The so called ISOLATOR is a name given to a three port CIRCULATOR with the
third port terminated in a load. Port 1 goes to the transmitter. Port 2 to
the antenna. Port 3 to the termination. At UHF and microwave these are
usually made using strip line and ferrites. I do not recall seeing too many
ISOLATORS at HF. I think Collins and Chu did build some using lumped
constant networks for the phasing networks. When I was with RANTEC we made
some at VHF using lumped constants. They were pretty big and very narrow
band. The purpose of these gems was to divert reflected power (or incident
power from collocated transmitters) from the transmitter. They did nothing
to change the SWR of the transmission line or the antenna.
Yes -- a nice attenuator in the transmission line will reduce the reading of
reflected power --- but it will not "match" the antenna system.
Harv
K6EXO
From: Phil T. (VA3UX) <phil@vaxxine.com>
To: <amps@contesting.com>
Sent: Monday, October 11, 1999 6:27 PM
Subject: Re: [AMPS] More Relevant SWR FINAL EXAM
>
> At 01:34 PM 10/11/1999 -0500, you wrote:
> >>
> >>? 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
> >you'll find some way to criticize that and parse it and pick it apart,
> >but so what.
> >
> >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
> >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."
> >
> >
> >--
> >FAQ on WWW: http://www.contesting.com/ampsfaq.html
> >Submissions: amps@contesting.com
> >Administrative requests: amps-REQUEST@contesting.com
> >Problems: owner-amps@contesting.com
> >Search: http://www.contesting.com/km9p/search.htm
> >
> >
> >
>
>
> --
> FAQ on WWW: http://www.contesting.com/ampsfaq.html
> Submissions: amps@contesting.com
> Administrative requests: amps-REQUEST@contesting.com
> Problems: owner-amps@contesting.com
> Search: http://www.contesting.com/km9p/search.htm
>
>
--
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