By fractional bandwidth, I mean the fraction of the operating frequency
that the bandwidth is; or in other words the ratio of the bandwidth to
the operating frequency. For example, if the operating frequency is 10
MHz and the bandwidth is 1 MHz, the fractional bandwidth is 0.1 (1 MHz /
10 MHz). If you scale the antenna to 20 MHz, the bandwidth of the scaled
antenna is 2 MHz. The fractional bandwidth is 2 MHz / 20 MHz = 0.1, the
same as before it was scaled.

I don't have enough information to answer your question, since you
didn't give the operating frequency. I hope the example I gave will
clarify what I meant.

I always enjoy Dayton. It's a pleasure to meet EZNEC users, potential
EZNEC users, and some of the many people who read this newsgroup. And if
rain bothered me, I sho' 'nuff wouldn't live here in Oregon!

Roy Lewallen, W7EL

JGBOYLES wrote:
When you scale an antenna's dimensions, including the wire diameter,the

*fractional* bandwidth remains the same. So if you scale it for twice the
frequency, the bandwidth doubles.
Hi Roy,
I have never heard of *fractional* bandwidth. Not unusual that I have never
heard of stuff. If one has a band that is 100khz wide and the 2:1 swr
bandwidth is say 20khz, what is the fractional bandwidth, and the bandwidth?
If you scale the antenna to double the frequency (neglecting losses, or
assuming negligible) and scale the dimensions, what are the 2 bandwidths?
I hope you enjoy Dayton, first time in 5 years I won't be there. It rains
too much when I am up the-(


73 Gary N4AST