Automatic Magnetic Loop Tuner – First QSO

On the 15th of March 2017, we were ready to test our final product. The Automatic Magnetic Loop Tuner was fully assembled, programmed and connected to the antenna and transceiver. Time to turn the VFO around and see if we can make some contacts.

Imagine the following situation: 15th of March 2017, 21:00 UCT, 20m band, no sunspots that day. One OM is alone in the workplace, the other OM is getting some stuff from the shack elsewhere in the house. When the second OM returns to the workplace, the first OM tells him he made a contact with K2GAV, Theodor from Connecticut, 5800 km away from their location. The signal report was 57

On top of that, the antenna setup is the one from the picture below. Inside the workplace, 1m apart from an aluminium garage door, steel beams in the roof.

Magnetic Loop And Automatic Magnetic Loop Tuner

I don’t have to explain to you the disbelieve of the second OM, who immediately grabs the mike and calls for K2GAV. K2GAV returns but the signal is getting weaker. A new contact is made, however this time with a report of 56. This antenna setup, the timing and the conditions were all but ideal, yet we managed to make a DX contact! This proves that the Magnetic Loop antenna is an ideal antenna for people with little space to put a big antenna. You don’t need to say your favourite hobby goodbye if you have to move to an apartment.

Long live the magnetic loop antenna and the Automatic Magnetic Loop Tuner!

Automatic Magnetic Loop Tuner – Assembly

The PCB is soldered, we did the metal work and the paint job on the project box. Now we are going to assemble it further and finish the Automatic Magnetic Loop Tuner. The only thing we need to do before we put the switches, screen and connectors in the project box and connect them to the PCB, is to solder the connection wires.

Afscherming swr brug

For these wires, I used Dupont wires, with female connectors of 2, 3, 4 or two times 6 pins. The one with two times 6 pins does not really exist, you have to make it yourself. For this, I took a rainbow colour multi cable Dupont wire. Removed the single female connectors and replaced them with 6 pin Dupont connectors.



Use some shrink tube to make sure all connections are well insulated and will not cause a short circuit.
When done, it’s only a matter of connecting the right switch to the right header on the PCB. Check the electrical diagram to know the function of each switch.

Automatic Magnetic Loop Tuner

When everything is connected, you might want to tie together some wires to tidy things up. Your project will certainly look better and not like a rats nest of wires. Put the lid on the box, fasten the screws and your Automatic Magnetic Loop Tuner is ready to be used.

Magnetic loop tuner