Everything you need to build the automatic magnetic loop tuner in just one picture. On the Flickr page, you can see the annotations. To reach the Flickr page, you need to click on the picture.

Automatic Magnetic Loop Tuner Kit

After some soldering, drilling, cutting, filing, screwing, programming and painting, … it will look like this:

31 Replies to “Automatic Magnetic Loop Tuner – Kit”

  • Nice work!! Are you selling the kit? How much?. What about just the circuit board? How much? How can i order?

  • Hello Kent,
    The kit on the picture was a result of the group buy that was organized by my local club and is not for sale.
    I’ve sent you an email about the PCB’s.

    73 de ON5IA

  • Hello Denis,

    I do have some leftovers from our club group-buy. I’ve sent you an email with details.

  • Hello there, congrats!!!
    Nice job. I have many questions: 1. can I use this controller with my Yaesu FT 1000 Mark V?
    2. Need it a special setup on the radio?
    3. You still have a PCB for this project?
    4. What about the software for this controller? how can obtain it?

    Thanks in advance and have a great evening.
    Gerardo. VA3GON

  • I would.like to buy a parts kit if any surplus are remaining. If you have enough interest may be you could put some more together. I have an FT450d radio but want to upgrade to may be icom as I want a pan scope. Will a pan scope be of use when using a mag loop as it is tightly tuned ?

  • A pan scope will still be of use when using a mag loop. It will help you to find the resonace point of the loop quickly. Although the weaker signals at the end of the band will not be shown anymore, you will not go completly blind when using a magnetic loop. I’ve send you an email with further details.

  • Hello, very interesting atu you develop. I’m wondering if it can be adapted to control a baby loop from ciro mazzoni. I own one but the commercial atu is only working in manual mode. In this antena the capacitor is tunned by a dc motor drived by l298n driver. Can we talk about this? 73’s

  • Hello, will your ATU work on an Icom IC7100 or Yeasu 817.

    Thank you! Tony KF7VLT

  • Hi Tony,

    Yes this tuner works with both the IC700 and the Yaesu FT-817. You can even store the two radio profiles in the memomry and switch between them.

  • Hi,
    I also have a Ciro Mazzoni Baby Loop. My controller has failed and I saw the above comment about it possibly being adapted for the loop, and it’s DC linear actuator. I’ve tried a PWM controller and tried tuning manually but it’s not very good.
    I’d be interested in seeing if this could be adapted though.
    73 Adrian M0OJR

  • Hello Adrian,

    If you swap the DC motor with a nema stepper motor, I’m pretty confident you can make it work with the Loftur tuner. I haven’t seen a Ciro Mazzoni Baby Loop irl, so I can’t tell you how easy it can be done.


  • Hi Don,

    Yes, PCB’s are still available. I’ve send you an email with details.

    73 de ON5IA

  • Hello Frederik, have you a kit of the automatic magnetic loop antenna? If not, have you a spare PCB and other spare parts?
    Thank you.
    73 Marco IU8HXM

  • Hello Marco,

    Not a full kit, but I’ve some PCB’s left. I’ve send you an email with details.

    73 de ON5IA

  • Hello
    I am struggling to find anyone that has stock of the teensy 3.2 controller. Do you have any available plus the kist pls?
    Mike ZL4MBW

  • Hello Mike,

    Unfortunately not. The Teensy 3.2 is hard to get. I read even more disturbing news on the PJRC website that the Teensy may never return to full production. That really does put a damper on this project. I still have PCBs and basic components, but no Teensy 3.2’s.

    73 de ON5IA

  • Bugger! that is so dispaointing. Is it possible for you to review the desing with e view to use a controller that is available? Its such a waste to shelve it just because its main component is no longer available.Surely there must be an alternative that can be used?

  • Reading out the frequency of the radio and moving the stepper motor should not be a problem with anther platform.
    However, measuring in real-time the SWR and adjusting the capacitor accordingly is a challenge that needs to be overcome.
    It’s this feature that makes the tuner “automatic”.

  • Hi Mike,

    For a automatic tuner without SWR readout, this will probably work. For the SWR readout we need more analoge bits than the Teensy 4.1 can support.
    I would have to dig deep into the code to find a way to go around this. It’s not something I’m planning to do in the near future.

    73 de ON5IA

  • I just found your site as I’d like to build the kit and a mag loop antenna. Do you have an update since March on the kit and / or parts status including the supply or replacement for the Teensy 3.2?

    TKS & 73

  • I’m not sure anymore if it was 47% or 74% memory usage of the Teensy 3.2. Anyway, it was enough to run the code Loftur programmed on the Teensy 3.2. The biggest challenge for the moment is getting hold of a Teensy 3.2. As these are not produced anymore. I’ve started with building this project around a Teensy 4.1. The hardware part is almost finished, but I’m still nowhere with the software part.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.