Topband: beverages

[Tom Rauch]

> It's been a while since I read Beverage's article on wave
antennas,
> but I, too, recall a discussion of diversity reception on
beverages
> which were multiple wavelengths long.

I don't know if Beverage said that, but if he did it
certainly isn't accurate on 160.

Making the Beverage needlessly long splits lobes by adding
nulls while barely increasing or actually decreasing
directivity. Also any signal arriving at one point isn't in
stable phase with a signal several wavelengths away, so you
could never add them directly to obtain "diversity".

Diversity requires a voting system or some equivalent and
separate channels, like stereo with two antennas far apart
and your brain doing the addition of signals. Otherwise you
actually increase fading by adding signals.

For example if I phase two Beverages 1000 feet or more apart
together, within seconds it is normally back out of phase.
The same is true for long antennas. The longest and/or
widest array I've been successful using is about 800 feet.

You just can't add signals together from a large area and
call it diversity. It doesn't work at microwave, it
especially doesn't work at HF.

73 Tom