Stryped wrote:
"If I use a conductive boom and ground it, is there no need for a
coaxial lightning arrester?"

That is my experience, provided that the driven element is a
short-circuit for lower frequencies, such as a folded dipole or a
short-circuit 1/4-wave stub.

My company had countless examples in high places over the world with no
damage to radios, including many solid-state models, operating 24-7.

W6SAI, Bill Orr gives plenty of examples of "plumber`s delight" Yagi-Uda
antennas in the eighteenth edition of "Radio Handbook" (1970). He also
warns on page 548: "Short large-diameter elements have low Q and are not
practical in parasitic arrays. Orr also says: "The Yagi antenna,
however, remains "the antenna to beat" for the 50-,144-, and 220-MHz
amateur bands."

Best regards, Richard Harrison, KB5WZI