Fred W4JLE wrote:
How can I test how well a choke balun is performing? I know how to test a
transformer balun, but am cluless as how I can compare several different
choke balun approaches.


You can measure the impedance by shorting the input conductors together
and the output conductors together. Then connect the input conductors to
one terminal of an impedance measuring device such as an antenna
analyzer or impedance bridge, and the output conductors to the other
terminal. An impedance of around 500 - 1000 ohms is generally adequate.

If you want to measure its effectiveness in place, you can construct a
current probe like the one shown in Fig. 12 of
http://www.eznec.com/Amateur/Articles/Baluns.pdf. It'll give you a
quantitative measure of the feedline current. You can use a snap-on
split core for convenience. The value at the choke should be very low,
but it might increase considerably about a quarter wavelength down the
line due to induced common mode current. The solution to that is to
insert another choke balun at that point.

Roy Lewallen, W7EL