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.

POTA Field Report: Finally putting Toxaway State Game Land on the air

The C-Ruck loaded and ready for the field!

I woke up Saturday morning (October 24, 2020) with one goal in mind for that day: activate Toxaway State Game Land (K-6960).

This year, I’ve had a blast finding game lands to activate for the Parks On The Air (POTA) program as they are typically are less crowded, have open areas to hang long antennas, and sometimes even give me a chance to do a little off-roading.

I’ve had Toxaway on my list of game lands to activate since April, but it’s a good 1.5 hour drive from the QTH and not in a part of the state I routinely drive through these days. After some searching, via the excellent WRC interactive map, I was able to find one access point that even appeared to have parking for a trail head.

I checked with the family and they were all up for a  drive and picnic lunch.

It’s still “leaf-looking” season here in the mountains of western North Carolina, so the roads were pretty crowded with tourists.  The closer we got to this relatively remote site, though, the less traffic. A very good sign!

Our location

Gear:

Chameleon Antennas recently sent me their new CHA MPAS Lite vertical to evaluate and I had planned on deploying it for this activation, but once I arrived on site, I realized I should have checked a topo map first: it was deep in a valley near a creek and I questioned the wisdom of using a short vertical in this situation. That and propagation wasn’t exactly stellar.

Fortunately, there were tall trees around, so I deployed the CHA Emcomm III Portable random wire antenna which has become one of my favorite field antennas.

Saturday was also the CQ WW SSB contest, so the phone portions of the bands were very busy with contest activity. I planned to make this primarily a CW activation.

After setting up the Icom IC-705, I attached my Elecraft T1 ATU to the rig and antenna. Since this turned out to be a parking area activation, I could have set up my portable table, but instead, I used the Red Oxx C-Ruck pack to support the IC-705 and ATU.

Using the C-Ruck as a mini field table saves time. I discovered how useful this pack was while evaluating the lab599 Discovery TX-500 in August.

I started calling CQ POTA on 40 meters and within seconds the the POTA site auto-spotted me via the Reverse Beacon Network (RBN). I only called CQ POTA twice before I started working pile-ups.

The Emcomm III Portable antenna performed admirably as I pushed a full 10 watts of power.

Indeed, for me, this activation was a bit of a sprint to answer everyone calling me in the amount of time I had at the site. To make the activation work in our Saturday schedule, I only allowed for one hour on the air.

QSO Map and logs:

Map courtesy of QSOMap.org Green=CW Red=Phone (Click to enlarge)

Not at all bad for 10 watts and a wire!

I could have worked many more stations had I moved to 20 meters CW and then back to 40 meters CW, but I did want to make a few SSB QSOs and even attempt hunting other POTA parks.

Some highlights: working my buddies (and fellow SEORAT members) Eric (WD8RIF) in park-to-park contacts, and Mike (K8RAT) who is one of the top hunters in POTA and also huge support to Eric and me in the field.

I was also very pleased to work another local park activator, Steve (KC5F), who is an excellent CW op–indeed, I believe this was our first SSB contact! Steve primarily operates CW with his Xiegu G90.  We typically struggle working each other because we’re simply too close geographically!

All in all, it was amazing fun!

Once again, I was impressed with the IC-705’s capabilities, the T1’s excellent matching skills, and the Emcomm III portable’s performance.

I also find the CW Morse Pocket Paddle to be a brilliant portable paddle. It’s slightly larger than my N0SA paddles, but still very portable. I’ve been carrying them in the top flap of my ruck sack.

I will plan to return to Toxaway, perhaps this winter, and spend more time at the site.


If you would like to post a field report on QRPer, drop me a line!

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 QTH.com 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).

Photos

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!

Parks On The Air 101: Some real-time, real-life videos of a typical POTA activation using the Icom IC-705

On Monday (October 19, 2020) I received an inquiry from Dale (KI5ARH) only an hour or so before packing up my radio gear to activate Lake Norman State Park (K-2740).

Dale is interested in using his recently acquired Icom IC-705 to get involved with Parks On The Air (POTA) and play radio in the field.

What’s in my field kit

Dale was curious about all of the components of the field kit I use with the IC-705, so I made this video:

Equipment links:

Since I had already set up my phone to record the video above, I decided to make a couple more.

I thought there might be some value in making real-time videos showing what it’s like operating CW and SSB during a POTA activation.  The videos have no edits and haven’t been trimmed.  It’s as if the viewer were there at the activation sitting next to me at the picnic table.

Operating CW with the IC-705

After setting up my station, I first started on the 40M band in CW. I meant to start the camera rolling during tune-up, but forgot to hit record. The video begins after I’d made a few CW contacts, but shows what it’s like changing bands and relying on the Reverse Beacon Network (RBN) to pick me up then the POTA website to auto spot me.

Note: to be automatically spotted by the RBN, you must schedule your activation via the POTA website in advance, or have been already spotted by yourself or someone else, so the system will know to look for you.

My video cut off abruptly due to a low battery message. I had to give my iPhone a quick power charge to make the next video.

Operating SSB with the IC-705

After operating CW for a while, I plugged in the hand mic that ships with the IC-705 for a little SSB action. My main goal with this video was to show how I call CQ and use the voice keyer memories in order to manage the field “work flow” process.  I also speak to how important it is to either self-spot or have a friend spot you to the POTA network while operating phone.

I spent so much time setting up and running the camera, I wasn’t actually on the air for very long, but I easily managed to achieve a valid activation and had a lot of fun in the process.

I’m not a pro “YouTuber” as I say in one of my videos. I much prefer blogging my experiences rather than “vlogging,” I suppose.

Still, I think I’ll do a few more “real-time” videos of POTA activations and speak to the various techniques I use to activate parks. Since these videos aren’t edited for time, they may not appeal to the seasoned POTA activator or QRPer–that’s okay, though. My goal is primarily to assist first-time POTA activators.

Have you been activating Parks or Summits lately?  Do you have any advice or suggestions I failed to mention? Or do you have suggestions for future topics? Please comment!

POTA Field Report: Mount Mitchell State Park (K-2747) with the Mission RGO One transceiver

On Thursday October 15, 2020, my family made an impromptu trip to Mount Mitchell State Park to enjoy the amazing weather and gorgeous fall colors.

The Blue Ridge Parkway and Mount Mitchell State Park were predictably crowded with tourists, although nowhere near as crowded as the following three days which were “peak” leaf color days.

After arriving at the park, we claimed one of the little picnic areas tucked away from the crowds.  After a picnic lunch, I set up the station, my wife painted, one daughter caught up on her favorite book, and the other daughter took a deep dive in her recently acquired Yaesu FT-60R (and also helped me log).

And Hazel, predictably, slumbered.

I swear that dog is only awake maybe one hour a day.

On this particular activation, I didn’t want to deploy a wire antenna. Being the highest elevation east of the Mississippi river, the trees are short .

Instead, I deployed my Wolf River Coils TIA vertical antenna.


I consider the WRC vertical to be a “compromised” antenna especially in our region which is rocky and has poor ground conductivity. But at times like this when the park is crowded, it’s a great low-profile way to get on the air–and it’s self-supporting!  In any other year, I’m actually okay with my radio set-up being conspicuous–I love telling passersby about ham radio and Parks On The Air–but at the moment I choose to keep my social distance.

When I use the WRC antenna, I typically pair it with one of my favorite transceivers: the Mission RGO One.

I love the Mission RGO One. It’s a superb transceiver (indeed, my full review of it will appear in the November 2020 issue of The Spectrum Monitor magazine).

I like to pair the RGO One with the WRC vertical because the RGO One is capable of 50 watts of output power (the real max for the WRC), which I feel makes up for a bit of the antenna compromise. I typically start at QRP levels and increase wattage if I get no response.

At Mt. Mitchell, I rarely have internet access via my mobile phone, so I rely on the Reverse Beacon Network to spot me to the POTA network when I call “CQ POTA.”

Within a minute of calling CQ, I started logging stations. Thanks RBN!

I operated for almost an hour off and on. I took a few breaks during low activity to help my daughter with the FT-60R. At one point, she was in hysterics over a conversation she picked up on a local repeater. (Hysterics in a good way, fortunately. I do worry about some of the conversations I hear on local repeaters at times!)

Here’s my tally from Mt Mitchell:

Mt. Mitchell is one of our family’s favorite state parks and is accessible from my QTH via the Blue Ridge Parkway.

Unfortunately, the Blue Ridge Parkway is often closed during the winter, so we hope to make at least one more trip to Mitchell within the next few weeks.

I’ll add that this was the third time I’d taken the CW Morse “Pocket Paddle” to the field. It’s a brilliant set of paddles. It’s has a fantastic field-adjustable response. I’m uncertain if they’re on the market yet–CW Morse sent them to me for evaluation in the field.

I also have a set of N0SA paddles I love and typically keep packed in my dedicated MTR-3B pack.

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.

Set-up

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!

MAT-TUNER mAT-705 woes

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.

Guest Post: Steve builds a DC30B QRP Transceiver

DC30B QRP Transceiver ProjectMany thanks to Steve (KZ4TN) who shares the following guest post:


DC30B QRP Transceiver Project

by Steve Allen, KZ4TN

I wanted to build a lightweight backpackable transceiver I could take hiking and camping. I chose the 30 meter band as it is specific to CW and the digital modes. I am also in the process of building Dave Benson’s (K1SWL) Phaser Digital Mode QRP Transceiver kit for the 30 meter band. Also, a 30 meter antenna is a bit smaller than one for 40 meters and the band is open most anytime of the day.

I sourced the DC30B transceiver kit, designed by Steve Weber KD1JV, from Pacific Antennas, http://www.qrpkits.com. It appears that they are now (10-11-20) only offering the kit for the 40 meter band. The following information can be used for the assembly of most any kit that lacks an enclosure.

Lately I have been finding extruded aluminum enclosures on Amazon.com and eBay.com. They come in many sizes and configurations. I like to use the versions with the split case which allows you to access the internal enclosure with the front and rear panels attached to the lower half of the enclosure. Most of these enclosures have a slot cut into the sides that allow a PCB to slide into the slots keeping it above the bottom of the enclosure without having to use standoffs. The one requirement for assembly is that the PCB needs to be attached to either the front or rear panel to hold it in place.

DC30B QRP Transceiver Project

As the enclosure is anodized, I didn’t want to rely on the enclosure for common ground. I used a piece of copper clad board that I cut to fit the slot width of the enclosure and attached it to the back panel. I was then able to mount the transceiver PCB to the copper clad board with standoffs. This basic platform of the enclosure with the copper clad PCB provides a good foundation for any number of projects. All you have to do is mount the wired PCB on the board, install the components on the front and rear panel, then wire it up.

DC30B QRP Transceiver Project

I wanted to have the choice of a few frequencies to operate on so I searched eBay for 30 meter crystals and found a source for 4 different popular frequencies. I installed a rotary switch on the front panel and added a small auxiliary PCB with two, 4 pin machined IC sockets. This allowed me to plug the crystals into the sockets. I wired the bottom of the socket PCB first using wire pairs stripped from computer ribbon cable leaving extra length. I marked the wires with dots to indicate which sockets each wire pair went to so I could solder them onto the rotary switch in the correct order. It was tight but I always work with optical magnification so I can see exactly what I’m doing. I have used this crystal switching method in the past with good success.

DC30B QRP Transceiver Project

DC30B QRP Transceiver ProjectThe rest of the assembly was straight forward. I find that most kits are well designed and documented, and if you take your time and follow the directions carefully all should go well. The two most common speed bumps seem to be soldering in the wrong component or bad soldering technique. I double check all component values and placements prior to soldering, and I always use optical magnification while working. I inspect each solder joint and look for good flow through in the plated through holes, and make sure there are no solder bridges.

DC30B QRP Transceiver Project

DC30B QRP Transceiver ProjectThe finished product. I bought a Dymo label maker and it works very well for projects like this. I love using these enclosures and they are a leap forward from the old folded aluminum clam shells I used in the past. I could stand on this without causing any damage. Power out is 1-3 watts depending on the DC power in. The receiver is sensitive and the ability to choose from four frequencies is a real plus.

73 de KZ4TN

Steve Allen
Elizabethton, TN


Wow, Steve! What a top-shelf job on this build! I’ll have to look for those aluminum enclosures as well. Beautiful little rig you’ve made there and I think it’s fantastic you’ve a few crystal frequency options! Thank you for sharing!

Eric’s DIY Cootie: “Levon”

Many thanks to Eric (WD8RIF) who writes:

Well, if K8RAT is going to tout Hermione, I guess I need to tout Levon.

My cootie/sideswiper was inspired by an article (http://sideswipernet.org/articles/w9ok-modernization.php) by W9LA about how hams in the 1930s might have constructed a cootie/sideswiper using a ceramic DPST knife switch. I didn’t have a ceramic DPST knife switch, but I did have a nice Leviton ceramic DPDT knife switch which I used as the basis for my cootie/sideswiper. Instead of using tape for the fingerpieces as described in the article, I used Fender guitar picks.

This cootie is the key I use most often for home-based operations.

While operating in the field, I usually use an inexpensive and lightweight Whiterook MK-33 single-lever paddle as a cootie key.

Levon is a handsome sideswiper, Eric! Thanks for sharing his story and your photo!

Thanks to both of you, I feel inspired to make my own “cootie” this winter. Perhaps I’ll try to find some historic context/inspiration as well!

Any other homebrew sideswipers, straight keys, or paddles you’d like to share? Please contact me and we’ll feature your creations!

I’ve got a very special one that’ll be featured later this week. Stay tuned!

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