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#1
July 7th 15, 11:25 AM
posted to rec.radio.amateur.antenna
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An antenna question--43 ft vertical
In message , Jerry Stuckle
writes Sure, there is ALWAYS VSWR. It may be 1:1, but it's always there. If there's no reflection, there can be no standing wave. So, being pedantic, there's no such thing as an SWR of 1:1! -- Ian |
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#2
July 7th 15, 01:25 PM
posted to rec.radio.amateur.antenna
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An antenna question--43 ft vertical
On 7/7/2015 6:25 AM, Ian Jackson wrote:
In message , Jerry Stuckle writes Sure, there is ALWAYS VSWR. It may be 1:1, but it's always there. If there's no reflection, there can be no standing wave. So, being pedantic, there's no such thing as an SWR of 1:1! Why do you say that? If there is no reflection the voltage on the line is purely due to the forward signal and so the VSWR is 1:1. What's wrong with that? -- Rick |
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#3
July 7th 15, 02:10 PM
posted to rec.radio.amateur.antenna
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An antenna question--43 ft vertical
rickman wrote:
On 7/7/2015 6:25 AM, Ian Jackson wrote: In message , Jerry Stuckle writes Sure, there is ALWAYS VSWR. It may be 1:1, but it's always there. If there's no reflection, there can be no standing wave. So, being pedantic, there's no such thing as an SWR of 1:1! Why do you say that? If there is no reflection the voltage on the line is purely due to the forward signal and so the VSWR is 1:1. What's wrong with that? You are, of course, right. I suspect that VSWR was defined to give technicians a nice easy number to aim for, rather than infinite return loss, to indicate no reflections. -- Roger Hayter |
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#4
July 7th 15, 04:09 PM
posted to rec.radio.amateur.antenna
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An antenna question--43 ft vertical
In message , rickman
writes On 7/7/2015 6:25 AM, Ian Jackson wrote: In message , Jerry Stuckle writes Sure, there is ALWAYS VSWR. It may be 1:1, but it's always there. If there's no reflection, there can be no standing wave. So, being pedantic, there's no such thing as an SWR of 1:1! Why do you say that? If there is no reflection the voltage on the line is purely due to the forward signal and so the VSWR is 1:1. What's wrong with that? A standing wave is caused by a reflection. If there IS no reflection, there is NO standing wave. So while you can have an SWR of 1.00000000000001-to-1 (because a standing wave DOES exist), you can't really have one of 1-to-1 (because there IS no standing wave). ;o)) [Just a bit of pedantic, lateral thinking on my part. Don't worry too much about it. It has absolutely no bearing whatsoever on the current discussions.] -- Ian |
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#5
July 7th 15, 06:41 PM
posted to rec.radio.amateur.antenna
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An antenna question--43 ft vertical
Ian Jackson wrote:
In message , rickman writes On 7/7/2015 6:25 AM, Ian Jackson wrote: In message , Jerry Stuckle writes Sure, there is ALWAYS VSWR. It may be 1:1, but it's always there. If there's no reflection, there can be no standing wave. So, being pedantic, there's no such thing as an SWR of 1:1! Why do you say that? If there is no reflection the voltage on the line is purely due to the forward signal and so the VSWR is 1:1. What's wrong with that? A standing wave is caused by a reflection. If there IS no reflection, there is NO standing wave. So while you can have an SWR of 1.00000000000001-to-1 (because a standing wave DOES exist), you can't really have one of 1-to-1 (because there IS no standing wave). ;o)) [Just a bit of pedantic, lateral thinking on my part. Don't worry too much about it. It has absolutely no bearing whatsoever on the current discussions.] Quite so: a voltage standing wave *ratio* of 1 means no standing wave. But in the name of the unit the "standing wave" is adjectival, and it is still a valid name even when there is no standing wave. And, anyway, you can still colloquially have a resistance of zero ohms even for a superconductor! -- Roger Hayter |
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#6
July 7th 15, 09:35 PM
posted to rec.radio.amateur.antenna
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An antenna question--43 ft vertical
On 7/7/2015 11:09 AM, Ian Jackson wrote:
In message , rickman writes On 7/7/2015 6:25 AM, Ian Jackson wrote: In message , Jerry Stuckle writes Sure, there is ALWAYS VSWR. It may be 1:1, but it's always there. If there's no reflection, there can be no standing wave. So, being pedantic, there's no such thing as an SWR of 1:1! Why do you say that? If there is no reflection the voltage on the line is purely due to the forward signal and so the VSWR is 1:1. What's wrong with that? A standing wave is caused by a reflection. If there IS no reflection, there is NO standing wave. So while you can have an SWR of 1.00000000000001-to-1 (because a standing wave DOES exist), you can't really have one of 1-to-1 (because there IS no standing wave). ;o)) [Just a bit of pedantic, lateral thinking on my part. Don't worry too much about it. It has absolutely no bearing whatsoever on the current discussions.] Sounds great, but that is not how the VSWR is defined.  -- Rick |
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#7
July 7th 15, 04:16 PM
posted to rec.radio.amateur.antenna
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An antenna question--43 ft vertical
On 7/7/2015 6:25 AM, Ian Jackson wrote:
In message , Jerry Stuckle writes Sure, there is ALWAYS VSWR. It may be 1:1, but it's always there. If there's no reflection, there can be no standing wave. So, being pedantic, there's no such thing as an SWR of 1:1! Wrong. An SWR of 1:1 indicates a perfect match, with no reflected power. It is recognized by all electronics texts and experts. My suggestion would be for you to learn some transmission line theory. Your statement here just showed you have no knowledge of it at all. Even when I took my novice test many years ago I had to understand SWR better than that. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
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#8
July 7th 15, 07:32 PM
posted to rec.radio.amateur.antenna
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An antenna question--43 ft vertical
In message , Jerry Stuckle
writes On 7/7/2015 6:25 AM, Ian Jackson wrote: In message , Jerry Stuckle writes Sure, there is ALWAYS VSWR. It may be 1:1, but it's always there. If there's no reflection, there can be no standing wave. So, being pedantic, there's no such thing as an SWR of 1:1! Wrong. An SWR of 1:1 indicates a perfect match, with no reflected power. It is recognized by all electronics texts and experts. My suggestion would be for you to learn some transmission line theory. Your statement here just showed you have no knowledge of it at all. Even when I took my novice test many years ago I had to understand SWR better than that. The point I'm trying to make is not technical. It's simply one of verbal logic. Without the presence of a standing wave, you can't possibly have something called a "standing wave ratio". But, like all RF engineers, an SWR of 1-to-1 is something I too strive to achieve! "Yesterday, upon the stair, I met a man who wasn't there. He wasn't there again today, I wish, I wish he'd go away..." -- Ian |
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#9
July 7th 15, 07:56 PM
posted to rec.radio.amateur.antenna
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An antenna question--43 ft vertical
On 7/7/2015 2:32 PM, Ian Jackson wrote:
In message , Jerry Stuckle writes On 7/7/2015 6:25 AM, Ian Jackson wrote: In message , Jerry Stuckle writes Sure, there is ALWAYS VSWR. It may be 1:1, but it's always there. If there's no reflection, there can be no standing wave. So, being pedantic, there's no such thing as an SWR of 1:1! Wrong. An SWR of 1:1 indicates a perfect match, with no reflected power. It is recognized by all electronics texts and experts. My suggestion would be for you to learn some transmission line theory. Your statement here just showed you have no knowledge of it at all. Even when I took my novice test many years ago I had to understand SWR better than that. The point I'm trying to make is not technical. It's simply one of verbal logic. Without the presence of a standing wave, you can't possibly have something called a "standing wave ratio". But, like all RF engineers, an SWR of 1-to-1 is something I too strive to achieve! "Yesterday, upon the stair, I met a man who wasn't there. He wasn't there again today, I wish, I wish he'd go away..." It doesn't matter what your verbal logic is, Ian. The correct term is "Standing Wave Ratio", and an SWR of 1:1 means there is no reflected power and you have a perfect match. That is the technical definition of a technical term. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
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#10
July 7th 15, 07:44 PM
posted to rec.radio.amateur.antenna
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An antenna question--43 ft vertical
Ian Jackson wrote:
In message , Jerry Stuckle writes Sure, there is ALWAYS VSWR. It may be 1:1, but it's always there. If there's no reflection, there can be no standing wave. So, being pedantic, there's no such thing as an SWR of 1:1! Despite the name, VSWR is defined in terms of complex impedances and wavelengths, not "waves" of any kind. -- Jim Pennino |
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