[AMPS] Hold on - SWR meter placement

[Steve Thompson]

-----Original Message-----
From: measures <measures@vcnet.com>
To: AMPS <amps@contesting.com>
Date: 09 October 1999 15:35
Subject: Re: [AMPS] Hold on - SWR meter placement


>
>>
>>Rich,
>>There are several possible reasons why your measurements
"varied all
>>over the place."
>>
>>1. You have a defective SWR meter
>>
> A halfwave of 93 ohm coax was connected to a 50 ohm
termination.  The
>50-ohm swr meter) was inserted at the end of the 93 ohm
section and the
>reading was 1:1.  At the center of the halfwave section,
the swr was
>93/50 =1.86:1.    .  .  The bottom-line is that when you
have a matched
>line, SWR-reading will not vary no matter where the meter
is inserted.
>However, with a mismatched line, placement of the SWR meter
matters.


If you used a SWR meter set up to work with Zo of 93ohms,
the reading would not change with position. If the setup
impedance of the meter and the impedance of the line between
the meter and the termination are different, then the
reading will vary with position.

Steve



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