I built an "ugly" air wound balun on a PVC water pipe according to this
description
http://www.hamuniverse.com/balun.html

I get 24 turns on a pipe having 75mm (about 3 inches) diameter measured
outside.

But recently i had the chance to look up the section in the ARRL antenna
book and there the number of windings is considerably smaller at a
higher winding radius.

Which description is right? Or does either have advantages and drawbacks?