[TowerTalk] sloping dipole arrays

[Roger (K8RI)]

jim Jarvis wrote:
> I have seen K1WA's excellent article in the Antenna Handbook for years
> regarding sloping half-wave dipole arrays.  His design switches both
> the center conductor and braid for each feedline.
>
> Is it really important to switch the braid?
> 73, Steve, K4FJ
> -0-
>
> YES.
>
> The K8UR sloper array design, and the variants upon that, require  
> that the
> reflectors not be connected to the driven element.   If you use a  
> switch which
> ties all shields together,  you'll have half of your reflectors and  
> your driven element
> fed together.   

That is why you install a choke/current balun on the feedline the proper 
distance from the antenna.  Then the shields can remain at DC ground 
(for safety)

73

Roger (K8RI)
>  God knows what pattern will result.   Or, knowing  
> this audience,
> only an adept NEC user with a lot of time will know what the  
> resulting pattern
> will be.
>
> The technique of feeding each dipole via 3/8 lambda coax from the switch
> is a particularly neat way to assure that the undriven elements  
> function as
> reflectors.
>
> N2EA
>
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
>