On Dec 10, 12:55*pm, " wrote:
I was reading about an Off-Center Fed Dipole *(OCFD) *antenna.

The following statement was made:

"An effective balun can be made by coiling up coax providing it is
self-resonate at or very near the operation frequency"

In the above statement, what does "self resonate" mean?

Lee *KA0FPJ

in that context it means that the coil of coax has distributed
capacitance and inductance that at some frequency presents a parallel
resonant circuit which makes a high impedance for currents on the
shield of the coax. you can see the effects in the table on my web
site (http://www.k1ttt.net/technote/airbalun.html) where there are
peaks in the impedance of the air core 'baluns'... it is actually more
correct to call them chokes than baluns since they really just try to
choke off the current on the shield of the coax at the feed point.