[TowerTalk] W2DU Balun and Type 31 Fair-Rite

[jeff_list at burnshome.org]

I am thinking of making a W2DU Balun using type 31 Fair-Rite cores. Will
this be any improvement over the standard #73 beads? 

 

I am looking at Fair-Rite core number 2631480002. These have an outside
diameter of 0.485 in, inside diameter of 0.2 in, and are 1 inch long. They
have an impedance of 115 Ohms at 10MHz. How many cores will I need for a
balun to work well from 160m to 10m?

 

These cores cost $0.80 a piece from 1 to 49 pieces, $0.70 from 50 to 100,
and $0.60 for more than 100.  At these prices I will need to be able to use
no more than 10 to be cost effective with a kit from "The Wire Man".

 

Jeff Burns

AD9T