[TowerTalk]

[i4jmy@iol.it]

Hi Tom,

isolated parasitic elements on the same boom are placed in different 
positions to be practically "transparent" to each other but fuctional 
to the belonging band, only.
A parasitic open sleeve structure is instead located in a single point 
of the boom but is functional on more bands.
Under this perspective, having the same position for more bands and 
beeing designed to be active on more bands, an open sleeve parasitic 
element has similarity to a trapped parasitic element.
On the other hand, the losses in a classic trap or the high Q in the 
higher band of an open sleeve are certailnly important parameters able 
to set the actual performances of an antenna. 

73
Mauri I4JMY

>  One final comment - someone said something to the effect that an open
> sleeve element
>  combination acts like a trapped element - not hardly. 
>
>  73, Tom, N6BT
>  Force 12, Inc.



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