Here's the link to the manual.
Page 39 gives the scramble function details.
http://inform3.kenwoodusa.com/Manual...62-1791-00.pdf
Yes, it is a standard connector type but not necessarily easy to find.
Looks like it may be SMA.
You would probably need to have a flexible RF adaptor made that will adapt the
antenna port on the radio to a more common type to allow the
use of an external roof top antenna.
This is nothing more than a short piece of very flexible coax between your radio
and the antenna's coax.
It will keep the antenna jack on the radio from becoming loosened by the strain.