[TowerTalk] W2DU Balun Bead Source

[AD5VJ Bob]

 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 at contesting.com 
> [mailto:towertalk-bounces at contesting.com] On Behalf Of K4SAV
> Sent: Wednesday, January 10, 2007 3:30 PM
> To: towertalk at 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 at contesting.com 
> >>[mailto:towertalk-bounces at contesting.com] On Behalf Of Keith Dutson
> >>Sent: Tuesday, January 09, 2007 4:23 PM
> >>To: towertalk at 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 at contesting.com 
> >>[mailto:towertalk-bounces at contesting.com] On Behalf Of Cecil Moore
> >>Sent: Tuesday, January 09, 2007 2:17 PM
> >>To: towertalk at contesting.com
> >>Subject: Re: [TowerTalk] W2DU Balun Bead Source
> >>
> >>    
> >>
> >>>From: "R. David Eagle" <kb8nnu at 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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