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=
>>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=
>>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
>>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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