Topband: 10 to 1 Ferrite Balun

[Chuck Dietz]

Wouldn’t you connect the secondarys in series and the primaries in parallel?

Chuck W5PR

On Tue, Mar 19, 2019 at 2:02 PM Richard (Rick) Karlquist <
richard at karlquist.com> wrote:

>
> On 3/19/2019 8:47 AM, Herbert Schoenbohm wrote:
> > I am working on an RX antenna that requires about balanced 800 match to
> 75
> > ohm RG-6.  I have some type 43 and 73 ferrite binocular cores but since
> > this is just an experimental RX antenna I wanted to use an easier
> approach.
> > I have two commercial baluns that are unmarked but bridge out to a 75-ohm
> > to 200- ohm match.  What would be the problem if I connected them with
> the
> > first balun output feeding the 75-ohm input of the second one with the
> > 200-ohm output of the first one? Anyone ever tried this. Would this also
> > give me excellent ground loop decoupling between the RG-6 and the
> antenna?
>
> What you have proposed (cascading transformers) would not work well.
> What I have done that does work is to connect two MiniCircuits
> ADT8-1+ transformers in series to form a 100 ohm to 800 ohm transformer.
>   "Connect in series" means to connect the two primaries in series, and
> connect the two secondaries in series.  This is different from cascading
> transformers.
>
> This is an amazing transformer, much better specs than similar models
> from MCL.  I dissected one of these in an attempt to reverse engineer
> it but was unsuccessful.  So you can't make your own with binocular
> cores.  At least not with the same performance.
>
> 73
> Rick N6RK
> _________________
> Searchable Archives: http://www.contesting.com/_topband - Topband
> Reflector
>