1:1 Ruthroff Voltage Balun

    This balun transformer can be used for impedance matching with tuned dipole. Also it gives a balance in voltage levels in the arms of dipole. Ofcource it is a voltage balun and uses Ferrite rod from old MW radio's. The Copper wire used is 18 SWG wound trifilar on ferrite rod.

Slim-Jim Antenna

      Just completed my slim-jim antenna last week. The materials used are 14 SWG copper wire from old electrical cable and some old PVC's and PVC Connectors. I used a 1.9 Meter 1/2" PVC to assemble element and 1'' PVC for covering the element with an PVC end cap on top and an so239 connector at the bottom end to connect the feeder.

      I used a RG 58 feeder cable and a small balun at the antenna feeder end. And here it is at my roof top. The calculation for element length can be found in google. Do consider a parasitic effect due to PVC and build the antenna with a tuning frequency slightly greater than the required tuning frequency.

Balun for 145.000 MHz.

Cheers !!! ...