"Sal M. Onella" wrote in message
...

"Cecil Moore" wrote in message
...
Sal M. Onella wrote:
A non-linear junction mixes two or more signals ...

I once had a cracked/cold solder joint in a 40m downspout
vertical that seemed to partially rectify the source
signal generating undesirable harmonics on 15m detected
by another ham 1/2 mile away. A jumper across the bad
junction cured the problem.

Yup. Navy ships have from a few dozen to several hundred such jumpers,
depending on ship type. Many are welded but some are bolted, especially
if
the object must be moved for use, etc.

I have heard that hams who use a tin roof as an HF ground plane are apt to
generate harmonics.

Sal


Some of the towers and masts used for broadcasting in the UK have welded-on
tabs that are welded together after the sections are bolted together. A
particular potential problem has existed since Band II was extended up to
108 MHz: that of generation and radiation of IPs in the band above, used for
VOR and ILS.

Chris