I'm trying to design a Flag antenna for 9 to 12 Mhz.
I have the standard 14ft by 29ft Flag. It seems to lose
it's front to back ratio as the frequency gets above 4Mhz or less.
So I suspect it needs to be reduced in size for higher frequencies.

Would I scale the size the same as the frequency ratio?

I'm using the demo version of EZNEC, the dimensions of length
to height seem quite forgiving.

Could this be the limited segments (20) of the demo, or are
the design dimensions just not that critical?

Your input is appreciated, I haven't found much info on higher
frequency Flag antennas.
Thanks,
Mike