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Anyone Know This Chart ....?
- Thread starter Wire Weasel
- Start date
Okay, Now that I have assembled this crack team of intelligent and cheery band of workers, I need more. There's always more isn't there? I should have elaborated further to start with but that would have been too easy.
I need a simple chart that any cow-pie kicking cotton-pickin' CBer can understand to show them that when they say they're seeing 500 watts out of their 2 pill crapbox when they further say that with their 2 pill crapbox on they also have a 2:5 to 1 SWR that much of what they're seeing is a false high reading. That, and their crapbox meter is also inaccurate.
Now get to work
I need a simple chart that any cow-pie kicking cotton-pickin' CBer can understand to show them that when they say they're seeing 500 watts out of their 2 pill crapbox when they further say that with their 2 pill crapbox on they also have a 2:5 to 1 SWR that much of what they're seeing is a false high reading. That, and their crapbox meter is also inaccurate.
Now get to work
B
BOOTY MONSTER
Guest
that #3 chart is what i use BJnut .
according to that chart you have to go to 1.95 vswr to just have a %10 power loss , which the chart says is .45 db of loss ..... or just a hair in 1/2 a db . two questions .....
how accurate is that chart ?
is the amount loss frequency dependent/effected ?
Not a chart but a calculator. Probably still not what you are looking for.
Voltage Standing Wave Ratio (VSWR) Loss Calculator
Voltage Standing Wave Ratio (VSWR) Loss Calculator
B
BOOTY MONSTER
Guest
B
BOOTY MONSTER
Guest
"I need a simple chart that any cow-pie kicking cotton-pickin' CBer can understand "
Thats why no Smith Chart...RatsoW8
Sorry WW...could not resist!:w00t:
Sound like one of Mack's answers right?op:
All the Best
BJ
Thats why no Smith Chart...RatsoW8
Sorry WW...could not resist!:w00t:
Sound like one of Mack's answers right?
op:All the Best
BJ
Okay, Now that I have assembled this crack team of intelligent and cheery band of workers, I need more. There's always more isn't there? I should have elaborated further to start with but that would have been too easy.
I need a simple chart that any cow-pie kicking cotton-pickin' CBer can understand to show them that when they say they're seeing 500 watts out of their 2 pill crapbox when they further say that with their 2 pill crapbox on they also have a 2:5 to 1 SWR that much of what they're seeing is a false high reading. That, and their crapbox meter is also inaccurate.
Now get to work
The best you are going to be able to do is use the figures from any of the charts linked too and see the ref power for an SWR of 2.5:1. IIRC the meter will show a different power output for a constant SWR of 2.5:1 depending on if the impedance is 125 ohms or if it is 20 ohms. Both values give an SWR of 2.5:1 but a meter will show two different forward power readings.
Booty: To answer you...The chart is very accurate IMHO and if you look at the graph CK linked, you find the same relative information...
The only thing I find Frequency dependent is the feed-line(loss) that would add/subtract to the equation.
That's why I never understand the frustration of some operators that will go out of their mind...
OMG! I have a VSWR of 1.6/1...I must be doing something wrong...I simply must get it down to Flat 1/1....WHY?
My experience case in point....My "Backfire" array...
2 dipoles/ 126ft. either side of center point/58ft spacing between dipoles/feed-line 450 ohm ladder line....
This antenna "might" be resonant at 3.5Mhz.
Yet at 3.8 MHz without a tuner the VSWR is somewhere around :"maybe 5-10/1" ??
Yet I would stack this antenna against any resonant coax feed dipole at same height...and stomp it into the dirt!
Also as I increase frequency it will improve over a tuned coax feed dipole at say 7-30 MHz (at the same height)...
Look at the information on the EDZ(ext Double Zepp) at frequencies higher than the intended fundemental...again personal experience in the field MHO...
Just the ramblings of an Old Fat/30+ year Hamy...Ya'know the ones some hear don't like>>>
All the Best
BJ
The only thing I find Frequency dependent is the feed-line(loss) that would add/subtract to the equation.
That's why I never understand the frustration of some operators that will go out of their mind...
OMG! I have a VSWR of 1.6/1...I must be doing something wrong...I simply must get it down to Flat 1/1....WHY?
My experience case in point....My "Backfire" array...
2 dipoles/ 126ft. either side of center point/58ft spacing between dipoles/feed-line 450 ohm ladder line....
This antenna "might" be resonant at 3.5Mhz.
Yet at 3.8 MHz without a tuner the VSWR is somewhere around :"maybe 5-10/1" ??
Yet I would stack this antenna against any resonant coax feed dipole at same height...and stomp it into the dirt!
Also as I increase frequency it will improve over a tuned coax feed dipole at say 7-30 MHz (at the same height)...
Look at the information on the EDZ(ext Double Zepp) at frequencies higher than the intended fundemental...again personal experience in the field MHO...
Just the ramblings of an Old Fat/30+ year Hamy...Ya'know the ones some hear don't like>>>
All the Best
BJ