Topband: phasing two verticals

[Ken Brown]

Hi,

Regarding the following:

>"How important/valid is statement:
>'Both verticals has to be the same' for 1/4 wave verticals/space to be
>fed in phase?  Can one be shunt tower and other inverted-L ?"
>

>"The problem with phasing unequal verticals arises when you want to phase
>them for a unidirectional endfire pattern.  Then you have to know the
>mutual impedances (difficult to determine without the proper
>instrumentation) between the verticals to be able to calculate the
>correct length of the delay line". 
>
Is the folloing true?

If you can make the verticals identical, and the surrounding ground 
system the same for each vertical, and the effects of nearby objects 
negligible, then you can determine the mutual impedances from well 
established equations or graphs, and you don't need instrumentation to 
determine it to sufficient accuracy to calculate the cable lengths and 
make the array work.

Thanks,

DE N6KB