Antenna Tuner with two capacitors controlled by Arduino

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The Arduino Sketch (source), Android source code (Eclipse project) and schematic can be downloaded on: and

This is my antenna Tuner prototyping.
It is not finished.

This video shows a prototype of an Antenna Tuner for Magnetic Loop Antenna.
In this version, I incorporated a fine-tuning capacitor to improve the precision during the operation. This capacitor is a kind of butterfly variable capacitor that works from 1 to 2 pF and it is connected in parallel to the main variable capacitor (from 6 to 160 pF).

As some old versions of my antenna tuner, an Android Device Remotely can control the Antenna remotely. The circuit board has an SWR meter stage that is excited by the radio RF signal. A relay switch the Antenna Loop to a resistive SWR Meter Bridge where the impedance of the irradiant system is compared to 50 ohms during the scan for the lowest SWR. The Arduino analog input reads the result and compere it with previous readings. This prototype has not finished the SWR meter stage

You can see this system working here: or here

Connected to the Arduino has a HC-07 or HC-05 Bluetooth to UART RS232 COM converter.
See:

The Software developed to integrate the Arduino and Bluetooth with an Android Device was inspired from some Android SDK examples.

See the second part of this project here:

I published photos, schematics, and source code about this subject on

You can see more about Magnetic Loop Antenna here: