Michael,
The choke ideas here work well, but I use a 1:1 unun 1/4 wave from the efhw.
Its a lot more packable. Since my par endfedz for 20m is single band, the 1/4 wave down feed line gives me the high current point where the choke will be most effective. The 1/4 wave also presents as a counterpoise also.
This cured my rf problems whilelst running the 59w amp where my display would lock up and preform odd behaviours in addition to odd tones.
Good luck and happy tapping.
regards,
Bryan, N0LUF
