RE: Wire and ferrite baluns

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From: Karl F. Larsen (k5di@zianet.com)
Date: Sat Sep 28 2002 - 15:33:46 CDT


It's used in this tuner for a balanced line feedline. I wound the balun
and put it in the Radio Shack Box along with all the other toroid coils
and have a switch that puts it in the output circuit when wanted.

On Sat, 28 Sep 2002, Dave Richards wrote:

> Karl,
> I am curious How do you use the 1:1 Balun on you 20 watt tuner?
> Dave
>
> -----Original Message-----
> From: owner-qrp-l@Lehigh.EDU [mailto:owner-qrp-l@Lehigh.EDU]On Behalf Of
> Karl F. Larsen
> Sent: Saturday, September 28, 2002 11:38 AM
> To: Low Power Amateur Radio Discussion
> Subject: Re: Wire and ferrite baluns
>
>
>
>
> Bill your trying to tell me that I do not understand and neither does
> MFJ. All I can tell you is the following: I got a balun kit from LBJ
> having a red powdered iron core and it was a 4:1 balun and did not work
> at all on any frequency. I bought a uncolored ferrite core and rewound
> the balun for 4:1 and it worked fine from 80 thru 10 meters. I then
> reconnected it for 1:1 balun and it is working fine now on my antenna.
>
> I used a small ferrite core and made a 1:1 balun on my Dan's
> Small Parts 20 watt T tuner I built. It works fine 80 thru 10 meters.
>
> All three of my MFJ antenna tuners have ferrite cores hooked up
> as 4:1 baluns because it makes it convienient to bring out to connectors
> in the back of the tuner. I reconnected one to 1:1 and it's working
> fine.
>
> Please give me an example of a balun that works using a powdered
> iron core. The Z-match is not a balun.
>
>
> On Fri, 27 Sep 2002, Bill Coleman wrote:
>
> > On 9/27/02 5:01 PM, Karl F. Larsen at k5di@zianet.com wrote:
> >
> > >As usual, your wrong Bill.
> >
> > I believe the converse is usually the case.
> >
> > >The MFJ-989 balun has a ferrite core. So does all my MFJ tuners.
> >
> > If it has a ferrite core, it cannot be a voltage balun. The windings
> > would have far too much inducance to do the job properly.
> >
> > If the cores are ferrite, as you say, the MFJ tuners must be using a
> > current balun. You cannot wire up a current balun to have a 4:1
> > transformation ratio with a single core. (You can with two cores)
> >
> > Bottom line: the materials used for voltage and current baluns are
> > different, and cannot be interchanged.
> >
> >
> > >On Tue, 17 Sep 2002, Bill Coleman wrote:
> > >
> > >> On 8/5/02 8:21, Karl F. Larsen at k5di@zianet.com wrote:
> > >>
> > >> >It appears your MFJ-989C is quite a bit bigger than my MFJ-989
> > >> >and has the coax wound balun while mine has the much smaller wire
> toroid
> > >> >type. It is easy to change from 4:1 to 1:1 if desired.
> > >>
> > >> Again, this is incorrect. You cannot just re-wire a 4:1 voltage balun
> > >> into a 1:1 current balun. The voltage balun has a powdered iron core.
> The
> > >> current balun will use ferrite. The two materials are vastly different.
> >
> >
> > Bill Coleman, AA4LR, PP-ASEL Mail: aa4lr@arrl.net
> > Quote: "Not within a thousand years will man ever fly!"
> > -- Wilbur Wright, 1901
> >
> >
>
> --
>
> - Karl Larsen k5di Las Cruces,NM Az ScQRPions -
>
>

-- 
                      
               - Karl Larsen k5di Las Cruces,NM Az ScQRPions -


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