The antenna was tested on the analyzer without the grounded antenna in place and then compared to two others; what I'm trying to determine right now is why the ohms are so different on this stick compared to the others (plus I'm just trying to understand the swr/ohm relationship overall)... I did think about the height issue though and want to play with the height of the rear antenna and see how it affects the gain and swr's...
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43 ohms ?
- Thread starter ROC1
- Start date
The antenna was tested on the analyzer without the grounded antenna in place and then compared to two others; what I'm trying to determine right now is why the ohms are so different on this stick compared to the others (plus I'm just trying to understand the swr/ohm relationship overall)... I did think about the height issue though and want to play with the height of the rear antenna and see how it affects the gain and swr's...
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Booty that's it (or part of it)... that explains how to calculte the SWR from the mismatch and answers one of my questions (VSWR is always greater than one).
So... when the analyzer calculates the SWR, I'm wondering if that figure is part of the mismatch or do I need to take that SWR reading and then adjust it for the mismatch?
Thanks for finding that; I've looked alot but never came accross that... that officially hits the favorites folder
Booty that's it (or part of it)... that explains how to calculte the SWR from the mismatch and answers one of my questions (VSWR is always greater than one).
So... when the analyzer calculates the SWR, I'm wondering if that figure is part of the mismatch or do I need to take that SWR reading and then adjust it for the mismatch?
Thanks for finding that; I've looked alot but never came accross that... that officially hits the favorites folder
No, that's not correct. The analyzer is showing 1.2:1 SWR and 43ohms. Both the 1.2 swr and 43 ohms is rounded off. 50ohms/43ohms = 1.16. Round off 1.16 to the nearest tenth (which is what your analyzer is doing) and you get 1.2 swr. It's as simple as that.
Whether you like the answer or not he is 100% correct. YOUR setup is nothing special and a 1.5:1 will do no more harm to YOUR setup then it will to hundreds or thousands of others with the same impedance.It truely is in fact negligible and acceptable.You can fuss and fume over it all you want to and try and correct it but in the end you will have spent a lot of time and gotten nothing in return.An SWR of 1.5:1 means that 4% of your power is lost,a paultry 4%. Go ahead and adjust the spacing of the antenna in relation to surrounding objects and also try and prune the wire tip if you want too. Sometimes you can pull the wire from the end of the coil at the top.Sometimes you may have to add a few inches to it.
People who fret and worry about THEIR setup being special enough to worry about a 1.5:1 SWR are often those same people that are not worth listening too. GET MY DRIFT? Take it easy man.
ROC1,
The desired impedance is 50 ohms. The measured impedance is 43 ohms. SWR is a ratio between desired (50 ohms) and actual (43 ohms) impedance. So, 50 / 43 = 1.16, which is the calculated SWR. there is very little difference between a 1.16:1 and a 1.2:1 SWR, certainly nothing to worry about. The difference is also about the accuracy tolerance of most SWR meters. But, there's more...
That 1.16:1 SWR can be the result of a measured (actual) 43 ohms impedance, OR the same SWR, 1.16:1 can also mean the actual impedance is 58 ohms, not 43 ohms. Why? Because an SWR meter can't tell the difference between 43 or 58 ohms impedance, only that the ratio of their relationship to '50 ohms' impedance is 1.16:1. Oh boy! Isn't that just 'ducky'?! Simply mar'vel'ious?! No, I'm not kidding. that's just one of the reasons why a simple SWR meter isn't exactly the best thing in the world when gauging how well an antenna is doing. It's very seldom -the- answer to antenna tuning unless the one doing the tuning has a decent idea of what's actually being done, and/or read by that meter.
Makes you wanna cry, don't it? You've got lots of company though. If 'we' haven't already shed one'a them tears, 'we' just ain't got there yet. 'We' will though...
- 'Doc
The desired impedance is 50 ohms. The measured impedance is 43 ohms. SWR is a ratio between desired (50 ohms) and actual (43 ohms) impedance. So, 50 / 43 = 1.16, which is the calculated SWR. there is very little difference between a 1.16:1 and a 1.2:1 SWR, certainly nothing to worry about. The difference is also about the accuracy tolerance of most SWR meters. But, there's more...
That 1.16:1 SWR can be the result of a measured (actual) 43 ohms impedance, OR the same SWR, 1.16:1 can also mean the actual impedance is 58 ohms, not 43 ohms. Why? Because an SWR meter can't tell the difference between 43 or 58 ohms impedance, only that the ratio of their relationship to '50 ohms' impedance is 1.16:1. Oh boy! Isn't that just 'ducky'?! Simply mar'vel'ious?! No, I'm not kidding. that's just one of the reasons why a simple SWR meter isn't exactly the best thing in the world when gauging how well an antenna is doing. It's very seldom -the- answer to antenna tuning unless the one doing the tuning has a decent idea of what's actually being done, and/or read by that meter.
Makes you wanna cry, don't it? You've got lots of company though. If 'we' haven't already shed one'a them tears, 'we' just ain't got there yet. 'We' will though...
- 'Doc
Thanks, really appreciate the input and explanation... that all makes sense. All I wanted was just to understand the basis better.
Great Captain-Save-a-Rat to the rescue...
You realize this is another post that can't seem to add anything constructive...
Why would you stick up for someone who was adding ZERO to a relatively intelligent conversation? If wanting to UNDERSTAND is a problem for you than I apologize. As far as my setup being "special" you bet... it's MINE and I'm taking pride in knowing it inside and out; understanding every facet of it or at least trying too... Additonally, I've been told many times that in a setup like mine, you want to limit SWR to 1.2:1 if possible... get MY drift????
I bet if this conversation was associated with me getting a ham ticket you would have no problem answering the questions... God forbid an 11 Meter Hack wants to "understand" anything...
Feel free to close this thread after your next witty reply Homer... Doc & Booty have answered my question and set me on my way for additional research...
I'm good at making friends...
He's running a bunch of power mobile. My Ameritron amp doesn't like an SWR over 1.5 either, otherwise it trips the overload protection...It's built that way on purpose.
ROC, noone is trying to beat you up. I think you're reading a whole lot of attitude into the posts of others that, quite frankly, you're the only one that is seeing. There's nothing wrong with trying to understand everything that is going on, and I don't see anyone beating you up here for asking questions.
Apparently you are too blind or too pigheaded to see where I made some suggestions on what you could do to resolve your problem that you are worring so much about.
REALLY?? I have yet to see proof of that.
There is nothing and I mean NOTHING in any posts of his in this thread that says that at all. He may well be running power but he should not expect people to know that unless he tells them. The Ameritron amp you are running is rather picky about what it sees for a load and thus has protection built in. Something CB amps do not have. If ROC1 had stated that he was running power then perhaps the replies would have been a bit differant. Once again, do not blame the uninformed for making posts based on the info they were given.
Maybe not for asking questions but perhaps it is for the replies that he gives to others when they attempt help. Here is a small hint ROC1,do not piss me off.The next time you get an answer you don't like ask youself this "Did I provide all the info necessary for others to understand exactly what I am up against?" Answer that question yourself first and then you will be better at making friends.
Sorry Mole but I hope you understand were I am coming from on this.
B
BOOTY MONSTER
Guest
ROC1 there is a great wealth knowledge thats shared here . complaining and disrespecting someone because they answered your thread about something in a manner that wasnt exactly what you wanted doesnt exactly make a great impression . i wasnt sure the "answer" i gave was correct because i really dont know and i googled it and it seemed like it may apply . that why i asked if it would help you .
some guys here give info freely , some make you work for it . that usually makes for a lesson learned rather than someone forgetting what they were told later . some of the CB forums dont like or agree with whats said here because its threatens their class C amp sponsors and crap-pack sponsors . but as youll notice here , you can post a link to any thing as long as its family friendly for the most part . they dont protect sponsors here .
my point is , stick around and try not to get disgruntled if you dont get the instant gratification of having your answer on a silver platter sometimes . as youll see , sometimes it takes a few pages to air all the laundry/theories/facts and rumors so the truth comes out .
some guys here give info freely , some make you work for it . that usually makes for a lesson learned rather than someone forgetting what they were told later . some of the CB forums dont like or agree with whats said here because its threatens their class C amp sponsors and crap-pack sponsors . but as youll notice here , you can post a link to any thing as long as its family friendly for the most part . they dont protect sponsors here .
my point is , stick around and try not to get disgruntled if you dont get the instant gratification of having your answer on a silver platter sometimes . as youll see , sometimes it takes a few pages to air all the laundry/theories/facts and rumors so the truth comes out .
He's running a bunch of power mobile. My Ameritron amp doesn't like an SWR over 1.5 either, otherwise it trips the overload protection...It's built that way on purpose.
There is nothing and I mean NOTHING in any posts of his in this thread that says that at all. He may well be running power but he should not expect people to know that unless he tells them.
Yeah, I know that. I didn't get it either until his last post with the part I quoted. I'm good at reading between the lines...let's just say it's a job requirement
Yeah, I know that. I didn't get it either until his last post with the part I quoted. I'm good at reading between the lines...let's just say it's a job requirement
Yep,me too. I am a father of two boys and I have to read between the lines in order to survive most days.
No anamosity intended from this end but it would have been easier if ALL the facts had been known from the start. For any barefoot setup an SWR of 1.5:1 is perfectly acceptable and hours spent trying to perfect it any more is simply time wasted.If running lots of power it becomes a differant story.I ran solidstate broadcast equipment up to 22,000 watts and even the slightest reflected power started to cause problems.The more power out the greater the problems became.I DO in fact understand where he is coming from NOW.It just would have been better if all the info was given at first instead of complaining about the answers that didn't suit him.
only in a purely resistive ac circuit does 50 / 43 = 1.16. the 1.2:1 figure is not so much the result of "rounding" of numbers as it is a reflection of the effect of reactance that is present. in the case of analyzers that don't display to two places to the right of the decimal point it is a combination of both. the problem with the popular analyzers is that they tell you there is reactance present but what they don't tell you is whether it's capacitive or inductive reactance. they leave you to determine that for yourself. impedance in an ac circuit is composed of both resistance and reactance and both affect the voltage/current standing wave ratio indicated by the measuring equipment. R (resistance) is absolute only when X (reactance) equals 0. that's something they left out of the articles referenced earlier in this thread.