[TowerTalk] Antennas "Looking Through" Other Antennas

[Nat Heatwole]

I've been wondering, what is the effect, if any, on the pattern of an
antenna if it is radiating in the direction of another antenna? For
example, suppose that a station consists of 2 towers spaced 100ft apart,
the first with stacked tribanders and the second with a pair of 40m
yagis. Now suppose that when beaming Europe, the tribanders are pointed
directly at the 40m tower and subsequently, directly at the 40m yagis.
Will this effect the performance of either the 40m yagis or the
tribanders? Does the interaction depend on frequency or any other
factors?

Also, is there any effect on the pattern of an antenna if it looks "down
on" or "up to" another antenna that is for the same band. For example,
suppose that one has a tower with stacked 40m beams at, say, 75 and
150ft. Now suppose that there is a wire 40m yagi running between the
tower and a nearby tree at 100ft high (between the two yagis). Will this
arrangement effect the performance of any of the yagis? Does it matter
where the rotatable yagis are pointed or how far the wire yagi is out
from the base of the tower? Any help would be greatly appreciated.

73!
Nat WZ3AR