DIY: ATU-10 by N7DDC - QRP version of ATU-100


I just would like to bring the ATU-10 to your attention. David N7DDC has released a new version of his ATU-100 as a low-power consumption and 10 W QRP version of his popular autotuner.

The design is focused on low power consumption during operation. Latching relay are used make this happen.
And it has a communication port to interface with the IC-705 for the tuning.

Link to files:

(Source:Pictures from Davids github page)

SMD soldering of those small part sizes is definitly not everyones cup of tea but I have seen first pre-orders on the usual chinese trade platforms show up.

Btw. official discussion board can be found here:

And as the PIC µC is difficult to source at the moment Glen VK3PE has developed PCB variations that use larger package sizes with better availability. And some infos on the experiences:

I am myself just collecting infos on how to source from Austrian and German webshops.

73 Joe


Looks very tasty :slight_smile:


Following up, is anyone offering a kit for this like the ATU-100 kits?

My Google-fu has failed to find anything. There are people selling completed and ready to use units on Alibaba and whilst I have no aversion to buying a ready built unit, there is still more fun to be had from building a kit.

Appears to be a few on eBay including non Chinese sellers, for example:

One like this ?

I bought mine built and ready to go. Working OK so far with no issues.

What did you use for a case John?

That is the ATU-100 so the 100 W version. The ATU-10 is the QRP version and I have not seen any kits so far.

I did some investigation in sourcing parts and got the reviesed Gerber files from Glen. But I was ending up over 100 € and I have no urgent need as I use resonant antennas.


@M0NOM Mine was pre-built but this might help

Yes the ATU-10 is the QRP version and uses latching relays so uses hardly any power apart from when actually finding a match. I have seen ready built units for £94 (110Eu) but I’m not sure if that includes VAT or not. ISTR Alibaba purchases now add the VAT on so you don’t pay when the package arrives in the UK and then pay a VAT collection handling charge as well.


I was looking at the ATU-130 Plus listed on Aliexpress by various sellers - I have a Phoenix Kits manual ATU to build after I’ve unwrapped it for xmas, but need something that can handle up to 200w power.

Does anyone have experience with the ATU-130 or ATU-130 or recommended sellers? Or should I buy a named brand tuner instead?

Cheers, Mark.

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I see this is now available to buy built on the well known auction site, not cheap though.

There is obviously not only joy at the moment, so pay attention to the details.

Thank you for the information. I don’t think I will be buying one at the moment.

I intend to develop a comparable tuner. As a latching relay, I use the ones that are installed in the KX2 atu. The 15 relays alone cost around 60 euros to purchase. Therefore, a total price of over 100 euros for the tuner is justified.

73 Chris


Hi all,anyone else using this tuner?
I’ve just recieved mine today,have yet to test it out on my home end feed.
I see from github that the minimal tuning power is 1W with the 1.6 firmware,can anyone confirm this?
That would rule out me trying to tune it with 5V on my trusdx.

It was very nicely packaged by the supplier of trusdx from China.

73 Karlo


Hi Karlo,
yes indeed, minimal tuning power of ATU10 fw 1.6 is app. 1W. I have one, and its minimal tuning power is 0,8 W, tested with KX3 on my home horizontal delta loop antenna on several bands. So it will not tune with trUSDX powered from USB source.
Mirko S52CU

Thanks Mirko,I tried it out today on my house antenna,it tuned just fine.
Took me a few minutes to figure out that i need to reset the tuning because no signal was getting into the radio,but after that it was a breeze. I am very satisfied with the tuner.

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I use one following the faff of linking and unlinking the links on my linked dipole with cold hands here in Scotland. I now use one of these with a Sotabeams bandspringer and it’s been faultless. I also used it on holiday in the caravan for a week with high usage and didn’t charge it once. Can’t comment on the tuning power other than it tunes on 2.5w from my 817.