Topband: Re: Beverage Length

[Tom Rauch]

Hi Jan,

>      Seems to me that anything much shorther then 4 wl doesn´t
>      work. If you check Misek's book you can see that you need
>      about 4 wl for 25-30 deg waveangle and anything higher than 
>      that is useless.

I don't follow that line of thought. Even a 1 WL Beverage has good 
response along the ground for groundwave, and at low wave angles 
for skywave. 

A 4 WL Beverage is about useless because the phase of the 
arriving wave randomly and rapidly changes in a few wavelengths of 
distance. 

It is virtually impossible to keep two points separated by more than 
1 or 2 wavelengths "in-phase" because of the effects of 
propagation. This is especially true at sunrise or sunset, when the 
ionosphere is changing.

I've had 3 WL Beverages, and quickly found in A-B comparison to 
shorter 1 and 1-1/2 wl Beverages they were generally worse....not 
better. All my long Beverages are now long gone. 

The few times the ionosphere is stable enough to allow antennas 
spread over a large distance to be effective, I can combine a bunch 
of smaller antennas into a large array from the operating position.

At least on 160 meters, the number of times a year I can use what 
amounts to a 4 WL long array numbers in the single digits!

73, Tom W8JI
w8ji@contesting.com


--
FAQ on WWW:               http://www.contesting.com/FAQ/topband
Submissions:              topband@contesting.com
Administrative requests:  topband-REQUEST@contesting.com
Problems:                 owner-topband@contesting.com