[BC] Bay spacing

[Robert Meuser]

On a really tall building a 2bay with traditional null fill works but 
all stations on that building with similar ERP should have close to the 
same gain on any angle of depression expected to provide service.

Pre 911 in NYC there were three stations each using a modified channel 6 
Cpole single bay. Two of them were on 95.5 and 97.1. The master for the 
rest of the stations was a null filled 2 bay ERI panel. It worked well 
for all stations except 96.3 where close in to Empire 95.5 and 97.1 
cause intermod on many radio close in on 34th st and 5th ave.

On 2/21/12 8:47 AM, Richard Fry wrote:
> Probably a bigger consideration for good, close-in building penetration for
> a 2-element array with 0.625-wave vertical spacing is the null in its
> elevation pattern at a depression angle of about 53° (link below).
>
> Using a single element would be better for your purposes, even though it
> needs more input power for the licensed ERP.
>
> The patterns in the link are based on elements having about 10% relative
> field at +/-90° elevation, which is fairly typical for a c-pol FM element in
> real life.
>
> The gains shown are for linear polarization -- c-pol gain is 1/2 that.
>
> http://i62.photobucket.com/albums/h85/rfry-100/Pattern_Compare.jpg
>