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Correct Place to Test SWR?
- Thread starter Riverman
- Start date
Well, thought I was done with this.
Readings with analyzer at shack end of coax:
CH 1 = 1.2
CH 20 = 1.3
CH 40 = 1.4
Removed analyzer and connected coax to SWR meter. Readings on meter:
CH 1 = 1.3
CH 20 = 1.2
CH 40 = 1.1
Why are they showing different directions of increase/decrease?
Is the SWR meter being influenced by the amp?
The readings are taken at the same location.
Readings with analyzer at shack end of coax:
CH 1 = 1.2
CH 20 = 1.3
CH 40 = 1.4
Removed analyzer and connected coax to SWR meter. Readings on meter:
CH 1 = 1.3
CH 20 = 1.2
CH 40 = 1.1
Why are they showing different directions of increase/decrease?
Is the SWR meter being influenced by the amp?
The readings are taken at the same location.
Riverman, IMO you are doing about like I did years ago...when I thought I was just chasing my tail trying to get a 1/2 wave dipole antenna to tune and work right.
I wish I could tell you simply and within reason, that solving CMC issues was easy and would really make a difference if you succeeded in minimizing them, so the coax cable to your antenna is transparent as installed.
Above, I demonstrated what my simple 1/2 wave dipole model shows, and Bob gave you his ideas on the subject.
Ordinarily I would recommend you do like Homer suggested, but maybe you're a little like me, and just can't let it go sometimes! I think Homer knows...that trying to explain this concept is not always easy.
Read Bob's post #24, again. Correct Place to Test SWR?
Question? I think you're talking about an A99, but I'm not sure, and I don't know any other details. Can you describe more about your antenna setup?
I wish I could tell you simply and within reason, that solving CMC issues was easy and would really make a difference if you succeeded in minimizing them, so the coax cable to your antenna is transparent as installed.
Above, I demonstrated what my simple 1/2 wave dipole model shows, and Bob gave you his ideas on the subject.
Ordinarily I would recommend you do like Homer suggested, but maybe you're a little like me, and just can't let it go sometimes! I think Homer knows...that trying to explain this concept is not always easy.
If you just want something to consider...as to what is going on, then you'll need to get into the nitty-gritty, and that too might not be so easy.
Read Bob's post #24, again. Correct Place to Test SWR?
Question? I think you're talking about an A99, but I'm not sure, and I don't know any other details. Can you describe more about your antenna setup?
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Homer when you use the analyser, that's the end of the feed-line that determines electrical length of outer braid & common mode impedance,
as soon as you hook a radio & vswr meter up the end of your feedline is now ground some undeterminable electrical distance from the feed-point,
a common mode impedance that could be lower or higher that will be seen in parallel with the antenna terminating the coax,
all these measurements anywhere in the system through 1/2waves or any other wave coax require no common mode or your pissing into the wind even thinking about where the meter should be placed,
it does not matter where you put a vswr meter, when it does matter you have a problem that should be fixed,
using 1/2wave of coax will repeat the conditions x & r terminating the 1/2wave coax,
it won't fix cmc or make a vswr meter read any more accurately than anywhere else along the coax if you know the loss in the coax,
folk should pay more attention to wires 3 4 & 5 if they want their fuel gauge to read gallons of gas with no leaky pipes,
only in cb & hamland do we deliberately install our plumbing full of leaks & think that's the right way to do it,
i rather fix my leaks before i buy fatter pipes, keeps Kirchoff happy,
stops or minimises rfi in the shack, less local noise pickup, less pattern distortion,
no head thrash over something that does not exist ( the right place to put the vswr meter ) why vswr is higher 3ft down the line & lips tingle with amp on, mouse wont work when you key, wtf is going on with the security cameras, neighburs moaning wifes hung coax over apple tree to grass vswrs gone up yadda yadda yadda. fck all that, fix the leaks as best you can.
as soon as you hook a radio & vswr meter up the end of your feedline is now ground some undeterminable electrical distance from the feed-point,
a common mode impedance that could be lower or higher that will be seen in parallel with the antenna terminating the coax,
all these measurements anywhere in the system through 1/2waves or any other wave coax require no common mode or your pissing into the wind even thinking about where the meter should be placed,
it does not matter where you put a vswr meter, when it does matter you have a problem that should be fixed,
using 1/2wave of coax will repeat the conditions x & r terminating the 1/2wave coax,
it won't fix cmc or make a vswr meter read any more accurately than anywhere else along the coax if you know the loss in the coax,
folk should pay more attention to wires 3 4 & 5 if they want their fuel gauge to read gallons of gas with no leaky pipes,
only in cb & hamland do we deliberately install our plumbing full of leaks & think that's the right way to do it,
i rather fix my leaks before i buy fatter pipes, keeps Kirchoff happy,
stops or minimises rfi in the shack, less local noise pickup, less pattern distortion,
no head thrash over something that does not exist ( the right place to put the vswr meter ) why vswr is higher 3ft down the line & lips tingle with amp on, mouse wont work when you key, wtf is going on with the security cameras, neighburs moaning wifes hung coax over apple tree to grass vswrs gone up yadda yadda yadda. fck all that, fix the leaks as best you can.
I agree, Bob. Nevertheless, when measuring at the same point, end of feedline, etc, the two different instruments show minor variations.
I try to tune my antenna as best I can before hooking up a coax. Using the best feed line system I can follows that. So far so good. My computer on my shack desk doing fine, nothing in the house going nuts, and my mic doesn't give me a loving kiss.
Only once in a while does my hair stand up when I key the mic.
I try to tune my antenna as best I can before hooking up a coax. Using the best feed line system I can follows that. So far so good. My computer on my shack desk doing fine, nothing in the house going nuts, and my mic doesn't give me a loving kiss.
Only once in a while does my hair stand up when I key the mic.
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Well, thought I was done with this.
Readings with analyzer at shack end of coax:
CH 1 = 1.2
CH 20 = 1.3
CH 40 = 1.4
Removed analyzer and connected coax to SWR meter. Readings on meter:
CH 1 = 1.3
CH 20 = 1.2
CH 40 = 1.1
Why are they showing different directions of increase/decrease?
Is the SWR meter being influenced by the amp?
The readings are taken at the same location.
Wow, back again...
Ok SWR that thing with AMP barreled out... for the Antenna...BE FAIR TO YOUR ANALYZER
But what I see in this "mirror" is the again not necessarily the Antenna - but the "ping" the amp does to your system as a "Hit" when it comes to this "CMC" issue.
Okay. Thank you EVERYBODY for you comments and suggestions.
Decided to make a change in the antenna setup and see what happens.
It was in the yard 5' above ground level. (yeah, I know. But it was stealthy.)
Put it on my 12' mast (yeah, I know. But it's all I have.) Also added a choke this time around. (6 coils, 4" diameter).
Went inside afraid to look.
SWR Meter: 1.10 across the entire band!!!
Analyzer (Same location in lieu of the SWR Meter):
CH 1: 1.10
CH 20: 1.24
CH 40: 1.40
The two aren't going to jive because of the plumbing. Should I adjust the tuning rings using the analyzer and just ignore the SWR Meter readings? Or put the analyzer back in the drawer and enjoy the Meter readings?
Decided to make a change in the antenna setup and see what happens.
It was in the yard 5' above ground level. (yeah, I know. But it was stealthy.)
Put it on my 12' mast (yeah, I know. But it's all I have.) Also added a choke this time around. (6 coils, 4" diameter).
Went inside afraid to look.
SWR Meter: 1.10 across the entire band!!!
Analyzer (Same location in lieu of the SWR Meter):
CH 1: 1.10
CH 20: 1.24
CH 40: 1.40
The two aren't going to jive because of the plumbing. Should I adjust the tuning rings using the analyzer and just ignore the SWR Meter readings? Or put the analyzer back in the drawer and enjoy the Meter readings?
Put both back in the Drawer and look for Sales on Christmas lights...
(so you can string them up before December....
(so you can string them up before December....
Removed the 12' jumper (don't need it anymore as antenna is now much closer to house). With a tweak of the rings, SWR Meter now reads:
CH 1: 1.05
CH 20: 1.00
CH 40: 1.05
Have no clue what the analyzer would read and couldn't care less what's lurking in the background.
Thread is closed except to additional cheap shots and low blows.
All of which are well deserved.
CH 1: 1.05
CH 20: 1.00
CH 40: 1.05
Have no clue what the analyzer would read and couldn't care less what's lurking in the background.
Thread is closed except to additional cheap shots and low blows.
All of which are well deserved.
- No one is chatting at the moment.