Arie,

I took a look at some handbooks to see exactly how the coils for their high
power amplifiers were made. (Personally, I chickened out at about 600V).
Anyhow, for a bandswitching transmitter:

A) All of them separated the coil into 2 or 3 segments.

B) Averaging about 6 designs, the 10 - 20 meter coil was wound with 3/16 or
1/4 inch copper tubing. In one case silver plated.

C) the remaining coil was most often wound with #10 copper wire; in one case
on 3 toroids glued together.

I had once calculated the Qs for inductors to use in antenna traps, and
unless I messed up, the coils described above would have unloaded Qs of at
least 400.

Tam/WB2TT