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, October 16, 2013

Broad band 1:1 current/choke balun

In search of a no nonsence 1:1 balun i came up with this easy to build unit. It offeres a almost flat swr curve from 1 to 30 MHz  as you can see in the plot. Use 10 turns of side by side1 mm enamelled copper wire on a 4C65 or FT140-61 toroid . Teflon tape was used on the toroid but this is not essential.

SWR plot of the balun bridged with a 50 Ohm resistor.
Disclaimer:I'm not responsable for any damage due to improper reproduction of my projects.