�A7805 After tuning is completed, during normal transmissions at high Switches +12v to ATU box, where the voltage is reduced to +5v by a Servo during tuning sequence (this happens at low power). Quite sensitive to HF, it is true that very high RF voltages are presentĪround the tuning box. Servo Control : The servo I used seems to be Signal handles supply (+12v) and control signal to servo, and power Standard CAT5 network cable and RJ-45, this is very handy. The ATU box is connected to the control bow by a In 1� steps (through a center position toggle switch). Necessary, the position of the variable C can be fine-tuned manually Once the best position is memorized (perīand), the ATU automatically returns to this position when changingīand - so there is no need to retune for each band change. Of the band, there is no need to retune towards the edges, the In practice, this complete procedure takes less In EEPROM the position for the band in question. Of 1�, and park variable C accordingly, then memorize
Step up to find the exact optimal position, in steps Then return to position where best SWR was Identification of approximate best SWR position. SWR detection), measure ever 10� the relative SWR. To find the best tuning position of variable C, Wound for secondary, and 2T 1.5mm dia wire as primary coil and is perfectįor 100w operation), on which 14T 1mm dia enameled copper wire are (this is what I had on hand in the junk box. The L is made of 2 'twinned' toroids type T106-6 The relay is energized by ARDUINO when TRX set to 40m. Value sri !) is switched in parallel to the variable C, through a Type, 500v working voltage for 100w HF, I don't remember the exact butįor 40m operation, an additional C (dipped mica Sketch, a parameter for 'backlash' is provided. The servo must have a good precision (in the The servomotor isĬontrolled by ARDUINO, choose a 180� servo type, and provide an adequate My variable C has a range of 10 to 55 pF. To the rotor.), 180� rotation, and moved by a RC-servomotor. The inductor is fixed, the C is variable - it isĪ split stator type (to minimize losses, no trailing contact The relevant CAT commands / readout here. this is a pity and forces to use an external SWR bridge / Soon as the 'TUNE' button is depressed, no more information can be before realizing that the SWR reading isĪvailable through CAT EXCEPT DURING 'TUNE' PROCEDURE ! So, as
Hours trying to get this running, looking into my code. Possibility to read it's the value by a CAT command. The IC-7000 has an integrated SWR bridge and the Note : instead of an EFHW antenna, a magnetic loopĪntenna could in principle be tuned in same manner. With a minimum external components & wiring required
Icom IC-7000 (but other Icom TRX should be compatible), by depressing The ATU working in a seamless manner with my Have the system/antenna operating dual band, on On basis of this principle, the idea was to have:ĪRDUINO tune the L/C circuit automatically, acting asĪ matching unit. System not only transforms the impedance, but matches as well to some The advantage of this method is that, by tuning the L/CĬircuit, a good match can be obtained under various conditions - so the Resonating L/C circuit to step-up the impedance from 50 Ohm to the requiredģk. One of the methods was invented by FUCHS, who used a Theory when radiating in 'free space' ) makes it necessary to feed it in anĪppropriate manner. Very high - measured in practice to be around 3.000 Ohm (up to 5.000 max, in The fact that this antenna has an end impedance which is
ARDUINO ANTENNA TUNER PORTABLE
Thus requiring only a minimum of grounding (counterpoise) - so this antenna is very 'portable' and ideal for a temporary or portable Why an EFHW antenna ? The big advantage of this typeĪntenna is that (1) it is end fed, thus very easily set up (horizontally,
ARDUINO ANTENNA TUNER FREE
Whatsoever and feel free to ask if you are missing something. I am hereby publishingĪll information I have on hand, so what is missing must be experimentallyĭefined in your setup ! My intention is not to withhold any information This project realization is for 'advanced' OM's. Tuner, for an end fed half wave (EFHW) antenna, dual band for 20 This project describes an ARDUINO based automatic antenna
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