Ok well that makes sense, since it did get (and I mean extremely hot) so I
made a mini heater for the shack.
Probably a good thing I took it off :0)
So the ferrite was in series with the signal path. Now this is going to take
some thinking on my part to picture something I pass
the coax thru being in series.
My mind wants to think like if I cut the center conductor and put a resistor,
capacitor or coil in between then that resistor, ect
is in series.
I *obviously* need to study up on the ferrite thing. I never even thought of it
being in series with the signal path.
Interesting new concept for me to resolve in my head.
Thanks very much for the input. I will try and find more on the basics of this
idea so I can understand it thoroughly.
Bob AD5VJ
> -----Original Message-----
> From: towertalk-bounces@contesting.com
> [mailto:towertalk-bounces@contesting.com] On Behalf Of K4SAV
> Sent: Wednesday, January 10, 2007 3:30 PM
> To: towertalk@contesting.com
> Subject: Re: [TowerTalk] W2DU Balun Bead Source
>
> Well I guess if no one else is going to say it, I will. The
> reason your balun got hot is because you put in in series
> with your signal not in series with common mode currents.
> You can't put a balun on a 160 meter T antenna. When you
> short the center to the shield of your 80 meter inverted vee
> and feed the whole thing against your tuner ground, there are
> no common mode currents, everything is single ended. Any
> balun you put on the coax will be directly in series with the
> main signal current to the antenna.
>
> Jerry, K4SAV
>
> AD5VJ Bob wrote:
>
> >I tried a Ferrite not long ago and took it off.
> >
> >I had a relatively small donut piece of ferrite and placed
> it over the
> >coax, I didn't wrap it or anything, just a quick test.
> Hoping to get rid of any common mode currents on 160Meters
> and quieted the noise down on my receiver.
> >
> >The first time I had ever used one.
> >
> >I have an adapter made to make my 80 meter inverted Vee into
> a T vertical for 160. It goes to the wire input of the tuner.
> >
> >I didn't smell anything, but reached over to take the pl-259
> off of the
> >barrel connector to take it off of the wire input and put it
> on the other antenna input to my tuner after working some of
> the 160 meter contest.
> >
> >So I could use the antenna for 80 meters again.
> >
> >I jerked my hand back rather quickly, however, because I had
> in no time
> >at all burnt a bluster on my thumb and forefinger because
> the ferrite was so hot.
> >
> >Then every time I transmitted for any length of time on 160, the
> >ferrite got so hot that it started making the insulation on
> my coax melt I could smell the burning.
> >
> > So I removed it.
> >
> >73,
> >Bob ad5vj
> >
> >
> >
> >>-----Original Message-----
> >>From: towertalk-bounces@contesting.com
> >>[mailto:towertalk-bounces@contesting.com] On Behalf Of Keith Dutson
> >>Sent: Tuesday, January 09, 2007 4:23 PM
> >>To: towertalk@contesting.com
> >>Subject: Re: [TowerTalk] W2DU Balun Bead Source
> >>
> >>There is a good discussion of baluns in the current issue of QST
> >>written by Ward Silver. The bead balun is a good choice.
> >>
> >>73, Keith NM5G
> >>
> >>-----Original Message-----
> >>From: towertalk-bounces@contesting.com
> >>[mailto:towertalk-bounces@contesting.com] On Behalf Of Cecil Moore
> >>Sent: Tuesday, January 09, 2007 2:17 PM
> >>To: towertalk@contesting.com
> >>Subject: Re: [TowerTalk] W2DU Balun Bead Source
> >>
> >>
> >>
> >>>From: "R. David Eagle" <kb8nnu@yahoo.com>
> >>>Subject: [TowerTalk] W2DU Balun Bead Source Howdy all...I am
> >>>
> >>>
> >>looking at
> >>
> >>
> >>>constructing 2 W2DU bead baluns as described in ARRL Antenna
> >>>
> >>>
> >>book that
> >>
> >>
> >>>uses 12 Amidon FB-77-1024 beads.
> >>>
> >>>
> >>Not trying to change your mind, but you get more balun for
> the money
> >>with multi-turn toroids. Multi-turn toroids yield a choking
> impedance
> >>proportional to the square of the number of turns. Turns are cheap.
> >>W2DU baluns yield a choking impedance proportional to the number of
> >>beads. Beads are expensive. I have the very W2DU chokes
> that you want
> >>to build and don't use them.
> >>--
> >>73, Cecil, w5dxp.com
> >>
> >>_________________________________________________________________
> >>Dave vs. Carl: The Insignificant Championship Series. Who
> will win?
> >>http://clk.atdmt.com/MSN/go/msnnkwsp0070000001msn/direct/01/?h
> >>
> >>
> >ref=http://dav
> >
> >
> >>evscarl.spaces.live.com/?icid=T001MSN38C07001
> >>
> >>
> >>_______________________________________________
> >>
> >>
> >>
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> >>
> >>
> >>
> >
> >
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> >
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>
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