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Re: [TowerTalk] SWR is what SWR meter measures

To: Jim Lux <jimlux@earthlink.net>
Subject: Re: [TowerTalk] SWR is what SWR meter measures
From: Gary Schafer <garyschafer@comcast.net>
Reply-to: garyschafer@comcast.net
Date: Fri, 13 May 2005 11:08:59 -0400
List-post: <mailto:towertalk@contesting.com>

Jim Lux wrote:
> <monster snip>
> 
>>>73 Tom
>>>
>>
>>I agree with Tom about reflected power not being dissipated in the
>>transmitters final. For all practical purposes, it all gets returned to
>>the antenna and radiated except for the small amount of loss the
>>transmission line causes from the mismatch.
> 
> 
> For a tube amp, sure.  And for a solid state amp with a tuner on the output.
> But not for a broadband SS amp, in general.  While they're not 50 ohm
> resistive, they're also probably not too far away, so the mismatch at the TX
> output isn't going to be all that huge.  If there's not a big mismatch, most
> of the reflected power winds up "inside" the TX, and gets dissipated (or fed
> back into the power supply, if you've got an amplifier that can do that).
> 

There will be the same degree of mismatch at the antenna that caused the 
reflection as there is at the transmitter.

73
Gary  K4FMX


> 
>>If a tuner was in line and matched the transmitter would never see any
>>reflected power. The tuner does not absorb the reflected power but
>>reflects it back to the antenna.
> 
> 
> exactly..
> 
> 
> 
> 



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