Reg Edwards wrote:
. . .
Furthermore, the choke does NOT do what the old-wives say it does, ie., stop
radiation from the line and prevent noise pick-up. It might even make
matters worse. The choke merely shifts the volts and amps standing waves to
other places along the line.

Have I upset the apple cart again?

Once again I proudly don the mantle of a Reg's Old Wife.

A common-mode choke, aka "choke balun" or "current balun" can have the
effect Reg mentions, but that's not the only possibility. Depending on
the lengths of the antenna and transmission line and the placement of
the choke, it can reduce the common mode current to a much lower value
everywhere on the line. This is done by the same mechanism as an
insulator reduces the current induced on a guy wire -- by making a
formerly resonant line non-resonant. In stubborn cases, two (or perhaps
very seldom, more) chokes placed about a quarter wave apart are required
to get a low value of common mode current everywhere on the line.

The general principles are easily illustrated by modeling(*). In
practice, the actual path along the feedline from antenna to ground
isn't well known so can't be modeled well, and some experimentation
might be necessary.

(*) Anyone having an EZNEC program, including the demo, can look in the
manual index under "Coaxial Cable, Modeling" for information. To
simulate a choke balun, insert a resistive or inductive load in the wire
which represents the outside of the coax. 500 - 1000 ohms is a
reasonable value to use.

Roy Lewallen, W7EL