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Re: Need clarification on RF related concepts

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On 2016-10-16, dakupoto@gmail.com <dakupoto@gmail.com> wrote:
> Could some electronics guru please help ?
> I am a bit rusty on some RF concepts so I
> request some clarifications from the gurus 
> here.
>
> By definition, a 4:1 balun has 4 times 
> the impedance on the balamced side as the 
> unbalanced side. For any inductor, the 
> impedance is based on the reactance, which 
> in turn is based on the frequency of 
> operation.
>
> So, what frequency is being considered 
> here ? The reason I ask is that a balun
> could be used as broadband impedance 
> matching device. Thanks in advance for 
> your help.

A balun is a transformer, a 4:1 balun is a 2:1 ratio transformer.

(this suprising relation can be derived from P=I squared R)

Useful frequency depends on the design of the transformer. 4:1 
baluns good* for 45 to 900 MHZ operations were common in the days of
analogue broadcast television.

(*) good-enough anyway.

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Need clarification on RF related concepts dakupoto@gmail.com - 2016-10-15 23:44 -0700
  Re: Need clarification on RF related concepts amdx <nojunk@knology.net> - 2016-10-16 04:37 -0500
  Re: Need clarification on RF related concepts Phil Allison <pallison49@gmail.com> - 2016-10-16 05:14 -0700
    Re: Need clarification on RF related concepts amdx <nojunk@knology.net> - 2016-10-16 08:04 -0500
  Re: Need clarification on RF related concepts Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2016-10-16 17:36 +0300
    Re: Need clarification on RF related concepts dakupoto@gmail.com - 2016-10-16 23:27 -0700
      Re: Need clarification on RF related concepts amdx <nojunk@knology.net> - 2016-10-18 08:44 -0500
        Re: Need clarification on RF related concepts Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2016-10-18 11:06 -0400
        Re: Need clarification on RF related concepts "Michael A. Terrell" <mike.terrell@earthlink.net> - 2016-11-07 13:38 -0500
          Re: Need clarification on RF related concepts George Herold <gherold@teachspin.com> - 2016-11-07 11:00 -0800
            Re: Need clarification on RF related concepts "Michael A. Terrell" <mike.terrell@earthlink.net> - 2016-11-09 18:35 -0500
              Re: Need clarification on RF related concepts Jeff Liebermann <jeffl@cruzio.com> - 2016-11-09 19:59 -0800
                Re: Need clarification on RF related concepts "Michael A. Terrell" <mike.terrell@earthlink.net> - 2016-11-12 08:46 -0500
          Re: Need clarification on RF related concepts "nuny@bid.nes" <Alien8752@gmail.com> - 2016-11-07 11:09 -0800
            Re: Need clarification on RF related concepts "Michael A. Terrell" <mike.terrell@earthlink.net> - 2016-11-09 18:22 -0500
  Re: Need clarification on RF related concepts Tim Wescott <tim@seemywebsite.really> - 2016-10-16 14:28 -0500
  Re: Need clarification on RF related concepts rickman <gnuarm@gmail.com> - 2016-10-17 04:04 -0400
    Re: Need clarification on RF related concepts "Tim Williams" <tiwill@seventransistorlabs.com> - 2016-10-18 07:00 -0500
      Re: Need clarification on RF related concepts Jeroen Belleman <jeroen@nospam.please> - 2016-10-18 16:45 +0200
  Re: Need clarification on RF related concepts Jasen Betts <jasen@xnet.co.nz> - 2016-10-17 09:43 +0000

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