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[AMPS] Benefit

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Subject: [AMPS] Benefit
From: (Jon Ogden)
Date: Fri, 13 Mar 98 16:12:29 -0600
>Is there really ant signal benefit between the AL-80B at 1000 watts or
>the AL-1200 at 1500 watts?I can't make up my mind,am looking for some
>opinions.Thanks   John KB9RPM

Well, the actual benefit is not as great as you would think or as to what 
people might have you believe.

S-meters on a radio are calibrated in dB.  If at 100 watts your signal is 
at S9, at 1000 Watts you would be 10 over 9 at best.  1000 watts is 10 dB 
greater than 100 watts.

However, realize that everytime you double your watts, you only increase 
your signal by 3 dB.  So going from 100 to 200 watts is a 3 dB increase.  
3 dB higher than 1000 watts is 2000 watts and 3 db over 2000 watts is 
4000 watts, ad naseum.  This is because the dB scale is a logarithmic 
scale and not linear.

1500 Watts is therfore only about 1.5 dB more power than 1000 watts.  
Going back to our signal strength example of above, a 10 over 9 signal at 
1000 watts would only be a 11.5 over 9 signal at 1500 watts, and even at 
2000 watts it would be just 13 dB over 9.  Hardly noticeable.

1500 Watts over 1000 Watts will NOT make a 10 dB over 9 signal a 20 dB 
over 9 signal.

The only time when it might make a real difference is when you are so far 
down in the noise that the extra 1.5 dB actually brings you above the 
noise floor.  Then it is a benefit.

Frankly, you'd probably be better off getting a higher gain antenna.

Don't get me wrong, when my amp is finished, I want it running with as 
much Pout as legally possible.  You just have to realize that the benefit 
for the extra 500 watts is really not that much.




Jon Ogden

"A life lived in fear is a life half lived."

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