This is a updated collection of easy to build projects for radio amateurs and swl's. Have fun. 73 John
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.