There can be substantial radiation from an OCF dipole feedline even with
an effective choke in place. The asymmetrical positioning of the
feedline relative to the antenna results in a net induced common mode
current, while a choke only stops the current at one point. Effective
reduction of induced current can require two chokes placed about a
quarter wavelength apart, which isn't practical for a multi-band
antenna. In practice, you might have to fiddle with the feedline length
(since some lengths will result in more current than others on
particular bands) in addition to using two or more chokes in order to
drop the feedline radiation to a tolerable level. I think that with an
OCF dipole you've just about got to expect some feedline radiation.

Roy Lewallen, W7EL