This is a updated collection of easy to build projects for radio amateurs and swl's. See all my projects in the OLDER POSTS down this blog.
Have fun.
73' John

Mutual respect is the key to global peace.....

Wednesday, February 11, 2015

1:4 Voltage balun 3.5 - 30 MHz

Flat SWR  from 3.5 to 30 MHz with 8 double turns on a 4C65 or FT140-61 toroid.
SWR  1: 1.1 in the centre.
The 4C65 was used  because it was in stock . A FT240-43 with 12 turns wil provide a almost flat range from 160 - 10m.
Disclaimer:I'm not responsable for any damage due to improper reproduction of my projects.