Category Archives: QRP Radios

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

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.


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:

The new Mountain Topper MTR-4B V2 by LnR Precision

The venerable Mountain Topper MTR-3B

I’ve just noticed that LnR Precision has announced their new Mountain Topper MTR-4B V2.

They’ve released a few details with the promise of photos soon. Looks like the MTR-4B will of course sport four bands (80, 40, 30, and 20 meters) but adds two valuable tools its predecessors lacked: an SWR and RF power meter.

A full 5 watts output power is attained with a 12V supply, but the voltage operating range is 5.5 to 13volts.  The MTR-3B’s (photo above) has an upper operating range of 12V.

I look forward to checking out the MTR-4B and we’ll post photos as soon as they are available.

Here are the details from the LnR Precision Website:



“The Mountain Topper”

The LnR Precision MTR transceivers are designed to be efficient portable CW rigs. Whether climbing a mountain and operating SOTA or just out for an afternoon in the park, the MTR’s small size, light weight and meager battery requirements makes it a great choice for these activities.


  • Four bands – 80M, 40M, 30M and 20M
  • Very low receiver noise floor
  • Low current for maximum battery life
  • Wide operating voltage range – 5.5V to 13V
  • Full 5W “QRP” gallon with 12.0 Volt supply
  • 2 line, back lighted LCD display
  • SWR – RF Power display
  • Built in Real Time Clock
  • Internal Iambic B mode keyer, 5 to 31 WPM in 1 WMP increments.
  • Three Morse message memories with beacon mode.
  • Specifications: coming soon

Keith is impressed with the Elecraft K1’s selectivity

Many thanks to Keith (GW4OKT) who recently contacted me, noting that his took his Elecraft K1 to Llyn Brenig (Lake Brenig) in North Wales last weekend, and was impressed with its performance.

His outing coincided with the CQ Worldwide CW contest–a true test of any radio as this is one of the most RF-dense environments you’ll encounter on the CW portions of the HF bands.

Many lesser radios simply fall apart in contest environments like the CQWW.

Not the Elecraft K1, though! Keith noted that he was operating on 20 meters with his GWhip antenna on the roof of his car.

He made the following video:

Wow! I owned the K1 for a number of years and was incredibly impressed with its receiver although I can’t remember if I ever used it in a contest. It’s a brilliant field radio and sports a bullet-proof front end.

I should add, Keith, that I’m not the least bit envious of your Caterham Seven 310 SV. Not a bit. Not me.  🙂

Anyone else love the Elecraft K1 (or the Caterham Seven 310?) Please comment!

Video: QRP Labs QCX-mini 5W CW transceiver–now available to order

Hans at QRP Labs has just posted a video of the new QCX-Mini 5 watt transceiver kit. It looks like another thoughtful design:

Even though I’ve yet to build my QCX+ (!!!), I just ordered the QCX-Mini. This little kit will be a challenge for me–even though all of the SMD components are pre-populated, it’s still a tight board and requires some fancy toroid work!

Still, I’m buying it to support QRP Labs’ work and because I love the challenge of building kits. This one is awfully cute and I’m pretty sure I’ll use it to claim a summit!

My entire QCX-Mini kit with enclosure set me back $86.99 US with shipping and tax included. How could I resist? (Don’t answer that, please.)

Click here to check out the QCX-Mini product page. 

Steve’s new Icom IC-705 SOTA lap desk

I’ve been in touch with Steve (WG0AT) recently. He happened to be selling his FT-817 at the same time I was looking for a narrow CW filter.  The stars aligned and I now have a 500 Hz Collins CW filter in my FT-817ND.  Thanks, Steve!

Steve also took delivery of his Icom IC-705 recently so we’ve been trading notes about this fine rig. He and I both have a fear of the ‘705 falling off our laps when using it in the field for SOTA and POTA activations.

Steve, being the king of ham radio customization, started working on a portable desk. He shared iterations along the way and his final product seen in the photo above.

The desk is a brilliant design: it’s lightweight, sturdy, has holes for managing wires/cables, a strap to hold it your leg, and even a cup holder. The cup holder is a bit of genius because he likes a good cuppa tea in the field just like I like a good cuppa joe.

The IC-705 will be able to bolt directly to the lap desk so there’ll be no fear of it falling off a cliff in the field.

Of course, the desk will work with any field-portable radio. Steve shared a few more photos:

I’m going to attempt to build a similar desk for my IC-705. The great thing about it is it’ll easily fit in a backpack, too.

Thanks again for letting me share your photos, Steve! We look forward to seeing this desk in action at a summit near you!

Check out Steve’s excellent YouTube channel here.

What external battery do I pair with the Icom IC-705?

I typically pair my IC-705 with a 6 aH Bioenno LiFEPo battery pack (the blue battery between the transceiver and tuner above).

Many thanks for QRPer reader, Ron, who writes:

Dear Thomas, thank you for the great videos and information on POTA and QRP work. I’m very inspired.

Thomas, I received an Icom 705 recently and I was wondering about power. In your videos, is your battery 12 volts? This works okay? I wonder because of the 13.8 volt requirement in the manual.

Thank you for your time. I’ve already picked out a park that I will try to activate one day when I’m up to speed on POTA. 72 Ron

Thanks for your question, Ron. I’m very happy to hear you find the videos useful.

I almost exclusively use Bioenno LiFePo 12V batteries which actually output closer to 13-13.5 volts in use and can even briefly be a bit higher immediately after charging.

Most amateur radio transceivers (including the IC-705) typically have a bit of voltage flexibility and will operate a below 12 volts and tad higher than 13.8 volts. QRP radios especially. You’re wise, though to always check (the MTR-3B is a notable exception as it prefers a max of 12V).

In fact, I just checked the IC-705 specs and its voltage requirements are 13.8 V DC ±15% (12V – 15.87 volts). The IC-705 can actually run on much lower power because the Lithium Ion pack that is supplied with the IC-705 (BP-272) is only 7.4 VDC when charged.

I would suggest you check out a 4.5 or 6 aH LiFePo battery like this one at Bioenno. Either would have the capacity to carry you through a few hours of heavy use.

Of course, there are many, many more battery options out there, but I’m a fan of LiFePo batteries for their longevity, capacity, and stability.

Hope this helps!

POTA Field Report: A Tale Of Two Parks (And Two Antennas)

Yesterday, I *finally* activated two parks that have been on my list for most of the year: Elk Knob State Game Land (K-6903) and Elk Knob State Park (K-2728).

The game land had never been activated which I found quite puzzling since it seemed to be accessible based on my maps and was only 1.5 miles from (actually adjoining!) a state park which has been activated a number times.

Turns out, there’s a good reason it hadn’t been activated.

Elk Knob State Game Land (K-6903)

Upon entering the game land parcel, you’re greeted by the sign above which states that while the game land is a public resource, it is private land and the owner only allows hunting and trapping on it. First time I’ve ever encountered this.

This meant that I really couldn’t cross the barb wire fence that lined the one lane dirt road to activate the park in the woods (which I would have preferred).

Fortunately, I found one pull-off in the middle of the game land road. It was just wide enough to fit my car so that others on the road could pass me without a problem. It was rather tight, though.

Since I didn’t want to use a tree on the game land to support my antenna, I employed the Chameleon CHA MPAS Lite 17′ vertical.

I pushed the MPAS Lite spike into the ditch of the road and ran the counterpoise along the ditch as well. All was within the road right-of-way, yet within the game land so I felt it a proper compromise respecting the land owner’s wishes while still being able to activate the park.


For this activation, I chose the Elecraft KX2 since I had such a limited space in the back of my car to both operate the transceiver and log.

The great thing about the KX2 is it’s such a complete & compact package: it’s a transceiver, with an internal battery pack (that allows 10 watts of power), a built-in ATU, and attachable paddles. Everything easily fits on my clip board which then functions as an operating table.

I started calling CQ POTA and was quickly spotted to the POTA spots page via the Reverse Beacon Network (RBN).

I very quickly logged a number of stations in CW, but did eventually reach one road block when one of the contact posts in my KXPD paddles loosened. I’ve had this happen before. Thankfully, I keep precision screwdrivers in my EDC bag, so could make the fix. Unfortunately, it took me off the air for a good 5-10 minutes and I lost my pile-up.

I eventually changed modes and called CQ a few times on 40 meters phone.

In the end, I only logged 13 contacts. Certainly the smallest number I’ve ever had at an ATNO (All Time New One). I felt I had to cut it short, though, as cars/trucks had to slow down to pass me. Twice I was asked if I needed any help (assuming my car had broken down).

I was very grateful to have the CHA MPAS Lite antenna in my arsenal, though. I have few other antenna options that would have worked so effectively in such a tight space.

The MPAS Lite is also incredibly stealthy. I’m not sure many passersby even noticed it.

On to the next park!

Elk Knob State Park (K-2728)

Where Elk Knob Game Land was an incredibly challenging site, adjoining Elk Knob State Park was the complete opposite. A POTA activator’s dream site.


This was my first visit to Elk Knob State Park and I was most impressed. Not only is the park gorgeous and quiet, but the picnic area is expansive, well-spaced, and there are numerous large, old-growth trees. Absolutely perfect for POTA purposes.

The CHA Emcomm III Portable

Since I had the luxury of these tall trees, I decided to employ the CHA Emcomm III Portable which has quickly become my favorite field antenna. When I have the space, I use it because it gives me 160-6 meters and is easily matched by all of my antenna tuners.

Since I had a great picnic table surface to operate, I also used my Icom IC-705 transceiver and Elecraft T1 antenna tuner.

So turns out, I didn’t take a lot of photos of my site because I used my iPhone to make a video of the activation.

On YouTube, I’ve been encouraged by viewers/followers to continue making real-time, real-life videos of some of my park activations. These videos have no edits and are what I would generously call “Ham Radio Slow TV.” 🙂 The idea is the viewer is simply joining me as I set up and operate at a park–as if they were there with me in person. I hope there’s some value in these videos for newcomers to Parks On The Air.

The video ended up capturing the whole activation from start to finish. If you need something to put you to sleep, check it out:



All in all, it was a brilliant day and I’m pleased to have finally activated these two POTA sites.

It was a particular treat to discover Elk Knob State Park. I can’t wait to go back there to camp and to hike their trails.

Perhaps this is one of my favorite side benefits of Parks On The Air: it gives me a reason to explore state parks I might have otherwise overlooked. We’re huge supporter of state and national parks, so it’s truly a win-win!

The Elecraft KX1: Reunited and it feels so good.

The Elecraft KX1

A few weeks ago, I published a post about radios I’ve regretted selling or giving away.

Number one on that list was the Elecraft KX1.

Within a couple hours of posting that article, I had already purchased a KX1 I found on the classifieds. It was, by any definition, an impulse purchase.

The seller, who lives about 2 hours from my QTH, described his KX1 as the full package: a complete 3 band (40/30/20M) KX1 with all of the items needed to get on the air (save batteries) in a Pelican 1060 Micro Case.

The KX1 I owned in the past was a four bander (80/40/30/20M) and I already double checked to make sure Elecraft still had a few of their 80/30 module kits available (they do!).  I do operate 80M in the field on occasion, but I really wanted the 80/30 module to get full use of the expanded HF receiver range which allows me to zero-beat broadcast stations and do a little SWLing while in the field.

The seller shipped the radio that same afternoon and I purchased it for $300 (plus shipping) based purely on his good word.

The KX1 package

I’ll admit, I was a bit nervous: I hadn’t asked all of the typical questions about dents/dings, if it smelled of cigarette smoke, and hadn’t even asked for photos. I just had a feeling it would all be good (but please, never follow my example here–I was drunk with excitement).

Here’s the photo I took after removing the Pelican case from the shipping box and opening it for the first time:

My jaw dropped.

The seller was right: everything I needed (and more!) was in the Pelican case with the KX1. Not only that, everything was labeled. An indication that the previous owner took pride in this little radio.

I don’t think the seller actually put this kit together. He bought it this way two years ago and I don’t think he ever even put it on the air based on his note to me. He sold the KX1 because he wasn’t using it.

I don’t know who the original owner was, but they did a fabulous job not only putting this field kit together, but also soldering/building the KX1. I hope the original owner reads this article sometime and steps forward.

You might note in the photo that there’s even a quick reference sheet, Morse Code reference sheet and QRP calling frequencies list attached to the Pelican’s lid inside. How clever!

I plan to replace the Morse Code sheet with a list of POTA and SOTA park/summit references and re-print the QRP calling frequencies sheet. But other than that, I’m leaving it all as-is. This might be the only time I’ve ever purchased a “package” transceiver and not modified it in some significant way.

Speaking of modifying: that 80/30 meter module? Glad I didn’t purchase one.

After putting the KX1 on a dummy load, I checked each band for output power. Band changes are made on the KX1 by pressing the “Band” button which cycles through the bands one-way. It started on 40 meters, then on to 30 meters, and 20 meters. All tested fine. Then I pressed the band button to return to 40 meters and the KX1 dived down to the 80 meter band!

Turns out, this is a four band KX1! Woo hoo! That saved me from having to purchase the $90 30/80M kit (although admittedly, I was looking forward to building it).


The only issue with the KX1 was that its paddles would only send “dit dah” from either side. I was able to fix this, though, by disassembling the paddles and fixing a short.

Although I’m currently in the process of testing the Icom IC-705, I’ve taken the KX1 along on a number of my park adventures and switched it out during band changes.

Indeed, my first two contacts were made using some nearly-depleted AA rechargeables on 30 meters: I worked a station in Iowa and one in Kansas with perhaps 1.5 watts of output power.

I’m super pleased to have the KX1 back in my field radio arsenal.

I name radios I plan to keep for the long-haul, so I dubbed this little KX1 “Ruby” after one of my favorite actresses, Barbara Stanwyck.

Look for Ruby and me on the air at a park or summit near you!

POTA Field Report: Pairing the Icom IC-705 with the Elecraft T1 and CW Morse Pocket Paddles

The new CW Morse “Pocket Paddle.”

On Wednesday, October, 14 2020, the weather was gorgeous so I decided to make an impromptu POTA activation of Pisgah National Forest and the Pisgah Game Land (K-4510 and K-6937). These sites are the closest to my QTH and only a 15 minute drive (in fact, I can even hike up to the same trail network from my back yard).

My canine companion, Hazel, jumped into the car before I could even invite her to come along.

We drove to the trailhead, parked, and hiked a short distance into one of my favorite spots where it’s relatively flat, with lots of tall trees and almost no foot traffic from other hikers.

This activation gave me an opportunity to use the Icom IC-705 in more of a “backpack” setting since I hiked in with only my pack, Hazel, and my folding three-leg stool. Up to this point, I’d only used the IC-705 on picnic tables and flat surfaces since it can’t easily fit on my clip board like my MTR-3B, KX2, and KX1 can.

The activation also gave me a chance to evaluate a new product sent to me by the CW Morse company: their “Pocket Paddle” designed specifically for portable operations.

After reaching the site, I easily deployed the EFT-MTR antenna using my arborist throw line.

I decided to set up the Icom IC-705 much like I did the lab599 Discover TX-500 when I took it on hikes: mount the radio above the front pocket of my Red Oxx C-Ruck backpack.

The arrangement works quite well–I simply sit on the stool in front of the pack and hold my simple logging notepad and paddles on a clipboard.

While this particular site is great because it’s so accessible to me, the negative is it’s deep down in a valley surrounded by high ridge lines. I feel like this does have some impact on how well my signal travels.

Wednesday, it took nearly 50 minutes to rack up a total of 12 contacts in CW mode.  I never bothered with SSB/phone because this site had no cell phone service and, thus, there was no way to spot myself on the POTA network.

That’s okay, I felt pretty chuffed about racking up 12 contacts with 5 watts and a wire! This is what field radio is all about, in my opinion.

Loving the Elecraft T1

The Elecraft T1 ATU pairs beautifully with the Icom IC-705.

After a little falling out with the mAT-705, I decided I wanted to try other ATUs with the IC-705. I used to own an Elecraft T1 ATU and loved it, but I eventually sold it for a song to a friend since all of my field rigs at that point had internal ATUs.

I reached out to Elecraft and they sent me a T1 on loan to give it a go.  I’d forgotten how much I love this simple, effective ATU.

Even though the EFT-MTR is resonant on 40, 30, and 20 meters, moving to the 30 meter band requires lowering the antenna, pulling off an SMA cap on the coil, then re-hanging it.  Not a big deal at all, really, but it’s so much easier to simply press the tune button on the T1 and have it match 30 meters without going through the normal process.

CW Morse Pocket Paddle

I also thoroughly enjoyed using the CW Morse “Pocket Paddles.” I’m not sure when they’ll be available to purchase (perhaps they are already?) but I can highly recommend them.

The paddle action is field-adjustable and even though there’s an Allen wrench built into the paddle base, the machined screws are easy to twist by hand.

They feel very sturdy, too, much like the other CW Morse paddles and keys I’ve used.

I believe the Pocket Paddles are going to permanently pack with my IC-705!

The Icom IC-705 might be a ‘Holy Grail’ portable QRP SSB transceiver

While visiting my parents this week in the Piedmont of North Carolina, I took some time Monday afternoon to take the new Icom IC-705 to field and activate Lake Norman State Park (K-2740) for the Parks On The Air (POTA) program.

So far, most of my time with the IC-705 has been in CW mode but a number of my readers have been asking about SSB operation and performance.

My goal for this park activation was to give the IC-705 a proper shake-out on SSB.


The activation was very much impromptu–I only decided I could fit it into my day an hour before my start time. In addition, while it wasn’t raining per se, there was a very heavy mist/fog that, at times, felt like a light sprinkle/drizzle.

I packed and planned on using my IC-705, mAT-705 external ATU, and Vibroplex End-Fedz EFT-MTR wire antenna.

I had an issue with the mAT-705 ATU (read more here), so opted for my trusty and incredibly capable Emtech ZM-2.

I did begin the activation in CW and quickly racked up a dozen or more contacts in short order after spotting myself. One of the great things about Lake Norman State Park is it’s one of the few locations I activate these days with proper cell phone coverage for mobile internet so that I can update my own activation spots on the POTA site.

I also moved up to 20 meters and switched over to my recently (re)acquired Elecraft KX1 (FYI, I named her “Ruby” so no way will I sell her again).

I quickly snagged two states (Iowa and Kansas) with 1 watt of power from the KX1’s internal AA cells, then 20 meters fell silent, so I moved to 30 meters to work a few more stations.

SSB on 40 meters

I then moved to the 40 meter band and decided to record a quick video after spotting myself on 7197 kHz.  I wasn’t expecting such a productive mini pile-up.

As you can tell from the video, I had my hands full trying to hold my phone/camera, log, and manage the hand mic. Note, too, I prefer not hooking up the speaker portion of the microphone because audio from the IC-705 internal speaker is far superior:

I operated SSB for a good 30 or so minutes and was busy with contacts thanks to all of those excellent POTA hunters.

IC-705 Voice Memory Keyer

Before packing up, I remembered that my buddy Dave had asked me to make a video showing how I use the IC-705’s voice memory keyer, so I moved up to 20 meters (which you’ll see was pretty much dead) and recorded this.

Doh! I had the SSB position in LSB instead of USB! Thanks to one of my YouTube viewers who noticed this. I had been tinkering with mode settings earlier while evaluating the rig. No worries, though, this was more a demo of the memory keyer–check out SSB operation in the video above.

I was actually very relieved 20 meters was dead because I’m terrible at managing a camera, a tablet, and a microphone all at once!

The Icom IC-705 is an SSB champ

Photo taken at South Mountain Game Land last week.

Despite the fact that I was using the default microphone settings and had not even touched the TX EQ or compression, I received no less than three unsolicited compliments about my audio during this activation.  That is probably a personal record.

No doubt, the IC-705 is a very capable rig for QRP SSB where audio quality is essential.

On top of that, the eight voice keyer memories are incredibly useful when activating a park, a summit, or even running a contest where you could truly automate your exchanges.

Have you been using the IC-705 in the field? What are your thoughts? Do you have any questions? Please feel free to comment!