Re[2]: [TowerTalk] Mismatch Loss and Tuners

Tue, 25 Aug 98 07:52:14

     Hi Tom:

     Thanks for the comments.

1. In my long post (sorry again), I did include matched line loss in my final 
statements - please check again.  I think I compared the two cases with equal 
one way loss.

73 Steve

______________________________ Reply Separator _________________________________
Subject: Re: [TowerTalk] Mismatch Loss and Tuners
Author:  w8ji.tom@MCIONE.com
Message-id: <0EY8008266Q9IN@PM02SM.PMM.MCI.NET> at 
InterNet
Date:    8/25/98 12:22 AM

Hi Steve,

You wrote:

>      SUMMARY -  A matched antenna will significantly outperform a 
>      mismatched antenna with a tuner.  A tuner cannot introduce 
"reflection 
>      gain" to change this fact.

1.) Assuming "significant" is a noticeable amount, that summary is 
incorrect. It ignores transmission line loss between the tuner and antenna.

Matched line loss MUST be included in your statement, or it is meaningless.

2.) The tuner does indeed add "reflection gain" that exactly cancels 
"mismatch loss" when adjusted for a conjugate match. The only loss 
remaining is the transmission line loss which is, as you and Walt pointed 
out, is increased by the higher circulating power. If the initial matched 
line loss is very low (as it can be in many cases), multiplying loss 
several times will not cause "significant" loss.

At least we are beyond thinking reflected power is dissipated in the tuner 
or transmitter, it's only a small step to accuracy now. 

73 Tom

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