La Radio

Locator : JN38RM

Licence 1992

The few lines of this pages deal essentially with ATU enabling to tune an asymmetric or symmetrical antenna, and with an optimization software of an antenna type “Levy” or “Center feld”.

 

F5IMV's bills of specification : The ATU

The universal coupling unit doesn’t exist because, as far as I know, there is no universal antennas that have the same characteristics (symmetry, impedance…). In the end, the choice of a coupling box will be the result of a compromise between a group of antennas and a type of coupling box. Exigencies regarding size, power handling, easy-to-use will add on, and so on...

 

And so much more ! This allow us to continue to experiment !

 

• Specifications :

  • no variable roller inductor because it requires a counter,

  • maximum 2 knobs (the limit for a 3rd "fine tuning" and one or two switches),

  • cover of 80m to 10m (160 m and 6m accessible, but not required),

  • minimum 100w power on all bands,

  • to work with antennas symmetric, asymmetric and "long wire". (one exception, the S-Match)

  • easily achievable with common components,

  • and finally, for fun, a ROS indicator.

• Les réalisations :

  1. S-Match : An ATU very pleasant to use, easy to carry. Excellent symmetry. Montage dedicated to balanced antennas.

  2. Z-Match New : Symmetrical mounting. Coupling box a little difficult to perform and to take in hand. Excellent performance and excellent symmetry in this arrangement improved the standard Z-Match. A must for QRP.

  3. Z-Match ATF-S : A completely different approach: autotransformer type assembly and asymmetrical. Easy to build, works very well with an air-coil. Balun 1:4 current for a symmetrical output.

  4. Transmatch : An ATU very easy. Symmetric and Asymmetric output. It allows traffic on the amateur bands from 160m to 6m. Excellent performance in low bands. Power handling 100W.

• Methods for the tests and results :

  • Method and equipment used to test the performance of the symmetry and for their power efficiency.

  • Tests results :

    • Symetrical. Below a value of 1.5 very good to excellent symmetry.

    • Efficiency.

ATU were tune on :

• Center Feld horizontal de 2 x 36 m + 21m ladder 300 Ohms.

• Center Feld horizontal de 2 x 23 m + 13,20m ladder 450 Ohms.

• Center Feld vertical de 2 x 6,23m + 14,50m ladder 450 Ohms.

• Vertical de 6,23m.

• Long wire : 36m.

 

Software implementation :

• Optimization software of an antenna Levy or Center Feld.

 

 

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