mAT-705 Plus

New release of MAT-705 plus Antenna Tuner

mAT-705 Plus

In this update you will not need a battery exchange, the front incorporates a USB charging connector.

mAT-705 Plus Automatic Antenna Tuner

mAT-705 Plus tuner is powered by two built-in lithium batteries instead of alkaline batteries. The user no longer has to open the tuner housing to replace the battery.

The tuner uses the type USB charging port, so users can easily use the mobile phone charger to charge the tuner.

The new version of the tuner eliminates the mechanical power switch. Its power supply is automatically controlled by the transmitter. After connecting the control cable, it will be turned on and off along with the transmitter, no need to manually turn on and off.

The tuner uses a larger LED lens and is mounted on a PCB.


  • Frequency Range: 1.8 ~ 54 MHz
  • Impedance Range: 5 ~1500 Ω
  • Tune Time: 5 seconds or less
  • Memories: 16000 channels
  • Charging Voltage: 4.5-5.5V, TYPE-C USB
  • Charging Current: 500mA, Max 700mA
  • Operating Temperature: -10°C ~ +50°C
  • Case Size (WHD): 67 x 29 x 151 mm Net
  • Weight: 237g, Gross weight: 330g

mAT-705 Plus  – Front Panel Information

mat-705 plus

mAT-705 Plus

mAT-705 Plus  – Back Panel Information

mAT-705 Plus

mAT-705 is a very capable ATU – it quickly finds matches from 160 to 6 meters. It also has an incredibly strong aluminum casing. It’s a very capable ATU in terms of finding matches quickly and efficiently, and on the surface it has excellent build quality.

But there is a big problem the user must remember every time he uses the mAT-705 to turn off the mAT-705 mechanical switch. If left in the “on” position by accident, even without connection to the IC-705 and while not in use, a 9V cell will be depleted in a few days.

mAT-705Plus tuner introduction and demonstration



mAT-705 Complicated battery removal

by Tom Witherspoon – K4SWL

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.


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