Hello, My father in law has an older model Hy gain 5 element Long John that I think is 26 ft boom. He says it is set for 10 meter from the factory and is looking for the correct specs to set it to 11 meter. I know very little bout RF, but I am assuming from this he is talking about the spacing of each of the sets of arials on the beam. Also, he keeps mentioning something about needing an RF filter or choke inline with the coax just before the antenna connection. Can anyone point us inthe right direction? Thanks for any help or suggestions. Also, his handle is "735 Texas - Antique" CB.