"Wayne" wrote in message
...
I don't have much experience with re-radiation. But, I can understand how
yagis might like the concept 
Yes it is a tricky undocumented subject.
Most authors say nothing about it.
Some as quoted by John S agree on the half power re-radiated at least.
For the amateur trying to put a maximum of antennas in his limited space
it can lead to false comparisons of performances.
For example you try a dipole close to a long yagi and then discard the yagi
on the ground that the dipole WAS almost as good :-)