Tag Archives: CW Morse Double Paddles

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

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.

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.


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.

POTA Portable, Picnic, Paddles, and Unpredictable Propagation

Practicing left hand lunching, right hand keying/logging!

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

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

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

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

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

Zebulon B. Vance Birthplace (K-6856)

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Unpredictable Propagation?

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

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

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

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

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

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

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