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Re: Topband: Return Loss Question?

To: topband@contesting.com
Subject: Re: Topband: Return Loss Question?
From: Wes <wes_n7ws@triconet.org>
Date: Sun, 17 Jan 2021 11:54:45 -0700
List-post: <mailto:topband@contesting.com>
Of course.

But be careful about who you believe when calculating the additional loss.   The absolute best info about this is at Dan's site:  https://ac6la.com/swrloss.html

Wes  N7WS

On 1/17/2021 10:30 AM, Chortek, Robert L. wrote:
How much return loss is acceptable certainly does “depend”.

I’ll throw in another consideration to further complicate matters:

The higher the VSWR, or lower the return loss, the more power is lost in the 
cable due to the mismatched condition.

How much power is lost depends on the type of cable, the cable length, the 
quality of the cable and of course the frequency.

The higher the frequency the more power will be lost in the cable due to the 
mismatch.

So while your transmitter and or antenna tuner may well be able to operate into 
an increasingly high VSWR (or low return loss) the price you will pay for that 
is more power loss in your cable.

Thus, return loss becomes more important as you operate higher in frequency or 
use longer cable runs.

Not too important at 160 meters but probably very important at VHF.

73 es DX,

Bob/AA6VB
Robert L. Chortek


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