Charlie, an antenna will need to have a choke only in the following
condition:
Check the Swr with feedline attached. Add another 1/4 wavelength of
transmission line with impdedance equal to the output of your
transmitter. If the Swr increases, then a choke is required. If Swr
goes down slightly, that only means that there is loss in the added
section of feedline.
The reason why this check works is that a choke is needed if current
exists on the outside of the coax. In that case, the current acts like
another wire attached to the antenna. This added wire changes the
effective length of the antenna causing a change in resonance with
added feedline.