These are the YagiCad dimensions of a 2 element RDF antenna for 166mhz:

ref 00.00m space .906m length
drv 0.069m space .657m length

This uses .010m diameter aluminum tubing. It is being used on a King radio,
which I believe is around 50 ohms. I am using 6 feet of rg58/u with a bnc
connector.

YagiCad says the f/b is 37.75db and 5.75db gain. Both the H and E patterns
are about what I would like in this RDF. It works pretty well when I use it
with the elements vertcal, but less well when they are horizontal. I
contructed this as accurately as I could.

I don't even know if this antenna SHOULD work, but am wondering if a hairpin
would improve what I have so far? Can someone suggest the dimensions of a
hairpin for this?

also, this is maybe a bumb question, but is the element spacing designated
in YagiCad designs center to center or true spacing between elements? Is
there a big diference?

Jim