Tag Archives: ATUs

Barry’ review of the ATU-10 QRP Antenna Tuner

Many thanks to Barry (KU3X) for sharing the following guest post originally posted on his website:


ATU-10 from Banggood.com

by Barry (KU3X)

There are times I find myself in need of an ATU. One example is when I use my half wave end fed 40. I can not always erect this antenna in the clear. I did purchase the LDG Z100 Plus 705 with interfacing cable. The unit does as advertised but I am not impressed with its performance. My biggest complaint is, when interfaced and the IC-705 tells the LDG to tune and it does not know the antenna is matched and resonant, the LDG adds capacitance and inductance which actually raises the SWR. It’s too dumb to go into bypass. I resolved this by not using the interface cable. Now I only tell the LDG to tune where needed. Most of the time I turn the LDG off by toggling between bypass and tune using the button of the front of the unit.

Size matters to me and the LDG ATU is too big. Another downside is it uses SO-239 connectors instead of BNC connectors. Everything I have relating to QRP operating uses all BNC connectors, including my home brew two position antenna switch. I do want to get my hands on an Elecraft T1 ATU but Elecraft can’t get the parts from the manufactures to make them. So the hunt was on for a small ATU with internal batteries and BNC’s instead of the dreaded SO-239 connectors. Here is what I came up with.

I ordered the above pictured ATU-10 from Banggood.com. I have also seen them posted on Amazon.com. They can be found on eBay as well. I did not provide a link for ebay because some ebay adds are dated. There is a very good demo posted on YouTube. Here is an overview of the ATU-10 [PDF].

My ATU-10 arrived 11 June 2022. Here are my findings:

The package contained an Allen wrench and a USB cable for charging the battery as well as for updating the firmware. The package DID NOT include the interface cable for the Icom 705 nor did it included any paperwork…….no manual! My battery showed about half charged and firmware version 1.4 was installed. If you forget to charge the battery and go on site with a dead battery, you can supply power to the ATU-10 via the USB charging cable. You may have to give it a few minutes for the batteries to take a little charge, but from that point on just leave keep the ATU-10 connected to the USB cable.

The needed interface cable is nothing more than a stereo audio cable with 1/8″ male plugs on both ends. But, the ATU works without the interface cable, it’s just not controllable from the radio. As for the matching, I can say it works as good as or as bad as my LDG Z-100 Plus. Where ever the LDG provided a match, so did the ATU-10. On 80 meters where the LDG did not do so well, neither did the ATU-10.

I first tried the ATU-10 without the interface cable. I just sent a carrier from the radio and the tuner went into the tune mode. It’s that simple. It takes anywhere from 2 to 5 seconds to find a reasonable match.

To use the ATU-10 with the interface cable, there is the setup procedure. Hook up all of the cables, including the interface cable to the IC-705. Now turn the ATU-10 on. Once booted, turn on the IC-705. Go into the, “Function” screen and tap the, “tuner” icon. You are ready to go. You do not have to change modes to have the ATU-10 go into the tune mode. In any mode on the radio, like SSB, just key the mic and the tuner will tune. Give it a second or two and you are ready to go. Change bands and key the mic, same results. I lost communication between the radio and the ATU-10 when I went to 80 meters. I have no idea why? I just turned the radio off, then back on and everything was reset…ready to go.

When I received my ATU-10, I noticed all of the hardware was not that tight. I retightened each nut and Allen screw.

User group for the ATU-10 and the ATU-100.

Pros:

  • Size…the ATU-10 is small enough to carry in your shirt pocket ( 5″ x 2-3/4″ x 1″ )
  • Antenna connections… BNC. All of my cables used when I set up portable use BNC connectors.
  • Power source ….the ATU-10 has two internal rechargeable batteries so no external power source is needed. Since the ATU-10 uses latching relays, the only power that is needed is for the display. The display has a time out timer and the ATU will turn off after 30 minutes on non use. The ATU will last you for months on end before needing to be recharged.
  • Display… the display shows SWR, power out and the state of charge for the internal batteries. It also shows what firmware is installed. The display will fall asleep after 5 minutes of non use. If power is applied, the display will wake up. The entire ATU will turn off after 30 minutes of non use.
  • Bypass mode (simply turn the ATU-10 off)
  • Construction…..the ATU-10 is built inside of a solid metal enclosure.

Cons:

  • Loss of communication….more than once communication was lost between the radio and the tuner. Easy fix by turning the radio off and then back on but this is very inconvenient.
  • No manual…..not even a little sheet of paper showing the specs. Whatever you need to know can be found on this site: ATU-10 info at GitHub.

Final notes:

For the price, it think this is a great buy. It does exactly what I want it to do and provides a reasonable match to make the radio happy. You can use the ATU-10 with any radio at power level of 10 watts or less. It’s a perfect size for backpackers. I don’t think the interfacing between the radio and the ATU-10 is all that importable. I myself choose not to use the interface cable. Since the tuner will go into a tune mode if the SWR is too high, that’s all that is really needed.

Norm recommends the MFJ-212 Matchmaker for effortless tuning

Many thanks to Norm (VE3WNS & M0CEL) who writes:

Hi Thomas,

[…]At my condo QTH in downtown Toronto I’ve been using a balcony tripod mounted MFJ 1886 along with my Icom 7300. I heard about the MFJ-212 Matchmaker and decided to try it out. It worked brilliantly. What it does is put out a signal in the form of hash and you can see the resonant point moving along the band scope on the radio as you tune the antenna. Once the hash is centered you are on frequency without ever transmitting.

I’m back at my QTH in Manchester where I have a pretty respectable station, you can see both on QRZ. Anyway, your videos are responsible in a large part for getting me interested in POTA so I’ve purchased an ICOM 705 and a Chameleon F Loop 3.0. I decided to purchase another MFJ 212 Matchmaker and again, it works brilliantly. No transmitting required as the antenna can be tuned visually on the 705 band scope. The 212 can be powered externally or, as in my case, I’m using the 9 volt battery option. I figure the battery will last for ages.

[…]I have to say the MFJ Matchmaker has made working with a hi Q loop a pleasure, especially one that tunes as smoothly and finely as the Chameleon F Loop.

73

Thank you for sharing this, Norm and for the kind comments! I had no idea such a product existed. I love the concept, though–this could be especially useful tuning antennas like loops with high Q and thus narrow bandwidth. 

Click here to check out the MFJ-212 Matchmaker at MFJ ($149).

Update: A number of you have pointed out that the MFJ-212 is a noise bridge! I think it’s so cool that, in a sense, this accessory is even more useful when paired with a transceiver with spectrum display. Thanks for the comments!

Richard recommends the Phoenix QRP Pocket Transmatch

Many thanks to Richard (M0RGM) who writes:

Hi Thomas,

Hope this email finds you well, and thanks for all the recent blog updates and videos.

Like many other QRP ops we sometimes need an ATU or matching unit. For a while I’ve been looking for a small compact unit for use with my QCX-mini, MTR-3B and TX-500. I was sorely tempted by the Emtech ZM2, but they are quite expensive over here in England, especially as I’m awaiting delivery of a Venus SW-3B!

After much research I stumbled on the Phoenix Transmatch sold by Kanga Products. Paul, the proprietor, sells quite a range of quality QRP goodies. Having purchased the assembled device (work gets in the way of construction these days), I can say that this is a really good lightweight model that suits my purposes fully. No, it doesn’t have the tuning range of the ZM2, but I rather hope my antennas are not too far out of resonance!

For size comparison, see the attached photo taken whilst playing in the sunshine….

For anyone interested, the web details can be found at https://www.kanga-products.co.uk/ourshop/cat_1750054-QRP-ATUs.html

I have no connection with Kanga other than being a satisfied customer!

Regards,

Richard M0RGM

Thank you for sharing this, Richard. I love the size of Phoenix Tranzmatch–I was not familiar with it. It would be a great additon to pretty much any field kit. I see you also have the N6ARA paddles–I think they’re great!

It also sounds like you, too, have a QRP radio addiction. I hope you realize there’s no cure, so don’t fight it! 🙂

Thanks again for sharing this, Richard. 

“What battery, antenna, and ATU should I pair with the Discovery TX-500?”

Many thanks to Vitor Morais who asked the following question in the comments section of my YouTube video:

Hi,

Greetings from UK.
I recently learned that POTA [is now in the] UK so I am really looking forward to it.

I also recently put an order for [the Discovery TX-500] so I am really excited as well.

I would like to create a very compact setup pouch for field use to pair with this radio; one that I could take to summits or parks and also travel abroad.

What battery and antenna would recommend?

Would you recommend an ATU?

Or would you compromise to fewer bands or pack a secondary antenna?

I love to know your opinion.
Thanks

Great questions, Vitor! In truth, these sorts of questions are easy to ask but quite complicated to answer due of the insane number of options and possibilities available. It’s impossible to cover them all so I’ll try to give you some suggestions based on what I tend to use in the field. Continue reading “What battery, antenna, and ATU should I pair with the Discovery TX-500?”

Hike and Talk: Non-Resonant vs. Resonant Antennas and should you buy an ATU?

I had a topic on the mind as I made my way back to the trailhead after a SOTA activation recently.

I get a lot of questions from readers and subscribers about resonant vs. non-resonant antennas and whether or not an ATU is a good or bad thing.

If you know me, you’ll know that I tend to lean towards qualitative research; meaning, I like to base my opinions on first-hand observations rather than laboratory or textbook explanations. Part of the reason is I’m not an engineer, so specifications and performance stats don’t influence me–I don’t understand them half the time–rather, I base my opinions on trying or field testing.

The proof is in the pudding, right?

So with the topic of antennas and ATUs on the brain, I decided to turn on the action camera and do an unscripted video on the trail as I hiked back to my car.

This video is essentially stream of consciousness: I won’t blame you if you skip it.

With that said, if you manage to stay awake for the whole video (congratulations in advance) I’m curious what your thoughts are so please consider leaving a kind comment!

Thank you & 73,

Thomas (K4SWL)

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.

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.