This UN-UN can be used on SWL or ham radio antennas.

The construction drawings are from http://www.iv3sbe.webfundis.net/html/UNUN.htm ,by Enrico 5Z4ES.

I've used this UN-UN to feed the fishing rod antenna,and sometimes a random wire.

For the first version I used some common black-red wire for speakers,wound on a T200-2 toroid.

To Build a UN-UN you need the following Items

Amidon Ferrite Toroid model T 200-2 ( 0-30 MHz )

Amidon Ferrite Toroid model T 200-6 ( up to 50 MHz )

about 2.4 metres of insulated copper wire 0,75mm

Fold the 2.4 metres of copper insulated wire in two. Mark the wires' end so to recognize them when the windings is done.

Wind 13 to 19 turns of the bifilar wire ( more turns better response to lower band ).

Connects the wire to the box terminal and the UHF connector ( SO 239 )






This is the second version of the UN-UN I made,with a larger size wire.



Copyright 2007 by IW7EHC all rights reserved