"RB" wrote in message
news
There are some commonly occurring lengths for multi-band dipoles. I see
105', 135', and 140'. Is 140' preferred over 135'? If so, what is the
benefit of going from 135' to 140'? Just curious.

Read the following:
http://members.dslextreme.com/users/w6wqc/antenna.html
The data on antenna efficiency is a misinterpretation of the NEC output
file. It refers only to copper losses, and does not include ground losses.
The discussion that "The length of an antenna wire is irrelevant" is the key
point made.

73,

Frank