On Tue, 25 Aug 2009 16:49:40 -0400, Dan Zimmerman N3OX wrote:
>> By what math? A 50 ohm (purely resistive) antenna is a 1.5:1 mismatch to
>> 75 ohm coax (and an antenna that is 50 ohms but not resistive would be a
>> mismatch to 50 ohm line). The SWR falls along the length of any real
>> transmission line due to line loss,
>The 1.5:1 SWR circle for lossless 75 ohm line intersects the real axis at 50
>ohms and 112.5 ohms resistive.
>112.5 ohms resistive is 2.25:1 50 ohm SWR when you transition back to a 50
>ohm system
OK, I understand your logic. But that's a worst case (lossless line, precise
odd number of quarter wave lengths) mismatch to a 50 ohm transmitter, NOT a
standing wave ratio on the line. Any reasonable antenna tuner should have no
problem making a transmitter happy with that load.
73,
Jim K9YC
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