sure if the AH-705 can be turned on in order to tune only via RF sensing without essentially modifying a control cable to trick the ATU into powering up.

I was a little surprised to see that the AH-705 “only” has 45 tuner memories. In truth, I never really pay attention to this spec because I’m primarily a field operator. My radio sessions are only an hour or two long and I routinely pair my transceivers with a wide variety of antennas, so a portable ATU never has a chance to develop a complex tuner memory map for any given antenna. But as a reviewer, I try to step in other operators’ shoes so I see where this could be a slight negative for those who plan to use the AH-705 at home and connected to only one antenna. As a point of comparison, the mAT-705Plus has 16,000 tuner memories. Still, memories only help shave off a bit of the auto-tuning time. This would never have an impact on my purchase decision.

Biggest positive for me? IP54 rating

Since the AH-705 is designed to be dust and weather resistant,  it could be mounted at the antenna feed point. At home, perhaps it could act like an externally-mounted, remotely-controlled antenna tuner. I’m not sure what the maximum length of the control cable could be, but Icom Japan even lists a 16 foot control cable as an accessory. Of course, you would still need to follow Icom’s guidance about protecting the antenna, transmitter and control cable connection points.

Biggest negative for me? The size.

If the AH-705 specs are correct, it’s a little surprising Icom designed a portable ATU that’s this large. As you can see in the image above, it easily fits in the LC-192, but frankly since I’ve been an Elecraft T1 tuner user, I’ll notice that the AH-705 is 3.1″ longer, 1.6″ wider, and .7″ taller than the T1. It will certainly take up more backpack space.

Of course, unless I build an IC-705 control interface for the Elecraft T1, I can’t directly pair it with the IC-705 like I could with the AH-705. That said? I personally prefer pressing a tune button on the T1 and sending “QRL?” instead of hitting the PTT or CW key and allowing the IC-705 to kick in a continuous tune cycle for a few seconds. You might have noticed in some of my videos that when I tune to a new CW frequency, I’ll listen for activity, then tap the TUNE button on the T1 and send “QRL?” or “QRL de K4SWL”. By the time I’ve sent that string, the T1 has typically already found a match.

How will it perform?

I’ve got to assume the AH-705 will perform well. Icom tends to give their products thorough QC before shipping them to customers. I don’t anticipate any issues with the AH-705 as I did with the original maT-705, for example.

I’ll plan to test the AH-705 after it’s available.

For more information about the AH-705, check out the product page on Icom Japan’s website.

CHA MPAS Lite: A military-grade compact field antenna

Note: the following post was originally published on the SWLing Post

Chameleon Antenna recently sent me a prototype of their latest antenna: the CHA MPAS Lite.

The MPAS Lite is a compact version of their MPAS 2.0 modular antenna system and designed to be even more portable.

Chameleon Antenna is a specialist antenna manufacturer that makes military-grade, field portable antennas that are low-profile and stealthy. Chameleon products are 100% made in the USA and their customers range from amateur radio operators to the armed forces.

Their antennas are not cheap, but they are a prime example when we talk about “you pay for what you get.” In all of my years of evaluating radio products, I’ve never seen better quality field antennas–they’re absolutely top-shelf.

Zeta

I’m currently in my hometown doing a little caregiving for my parents. I’d only planned to be here for a couple of days, but when I saw that the remnants of Hurricane Zeta would pass directly over us with tropical storm force winds and rain, I stuck around to help the folks out.

Zeta struck quite a blow, in fact. No injuries reported, but over 23,000 of us have been without power for over 34+ hours in Catawba county. With saturated grounds, the winds toppled a lot of trees and damaged power lines.

Yesterday, I wanted to take advantage of the power outage and get on the air. I couldn’t really do a POTA activation because I needed to manage things here at my parents’ house. Plus, why not profit from the grid being down and bathe in a noise-free RF space–?

I decided to set it up in their front yard.

CHA MPAS Lite

I had never deployed the MPAS Lite before, so I did a quick scan through the owner’s manual. Although the MPAS Lite (like the MPAS 2.0) can be configured a number of ways, I deployed it as a simple vertical antenna.

Assembly was simple:

  1. Insert the stainless steel spike in the ground,
  2. Attach the counterpoise wire (I unraveled about 25′) to the spike
  3. Screw on the CHA Micro-Hybrid
  4. Screw the 17′ telescoping whip onto the Hybrid-Micro
  5. Extend the whip antenna fully
  6. Connect the supplied coax (with in-line choke) to the Hybrid-Micro
  7. Connect the antenna to the rig

Although I had the Icom IC-705 packed, I wanted to keep things simple by using the Elecraft KX2 I’d also packed since it has a built-in ATU.

Important: the CHA MPAS Lite requires an ATU to get a good match across the bands.

I wasn’t in the mood to ragchew yesterday, but I thought it might be fun to see how easily I could tune the MPAS Lite from 80 meters up.

I checked the Parks On The Air spots page and saw NK8O activating a park in Minnesota in CW:

He was working a bit of a pile-up, but after three calls, he worked me and reported a 559 signal report. Not bad at 5 watts!

I then moved to 40, 18, and 20 meter and called CQ a couple times to see if the Reverse Beacon Network (RBN) could spot me. I like using the RBN to give me a “quick and dirty” signal report. I was very pleased with the bands I tested:

Those dB numbers are quite good for an op running 5 watts into a vertical compromised antenna.

The KX2 very effortlessly got near 1:1 matches on every band I tested.

Of course, after working a few stations in CW and SSB, I tuned to the broadcast bands and enjoyed a little RFI-free SWLing. Noting 13dka’s recent article, I’m thinking on the coast, the MPAS Lite will make for a superb amateur radio and SWLing antenna.

Durability

Although the remnants of Zeta had effectively passed through the area three hours prior, it was still very blustery outside. I was concerned gusts might even be a little too strong for the 17′ whip, but I was wrong. The whip handled the wind gusts with ease and the spike held it in place with no problem.

One of the things I have to watch with my Wolf River Coils TIA vertical is the fact it’s prone to fall in windy conditions and many ops have noted that this can permanently damage the telescoping whip (the weak point in that system).

I’m pretty certain this wouldn’t happen with the Chameleon 17′ whip–it feels very substantial and solid.

Ready to hit the field with the CHA MPAS Lite!

I’m a huge fan of wire antennas because I believe they give me the most “bang-for-buck” in the field, but they’re not always practical to deploy. I like having a good self-supporting antenna option in my tool belt when there are no trees around or when parks don’t allow me to hang antennas in their trees.

I’ve got a park in mind that will make for a good test of the CHA MPAS Lite: it’s a remote game land with no real parking option. I’ll have to activate it on the roadside–an ideal application for the MPAS Lite.

Click here to check out the CHA MPAS Lite.

Hiking to a POTA “two-fer” site from home

I feel pretty lucky that my QTH borders tens of thousands of acres of protected lands: a watershed, Pisgah National Forest, and Pisgah Game Land WRC. Our family enjoys hiking, so we often venture into the forest around our house  and explore the ridge lines, peaks, and views.

This year, while exploring all of the public lands available to activate in the Parks On The Air (POTA) program, I realized there were no less than two sites within a 30-35 minute hike of my home! Quite literally, in my back yard.

In fact, there’s a large area where two POTA entities overlap–Pisgah National Forest and Pisgah Game Land–giving me the opportunity to activate both sites simultaneously as a “two-fer.”

If it’s so close, you may wonder why I haven’t activated it yet–? Well, by the time I realized the park boundary overlap was within hiking distance of the house, we were well into spring, thus the forest was lush with vegetation and the hike to the site requires proper trail-blazing with an elevation change of 600′ (183M). It’s a much easier hike in fall and winter when you can actually see where you’re going through the trees.

Still: Saturday morning, the weather was so perfect for hiking I floated the idea by my teenage daughter, Geneva: “I’ve got a hankering to hike up the mountain today and do a POTA activation.” She replied, “I’ll need to pack my daypack and take the HT.” She was eager to see if she could communicate back to the house simplex with her mom and sis with her new FT-60R handheld.

My wife gave me her blessing, so I packed my trusty Red Oxx C-Ruck with my Elecraft KX2 kit, CHA Emcomm III Portable antenna, water, snacks, logbook and tablet, and used the ruck top flap to secure my three leg folding stool.

Pisgah Game Land WRC (K-6937) & Pisgah National Forest (K-4510)

We arrived at a suitable site about 40 minutes after leaving the QTH. My Garmin GPS and topo maps confirmed we were well within park boundaries. I found a rock outcropping and set up my station.

Even though the area was pretty dense with trees, Rhododendrons, and Mountain Laurel, I had no difficulty deploying the Emcomm III Portable antenna using my throw line.

That’s not a flying squirrel, it’s the winder/balun of the Emcomm III.

The Elecraft KX2 had no trouble at all matching the Emcomm III on all bands.

Even though Geneva was busy communicating with her sister (back at “Mission Control” via simplex) on the FT-60R, she actively logged all of my contact on the Surface Go tablet using N3FJP’s excellent contact log.

I quickly logged eleven contacts on 80 and 40 meters and my daughter suggested we cut the activation a bit short to take in more hiking.

We both wanted to follow a trail we found and see if it lead to the Blue Ridge Parkway.

Hazel has that “Seriously? You want to continue hiking?” look.

I packed up the station and hit the trail!

It turned out to be a good 45 minute trek along a ridge line increasing our elevation about 1,000′ (305M) ASL compared with home. The trail to the BRP was what I would call a moderately difficult trail (much easier than trail-blazing up the mountain!).

In the end, we found the Blue Ridge Parkway and the trail head to ascend Lane Pinnacle which is an excellent SOTA site. We decided to save Lane for another day this fall/winter with a very early departure from home.

Neva also discovered she could easily chat with her sister back at the QTH via 2 meter simplex at the parkway. This means I can definitely chat with the family back home when I eventually make that Lane Pinnacle SOTA activation.

The hike back to the POTA site was mostly downhill so only took about 40 minutes. I then veered off the path to trail-blaze our way back to the house. I did get a little off course which added about 25 minutes (!!) to our descent and requiring us to mitigate the steepest part of the ridge. Next time, I’ll pay more attention to my GPS map (although, in the winter, it’ll be much easier).

Still, it was a very enjoyable hike and certainly one of the more challenging I’ve been on in ages mainly due to the steep part at the end.

All-in-all: I discovered that there are no less than three POTA sites and one SOTA site within hiking distance of the QTH. The best part, by far, was the father/daughter time. Geneva is always up for an adventure (including currently studying for her General class license!).

POTA Portable, Picnic, Paddles, and Unpredictable Propagation

Practicing left hand lunching, right hand keying/logging!

It seems like lately I’ve had to work hard to log 10-15 contacts during my Parks On The Air (POTA) activations.  Propagation has been so flaky, I use every trick in the book to snag at least my ten contacts for a valid activation: change antenna configuration, run up to 40-50 watts output, employ both CW and SSB, have friends spot me on the network, and try every band possible (typically from 80-17).

Note that the majority of my activations are proper QRP and rarely do I spend longer than 60 to 90 minutes actually on the air. Indeed, many of my activations are only 60 minutes long including set-up and take-down. That may seem short to most POTA folks, but that’s what works in my schedule and family life: quick hits. It’s one of the reasons I’m not more active in Summits On The Air (SOTA)–I need more time for those sites as they’re not as accessible as our numerous POTA entities.

Still, our local star has been misbehaving, and I had not planned to do an activation on Sunday (September 28) because I saw the propagation forecast and it was rather discouraging (A index 26, SW 505, Bz -2).

From home that morning, I chased a few parks but found it challenging to hear most of them. QSB was incredibly deep–strong stations gone in an instant.

Still, my wife suggested we take a picnic to one of our favorite local spots and how could I possibly visit a park without activating it? Right–?

Zebulon B. Vance Birthplace (K-6856)

What we, as a family, love about this site is the large covered picnic area and historic log cabins. Also, the site receives very few visitors on Sundays when the main museum is closed.

Each time we visit the Vance site, we bring my MSR liquid fuel stove and make lunch/dinner.

I set up the stove, got lunch started and my wife took over food prep.

Knowing propagation was unstable, I opted for more than QRP power this time–at least, at first–so I chose the Mission RGO One transceiver (capable of 55 W output) and CHA Emcomm III Portable antenna for this activation.

I deployed the Emcomm III in a sloping configuration with the end of the 73′ radiator high in a nearby (dead) tree and the counterpoise on the ground. I also suspended the winder/balun from the corner of one of the shelter’s rafter’s with paracord.

Since it’s difficult to see a wire antenna in photos, I’ve labeled the components in the following image (click to enlarge):

I didn’t know if this configuration would prove useful, but I knew it would be better than attempting this activation with my Wolf River Coils TIA vertical antenna.

I hopped on the air starting on 80M CW (at the request of my buddy WD8RIF), worked him and three stations in rapid succession. After a few minutes of silence, I moved up to the 40 meter band and worked 16 stations. I then moved to 30 meters and worked 11 stations.

I was working more stations than I would have ever guessed beforehand.

Since I only had about 10 minutes to spare after working 30 meters, I decided to plug in the microphone and work some park-to-park contacts. While I always intend to hunt for other parks while I’m in the field, more times than not, I don’t have the luxury of an Internet connection to check the POTA spots page like I did at Vance on Sunday.

I worked 5 parks: 3 in SSB and 2 in CW.

Speaking of CW, this was my first field activation using CW Morse Double Paddles.

CW Morse recently surprised me by sending a few of their products to evaluate in the field (guessing they saw my previous post asking about keys–?).

I must say, I really love the CW Morse double paddles. They’re fully (and easily) adjustable, the action is responsive and smooth, and with the base, they’re incredibly stable on a hard surface. I highly recommend them.

At a setting like we had at Vance, I love the heavy base plate, but if I planned to hike into a site, I believe I’d remove the base to save on weight.

Unpredictable Propagation?

Perhaps there was a brief window of stability between solar events and I was able to take advantage of that while I was on the air? I’m not sure.

I never expected to log 37 contacts in the space of a little over an hour (with some of that time being off the air to help with picnic prep). Not on that Sunday when the solar numbers were in the dumps.

I’d like to believe it was a combination of things:

  • A large wire field antenna with decent gain and the ability to work multiple bands
  • 40 watts of power (at first, I backed down to QRP on 30 meters)
  • Using CW for 34 of the 37 contacts
  • Perhaps unintentionally good timing

All I know is, I had a blast! It’s hard to beat a combination of good radio, good food, good scenery, and good weather!

I suppose this was also a lesson in simply hitting the field and ignoring the propagation.

Or as Rear Admiral David G. Farragut once famously said, “Damn the torpedoes, full speed ahead!”

A field antenna’s best friend: The amazing arborist throw line

At least 95% of the time I’m playing radio in the field, I use wire antennas and suspend them in trees.

Since I do a lot of park activations for the POTA program, trees are typically very easy to come by and most of the time the park office doesn’t care if I hang an antenna in their tree for a couple of hours.

For years, I’ve been using a heavy steel nut–a nut that would fit a very large bolt–as a weight and attach it to fishing line. I then simply throw the nut into a tree and pray the fishing line deploys properly. I have reasonably good aim, so–on a good day–I typically only need one or two throws/tries to get the fishing line over a branch. On bad days? Well… let’s just not talk about that.

There are some inherent weaknesses in the fishing line/monofilament system:

First of all, I’m lobbing a heavy metal object into the trees. If it ricochets–and it eventually will–it can come back down to earth and land where you might not want it to (for example, on your radio, on your car, or on your friend’s head).  Fortunately, I’ve never hit anything or anyone as I’m careful to clear the area first, but unfortunately, I once had the nut hit a tree and come back down near me. That was a little scary.

Secondly, fishing line isn’t exactly recyclable and you simply can’t use it over and over. I get at most three deployments with a section of fishing line before it gets too stretched and unworkable.

Finally, fishing line is incredibly prone to tangle, especially near the end of the spool.

A Better Solution? The Arborist’s Throw Line

The arborist throw line is no recent innovation. For years, I’ve read recommendations from other ham radio operators who swear by arborist throw lines but I only recently decided to take the plunge after one very frustrating park activation where my fishing line knotted and almost got permanently stuck in a gorgeous tree. I’m very much a “Leave No Trace” kind of guy, so I was incredibly relieved when I was finally able to work the fishing line out of the tree.

When I got home from that activation, I ordered a Weaver Throw Weight and Line and a Throw Line Storage Cube. (Note: these are Amazon affiliate links that support this site.)

Forester Throw Rope folding/collapsible Storage Cube

I once talked with an arborist about throw lines and he stressed the importance of getting not just the line, but also a throw line storage cube. The cube allows you to both deploy and take up the line without any tangles or knots.

All in, I spent about $50.00 US for both.

Preparing the throw line

My arborist buddy gave me an important tip: the throw line needs to be stretched.

As you can see in the photo above, the throw line is packed in a bundle that’s easy to unroll. After you unroll it for the first time, though, the line has a “memory” of all those bends from its life in the package.

You can remove much of the throw line memory by tying one end of the line to a tree and stretching the line to its full length. The line is 150 (or so) feet long, so you’ll need an open space to do this.

The arborist in this video shows how this is done (I’ve queued it to the point in the video where he shows how to do this):

Knots

You’ll need to attach the throw line to the throw weight, of course.

There are a number of knots arborists use, but I’m a fan of the slipped simple noose knot. Perhaps it’s because it’s easy to tie even with semi-rigid line, it holds quite well and, most importantly, it’s easy to untie.

Looks like arborists use it too because when searching for an instructional video, the first result was from an arborists’ channel:

Throwing up!

There are a few different ways to launch a throw line into a tree.

Take my advice here: practice at home before you hit the field! It could save you a lot of embarrassment, although, admittedly, my at-home practice sessions gave my wife and my daughters good reasons to chuckle.

I’ve only been using the throw line for a little over a week, so I’m still sorting out which method works best for me. One thing I discovered very quickly, though: no matter which launch method I use, I can send that throw weight into a tree at least 60% higher than I could before.

No doubt, the throw line and weight really put the laws of physics in your favor!

Here’s a great video highlighting different throw line launch techniques:

In practice

I took the throw line to the field today for the first time and I’m very pleased with how effectively it works.

I was able to place my antenna on a much higher branch than I could have otherwise. It took me three tries today, but it had more to do with my poor aim. As with any skill, this will, I think, improve with practice.

The storage cube folds down flat and keeps the line from tangling

Besides the improved antenna height, I love that the line can be used over and over again. Also, it’s strong enough that should it ever get caught in a tree, I can pull it out without the line breaking.

I can also reel in the line at least three or four times faster than I could with fishing line. Simply flake it into the storage cube one foot at a time.

When the line has been stored along with the throw weight, you can fold the storage cube down flat, then fold and secure it into a compact triangle.

Are there any negatives with the throw line system? Here are a few I’d note:

  • Bulk. Even when packed down, the line in the storage cube take up much more space than fishing line. Although it easily fits in even my smallest backpack (the GoRuck Bullet), I’m not sure I’d take it on a long hike.
  • This system requires a little practice and skill–you can’t pull it out of the package for the first time in the field and expect perfect line launches.
  • The throw line is more conspicuous than fishing line. If you’re trying to be a bit stealthy–as many of us are these days during the Covid-19 pandemic–the bright yellow throw line will attract more attention and questions from other hikers/campers, etc.
One happy activator!

Even though it’s bulky by my standards, I see the throw line becoming a permanent part of my field kit and I expect I’ll use it on most of my POTA activations.

Have you been using a throw line to hang field antennas? Or do you use a different system?  Please comment!