Jumper wire ???????????
- Texas Mobil 219
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Jumper wire ???????????
Now that i got time the 9913 is going in the mobil. And i have a few question about jumper wires.
The way i want to set it up. Its going to have 9' jumpers and a 12' run of feedline. Is there an ideal way or will this set up work.
The way i want to set it up. Its going to have 9' jumpers and a 12' run of feedline. Is there an ideal way or will this set up work.
- Texas Mobil 219
- Wordwide & Qualified
- Posts: 1,244
- Joined: Aug 24 2008, 06:17
- Radio: Uniden 78
- Texas Mobil 219
- Wordwide & Qualified
- Posts: 1,244
- Joined: Aug 24 2008, 06:17
- Radio: Uniden 78
- Texas Mobil 219
- Wordwide & Qualified
- Posts: 1,244
- Joined: Aug 24 2008, 06:17
- Radio: Uniden 78
Texas Mobil 219,
I wish I could tell you exactly where to look, but i can't. I'm just not familiar enough with this forum.
The simplest way of explaining it is that jumper length doesn't make any difference unless something else isn't 'right'. If the output of the radio isn't what it should be (50 ohms impedance), and/or the input to the next 'device' isn't what it should be (50 ohms impedance), and if the input to the antenna isn't what it should be (50 ohms impedance again), then jumper/feed line length can make a difference. Which simply means that if jumper length does make a difference then you need to correct the problem -where- the problem IS, not just by changing jumper lengths. (Watch me catch @#$$ for that one! )
It isn't always easy, and you gotta know what you're doing, but it isn't impossible by any means.
- 'Doc
I wish I could tell you exactly where to look, but i can't. I'm just not familiar enough with this forum.
The simplest way of explaining it is that jumper length doesn't make any difference unless something else isn't 'right'. If the output of the radio isn't what it should be (50 ohms impedance), and/or the input to the next 'device' isn't what it should be (50 ohms impedance), and if the input to the antenna isn't what it should be (50 ohms impedance again), then jumper/feed line length can make a difference. Which simply means that if jumper length does make a difference then you need to correct the problem -where- the problem IS, not just by changing jumper lengths. (Watch me catch @#$$ for that one! )
It isn't always easy, and you gotta know what you're doing, but it isn't impossible by any means.
- 'Doc
- Texas Mobil 219
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'Doc wrote:Texas Mobil 219,
I wish I could tell you exactly where to look, but i can't. I'm just not familiar enough with this forum.
The simplest way of explaining it is that jumper length doesn't make any difference unless something else isn't 'right'. If the output of the radio isn't what it should be (50 ohms impedance), and/or the input to the next 'device' isn't what it should be (50 ohms impedance), and if the input to the antenna isn't what it should be (50 ohms impedance again), then jumper/feed line length can make a difference. Which simply means that if jumper length does make a difference then you need to correct the problem -where- the problem IS, not just by changing jumper lengths. (Watch me catch @#$$ for that one! )
It isn't always easy, and you gotta know what you're doing, but it isn't impossible by any means.
- 'Doc
Your right on Doc, for awhile i thought it always had to be a half wavelength taking into account velocity factor and such. I have argued several times in the past one side or the other on transmission line theory, but as you said, it basically depends if your system is straight or not. Any number of underlying factors/variables can change SWR. Cutting or changing coax lengthy merely adds more inductance/capacitance changing what the meter "thinks" it is seeing. In fact the coax will actually become part of the antenna. but now it is getting complicated. LOL