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[AMPS] More Relevant SWR FINAL EXAM

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Subject: [AMPS] More Relevant SWR FINAL EXAM
From: hbrown@voicenet.com (Harry Brown)
Date: Mon, 11 Oct 1999 23:07:40 -0400
An isolator is a very common rf device in the uhf and microwave business.


It is a circulator with one terminal that has a 50 ohm load (you frequently=
 can not see the load but it's in there). It has two external ports, one is=
 an input port and the other is the output port. Rf going into the input=
 port is passed to the output port with a little attenuation, typically less=
 than 1 dB. RF entering the output port is primarily passed to the built-in=
 load. Some does get out the input port. A single section isolator will=
 typically have 20 or so dB of attenuation.


It is not a resistor or a ham radio marketing term. It's common in uhf and=
 microwave ham and commercial gear but I can't recall seeing it in HF gear.=
 They tend to be sized somewhat in proportion to the wavelength.


I would guess that they are fairly rare at 14 MHz but I'm sure that one=
 could be built for this frequency.I believe that most microwave and UHF=
 isolators have garnet material in them although I have seen articles using=
 discrete components and active devices.=20


Hope this helps.


73, Harry, W3IIT


At 09:27 PM 10/11/99 -0400, Phil T. (VA3UX) wrote:

>

>At 01:34 PM 10/11/1999 -0500, you wrote:

>>>

>>>=80  What is a 50-ohm isolator?

>>

>>Rich, you don't know much about RF, do you?

>>

>>An isolator is a device that is typically used at higher frequencies than=
=20

>>HF that effectively makes any load "look" like 50 Ohms.  Now I KNOW=20

>>you'll find some way to criticize that and parse it and pick it apart,=20

>>but so what. =20

>>

>>So Rich, instead of just criticizing, how about stepping up to the plate=
=20

>>and answering some of my questions?  Afraid that you may have to=20

>>backtrack on some things?

>>

>

>Ah, Rich didn't criticize anything Jon...he just asked a question.  He

>asked because "isolator" probably isn't part of the common jargon in RF

>circles for a device that does what you describe...."attenuator" is the

>commonly used technical term.  "Isolator" appears to be ham radio marketing

>jargon.

>>Jon

>>KE9NA

>>

>>

>>-------------------------------------

>>Jon Ogden

>>KE9NA

>>

>>http://www.qsl.net/ke9na    <<--- CHECK IT OUT!  It's been updated!!!!!

>>

>>

>>"A life lived in fear is a life half lived."

>>

>>

>>--

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>>

>>

>>

>

>

>--

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>

>

>

<center>Visit the Mt. Airy VHF Radio Club at:

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</color></underline>Check the June 1999 VHF Contest Photos at the Web
site


Info on VHF/Microwave Nets, Beacons & Subscription to Cheesebits

</center>Beacons at 50.080, 144.284, 222.065, 432.295, 903.071,
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