I am in the process of trying to gain a better understanding of amateur
radio antennas and transmission line issues.

I am mulling-over the issues associated with driving a dipole. Let's
say I have a (resonant) dipole close to ground, but perfectly
symmetrical. If I were to drive the dipole from a grounded radio
transmitter through some length of coaxial cable, I would expect that
the drive voltages at the driving point of each wire (measured with
respect to ground) would be far from equal and opposite. As a result,
I would expect that some current would need to return to the ground
terminal at the transmitter through some means other than the inner
surface of the coax shield. This spurious current could return on the
outside of the shield and/or through the ground itself, leading to line
radfiation and/or power loss. Of course, I would not expect a ladder
line to solve the basic problem.

So, it would seem that driving a dipole directly with coax is not the
best way to do things. Is that correct?

I suppose one needs a so-called "current balun" to ensure that the
antenna currents are equal and opposite, avoiding a spurious return
current. My simplistic way of understanding why all of the return
current flows along the inside of the braid is that the outside of the
braid is shielded from the center conductor, resulting in a huge
outer-braid loop inductance. And current takes the path of least
impedance, which is the low-inductance loop formed by the center
conductor and inner-braid.

That's it for now. Any comments will be appreciated.

73
-JJ