[TowerTalk] perspective

[Tom Rauch]

Hi Yuri,

> W8JI is right on point of pattern and noise, but saying that gain is not
> important, is like saying that you can start dropping your power (dBs) and
> it will not make the difference?

S/N is a ratio of signal and noise, you can't modify it by simply 
making both louder. It is the directivity that improves S/N. It is the 
gain that makes you louder at the other fellow's house. The limit is 
when you get down into internal noise of the system. At that point 
gain becomes important.

> Isn't gain of antenna tied to pattern?

Gain includes directivity and losses, and ignores minor lobes than 
can gather noise. For receiving pattern shape is critical. You don't 
want minor lobes or other responses that gather noise. 

For transmitting, you don't care. You just want maximum gain at 
the desired angle and direction.  

The best transmitting antenna is often not the best receiving 
antenna for that reason.

> Can you make dipole with nice narrow pattern?

Compared to what? I can make a dipole that has a much narrower 
pattern than a vertical.

> What I know that when I started to add dBs and minimizing the loss dBs in
> the station's design, my scores jumped about 40% going from the "average"
> TH6 installation to stacked monoband Razors. 

I learned (when I was a teenager) in the 60's every time I fill my gas 
tank I total-out my car. Same thing happened to my buddies. I quit 
filling my gas tank, and haven't had a car wreck since.

Is that because of the change in my gas tank, or because I 
became a better driver? How much because of each? 


73, Tom W8JI
w8ji@contesting.com

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