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Re: Coaxial cable calculation

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On 4/11/2018 1:38 PM, benj wrote:
> On 4/11/2018 9:36 AM, Sergio wrote:
>> On 4/10/2018 2:28 PM, benj wrote:
>>> On 4/10/2018 5:33 AM, Trevor Wilson wrote:
>>>> On 10/04/2018 7:20 PM, benj wrote:
>>>>> On 4/10/2018 2:42 AM, Trevor Wilson wrote:
>>>>>> Here's a question that stumped me back in the old slide rule days:
>>>>>>
>>>>>> A coaxial cable, having an inner diameter of 0.0254mm (0.001") and
>>>>>> using an insulator with a dielectric constant of 2.56, is yo have a
>>>>>> characteristic impedance of 2,000 Ohms. What must be the outer
>>>>>> conductor diameter?
>>>>>>
>>>>>> You guys can locate the appropriate method of calculation.
>>>>>
>>>>> You think that nobody is smart enough to even Google?
>>>>>
>>>>> Answer is right in Wikipedia, you idiot.
>>>>>
>>>>> https://en.wikipedia.org/wiki/Coaxial_cable
>>>>>
>>>>> But wait, this takes a little knowledge of mathematics so that lets
>>>>> you out. Slide rules were a stupid idea when it was a new idea. Hint:
>>>>> nobody even knows what they are anymore.
>>>>
>>>> **I do. I still use a couple. Mostly for intellectual stimulation and
>>>> a bit of fun. My scientific calculators make life too easy. The nice
>>>> thing about slide rules is that you need to have a rough idea of the
>>>> answer before you start.
>>>>
>>>>>
>>>>> Just write L/C take square root set to 2000 and solve for inside
>>>>> diameter of outer conductor. Like I said you do need to know some
>>>>> algebra.
>>>>>
>>>>> It's obvious you are not asking for the complex impedance since you
>>>>> didn't give enough information for that. Any idea what we are talking
>>>>> about here genius?
>>>>
>>>> **I note your inability to supply a correct answer.
>>>>
>>>> NEXT!
>>>
>>> The idea is the important thing, bunkie!
>>> I note your usual fantasies of being the smartest person on the planet
>>> and everyone else being inferior to you.
>>>
>>
>> nothing wrong with that, Trump, Hillary, Putin, Mays, James McGinn, most
>> all the worlds leaders, Elizabeth Holmes, Martin Shkreli, Rahm Emanuel,
>> and especially Carlos Danger.
>>
>> https://www.youtube.com/watch?v=vqJxp7w919o
>>
>> Trevor asks for one equation, ez google, where one solves for D, but
>> typically we do not provide answers here for students homework, or
>> taking tests, and ask them to work through the problem so they can learn.
>>
>> So, we are kicking this around for a while, to make sure it is past
>> homework/test time.
>>
>> But you could go ahead and find the equation, rearrange terms to solve
>> for D, and post here.  then we can plug in #s.  [also include the cutoff
>> frequency equation]  Then we can show you where the solution is
>> impracticable. [like watts, materials, physical realization, delay...]
>>
>> also realize that Zo is complex, and "characteristic impedance" is
>> typically limited to a range of frequency, some are broad, some are not,
>> so there is another term used when the cable is terminated with its
>> "characteristic impedance" then one measures VSWR and it needs to be
>> less than 1.2 for high power, and about 2 for other uses. This is also
>> calculated, and one needs to know frequency bands of intended use, as Zo
>> will spiral out of 2 VSWR to 20 and greater, or to 0.
>>
> Yes, I could easily do all that. But Trevor thinks he's my boss and I
> should do everything he asks. Big Hint: He's not.

I worked for a while for a guy a bit like Trump, he used to say, "its my
way or the highway" in his staff meetings,  His name was Clive, part
russian, you could not reason with him, he would tell you what is, and
you could suggest things. He liked to rule by fear (old school stuff),
so I avoided him where I could.

But... Clive was like a loose cannon, and we used Clive too,  just
suggest a reason, he would get a name,  and then he would go and blast
somebody.  (perhaps Trump is getting aimed by Tweeter?)

anyhow he drove off a lot of good people, then he got the axe.  One Guy,
Bob, when Clive for the first time said "its my way or the highway", Bob
said "Ok, By By!", walked out of the meeting and quit that day and got a
better $$$ job a week later, without the BS.

anyhow Trump is far better than Hillary.
Paul Ryan is saying he is not going to run again.

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Thread

Coaxial cable calculation Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au> - 2018-04-10 16:42 +1000
  Re: Coaxial cable calculation benj <benj@nobody.net> - 2018-04-10 05:20 -0400
    Re: Coaxial cable calculation Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au> - 2018-04-10 19:33 +1000
      Re: Coaxial cable calculation benj <benj@nobody.net> - 2018-04-10 15:28 -0400
        Re: Coaxial cable calculation Sergio <invalid@invalid.com> - 2018-04-11 08:36 -0500
          Re: Coaxial cable calculation benj <benj@nobody.net> - 2018-04-11 14:38 -0400
            Re: Coaxial cable calculation Sergio <invalid@invalid.com> - 2018-04-11 13:55 -0500
      Re: Coaxial cable calculation benj <benj@nobody.net> - 2018-04-10 15:45 -0400
    Re: Coaxial cable calculation Libor Striz <poutnik4REMOVEnntp@CAPITALSgmail.com> - 2018-04-10 12:24 +0200
      Re: Coaxial cable calculation benj <benj@nobody.net> - 2018-04-10 15:37 -0400
  Re: Coaxial cable calculation Sergio <invalid@invalid.com> - 2018-04-10 10:59 -0500
    Re: Coaxial cable calculation Libor Striz <poutnik4REMOVEnntp@CAPITALSgmail.com> - 2018-04-10 18:21 +0200
      Re: Coaxial cable calculation Lofty Goat <rlwatkins@gmail.com> - 2018-04-10 11:32 -0500
        Re: Coaxial cable calculation Sergio <invalid@invalid.com> - 2018-04-10 11:44 -0500
          Re: Coaxial cable calculation benj <benj@nobody.net> - 2018-04-10 16:03 -0400
            Re: Coaxial cable calculation Sergio <invalid@invalid.com> - 2018-04-10 17:18 -0500
              Re: Coaxial cable calculation Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au> - 2018-04-11 08:24 +1000
                Re: Coaxial cable calculation Sergio <invalid@invalid.com> - 2018-04-10 17:38 -0500
                Re: Coaxial cable calculation Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au> - 2018-04-11 08:42 +1000
                Re: Coaxial cable calculation benj <benj@nobody.net> - 2018-04-11 07:36 -0400
                Re: Coaxial cable calculation Sergio <invalid@invalid.com> - 2018-04-11 08:38 -0500
                Re: Coaxial cable calculation Lofty Goat <rlwatkins@gmail.com> - 2018-04-11 21:57 -0500
              Re: Coaxial cable calculation benj <benj@nobody.net> - 2018-04-11 07:23 -0400
                Re: Coaxial cable calculation Sergio <invalid@invalid.com> - 2018-04-11 08:39 -0500
                Re: Coaxial cable calculation Sergio <invalid@invalid.com> - 2018-04-11 11:20 -0500
    Re: Coaxial cable calculation Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au> - 2018-04-11 05:48 +1000
      Re: Coaxial cable calculation benj <benj@nobody.net> - 2018-04-10 16:10 -0400
      Re: Coaxial cable calculation Sergio <invalid@invalid.com> - 2018-04-10 17:30 -0500
      Re: Coaxial cable calculation Lofty Goat <rlwatkins@gmail.com> - 2018-04-11 21:57 -0500
    Re: Coaxial cable calculation benj <benj@nobody.net> - 2018-04-10 15:54 -0400
      Re: Coaxial cable calculation Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au> - 2018-04-11 06:01 +1000

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