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Author Topic: Raising 7MHz Inv V feedpoint 10 meters higher with interesting results  (Read 1042 times)
WA7ARK
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Posts: 457




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« Reply #15 on: February 05, 2019, 04:28:13 AM »

It would be better to consider what you measured as an SWR dip rather than a resonance. The latter means that there is no reactance in the complex impedance. Having a clear understanding of the difference can be very helpful when you get back to adjusting your antenna.

However, the only thing you can adjust by either lengthening, or shortening a simple dipole or inverted-V wire antenna is where the SWR dip falls relative to the part of the band you want to operate.

Lengthening or shortening a wire by a small% is changing the jX part of the feed-point impedance much more than it is changing the R term...
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Mike, WA7ARK
W9IQ
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Posts: 2714




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« Reply #16 on: February 05, 2019, 04:48:41 AM »

It would be better to consider what you measured as an SWR dip rather than a resonance. The latter means that there is no reactance in the complex impedance. Having a clear understanding of the difference can be very helpful when you get back to adjusting your antenna.

However, the only thing you can adjust by either lengthening, or shortening a simple dipole or inverted-V wire antenna is where the SWR dip falls relative to the part of the band you want to operate.

Lengthening or shortening a wire by a small% is changing the jX part of the feed-point impedance much more than it is changing the R term...

Also note that he changed the height of the antenna which, as we know, can have a significant effect on the real part of the impedance.

- Glenn W9IQ
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- Glenn W9IQ

I never make a mistake. I thought I did once but I was wrong.
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