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Re: [RFI] Ferrite Question...

To: rfi@contesting.com
Subject: Re: [RFI] Ferrite Question...
From: David Cole <dave@nk7z.net>
Reply-to: dave@nk7z.net
Date: Fri, 20 Jun 2014 16:56:17 -0700
List-post: <rfi@contesting.com">mailto:rfi@contesting.com>
Hi Al,
I thought that once the feedline hit the tuner, that was the end of the
feedline acting like an antenna...  The Ferrite's are between the radio
and the tuner...  Am I understanding you correctly?
-- 
Thanks and 73's,
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On Fri, 2014-06-20 at 16:52 -0500, Al K0VM via RFI wrote:
> If there is rf on the outside of the feed line then the feedline is a 
> part of the antenna SYSTEM and a part of the impedance presented to the 
> radio.  If there is rf on the feedline then adding a ferrite snapped on 
> around the feedline will change antenna SYSTEM and thus the impedance 
> presented to the radio.  The change may or may not be beneficial to the 
> radio and/or radiation efficiency.
> 
> If the feed line is not a part of the antenna system ( no currents on 
> the outside of the feed line ) then other things are more predictable.
> 
> 
> AL, K0VM
> 
> On 6/20/2014 2:26 PM, David Cole wrote:
> > Hi,
> > I should have asked a different question...  Any idea why the rig is
> > getting warmer than if no ferrite's...
> >
> > Here is some more information...
> >
> > A fellow wrote me off list asking for more info...
> >
> > Antenna is on roof, and AC wiring is I am sure in attack area.  About
> > three feet of coax between the tuner and radio.  He is running 30 watts,
> > no grounds, all bonds are via coax, one ground to tuner.  No balun on
> > the OCF...
> >
> > I get that the OCF makes things very unbalanced, (he has no balun on
> > it), and I get that a single ferrite won't correct this, (he did no
> > winding), but why might the rig get warm?  I thought I had a handle on
> > how this stuff was working, but for the life of me, I can't imagine why
> > the rig gets warm...  It always sees a 1:1 because he is tuning it the
> > feedline to 1:1 as it feeds the rig...
> >
> >
> >
> 
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