Category Archives: Antennas

Antennas, Field Reports, News, POTA

Mistakes and miscalculations might make us better field radio operators

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I don’t know about you, but part of the fun of playing radio in the field are the inevitable frustrations.

It might not feel like it in the moment, but when I eventually overcome the challenges of a mistake, I feel like I’ve truly accomplished something.

That was my little epiphany this morning: making mistakes has perhaps made me a better radio operator. Less-than-efficient field deployments have honed my skills and had a major influence on the gear I pack.

If you’ve read some of my (rather rambling) field reports in the past, you’ll note that I rarely do field activations with the exact same gear combinations each time. I feel fortunate enough that I can pair different radios with different antennas and different accessories.  I get a small thrill out of not knowing exactly how well a combination will work, especially if I’m not activating a rare all-time new park or tough summit for that matter. In cases where getting to the site is a challenge in and of itself, I want to use a trusted combo of gear.

It’s that wee bit of mystery that attracts me to the field.

If I approached POTA more like a contest–where activation and contact numbers were my focus–I would have installed a mobile HF rig in my car a long time ago. I could rack up way more parks and contacts that way. It especially simplifies multi-site activation days since it effectively eliminates the time involved in setting up and later packing up gear.  Mobile operating is the most efficient way to hit number goals: drive up to a site, start calling CQ, work your stations, then move on.

K-6937 & K-4510

(Photo credit: K4TLI)

Yesterday, I did a last minute “two-fer” activation of Pisgah National Forest and Pisgah Game Land. I had not planned to do an activation that day–temps never rose above 29F (-2C) at the QTH day and it also snowed and flurried all day long. Winds were very gusty as well, so it effectively felt much colder on the skin.

I wanted to hike up to the ridge line behind my QTH and do the activation but I knew up there temps would be lower and (worse) winds much stronger. Cold doesn’t really bother me, but strong winds do. This was also the first weekend my ankle felt almost normal after twisting it badly last month. It’s healing and I hope will be in shape for a long hike from my QTH to a six point SOTA summit next weekend with my daughter (K4TLI).

All of those factors combined pointed toward simply staying at home, drinking coffee, and reading a book.

Hazel was ready for some field radio fun, though. (Photo credit: K4TLI)

But I really wanted some outdoor time. And I really wanted to make an activation with my Elecraft KX1, so I decided that instead of hiking up in elevation 800 feet, I’d drive down about 900-1,000 feet to a forest trailhead. That would get me on the air in a protected valley with less wind,  less snow, possibly warmer temps, and much less hiking which would be easier on my ankle.

The Last-Minute Antenna

When I use the KX1 in the field, I typically pack a very simple antenna: one length of radiator wire and one length of counterpoise wire–connected to a BNC binding post adapter, I let the built-in ATU sort out the match.

When I owned my first KX1, I had a magic length of radiator wire (the length of which I can no longer remember) that seemed to work amazingly well  on 40, 30, and 20 meters.

My new-to-me KX1 came with two lengths of wire: one 23′ and one about 20′. Although I made a fun and successful activation with this setup, the radiator was simply too short for the KX1 to find a decent match on 40M.

On the way out the door, I decided to cut a new radiator and counterpoise out of scrap wire I use for antenna experiments.

Being a bit stubborn and also in a hurry to beat sunset, I did no Internet research to sort out the ideal lengths for 40 meters.  I simply cut a 17′ length for the counterpoise and about 27.5′ for the radiator.

In the Field

After arriving on site, I deployed the antenna and tried finding a match on 40 meters with the KX1’s internal ATU.

No go.

I tried a few times hoping maybe the ATU would find something even semi-reasonable in terms of a match, but there simply wasn’t enough radiator to make it work. That was a shame because forty meters would have been the ideal band for yielding quick contacts this time of the afternoon.

I had options, but I wanted to make what I had work.

The activation took time and patience. The 30 meter band was now my best bet and it’s where I logged all ten contacts for a valid activation. I tried 20 meters where I had a 1:1 match, but the band was dead.

At one point, I switched out the KX1 with my KX2 that I also packed. I tried to find a 40 meter match with the superior KX2 ATU, but physics got in the way again. 🙂

40 meters was an option

Let’s be clear here: I could have easily cut 4′ off of the counterpoise and attached it to the radiator and I bet I would have gotten a match on 40M. Since the counterpoise was lying on the ground, its length was less crucial.

The EFT Trail-Friendly end fed antenna was also in my pack.

I also had a perfectly capable 40/20/10 en-fed antenna in my pack. Switching out the antenna would have only taken four minutes.

I bet I could have easily yielded 20 additional contacts on 40 meters because the band was in great shape. Almost without fail, 40 meters is my most productive band.

Working with limitations

Thing is, I’m starting to understand that I like working with self-imposed limitations.

Perhaps this is why I love QRP and low-power radio so much: I get a little thrill out of doing more with less.

Yesterday, even after I realized it would be a struggle to log my final three contacts on 30 meters, I persisted. One motivation was I’ve never completed a full activation using only 30 meters. With a little patience, I knew I could snag my ten contacts.

The only things making it a challenge were the facts that temps were dropping rapidly, winds were picking up, and the sun was setting. Hazel (the POTA dog) who so eagerly jumped in the car when she saw me put on my hiking boots earlier, was also starting to shiver.

Fortunately, after trying another short stint on 20 meters, I returned to 30 and worked two more stations in quick succession giving me a total of nine contacts.

It started to get darker, so I hunted and found an operator calling CQ  on 30 and simply made contact with him. He wasn’t a POTA station, just a general CQ call. He kindly gave me his details for the logs.

Lessons learned

I made a video of most of this activation and will upload it when I have a little bandwidth to do so. I’ll embed it in a shorter field report here on QRPer since I’ve described so much already.

Even though it was a challenge making ten contacts to accomplish a valid field activation with my time constraints, I’ll admit that I really enjoyed the challenge.

Next time I head to the field with the KX1, I’ll actually test the antenna prior to leaving the QTH.

In fact, I’m planning to make two radiators: one at an ideal length for 40 meters and above, and another–much longer–for 80 meters and above. Any advice and personal experience from KX1 owners would be much appreciated.

Perhaps most importantly, it’s only now dawned on me how much I enjoy making the most with self-imposed limitations or “trying to make lemonade with lemons.”

Do you feel the same? I’d love to hear your comments.

Antennas, Field Reports, Grab And Go, News, Portable, POTA, QRP

POTA Field Report: Pairing the Elecraft KX3 with the AX1 antenna and seeking distant stations

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Although I’m a huge fan of wire antennas in the field, since I started using CW during my Parks On The Air (POTA) activations, I’ve really enjoyed experimenting with compromised portable antennas.

Typically, there’s a trade off with field antennas:

High-performance antennas tend to take more time to install. Some of my highest performance antennas are dipoles, doublets, delta loops, and end fed wire antennas. All of them require support from a tree if I want maximum height off the ground. Some (like the dipole) require multiple supports. While I actually enjoy installing wire antennas in trees, it typically takes me at least 10 minutes to install a wire antenna if it only needs one support and one counterpoise.

Compromised or low-profile antennas may lack performance and efficiency, but are often much quicker and easier to deploy.

In my opinion, field operators should keep both types of antennas in their arsenal because sometimes the site itself will dictate which antenna they use. I’ve activated many sites where wire antennas simply aren’t an option.

That was not the case last Tuesday, however.

Tuttle Educational State Forest (K-4861)

On Tuesday, December 29, 2020, I stopped by Tuttle Educational State Forest (K-4861)–one of my favorite local state parks–for a quick, impromptu activation.

I had no less than four antennas in my car that day and Tuttle is the type of site where I can install pretty much anything: they’ve a spacious picnic area with large tables, tall trees, and parking is close by. Tuttle is the perfect place to deploy not only a large wire antenna, but a large radio if you wish since you don’t have to lug it far from the car.

But en route to Tuttle I decided to take a completely different approach. One of the four antennas I had in the car that day was the Elecraft AX1 antenna.

Without a doubt, the AX1 is the most portable antenna I own. It’s so compact, I can carry it in my pocket if I wish.

When I first purchased the AX1, I was very skeptical and assumed it would only work when “the stars aligned”–days with better-than-average propagation and lots of POTA hunters/chasers looking for me.

The first time I used the AX1 in the field, it impressed me (understatement alert).

The second time, same thing.

In all of my AX1 activations, however, I had only operated on the 40 meter band where the antenna’s footprint looked more like a NVIS antenna than a vertical. Meaning, most of my contacts were in neighboring states like Tennessee, South Carolina, Virginia, and Georgia (typically, those states are in my 40 meter skip zone).

The reason I hadn’t tried 20 or 17 meters with the AX1 is because I would start an activation on the 40 meter band and accumulate enough contacts to achieve a valid activation. Since I’m often pressed for time, I simply didn’t bother configuring the antenna for the higher bands.

Time for that to change!

The question I wanted answered at Tuttle: could the AX1 antenna work “DX” stations? By DX, I mean POTA DX, so distant states and provinces primarily–not necessarily other countries.

Gear:

On the air

I paired the Elecraft KX3 with the AX1 at Tuttle. This was the first time I’d ever tried this particular transceiver/antenna combo.

After setting up, I started on the 20 meter band and called CQ for a few minutes.

The first two stations I worked were in Texas (KF9RX and K5RX).

The third station (W6LEN) was in California.

California!?!

Honestly, it was/is hard for me to fathom how in the world 10 watts into a tabletop telescoping whip antenna could work a station exactly 2,083 miles (3,352 km)–and three time zones away–from my picnic table. I’m sure W6LEN has a great antenna on the other end, but I bet he would be surprised to learn that my 10 watt signal was being radiated by such a wee antenna.

 

 

I then worked stations in Florida (K2WO), Minnesota (N0UR), and New Hampshire (W2NR) and decided to move to 17 meters.

On 17 meters I worked W2NR in New Hampshire once again.

I should note here that each time you work a station on a different band or with a different mode, it counts as a separate contact in POTA. In other words, my contacts with W2NR on 20 meters and 17 meters counts as two logged contacts toward my overall QSO count. I’m very appreciative of hunters who go out of their way to work me on different bands and modes: those extra contacts help me achieve a valid activation in short order.

I then moved to 40 meters and worked stations from Tennessee, West Virginia, Ohio, and Michigan.

Video

Here’s a video of the entire activation. It’s a long video as it starts at set-up and continues until my last contact. There are no edits in this video–it’s a real-time, real-life deal and contains all of my bloopers:

Note that in the video I had the KX3’s volume maxed out so that it could be picked up by my iPhone microphone. The KX3’s wee internal speaker was vibrating the chassis ever so slightly. On the 40 meter band, it resonated enough that it moved the encoder slightly. Next time, I’ll plan to bring a portable external speaker (if you have any suggestions of good ones, let me know).

And here’s a QSOmap of the activation:

Click to enlarge.

Bioenno 3aH LiFePo battery

I should also add that I’m very pleased with my new Bioenno 3aH LiFePo 12V battery. You can see it in the photo above–it’s slim, lightweight, and very compact.

I purchased it during Bioenno’s Black Friday sale. I was a little concerned it might not have enough capacity to carry me through multiple activations–my other LiFePo batteries re 4.5 and 15 aH–but that does not seem to be the case at all! Not only did it provide nearly an hour of intense use on this activation, but it also powered three activations the previous day–all four activations on one charge! Brilliant!

Radio magic

As I mentioned in a previous post, this was one of those activations that reminded me of the magic of low-power radio. It was incredibly fun!

For all of those phone/SSB operators out there, I will eventually see how successful I can be doing a phone-only activation with the AX1 antenna. I’ll plan to make a video of it as well. I’ll need to plan this for a day when I have more time to spend on the air and at a site where I know I’ll have internet access to spot myself to the POTA network.  SSB isn’t quite as effective as CW when operating with a setup this modest. Still–it can be done! It just requires a little more patience. Please let me know if this sort of thing would interest you.

Until then, Happy New Year and 73s to everyone!

Cheers,

Thomas (K4SWL)

Antenna Tuners, Antennas, News, Portable, QRP

Could the Icom AH-705 be used as a permanently-mounted remote ATU? Sure, but I believe there are better options.

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Icom uses this photo to demonstrate one of the ways the AH-705 ATU can be mounted for remote operation.

Many thanks to Bruce (W0MBT) who writes:

Hey Thomas,

After many years of inactivity, the combo of this blog, the IC-705, and Covid shutting down all the other fun things I like to do has finally got me somewhat active again. I agree with you that [the Icom AH-705] seems pretty large and expensive for a portable tuner, given the available alternatives. To me, the most interesting possible application is in a semi-permanent outdoor installation.

Currently, my setup is an EmTech ZM-2 installed in a watertight toolbox on my fifth floor balcony, grounded into the metal siding of my building, with a stealth radiating wire tossed onto a conveniently-located tree. It seems to get out pretty well, but QSYing across bands is a pain, and not really practical when it’s raining, which happens a lot in Seattle. I could replace that whole setup with an AH-705 stuck to the siding with double-sided tape.

My questions (and I realize you won’t yet have answers) are:

* How long will it run on AAs? This will determine whether I need to run 12V out to my balcony.
* What’s the maximum control cable run? In my current apartment layout, I’m looking at about 25′.

Bruce
W0MBT

Hi, Bruce,

First of all, I’m so glad to hear you’ve gotten back on the air and honored to hear this blog might have contributed to that a bit! Based on your current setup, it’s obvious that you’ll go out of your way to play radio. Anyone who’s willing to manually adjust a remote ATU each time they wish to hop around the band is dedicated to their radio play!

Since the AH-705 hasn’t been released yet at time of posting, I really know nothing about the AH-705 other than what I’ve read in the specs. I’m not sure how long a control cable could be nor how long AA batteries would last. We won’t know this until the AH-705 is tested.

If I were in your shoes, though, I wouldn’t wait on the AH-705.

I can think of  at least two other options I consider to be better choices for a permanently-mounted remote antenna tuners:

1.) Assemble a remote tuner box

So at my QTH, like yours, I rely on an external, remotely controlled ATU. My shack is located on the first floor of my house. There’s a carport with a metal roof behind my shack. Since we designed and built this house. we installed conduit in the walls so that I could run cable from my shack to an antenna switching and tuning point mounted outside.

It’s built around an LDG Z11 Pro which is not marketed as a remote ATU. The Z11 Pro is mounted in a (rather ugly but effective) weather-proof box a friend gave me–I think the box was originally  used in a remote sensing application. It actually has some penetration points on the side I was able to use.

In 2011, when I installed this ATU, I found an old sealed lead acid battery to power the Z11 Pro knowing the Z11 actually requires very little in terms of power. I had planned to bring the battery indoors and occasionally recharge it, but I also happened to have a 5 watt solar panel and Micro M+ charge controller, so I put them to use charging the remote ATU battery.

From inside my shack, I bypass all internal ATUs in my transceivers and only use my remote Z11 Pro.

The Z11 Pro is RF-Sensing, so as I move across the band, it automatically finds matches and keeps the SWR well within an acceptable range (I monitor it indoors with an SWR and Power meter, of course).

This entire system costs less than the $350 projected cost of the AH-705 and doesn’t require a control cable. The best part is it can be used with *any* radio and can handle 125 watts.

I used the Z11 Pro because I already owned it, but there are less expensive, smaller LDG tuners that could be used. You wouldn’t need to have solar charging as you could simply replace an external battery from time to time. These tuners are super efficient–so efficient, the sealed lead acid battery I installed in 2011 was nearly dead back then, yet it has provided enough voltage via my small PV panel to reliably power the Z11 Pro over 10 years of seasonal temperature swings.

But there’s still an easier and possibly cheaper solution.

2.) Buy a proper remote ATU

When I originally built my remote tuning system, there were really no affordable options commercially available. I believe SGC and Icom had remote tuners but they were very pricey.

Since then, LDG introduced the RT100 remote antenna tuner.

The RT100 costs $250 US and is designed to be used outdoors permanently-mounted. You need no outdoor power source because the ATU is powered from a Bias T 12V source via the same coax cable between your transceiver and the ATU. Makes for a neat, tidy package outdoors.

Again, this ATU–unlike the AH-705–can handle up to 125 watts and work with any transceiver in your shack.

Indeed, I’ve been thinking about grabbing an RT100 for use with another outdoor antenna I plan to build!

Also check out the MFJ-926B for $330 US. If you’re like me, you may never operate north of 10-20 watts, but some may appreciate the 200 watt power handling of the MFJ.

Summary

To get back to your original question, I suppose what I’m trying to say here is the Icom AH-705 is a portable antenna tuner that can be put into service as a remote antenna tuner. It can do both jobs.

To me, though, it makes more sense to split these two applications: install a permanent remote ATU–that works with any transceiver–and also invest in a quality portable ATU for field work.

What are the major drawbacks of the AH-705 compared with a proper, dedicated remote ATU?

  • You’ll need to change AA batteries in the AH-705 on occasion or design a 12V source that can easily be recharged.
  • The AH-705 may (we don’t know yet) only work with the IC-705 and possibly similar Icom models. The LDG and MFJ ATU models above work with any radio.
  • The maximum power handling of the AH-705 is 10 watts–if you use other transceivers (if that is even possible) you’ll have to be extremely careful of your power settings, else fry the AH-705.
  • The AH-705 is pricey if the actual retail price ends up being near the projected $350 mark. Hopefully, it’ll be less than this.
  • The AH-705 will require a control cable. The options above are RF-sensing and do not.

My advice?

Build or buy a permanent remote tuner and hit the parks and summits with the ZM-2!

Since you already have the Emtech ZM-2, you’ve got a fabulous manual portable ATU. I use my ZM-2 in the field all the time (see photo above). Some folks prefer an automatic tuner for ease of use, but I’m guessing at this point, you’re an expert ZM-2 “tuner upper!”

Later, if you want to add an automatic portable ATU to your field kit, consider the Elecraft T1, the Icom AH-705, or an LDG model.

Readers, feel free to comment with your suggestions as well. I’m sure there are a number of options I haven’t considered!

Announcements, Antennas, New Products, News, Portable, QRP Radios, Reviews, Videos

Testing the updated and upgraded Mat-Tuner mAT-705Plus portable IC-705 antenna tuner

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On Wednesday (December 16, 2020) I took delivery of the new Mat-Tuner mAT-705Plus ATU.

Mat-Tuner sent this updated and upgraded version of the mAT-705 ATU to me at no cost and asked that I give it a thorough evaluation in the field.

History of the mAT-705

If you’ve been following the story of this tuner, it was the first introduced in September 2020 and designed to pair directly with the Icom IC-705 transceiver. Note that Icom plans to introduce their own IC-705 antenna tuner (the AH-705) but it is not yet on the market at time of posting, so the mAT-705 has certainly had a market opening.

The original mAT-705 had a mechanical power switch on the front/faceplate.

I received the original mAT-705 ATU via Mat-Tuner US distributor, Vibroplex, around the same time I received my Icom IC-705 in early October. I took the original mAT-705 to the field and made a quick video demonstrating its ability to find matches from 160 to 6 meters. In short, it did a brilliant job.

A couple weeks later, however, I discovered that the original mAT-705 had some design shortcomings. I updated my review with this follow-up post.  In brief, the mAT-705 could deplete a 9V alkaline battery within a couple of days if you failed to turn off the tuner’s mechanical on/off switch.

Replacing the internal 9V battery was a complicated procedure requiring the user to carefully detach the front panel without losing the LED lenses that were prone to simply pop out. The 9V battery was mounted internally on the board with adhesive–obviously, not an ideal situation for an ATU that would require frequent battery replacement. Due to this, I simply could not recommend the original mAT-705–it was too pricey at $220 for an antenna tuner with so many design shortcomings. For full details, read this post.

Introducing the mAT-705Plus

Mat-Tuner was obviously listening to customer feedback, because within two months they introduced the upgraded and updated mAT-705Plus antenna tuner.

I love the USB-C charging port!

Here are the mAT-705 upgrades:

  • No mechanical on/off switch–power is internally managed
  • 9V battery replaced with 1000 mAh internal lithium cells
  • Batteries are internally charged via USB-C port
  • No longer necessary to open the enclosure/housing

Update: Using the mAT-705Plus with other transceivers

Since the new mAT-705Plus lacks a power switch to manually turn it on, I originally noted that I was unsure if it could be engaged via RF sensing when paired with other transceivers. I tried to no avail. Before posting this review, I sent an inquiry to Mat-Tuner about this. Here is their reply:

The power of the new version of the mAT-705Plus tuner is controlled by the KEY signal of the control cable. When KEY is high, the tuner is automatically turned on. The function of following the transmitter to automatically turn on and off is realized.

In addition, the mAT-705Plus tuner follows the ICOM tuner protocol. Like other ICOM tuners, you can manually start the tuning cycle by manually customizing the control cable, just like the AT-120 tuner.

After you solve the KEY signal to trigger the tuner to start and make a manual control cable, you can use it [the mAT-705Plus] for other non-ICOM brand transmitters.  But we do not recommend you to use it this way.

Because it is specially designed for the IC-705 transmitter, [it must be modified for use with] other transmitters, which many customers cannot do.

[Since] it uses a magnetic latching relay, after completing the tuning cycle, you can completely turn off the IC-705 transmitter power and connect the tuner to other transmitters.
The tuner will remain in the tuning state.

To clarify, I believe what the Mat-Tuner engineer meant is that if you tune an antenna with the IC-705, you can power the rig down, connect the mAT-705 to another transmitter and the mAT-705 will preserve the last tuner setting (the last match).

Let’s see the mAT-705Plus in action!

Yesterday, I took the mAT-705Plus to the field and paired it with my Chameleon Emcomm III Portable random wire antenna.

I made the following real-time no-edit video yesterday afternoon. Other than charging the mAT-705Plus batteries the night before, this video captures its first time being connected and used.

The Emcomm III Portable random wire antenna’s frequency range is 160-6 meters–the mAT-705Plus quickly found matches on every band.

Summary

At first blush, the mAT-705Plus looks like the ATU Mat-Tuner should have released on the first go: it’s portable, lightweight, fully automatic, rechargeable, and quickly finds matches across the HF spectrum.

Size comparison: mST-705Plus (left) Elecraft T1 (right)

 

We’ll see how well the power management works in real life. I plan to take it to the field over the next few months and carry a small USB battery pack to recharge the mAT-705Plus when the batteries are finally depleted. Hopefully, I won’t need to recharge it for a long time! The proof will be in the pudding!

Of course, I’ll also pair the mAT-705Plus with an assortment of antennas: random wires, verticals, delta loops, doublets, dipoles, and end-feds.

Stay tuned! [See what I did there? Rimshot anyone? Anyone–?] 🙂

Mat-Tuner authorized distributors:

Antennas, Field Reports, Morse Code, News, POTA, Videos

Impromptu POTA activation using the Elecraft AX1 Antenna

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A few weeks ago, I posted a report about doing my first park activation with the Elecraft AX1 super compact antenna. If anything, I felt the activation almost went *too* well using such a small antenna. I didn’t want to give others the impression this is all the antenna you’ll ever need–it’s just a brilliant compact antenna designed for convenience and accessibility. It’s a fun field companion and can be used pretty much anywhere.

Yesterday morning, I had a number of errands to run on the south side of Asheville and had not planned to do a POTA activation. While I was waiting on a curbside delivery, however, I was admiring the nice weather and thinking that I might venture out later in the day to do a Parks On The Air (POTA) activation. Part of me knew, though, that if I returned home, I’d get involved with projects and never make it back out to the field.

I always carry a transceiver and antenna in my car, so I opened the trunk and found my Elecraft KX2 transceiver field kit which included the Elecraft AX1 antenna. Technically, that’s a whole station! Why not give it a go–? I’m always up for a challenge.

Since I would be passing by the Blue Ridge Parkway on the way home, I quickly scheduled an activation on the POTA website via my phone so that the spotting system would know to grab my information from the Reverse Beacon Network (RBN) when I started calling CQ.

Blue Ridge Parkway (K-3378)

I knew this might not be an “easy” activation: I would be using a super compact field antenna that’s quite a compromise in terms of performance, propagation wasn’t exactly stellar, and I was activating a popular (hence somewhat stagnant) park on a Monday morning. Not necessarily ideal ingredients for a successful activation.

I also discovered my phone tripod in the trunk of the car, so decided to make one of my real-time, real-life, no edit videos of the entire successful or failed activation. (Hint: It turned out to be a success.)

Gear:

If you’d like to accompany me on this park activation, check out my video on YouTube:

At the end of the day, the AX1 continues to impress me. It is a compromise? Yes. Does it perform as well as a resonant wire antenna? No. Can it activate a park as well as my other antennas? Yes.

AX1 QSO Map

Click to enlarge

No doubt, part of my success with the AX1 is because I’m primarily using CW instead of SSB to complete activations. I’ve made SSB contacts with the AX1, but I’ve never completed full park activations with it yet–in truth, though, I’ve never tried.

In fact, perhaps it’s just a lucky streak, but so far the AX1 has been as effective as many of my wire antennas in terms of simply completing valid park activations in less than an hour. My signal reports aren’t as strong as they would be with, say, my EFT-MTR resonant antenna or Emcomm III Portable random wire antenna, but it’s enough to get the job done.

If nothing else, I’ll admit that the AX1 reminds me of the magic of low-power radio each time I use it. When I log stations hundreds of miles away, with such a modest station, I feel like I’ve accomplished something.

In short? It’s fun to use.

Black Friday Sale

FYI: I just received Elecraft’s latest Black Friday 2020 ad and noticed that the AX1 antenna package (which doesn’t include the 40M extension) is on sale. Click here to check it out.

Antennas, News

QRPGuys Tri-Band Vertical Antenna

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On a tip from my buddy Eric (WD8RIF), I ordered a QRPGuys Tri-Band Vertical Antenna kit last week.

Not only will this antenna pair beautifully with my MTR-3B, KX1, and FT-817ND but I had completely forgotten I ordered it.

When I pulled the QRPGuys package from my post box, it was as if a little Christmas had arrived. I mean, is there a better feeling than getting a new kit in the mail–? I don’t think so.

Time to heat up the soldering iron!

Antennas

RigExpert rebates through January 15, 2021

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Many thanks to Paul Evans (W4/VP9KF) who writes with the following tip:

The following instant rebates will be valid for purchases made between November 15, 2020, and January 15, 2021: (direct or dealers)

Model Instant Rebate
RE AA-230 ZOOM 25.00 USD
RE AA-600 25.00 USD
RE AA-1000 50.00 USD
RE AA-1400 60.00 USD

Got it sent to me by e-mail…

Thanks, Paul! A good time to buy if one’s been eyeing one of these RigExpert products.

Click here to check out RigExpert’s website.

Antennas, News, Reviews

CHA MPAS Lite: A military-grade compact field antenna

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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.

Antennas, News, Portable, QRP, Reviews

MAT-TUNER mAT-705 woes

24 Comments

UPDATE: Mat-Tuner released the latest updated and upgraded version of the mAT-705 in December 2020. It’s called the mAT-705Plus. Click here to read my initial review of the mAT-705Plus. Note that the following article pertains to the original mAT-705 which is no no longer being produced, but still available for sale (at time of posting) both new and used.

Last week, I posted a review of the Mat-Tuner mAT-705 antenna tuner that is designed to pair with the new Icom IC-705 transceiver.

My initial assessment was very positive, but since then the shine has worn off. I’ll explain…

On Monday, I took the IC-705 and mAT-705 to the field for a little Parks On The Air (POTA) fun.

The Par EndFedz EFT-MTR triband (40/30/20M) antenna

Enroute to the site, I thought it would be a good test for the mAT-705 to attempt to tune the excellent EFT-MTR antenna (which is resonant on 40, 30, and 20 meters) on all bands above 40 meters.

After arriving on site, I very quickly deployed the EFT-MTR antenna using my throw line. I then hooked the EFT-MTR up to the mAT-705 ATU and connected the ATU to the IC-705.

After turning on the IC-705, I opened the menu screen and tried to engage the mAT-705 ATU. Unfortunately, the ‘705 didn’t recognize the tuner. I double-checked to make sure the control cable to the mAT-705 was secure–it was. After some head-scratching, I realized I must have left the ATU’s mechanical power switch in the “on” position while using it a few days prior.

This evidently depleted the mAT-705’s internal 9V battery. What a bummer!

I bragged about the mAT-705 in a previous post because, frankly, it is a very capable ATU–quickly finding matches from 160 to 6 meters on my random wire field antenna and horizontal loop antenna at home. It also has an incredibly sturdy aluminum enclosure.  It’s a very capable ATU in terms of quickly and efficiently finding matches and, superficially smacks of superb build quality.

Issues

But if I’m being honest, my love affaire with the mAT-705 ended Monday due to a number of discoveries.

9 volt batteries

The mAT-705 next to the IC-705

According to Mat-Tuner’s product description, the mAT-705:

“[I]s powered by an internal standard 9 volt alkaline battery. Power saving technology inside the tuner allows the use of the unit for months without replacement. No battery power is consumed by the unit when powered off.”

Turns out, they mean it saves power only with the mechanical power switch turned “off.”

This, in turn, means that the user must remember each time they use the mAT-705 to flip the mAT-705 mechanical switch off.  If left in the “on” position by accident, even with no connection to the IC-705 and while not in use, it will deplete a 9V cell in a matter of a few days.

This is a significant issue, in my opinion, and is compounded by a few other design choices:

Complicated battery removal

There is no “easy access” to the mAT-705 battery. The user must use a supplied (standard) Allen wrench and unscrew the rear panel from the chassis.

As we mentioned in our previous post, Mat-Tuner actually has a procedure for opening the case and replacing the 9V battery in order to prevent the LED illuminators from falling out. I followed this procedure to the letter, yet the illuminators still fell out. They simply aren’t secured properly and would be very easy to lose if replacing a battery in the field.

The LED illuminators

Once open, you discover that the 9V battery’s holder is a piece of double-sided tape. Seriously:

The mAT-705’s 9V battery holder

In addition, the ATU board essentially “floats” in the chassis secured in slide-in slots. The problem is the back panel–which you pull to remove the board–is only secured to the ATU board with three wired solder points.

Even when I lay the board down carefully, gravity will bend those BNC connections.

I can’t imagine this holding up with multiple battery replacements.

No external power port

Given that battery removal will take a user at least 5 minutes, I find it a little surprising that there’s no external power port.

It would be no problem at all for me, if the 9V battery died, to simply hook the mAT-705 up to my portable DC distribution panel like I can do with other external ATUs. But since this isn’t an option, you’re simply out of luck in the field. Better carry spare 9V batteries!

Where the lack of an external power port is really an issue, though, is for mAT-705 users in the shack. If the IC-705 becomes one of your main radios, you’ll have to be very disciplined to turn it on and off each time you use it, else you’re going to be replacing a lot of 9V cells.

Command connection to the IC-705 is basic

It seems to me that if you build an antenna tuner specifically to pair with a radio via a dedicated control cable, the tuner could potentially:

  • derive power from the transceiver
  • or at least be told by the transceiver to turn completely off when not actively in use. Especially since once a match is found, it’s locked into position even if the mAT-705 has no power.

The mAT-705 can’t do either.

Is it a good ATU? Yes. But inside it could be better.

As I said above, my original review stands in terms of the mAT-705’s ability to match antennas, I think it’s brilliant.

But I can no longer recommend the mAT-705 until some of these design shortcomings are addressed.

I’ve never owned a portable ATU that required so much discipline from the user in order to preserve the battery. I’ve also never owned one that was so fragile internally. Most portable ATUs *only* turn on when finding a match and then either “sleep” or turn off when not in use.

And portable ATUs like the Elecraft T1, for example? Even have a convenient battery compartment for easy removal. (And, oh yeah, the T1 will run ages on a 9V!)

The Elecraft T1 ATU 9V battery compartment

To add insult to injury, it’s one thing to discover that your mAT-705 ATU eats 9V batteries if left on but not in use, but it’s quite something else to discover your $220 ATU’s 9V battery is held in with a piece of double-sided sticky tape.

How long could this possibly function if you’re replacing batteries frequently in the field?

My hope is that Mat-Tuner will sort out this design and re-introduce the mAT-705 to the market. I’ve heard so many positive things about other Mat-Tuner models which is why I wanted to try one out with the IC-705.

Mat-Tuner ATUs are sold by respected retailers in the ham radio world (like Vibroplex, who loaned this model for review) so I expect they’ll address these concerns in the coming months. I’ll certainly post all updates here on QRPer.

Until then, I have to recommend skipping the $220 mAT-705 and instead purchasing the excellent ($160 kit/$190 assembled) Elecraft T1.

Antennas, News, POTA, QRP

Icom IC-705: Reviewing the Mat-Tuner mAT-705 in the field

8 Comments

UPDATE: My review of the mAT-705 ATU below is accurate as of its original posting. Since this review, however, I’ve discovered some design issues that prevent me from continuing to recommend it. Click here for details.

UPDATE 2: Mat-Tuner released the latest updated and upgraded version of the mAT-705 in December 2020. It’s called the mAT-705Plus. Click here to read my initial review of the mAT-705Plus. Note that the following article pertains to the original mAT-705 which is no no longer being produced, but still available for sale (at time of posting) both new and used.

Last week, Vibroplex sent me their new Mat-Tuner mAT-705 external ATU on loan to evaluate with my recently acquired Icom IC-705.

Here’s some info about the mAT-705 from Vibroplex’s product page:

The new mAT-705 antenna tuner is designed specifically for use with the new Icom IC-705 QRP transceiver. Connect the mAT-705 directly to the TUNER jack on the IC-705 with the included cable and control the antenna tuner directly from the front panel of the radio or use RF-sensing to actuate the tuner when changing bands. 1.8-54 MHz, 5-1500 ohms matching range, 16000 user memories recalling previous used settings internal to the tuner when returning to an earlier used frequency.

The tuner is powered by an internal standard 9 volt alkaline battery. Power saving technology inside the tuner allows the use of the unit for months without replacement. No battery power is consumed by the unit when powered off.

Yesterday, I stopped by South Mountains State Game Land (K-6952) to give the mAT-705 some field time. Up to this point, I had not used the tuner other than tuning to the 80 and 40 meter bands from home (mainly to make sure it worked before hitting the field).

To really give the mAT-705 a workout, I deployed my CHA Emcomm III Portable random wire antenna. The Emcomm III is the only field antenna in my arsenal that covers 160 meters – 6 meters–an exceptionally wide frequency range.

What I like about this particular POTA site is the open parking area which allows me to configure the Emcomm III a number of ways.

The Emcomm III, being a wire antenna, is incredibly stealthy. Since you can’t see it in the photo above, I’ve marked up the configuration below (click to enlarge):

I’m guessing the apex of the antenna was easily 45′ high.

Activating

I started my activation on the 80 meter band.

After working a few stations on 80 meters, I decided to test the mAT-Tuner over a fairly wide frequency range before calling CQ on the 40 meter band.

Here’s a short video:

POTA Hunters: look for me on the 160 meter band this fall and winter! I’m so impressed how well it matched the Emcomm III on 160.

 

Indeed, I am very pleased with how quickly and efficiently the mAT-705 found matches on every band I tested.

In terms of form factor, the mAT-705 is quite compact, but a little longer in length than I had anticipated. Honestly, though, there’s nothing here to complain about.

The enclosure/chassis is incredibly strong. I’m willing to bet you could accidentally drive over it with your car and it would survive in tact.

The mAT is powered by an alkaline 9V battery. Vibroplex expects that this battery will last for months under normal use.

Note that there is a specific procedure for replacing the battery in order to protect the LED “illuminators” that are press-fit to the board.:

  1. Remove the case by removing the 4 rear 2mm allen screws.
  2. Turn the tuner upside down and shake it a little to get the PCB to slide out of the case enough to grab.
  3. Carefully grasp the PCB sides and slide the board out slowly.

Update: I’ve followed the procedure above and still had an issue with the illuminators falling out. They really need to be secured better. I was able to re-insert them and close the ATU, but when you open the mAT-705 to change the battery, be in a space where you can capture both of them if they fall out.

Any mAT-705 negatives?

Not really, but I do feel the price is a little steep at $219.95–but then again the mAT-705 seems to do the job and do it well. I have to assume the TBA Icom AH-705 ATU will cost at least as much. I’m okay with paying at the top end of the market if I’m getting a quality product and this certainly seems like one.

I like the fact that the mAT-705 integrates perfectly with the IC-705 via the control cable and that I don’t have to worry about protecting it at all in my backpack. It’ll also take the IC-705 through the entire HF spectrum and even up to 6 meters.

 

I plan to continue using the mAT-705 for a while and even test it on severely non-resonant antennas just to see how far I can push it for a match.

Stay tuned! (See what I did there–?)

Many thanks to Vibroplex, again, for lending me this mAT-705 for review and evaluation.

Click here to check out the mAT-705 at Vibroplex.