[Amps] coaxial stub on amplifier output

[Dr. David Kirkby]

David Cutter wrote:
> Thanks for doing the sums, Jim, I was interested in the theory.  I thought energy would be reflected in both cases of open and closed circuit stubs.  
> 
> Something new to learn every day.
> 
> David
> G3UNA
> 
> 
>   ----- Original Message ----- 
>   From: James Colville 
>   To: David Cutter 
>   Cc: Jim Brown ; amps at contesting.com 
>   Sent: Saturday, April 03, 2010 5:48 PM
>   Subject: Re: [Amps] coaxial stub on amplifier output
> 
> 
>   Get your calculator out.  30dB down from 1500 watts is how much power?  
> 
> 
>   1500 watts=+61.8 dBm minus 30 db (which is what the harmonic would be down normally) =  +30dBm.  +30dBm = 1 watt. Evenif the harmonic is only down 25 db, that is only 3 watts.
> 
> 
>   Not much power do dissipate is it?
> 
>   73
>   Jim W7RY
>

I don't know how you arrive at 1 W, but just by looking at it one should be 
immediately possible to see it will be 1.5 W. No need for a calculator.

dave