[BC] High Gain vs Low Gain Antennas

[Craig Bowman]

I have replaced many many 12 bay antenna's with 8 bay antennas and had 
dramatic results every time.  Having said that, I also conducted full 
scale pattern studies at the manufacturer's test site and many times 
incorporated parasitic elements to help minimize the overall pattern 
distortions caused by the tower.  The commissions policy has long been 
"so long as you do not increase any null and do not increase the max of 
any lobe you are making the antenna less directional.  This ruling was 
posted on the wall at the ERI test range for many years.  I have not 
done any 10 bay systems to know where the cutoff is.  In my book, 8 bays 
is the magic number.

Craig Bowman
Bowman Engineering
Durand, MI 48429

Richard Fry wrote:
>> Wow... so the better signal pattern is the 6-bay... but at ~1.5-2 miles
>> from the tower, you have the equivalent signal as 53 miles away!
> _________________
>
> In theory the relative field in all of those nulls goes to zero.  The 
> plot doesn't show that because the calculations were done at 0.1° 
> degree intervals, which didn't happen to capture the zero values.
>
> In practice the nulls measured/received near the ground are to some 
> extent filled by reflections, so probably they wouldn't go to zero 
> anyway. And they probably won't occur at the calculated distances 
> either, because of the affect of the tower on the theoretical, 
> free-space elevation pattern of the array.  As you noticed, there can 
> be some "multipath distortion" in the nulls, wherever they land.
>