It works fine on my second build.? I DID use shielded cable for the key jack as it passes right over the TX RF section to the back panel of my enclosure.? I don't know if the earphone has to be shielded wire or not but I had plenty of small diameter 3 wire shielded cable salvaged from an old computer microphone so I used it for the earphone as well.? Doesn't hurt to shield it for sure.
Jim - W0EB
Jim Sheldon