K9AY version 2.3

Current version 2.3(Edit)


Assembled KIT(Edit)

Why variable Rload???(Edit)

- look at far field plots from MMANA

The drill drawing(Edit)

Paste the drawing on the box and fix it with some tape.

Schematic diagram(Edit)

- Schematic Version 2.3

Voltage controlled resistor(Edit)

- insert VAC plus to plus - check package

Protection diodes(Edit)

- solder 5 + 5 diodes

- these diodes protect Rload resistor against high power, electrostatic etc.

Insert rest parts(Edit)

chooce the control way...(Edit)

- By the jumper JP2 you can select controlling over coax or DC voltage on connector X3

TRANSFORMERS winding - very important thing!(Edit)

    • for 50 ohm coax feed line : 2 turns on primar (coax) and 6 turns on secondar side (loop)
    • for 75 ohm coax feed line : 2 turns on primar (coax) and 5 turns on secondar side (loop)

- In version 2.3 and higher, you can select Coax impedance by jumper JP3.

- Transformer should have 5 + 1 turns.

Common-mode coax choke(Edit)

- choke measurements

Wind the coax(Edit)

- Wind the coax as is on the picture, there should be 7 or 8 turns.

- fix it by one binder and use second one to fix choke to the PCB

Solder the coax (Edit)

KIT - all parts assembled.(Edit)

Example of controller.(Edit)

- Injector to coax line:

- direction and VAC Rload controller

K9AY loops design example.(Edit)

  • It is VERY recomended to place K9AY loop antenna as far as possible from metal towers, antennas and wires. This hepls to obtain better paramaters of antenna ( directivity and noise ).
  • K9AY Loop design page